Abstract Book - SEB Conference 2022

ABSTRACT BOOK SEB CONFERENCE MONPELLIER 2022 5 JULY - 8 JULY 2022 SEBIOLOGY.ORG #SEBCONFERENCE

MONTPELLIER 2022

SOCIETY FOR EXPERIMENTAL BIOLOGY

ANNUAL CONFERENCE MONTPELLIER 2022

ABSTRACT BOOK 03

CONTENTS 1. SCIENCE ACROSS BOUNDARIES ABSTRACTS (ANIMAL, CELL AND PLANT BIOLOGY)

04

2. ANIMAL BIOLOGY ABSTRACTS

26

3. CELL BIOLOGY ABSTRACTS

160

4. PLANT BIOLOGY ABSTRACTS

176

SCIENCE ACROSS BOUNDARIES ABSTRACTS (ANIMAL, CELL AND PLANT BIOLOGY)

1

ANNUAL CONFERENCE MONTPELLIER 2022

SCIENCE ACROSS BOUNDARIES ABSTRACTS 06

AP1 - MECHANICAL ECOLOGY – TAKING BIOMECHANICS TO THE FIELD

ANNUAL CONFERENCE MONTPELLIER 2022

few monocot genera, all belonging to the Asparagales, are able to modify their tissue structure via secondary thickening growth. Despite the limitations on tissue level, monocots evolved diverse mechanical properties, that are based on their fiber reinforced bauplan such as very stiff bamboo culms or highly compliant pulvini. However, the mechanical architecture of monocots, and here especially the nodus, remain relatively unexplored, despite the fact that it is the crucial connecting element between internodes and laterals. Here I present how biomechanical experiments and 3D imaging using µCT and MRI techniques as well as plant specific image optimization techniques help to unravel structural design patterns in monocots.

ORGANISED BY: SIMON POPPINGA (TECHNICAL UNIVERSITY OF DARMSTADT) AP4 GAME OF THORNS: HOW HOOKED TRICHOMES PROTECT PLANTS FROM HERBIVORY AND HOW SPECIALISED CATERPILLARS CAN DEAL WITH THEM Thursday 7th July 2022

10:00

Ritabrata Chowdhury, University of Cambridge rc855@cam.ac.uk Interactions between plants and herbivores are essential for land ecosystems, and their diversity is driven by an evolutionary arms race between plant defences and insect counter adaptations. Plants protect themselves against herbivory by chemical and physical defences, while many insects have evolved mechanisms to overcome these.

Compared to chemical plant defences, little is still known about the role of physical defences and insect counter adaptations. We investigated the role of hooked trichomes in Passiflora adenopoda as a physical defence against herbivores and how certain Heliconius caterpillars can cope with these trichomes. Behavioural assays and video analysis showed that hooked trichomes of P. adenopoda arrested the movement of "generalist" H. melpomene caterpillars, and killed them by piercing their cuticle. Moreover, if H. melpomene caterpillars managed to ingest trichome-bearing leaves without external injuries, they still always died. As the caterpillars developed normally when fed with leaves where trichomes had been "shaved", this effect must be based on internal mechanical damage. We found that ingested hooked trichomes penetrated the gut peritrophic matrix in H. melpomene caterpillars. By contrast, "specialist" Heliconius charithonia caterpillars could easily crawl over the leaves by pulling their prolegs away from the trichomes. They also successfully fed on trichome-bearing leaves, likely due to modifications in their gut peritrophic matrix. Light and scanning electron microscopy of the caterpillars' cuticle and the gut peritrophic matrix revealed characteristic differences between both Heliconius species. Our study helps to understand an important but as yet little-explored aspect of the evolutionary arms-race between Passiflora and Heliconius.

P46 A PORTABLE RAIN AND HAIL SIMULATOR FOR BIOMECHANICAL FIELD STUDIES ON PLANTS Thursday 7th July 2022

11:45

Janine Drube, University of Bristol.

Co-authors: Anne-Kristin Lenz, University of Bristol.

Ulrike Bauer, University of Bristol janine.drube@t-online.de

Thursday 7th July 2022

In times of changing climate, extreme weather events are increasingly frequent. Hail and rain storms cause significant crop losses and soil erosion, with implications for agricultural economy and food security.

A detailed understanding of the interaction of foliage with impacts from hail and rain is key to mitigating this threat; however, our current knowledge is based on lab experiments, usually with individual leaves under highly artificial conditions. We developed a portable setup to study the biomechanics of raindrop and hailstone impacts on plants in the field. ‘Rain’ drops are generated with an infusion drip unit, and the custom-built hail simulator uses a spring mechanism to accelerate plastic beads of varying sizes. A light barrier cross-beam triggers two synchronized high-speed video cameras, allowing full 3D reconstruction of the impact-induced leaf movement. We successfully employed the setup to study rain impact responses of 50 different plant species in situ in the Bristol Botanic Garden. Preliminary results indicate that interactions of leaves with raindrops vary across species and depend on leaf size, shape and surface properties, as well as the impact location. By studying leaf impact responses under natural conditions, we hope to unravel the adaptations that allow some plants to survive rain or hail storms unscathed. This may not only help to identify key traits for breeding more resilient crop plants, but can also provide inspiration for architects and engineers aiming to construct buildings that are better equipped for withstanding earthquakes and increasingly frequent superstorms.

P47 STRUCTURAL DIVERSITY AND BIOMECHANICS IN MONOCOTS Thursday 7th July 2022

P48 HOW THE MECHANICAL PROPERTIES OF PASSIFLORA DISCOPHORA’S SPRING-LIKE TENDRILS CHANGE OVER TIME

15:05

Linnea Hesse, Plant Biomechanics Group, Botanic Garden, Freiburg University.

Co-author: Lea K. Westermann, Freiburg University. linnea.hesse@biologie.uni-freiburg.de Monocotyledons comprise about one-quarter of all flowering plants, colonize all bio-geographical and climatic regions of the planet and reveal a striking growth form diversity ranging from tiny swimming to large arborescent species. This growth form diversity is based on a rigid fibrous vascular network embedded into a viscoelastic parenchyma matrix and is established and limited by primary vascular growth. Only

marc.thielen@biologie.uni-freiburg.de The passion flower Passiflora discophora is a climbing plant that attaches to its substrate by means of adhesive pads, which are located at the distal end of branched tendrils. At the beginning of this process, a circumnutation motion is performed, which serves to locate a host substrate in 3D-space. Once the tips of the tendril are in contact with the substrate, callus-like growth is induced, causing the pads to develop. After the pads become firmly attached to the support, the main axis of the tendril winds up into a coil and thereby shortens. Here we investigate the change in mechanical properties of these springlike structures during their ontogeny by performing tensional tests on individual tendrils in different ontogenetic stages. As the tendrils from any individual stem are at different stages of their respective ontogeny, depending on their location along the stem, the quality of the stem's attachment changes from its apical end (turgescent tendrils) to its basal end (senescent tendrils). Furthermore, we show for the first time in situ the forces generated during the spiralling of the tendrils.

P49 A PORTABLE FIELD RHEOMETER REVEALS AGE-DEPENDENT CHANGES OF VISCOELASTIC TRAP FLUIDS IN CARNIVOROUS PLANTS 11:30

Nathaniel Kelly, University of Bristol.

Co-authors: Sam Rowbotham, University of Bristol, Bart Hallmark, University of Cambridge, Ulrike Bauer, University of Bristol nathaniel.kelly@bristol.ac.uk

Plants consist of over 80% of water, but unlike water, many plant secretions have non-Newtonian, viscoelastic properties. Examples are the trap fluids of many tropical pitcher plants (Nepenthes), where viscoelasticity has been shown to aid prey capture and retention.

Measuring the viscoelasticity of pitcher fluids accurately requires in situ rheometry, in the tropical field locations where these plants grow, because the fluid properties degrade rapidly in storage. With an interdisciplinary team of biologists and engineers, we designed a portable extensional rheometer that weighs less than 1kg and can be dismantled into parts for easy transport. We used this device to characterize trap fluids of two pitcher plant species: N. rafflesiana in Brunei, Northern Borneo, and N. pervillei in the Seychelles. Viscoelastic behaviour, quantified as the relaxation time after rapid stretching of a small quantity of fluid, appeared relatively late during trap development (before opening), and dropped off sharply around two to three weeks after trap opening. Our results show that fluid properties are highly dynamic over the lifespan of a pitcher trap, with times of maximum fluid viscoelasticity coinciding with times of high attractiveness and prey capture efficiency.

14:50

Marc Thielen, Plant Biomechanics Group, University of Freiburg.

Co-authors: Frederike Klimm, University of Freiburg and Cluster of Excellence livMatS @ FIT, Jaro Homburger, University of Freiburg, Thomas Speck, University of Freiburg and Cluster of Excellence livMatS @ FIT

Thursday 7th July 2022

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P50 FOLIAGE LEAVES: RESPONSE AND ACCLIMATION TO CONTRADICTORY MECHANICAL REQUIREMENTS Thursday 7th July 2022

15:20

Olga Speck, Plant Biomechanics Group, University of Freiburg and Cluster of Excellence livMatS @ FIT. Co-authors: Max Langer, University of Freiburg and Cluster of Excellence livMatS @ FIT, Thomas Speck, University of Freiburg and Cluster of Excellence livMatS @ FIT olga.speck@biologie.uni-freiburg.de Foliage leaves can respond immediately to various environmental stresses, such as wind or passing animals, by bending and twisting.

A petiole with high flexural rigidity ensures support of the lamina, whereas low torsional rigidity guarantees that the leaves align streamlined. This mechanical trade-off between flexural and torsional rigidity is described by the twist-to-bend ratio. In a comparative study, we investigated morphology, anatomy and biomechanics of foliage leaves with various bodyplans (monocotyledons and dicotyledons) and/or spatial configuration of petiole and lamina (2-dimenional = petiole at lamina base or 3-dimensional = peltate). The twist-to-bend ratios of the selected petioles ranged from 12 to 39.

In addition, we subjected peltate leaves of the Ufo plant (Pilea peperomioides) to mechanical stimuli (wind, touch, wind and touch) for six weeks. We determined the twist-to-bend ratios of both the petioles and the transition zones between the rod-shaped petiole and the planar lamina. The petioles of the control group and of all treatment groups were stiffer in bending than in torsion. In contrast, the transition zones of all groups revealed that they are stiffer in torsion than in bending, reflected by a twist-to-bend ratio of less than 1.0. Although we did not find significant thigmomorphogenetic changes in geometric and mechanical properties, the twist-to-bend ratio increased for all mechanically stimulated petioles and transition zones (with the exception of the wind-stimulated group). Based on these twist-tobend ratios, we hypothesise that bending loads are accommodated by the petiole, while torsional loads are shared between the transition zone and the petiole.

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P53 STEM STRAIGHTNESS AND ADAPTIVE ROLE OF THE BARK IN POPULATIONS OF PINUS PINASTER Thursday 7th July 2022

09:45

Gianluca Segalina, Universidad de Valladolid – iuFOR. Co-authors: Rosario Sierra de Grado, Universidad de Valladolid – iuFOR, José Climent Maldonado, INIA-CSIC gc4345251@gmail.com Pinus pinaster is a Mediterranean species naturally distributed from France to Morocco, in Mediterranean environments prone to wildfires.

It’s characterized by a high phenotypic variability among geographic provenances in many characters, particularly in the straightness of the stem and strategies of adaptation to fire.

We are investigating whether there is a trade-off between the functions of mechanical stability and fire resistance.

To do that, we established a trial of provenances with seven between straight and crooked populations, and 9-year-old plants. An artificial bending of the trunk was produced for one month and then released.

One year later we harvested the trees and a set of variables related to different functions were measured (outer bark, inner bark, xylem, and compression wood thicknesses and densities, total bark, xylem, and compression wood areas, modulus of elasticity (MOE), modulus of rupture (MOR), tannins, phenolics, and carbohydrates in both north and south orientation and yearly height and width growth).

We found that straight provenances produce a higher amount of bark on the treetop compared with crooked provenances ; we will analyze the rest of the variables looking for trade-offs in the lower part of the stem.

P61 ECOMORPHOLOGY OF MULTIFUNCTIONAL WRINKLES ACROSS TERRESTRIAL AND AQUATIC ORGANISMS – A SOURCE OF INSPIRATION FOR FUNCTIONALIZED BIOMIMETIC SURFACES Thursday 7th July 2022

15:35

Venkata Amarnadh Surapaneni, City University of Hong Kong.

Co-authors: Jan Wölfer, Humboldt Universität zu Berlin, Mike Schindler, City University of Hong Kong, Luciano Caruggi de Faria, University College London, Frederik H. Mollen, Elasmobranch Research, Shahrouz Amini, Max Planck Institute of Colloids and Interfaces, Sean Hanna, University College London, Mason Dean, City University of Hong Kong amar.sv@cityu.edu.hk Wrinkled structures in nature are omnipresent at hugely diverse length scales, arising through ontogenetic variation in the material properties of multi-layered tissues and the magnitude and orientation of intrinsic strains. The natural variation in tissue types and properties therefore translates to a huge diversity of complex surface wrinkling patterns, which in turn are deployed for a wide range of functions.

We performed a broad-scale meta-analysis of surface wrinkling in various terrestrial and aquatic organisms, in order to examine how

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wrinkles are implemented across biological systems and their structurefunction relationships. Our meta analysis demonstrates the presence of wrinkles in a wide range of extinct and extant taxa. Depending on the organism’s environment, wrinkle morphology, and mechanical characteristics, wrinkles may control adhesion, friction, wetting, or drag; promote interfacial exchange; act as flow channels or a fluid reservoir; or contribute to stretching, mechanical integrity, or structural colour. The results allow comparison of functional morphology of surface wrinkles across biological systems and classification of wrinkle function in relation to the size and the ecology of the organisms. This study, in turn, aids in understanding organismal structure-environment links, creating a morphology-performance space that can also act as a platform for exploring anatomies with particular functions (and vice versa). We demonstrate the utility of this pursuit in several case studies of micro-scale wrinkles in extant and extinct organisms from the meta-analysis, and our biomechanical experiments on plant leaves and basking shark gill rakers, providing an outlook for the development of functionalized biomimetic surfaces.

P62 LOCOMOTING IN A TURBULENT ENVIRONMENT: WAYS TO STUDY MICROSCALE PROCESSES IN A LARGE-SCALE OCEAN Thursday 7th July 2022

16:50

Mimi Koehl, University of California, Berkeley. cnidaria@berkeley.edu Fluid mechanics is an important tool for understanding the biology and ecology of marine life. A major challenge in studying how microscopic aquatic organisms function in their natural habitats is integrating the different scales at which critical physical and biological processes occur. How can we make large-scale field measurements and models that include the behaviors and physical features of real organisms?

Conversely, how can we design small-scale experiments to measure those biological factors under hydrodynamic conditions that reflect what the organisms actually experience in the large- scale ocean? I will discuss examples of some of the approaches we have used to span different scales in our studies of how the interaction between the locomotion of microscopic organisms and the turbulent, wavedriven water flow around them determines how they move through the environment. We studied how the microscopic larvae of bottomdwelling marine animals navigate to suitable habitats on the sea floor by combining field flow measurements in marine environments with flume studies, experiments in fluidic devices, experiments with dynamically-scaled physical models, and agent-based models of different locomotory strategies in measured turbulent flow fields.

A159 BUG OFF: BIOMECHANICS UNDERLYING THE DEFENSIVE F LICKING BEHAVIOUR OF ASTRAEUS JEWEL BEETLES Thursday 7th July 2022

16:20

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Lu-Yi Wang, The University of Melbourne.

Co-authors: Devi Stuart-Fox, The University of Melbourne, Ko-Huan Lee, Macquarie University, Amanda M. Franklin, The University of Melbourne luyiwangtw@gmail.com Escape is a life critical defensive behaviour. Some animals, such as click beetles, escape using ultrafast movements produced by power amplification systems. Similarly, Astraeus jewel beetles flick themselves into the air by rapidly opening their hardened forewings (elytra). This behaviour has not been observed in other animals, and the mechanism and kinematics remain a mystery. Here, we combine high-speed videos, SEM images, and micro-CT data to describe the kinematics of the behaviour and identify potential associated structures. Initial data indicates the elytra open at speeds up to 53 m/s, comparable to other known ultrafast movements in insects. Such speeds cannot be achieved by muscles alone, indicating that the behaviour is likely produced by a latch mediated spring actuated (LaMSA) system. We also conducted a behavioural experiment to demonstrate that jewel beetles can flick at much lower body temperatures (~15°C) than required for walking (~30°C) or flying (~37°C). This indicates that the behaviour could be a particularly important escape strategy at low ambient temperatures.

Taken together, we reveal a unique, power-amplified, fast movement and showed the potential adaptive values of this defensive behaviour.

A160 GROWING UP IN A ROUGH WORLD: ONTOGENETIC SCALING OF FRICTIONAL ADHESION AND MORPHOLOGY IN TOKAY GECKOS Thursday 7th July 2022

15:50

Tim Higham, University of California, Riverside.

Co-author: Anthony Cobos, University of California, Riverside thigham@ucr.edu Many geckos have the remarkable ability to reversibly adhere to surfaces using a hierarchical system that includes both internal and external elements. The vast majority of studies have examined the performance of the adhesive system using adults and relatively unnatural substrates (e.g., Acrylic). Almost nothing is known about how the system changes through ontogeny, nor how these changes would influence the ability to adhere to surfaces in nature. Using Tokay geckos (Gekko gecko), we examined the ontogenetic scaling of morphology and frictional adhesive performance in animals ranging from 5 to 125 grams in body mass. We quantified setal density, setal length, and toepad area using SEM. This was then used to estimate the theoretical maximum adhesive force. We tested performance with 14 live geckos on eight surfaces ranging from extremely smooth (Acrylic) to relatively rough (100-grit sandpaper), encompassing a range of surface roughness that might be found in nature. Surfaces were attached to a force transducer, and multiple trials were conducted for each individual. We found that setal length scaled with negatively allometry, but toepad area scaled with isometry. Setal density remained constant throughout ontogeny.

The relationship between body mass and adhesive performance was generally similar across all surfaces, but rough surfaces had much lower values than smooth surfaces. Safety factor went down with body mass and with surface roughness, suggesting that smaller animals may be more likely to occupy rough substrates in their natural habitat.

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A161 MECHANICAL ECOLOGY OF INSECT–PLANT INTERACTIONS Thursday 7th July 2022

11:00

Walter Federle, University of Cambridge. wf222@cam.ac.uk Using examples of insect-plant interactions, I will show how biomechanical research can provide important insights into ecological and evolutionary questions. Insect-plant interactions must always be studied at least partially in the field, as essential aspects of their biology can be overlooked in the laboratory. Biomechanical factors play an important role in many insect-plant interactions such as pollination, herbivory and plant carnivory. Similar to the effects of plant chemical compounds or optical cues, plants can use mechanical ways to manipulate insect behaviour. For example, rockroses can mechanically detect visiting insects and guide pollinators to as yet unpollinated flowers, hollyhocks deploy slippery petals to guide insects to the fertile flower parts, and some pitcher plants have developed climbing barriers that prevent insects from walking around the pitcher to direct them to the slippery trapping surfaces. Again analogous to chemical factors in interactions, biomechanical factors can lead to adaptations and counter-adaptations, with far-reaching ecological and evolutionary consequences. The complexity of biological effects resulting from biomechanical factors is illustrated by Macaranga antplant mutualisms, where 'wax barriers' and 'wax-running' ants have triggered a whole range of secondary secondary ant and plant adaptive traits, including the presentation of food, epidermis longevity, the presence of preformed entrance holes, and ant colony density and aggressiveness. 'Mechanical ecology' – the study of organisms in their natural habitat with a biomechanical perspective - is not only important to elucidate adaptations of organisms, but also allows a broader search for new phenomena and organisms that could serve as inspiration for biomimetics.

A312 ADAPTIVE EVOLUTION OF FLIGHT IN MORPHO BUTTERFLIES Thursday 7th July 2022

10:15

Camille Le Roy, Wageningen University & Research.

Co-authors: Dario Amadori, Maritime Research Institute Netherlands, Samuel Charberet, L’Institut de Systématique, Évolution, Biodiversité, Muséum National d’Histoire Naturelle, Jaap Windt, Maritime Research Institute Netherlands, Florian T. Muijres, Wageningen University & Research, Violaine Llaurens, L’Institut de Systématique, Évolution, Biodiversité, Muséum National d’Histoire Naturelle, Vincent Debat, L’Institut de Systématique, Évolution, Biodiversité, Muséum National d’Histoire Naturelle camille.leroy@wur.nl The diversity of flying animals suggests that countless combinations of flight morphologies and behaviours have evolved with specific lifestyles, thereby exploiting diverse aerodynamic mechanisms.

Elucidating how morphology, flight behaviour and aerodynamic properties together diversify with contrasted ecology remains rarely accomplished. Here, we studied the adaptive co-divergence in wing shape, flight behaviour and aerodynamic efficiency among Morpho

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butterflies living in different forest strata, by combining high-speed videography in the field with morphometric analyses and aerodynamic modelling. By comparing canopy and understory species, we show that adaptation to an open canopy environment resulted in increased glide efficiency. Moreover, this enhanced glide efficiency was achieved by different canopy species through strikingly distinct combinations of flight behaviour, wing shape and aerodynamic mechanisms, highlighting the multiple pathways of adaptive evolution.

A322 OPTIMISATION OF DYNAMIC SOARING IN A FLAP-GLIDING SEABIRD IMPACTS ITS DISTRIBUTION AT SEA Thursday 7th July 2022

17:20

James Kempton, University of Oxford.

Co-authors: Joe Wynn, Institut für Vogelforschung Vogelwarte Helgoland, Graham K. Taylor, University of Oxford james.kempton@biology.ox.ac.uk Dynamic soaring harvests energy from a spatiotemporal wind gradient, allowing albatrosses to glide over vast distances. However, its use is challenging to demonstrate empirically, and has yet to be confirmed in other seabirds. We investigate how flap-gliding Manx Shearwaters optimize their flight for dynamic soaring. We do so by deriving a new metric, the horizontal wind effectiveness, that quantifies how effectively flight harvests energy from a shear layer. We evaluate this metric empirically for fine-scale trajectories reconstructed from birdborne video data using a simplified flight dynamics model. We find that the birds’ undulations are phased with their horizontal turning to optimize energy harvesting. We also assess the opportunity for energy harvesting in long-range, GPS-logged foraging trajectories, and find that Manx Shearwaters optimize their flight to increase the opportunity for dynamic soaring during favourable wind conditions.

Our results show how small-scale dynamic soaring impacts large-scale Manx Shearwater distribution at sea.

A344 MEASURING AND ANALYSING ANIMAL CLOSING FORCES: A MOBILE SETUP AND NEW R PACKAGE Thursday 7th July 2022

12:00

Peter Rühr, University of Bonn.

Co-author: Alexander Blanke, University of Bonn ruehr@uni-bonn.de Animal closing forces such as bite and pinch forces may determine access to food and mates and are therefore important performance metrics related to fitness. However, despite the diversity and ecological importance of smaller animals such as many crustaceans and insects, knowledge on the predictors and evolution of closing forces in these taxa is extremely scarce. Here we present a mobile and light-weight closing force measurement setup that is tailored to measure closing forces of a wide range of animals, especially smaller taxa, and an R package for analysing the measurements. During a measurement, in vivo closing forces are converted to an electrical signal by a highly sensitive piezoelectric force transducer. The transducer is housed in a setup that can be manufactured with a 3D printer and generic parts,

SCIENCE ACROSS BOUNDARIES ABSTRACTS 10

and the electric signal is amplified by a custom charge amplifier. The R package automatically extracts maximum force values and individual force curves for further curve shape analyses. The shape of these curves may yield information on the underlying biomechanics, physiology, and behaviour during biting/pinching, and has only rarely been studied. We think that the new measurement setup, its ease of use, reproducible components, and fast assembly will enable rapid force measurements in the field and in the lab. In combination with the R package, it will facilitate research on the micro- and macroevolution of animal closing forces in a wide range of taxa, especially in smaller vertebrates and the megadiverse arthropods.

A406 BIOMECHANICS AND DISPERSAL OF THE DANDELION FRUIT Thursday 7th July 2022

14:20

Madeleine Seale, University of Oxford. maddy.seale@plants.ox.ac.uk Wind dispersal of the dandelion fruit is enabled by its parachute-like pappus – a set of hairs, which are essential for flight. The pappus structure manipulates the flow of air around it to generate a specialised vortex ring, which influences flight capacity and stability. Remarkably, the dandelion pappus is not a completely passive structure but can change shape in response to environmental conditions. Moisture causes the pappus to close by bundling its hairs together. This arises from specific swelling of a carefully patterned radial tissue structure.

Morphing of the pappus modifies both the fluid mechanical properties and the capacity for dispersal. Air pressure changes conferred by the vortex ring alter as the pappus changes shape making it more streamlined. This affects both the initiation of dispersal as the pappus detaches from the parent plant, and the subsequent flight characteristics. Simulating this process via modelling demonstrates the ecological consequences for dispersal for different pappus morphing scenarios. In this way we use the humble dandelion fruit as a case study connecting biomechanics, modelling, fluid dynamics and ecology to understand plant form and function.

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CP1 - CELL BIOLOGY OF THE PLANT VACUOLE ORGANISED BY: LORENZO FRIGERIO (UNIVERSITY OF WARWICK) JOE MCKENNA (UNIVERSITY OF WARWICK) CP1 HOW CARGO PROTEINS ARE RECOGNIZED AND SORTED TO THE VACUOLES Thursday 7th July 2022

10:15

Kam-Bo Wong, The Chinese University of Hong Kong.

Co-authors: Hsi-En Tsao, State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shu Nga Lui, Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Anthony Hiu-Fung Lo, State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hiu Yan Wong, State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Liwen Jiang, State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong kbwong@cuhk.edu.hk In plant cells, cargo proteins destined to the vacuoles contain sequence specific information known as vacuolar sorting determinant (VSD) that is recognized and sorted by vacuolar sorting receptors (VSRs) to the vacuoles. To understand how VSR recognizes its cargos, our group have determined the crystal structures of the PA domain of Arabidopsis VSR1 in complex with the vacuolar sorting determinants (VSDs) of a protease aleurain [1] and a 12 S globulin cruciferin (CRU) 1 [2]. Structural comparison with the apo-form of VSR1-PA suggests that cargo-binding induces conformational changes in four regions of VSR1-PA. The VSDs bind to the cargo-binding loop consisting of a conserved motif of 95RGDCYF100. The invariant Arg-95 residue was found to be essential for receptor-cargo interactions and vacuolar sorting of cargo proteins. In vitro pull-down assay showed that VSR1 interacts with the C-terminal decapeptide sequences of CRU1, CRU4 and vicilin-like seed storage protein (VL) 22, but not with those of CRU2, CRU3, VL21 and VL43. Tagging the C-terminal sequences of CRU1 and VL22 to the secretary red fluorescent proteins are sufficient in redirecting the proteins to the vacuoles in Arabidopsis protoplasts.

A P453A substitution converts the C-terminal sequence of CRU2 to a C-terminal VSD that is recognized by VSR1. Structural insights on receptor-cargo obtained could be useful in targeting recombinant proteins to protein storage vacuoles in seeds.

This work was supported by grants from the Research Grants Council of Hong Kong Special Administrative Region, China (CUHK14151416, C4041-18EF, AoE/M-05/12, AoE/M403/16, and C4033-19E) and The National Natural Science Foundation of China (91854201 and31670179) and by direct grants from The Chinese University of Hong Kong.

[1] Luo F. et al. (2014) “How vacuolar sorting receptor proteins interact with their cargo proteins: crystal structures of apo and cargo-bound forms of the protease-associated domain from an Arabidopsis vacuolar sorting receptor.” Plant Cell, 26, 3693-708 [2] Tsao H.E. et al. (2022) Structural insights into how vacuolar sorting receptors recognize the sorting determinants of seed storage proteins. Proc Natl Acad Sci USA, 119, e2111281119.

CP2 WHOLE-CELL ELECTRON TOMOGRAPHY ANALYSIS OF VACUOLES IN PLANT CELLS Thursday 7th July 2022

11:45

Liwen Jiang, The Chinese University of Hong Kong ljiang@cuhk.edu.hk Membrane trafficking and organelle biogenesis play important roles in plant growth and development, as well as responses to external signals. The plant endomembrane system contains several functionally distinct membrane-enclosed organelles, including the endoplasmic reticulum (ER), Golgi apparatus, trans-Golgi network (TGN) or early endosomes (EE), prevacuolar compartment (PVC) or multivesicular body (MVB) and vacuole. One of our major research programs has been focused on illustrating the underlying mechanisms of vacuolar trafficking and vacuole biogenesis and function in plant cells. One major approach has been the whole-cell electron tomography (ET) analysis with nanometer resolution of vacuole formation and distribution in different cell types of developmental stages, including root cells, stomatal lineage cells and developing pollens in Arabidopsis. Here I will present our recent work and models of vacuole biogenesis and function in plants from the ET analysis. Supported by grants from the Research Grants Council of Hong Kong and CUHK.

P2 THE VACUOLE–CYTOSKELETON CONNECTION: A HANDLE TO REGULATE GROWTH Thursday 7th July 2022

09:00

David Scheuring, Technische Universität Kaiserslautern scheuring@bio.uni-kl.de Changing the morphology of the plant vacuole depends on the integrity of the cytoskeleton. So far, only little is known about the nature of this relationship. The plant-specific Networked (Net) family of membrane-associated actin-binding proteins contains two members, Net4A and Net4B, which are of special interest since they localize to the tonoplast. Recently, we could show that Net4 modules the compactness of vacuoles and this in turn affects its space-filling function and eventually inhibits cell elongation and growth. Since the net4a net4b double mutant only has a mild phenotype and other NETs seems not to compensate, we expected a higher molecular complexity and searched for new interactors. Pull-down experiments followed by MS-MS identified several new interactors, potentially participating in the regulation of the vacuole-cytoskeleton interface.

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C3 IT'S ALL JUST A PHASE: PHASE SEPARATION DRIVING ORGANELLE BIOGENESIS Thursday 7th July 2022

09:30

Joe McKenna, University of Warwick

CP12 SUBCELLULAR VOLUME CHANGES IN STOMATA OPENING: VACUOLAR VERSUS CYTOSOLIC VOLUME CHANGES Thursday 7th July 2022

11:30

Alexis De Angeli, CNRS

joe.mckenna@warwick.ac.uk The vacuole is a hallmark of the plant cell, generating turgor pressure and thus driving growth. Seed plant embryos also contain numerous specialised Protein Storage Vacuoles (PSV) which are repositories for the nutritional content of seeds. But how do these specialised PSVs form and what mechanism drives this process? Recent work has demonstrated that PSVs are formed by the remodelling of the single embryonic vacuole into many fragmented PSVs. The main constituent of these PSV are seed storage proteins (SSP). We have shown that SSP undergo liquid-liquid phase separation forming a droplet within the vacuole and these SSP droplets can bend the tonoplast membrane. However, can this process of SSP phase separation drive fragmentation of a single embryonic vacuole into multiple PSV? Additionally, which proteins and conditions drive phase separation of SSP in the embryonic vacuole? We have identified and are characterising protein candidates for drivers of phase separation in the embryonic vacuole and determining their role in PSV biogenesis.

CP11 VACUOLAR TRAFFICKING IN CEREAL SEEDS Thursday 7th July 2022

SCIENCE ACROSS BOUNDARIES ABSTRACTS 12

09:45

Elsa Arcalis, University of Natural Resources and Life Sciences Vienna (BOKU) elsa.arcalis@boku.ac.at

Stomata are anatomical structures at the surface of leaves controlling gas exchanges between the plant and the atmosphere. The stomatal pore aperture is regulated by two specialized cells, the guard cells, having the capacity to reversibly change their volume and shape. The changes of the guard cells’ volume are under tight control of signaling cascades regulating the ionic transport processes across the plasma and the vacuolar membranes. In guard cells the vacuole can reversibly change its volume during the opening and closure of stomata. We have used a 3D reconstruction approach to visualize the dynamics changes subcellular compartments volumes in living guard cells. The method we developed allowed us to simultaneously quantify the volumetric modifications of the cytosol and the vacuole. Notably, we could follow modification of the subcellular organization in parallel with the ion transport dynamics at the plasma and vacuolar membranes. Our data show that the vacuole accounts for the whole guard cell volume changes. This suggests that the turgor changes of the guard cells are driven by the vacuole during stomata aperture.

CP13 COORDINATION OF GROWTH IN PLANTS 11:00

Jürgen Kleine-Vehn, University of Freiburg, juergen kleine-vehn@biologie.uni-freiburg.de

The endosperm of cereal seeds serves to store proteins and starch used by the embryo during germination. The high degree of specialization of this tissue is reflected in its endomembrane system containing ERderived protein bodies and protein storage vacuoles (PSVs). In maize seeds, the major storage proteins are zeins, which form transportincompetent aggregates within the ER lumen and eventually assemble into protein bodies that bud from the ER. In contrast to the zeins, maize globulins are less abundant and are deposited in the vacuolar storage compartment of the maize endosperm, which has not been fully described. In other cereals, such as barley, the PSV is the major protein storage compartment and prolamins are deposited together with the globulins, following an ER to vacuole route bypassing the Golgi. The pathways of the storage proteins to the vacuole as well as the role and morphology of the vacuolar organelle during seed development are subject to temporal changes and also show spatial differences across the endosperm layers. We have therefore used different microscopy techniques, including live-cell imaging and 3D electron microscopy techniques (SBF-SEM), to generate a multi-scale dataset towards clarifying the role of vacuolar compartments in cereal endosperm cells.

POSTER SESSION C2 'ACTIN-UP' ON THE VACUOLE Thursday 7th July 2022

alexis.deangeli@cnrs.fr

Thursday 7th July 2022

ANNUAL CONFERENCE MONTPELLIER 2022

Cells typically remain relatively small, because if cells grow beyond a critical limit, the surface of the plasma membrane eventually ceases to accommodate intracellular needs. Compared to animals, plant cells can dramatically increase their size without the apparent need for surface furcation. The vacuole is the biggest plant organelle and has a space-filling function, allowing to occupy up to 90% of the cell volume (Löfke et al., 2015; Scheuring et al., 2016; Dünser et al., 2019).

The dynamic regulation of vacuolar size allows plant cells to expand with little increase of the cytosol (Dünser et al., 2019; Dünser et al., 2022), maintaining a favorable cell surface to cytosol ratio during growth. Here we discuss subcellular mechanisms that ensure the coordination of cellular and vacuolar size expansions.

POSTER SESSION

Charlotte Jones, University of Warwick Co-authors: Joe McKenna, University of Warwick, Lorenzo Frigerio, University of Warwick charlotte.jones.3@warwick.ac.uk The vacuole is one of the most important organelles in the plant cell, playing a key role in development and growth as well as performing multiple functions, from acting as a storage compartment for plant metabolites to driving cell wall expansion via controlling turgor pressure.

As the vacuole is such a multifaceted organelle, understanding how it performs its functions is integral to increasing our knowledge of how plants function. It is known that actin plays a crucial role in manipulating and modifying the vacuole to perform different functions. However, the ability to investigate these interactions is limited by two major factors: the abundance of actin in the cell complicates distinguishing between specific transient actin formations and background signal, and low resolution hampers the ability to detect actin directly interacting with the vacuole. In order to overcome these challenges, the lab has produced fluorescent actin binding chromobodies targeted to the vacuole membrane. In the absence of actin, these probes move freely through the tonoplast, too diffuse to produce signal, but in the presence of actin within close proximity to the membrane they bind and immobilise causing a cluster of florescence, therefore acting as a highly specific and dynamic actin-tonoplast probe. Confocal imaging of plant cells expressing this probe has allowed us to observe spatiotemporal vacuole actin dynamics with accuracy.

SCIENCE ACROSS BOUNDARIES ABSTRACTS 13

ANNUAL CONFERENCE MONTPELLIER 2022

SCIENCE ACROSS BOUNDARIES ABSTRACTS 14

CP3 - GENERAL CELL AND PLANT BIOLOGY ORGANISED BY: DAVID EVANS (OXFORD BROOKES UNIVERSITY) AP1 FIG ABORTION AS A DEFENSE MECHANISM FOR FICUS TREES AND POLLINATING FIG WASPS Wednesday 6th July 2022

09:30

Anthony Bain, National Sun Yat-sen University, Co-authors: Bruno Di Giusto, Ming Chuan University, Shang-Yang Lin, Institute of Ecology and Evolutionary Biology, National Taiwan University anthonybain22@mail.nsysu.edu.tw Nonpollinating fig wasps (Hymenoptera: Chalcidoidea) are the most remarkable exploiters of the Ficus (Moraceae) and pollinating fig wasp (Hymenoptera: Agaonidae) mutualism. Both pollinating and nonpollinating fig wasps lay their eggs inside the inflorescences of the fig trees (Ficus), where their larvae grow. The nonpollinating fig wasps (NPFWs) negatively impact the pollinator population and fig seed production because, for each NPFW hatch in a fig, a pollinator or a seed has been terminated. Moreover, NPFWs can kill all the pollinating males in a fig and doom all the wasps in a single fig, as pollinating males dig the exit hole out of a fig. Up to now, only experimental studies based on the absence/presence of NPFWs have been done. To better quantify the impact of NPFWs, we conducted bagging experiments using a controlled number of fig wasps. Pollinating wasps were introduced in bags containing receptive figs and different numbers of NPFWs (from none to five). For this experiment, we used the pollinating wasp, Ceratosolen wui, and the NPFW species, Philotrypesis taida living on the fig tree Ficus benguetensis in Northern Taiwan. We found that higher numbers of NPFWs increased the fig abortion rate before maturation and decreased the number of emerging wasps and the proportion of pollinators. In conclusion, we suggest that selective abortion in the early stage of fig development is a density-dependent defense mechanism against NPFWs.

CP5 CHARACTERISATION OF ‘PHYCOLIGNIN’ IN THE CELL WALL OF CHLOROPHYTE SEAWEEDS Wednesday 6th July 2022

11:30

Alexander Goodridge, Durham University, Co-author: John Bothwell, Durham University alexander.j.goodridge@durham.ac.uk

The evolution of lignification in vascular plants conferred improved structural support, defence, and water transport, improving the success of plants on land. Despite lignification being a land plant specific expansion, lignin-like compounds have been identified in the cell walls of intertidal seaweeds. Here, I aim to characterise the function and structure of the ‘phycolignin’ fraction of the chlorophyte seaweed Ulva compressa. UV excitation of Ulva cell wall autofluorescence using confocal microscopy induced a blue-green emission profile comparable to that of lignin, which was significantly elevated under hyposaline stress (1.7X fold change to control, ***) and significantly reduced under hypersaline stress (0.5X fold change, ***), indicating a possible osmoprotective role. Cell walls were then isolated and fractionated into pectin, hemicellulose, and ⍺-cellulose to identify this fluorophore, with plant biomass also fractionated as a ‘lignin positive’ control. Several biochemical tests were performed to identify which polysaccharides lignin-like structures were associated with, followed by ATR-FTIR and NMR. ‘Phycolignin’ in Ulva appeared to be associated with cellulose and hemicellulose, with potential aromatic groups identified by ATR-FTIR and 1H NMR (solution-state). Positive identification of lignin within plant extracts showed that Ulva ‘phycolignin’ displayed fundamental structural differences to true lignin. However, the lack of available reference spectra for FTIR of chlorophyte phenolics, and the general insolubility of the Ulva cell wall in conventional NMR solvents limited data interpretation. Better structural characterisation of ‘phycolignin’ in Ulva will increase our understanding on how multicellularity, the metabolome, and stress responses evolved and diverge within the green lineage.

C10 THE LATEST HYPE(R) IN PLANT H2O2 BIOSENSING Wednesday 6th July 2022

15:35

José Ugalde, INRES-Chemical Signalling, University of Bonn, Co-authors: Michelle Schlößer, INRES-Chemical Signalling, University of Bonn, Armelle Dongois, BPMP, University of Montpellier, Alexandre Martinière, BPMP, University of Montpellier, Andreas Meyer, INRES-Chemical Signalling, University of Bonn jugaldev@uni-bonn.de Hydrogen peroxide (H2O2) is widely used as a signalling molecule. It is critical to measure H2O2 with a high spatial and temporal resolution to better understand its role as a messenger. The most frequent approach to detect H2O2 has been using chemical probes, which have the disadvantage of limited specificity and cannot report any dynamics or spatial information. Genetically encoded probes have made significant advances to overcome these limitations. Probes of the HyPer family

ANNUAL CONFERENCE MONTPELLIER 2022

consist of a circularly permuted yellow fluorescent protein (cpYFP) core and a sensing domain from a bacterial H2O2-activated transcription factor (OxyR). These, however, have a pronounced pH sensitivity. Other H2O2 sensors, such as roGFP2-Orp1, have shown to be pH-insensitive but lack the responsiveness to detect low nanomolar H2O2 changes, possibly due to the strong reducing effect of the glutathione redox potential (EGSH). A new ultrasensitive HyPer7 fuses the OxyR of N. meningitidis to an optimized cpYFP largely pH-independent. Here, we have generated and characterized stable Arabidopsis thaliana plants expressing a cytosolic version of HyPer7 and prove that the reduction of this sensor is mostly EGSH-independent and highly responsive to externally imposed oxidation via H2O2 feeding. Furthermore, HyPer7 could sense stress-induced H2O2 in live-cell plants exposed to herbicides, such as methyl viologen or the flagellin-induced apoplastic ROS burst, much better than the previously mentioned H2O2 probes.

HyPer7 sensitivity also allowed us to see that the laser light used for excitation is sufficient to induce H2O2 release from chloroplasts in amounts only detected by this ultrasensitive sensor.

P10 EVALUATION OF DIFFERENT EMASCULATION TECHNIQUES IN SESAME (SESAMUM INDICUM L.) Wednesday 6th July 2022

10:00

Hina Saleem, University of Agriculture Faisalabad hinah3054@gmail.com Background: Sesame is an ancient oilseed crop that is well known around the world for its various uses and benefits, but unfortunately very little work has been done on its emasculation and pollination.

Aim: The present study was planned to determine the efficiency of various emasculation techniques that could be utilized in sesame breeding programme. For this efficiency and applicability of a various methods of emasculation’ were evaluated in a set of crosses.

Results: The results concluded that successful emasculation techniques were Alcohol method in the genotypes under study.

Conclusion: Alcohol method was the best method for the emasculation of genotypes under study as sesame flower is delicate this method can be easily used without harming the flower.

Recommendations: The information generated can be utilized in future breeding programs regarding sesame crossing as previously very little work has been done on this crop in this context.

C11 OXIDATIVE STRESS INDUCED BY MILD HEAT SHOCK AT 40°C ACTIVATES A CELL SURVIVAL RESPONSE MODULATED BY NRF2 Wednesday 6th July 2022

10:15

Georges Hraoui, Université du Québec à Montréal Co-authors: Diana Averill-Bates, Université du Québec à Montréal, Sophie Breton, Université du Québec à Montréal georgehraoui@yahoo.ca

SCIENCE ACROSS BOUNDARIES ABSTRACTS 15

The cellular adaptive response is a defense network that allows cells to survive and proliferate in the presence of stressful factors. These stressors, which include hypoxia, radiation, thermal shock, and heavy metals, damage cells by increasing oxidative stress via increased generation of reactive oxygen species (ROS). The exposure to mild stress (e.g. thermal shock of 40°C) for an extended period can activate the cellular adaptive response and protect the cell against subsequent exposures to lethal stress doses (e.g. lethal thermal shock of 42°C).

However, the mechanisms by which this response is activated are still poorly understood. Nrf2, a transcription factor found as a cytosolic heterodimer with Keap1, is activated in response to oxidative stress and translocates to the nucleus where it binds to the antioxidant response element and initiates a host of antioxidant defenses. The role of Nrf2 in the cellular adaptive response is of the utmost importance.

Our studies seek to understand 1) ROS generation in response to mild heat stress, 2) how these increased ROS modulate activation of the cellular adaptive response, and 3) the role of Nrf2 in the modulation of ROS generation and activation of the cellular adaptive response. Our results in HeLa cells show that increased ROS at 40°C originate from both mitochondria and NADPH oxidase. Modulation of Nrf2 activity via overexpressor and knockdown cell lines significantly impacts ROS generation during mild heat stress. Elucidating the role of ROS in the establishment of the cellular adaptive response paves the way to new potential therapeutic treatments.

P17 ONE-POT PROCESSING OF ULVA SEAWEED BIOMASS WITH DEEP EUTECTIC SOLVENT-OPTIMIZED FERMENTATION Wednesday 6th July 2022

11:15

Akanksha Agrawal, Durham University Co-author: John Bothwell, Durham University akanksha.agrawal@durham.ac.uk We demonstrate that one-pot consolidated bioprocessing using deep eutectic solvents can improve the extraction of fermentable sugars from the green seaweed, Ulva linza. Ulva biomass was first pretreated with either sulfuric acid, the deep eutectic solvent choline chloride-oxalic acid, or the ionic liquid 1-ethyl-3-methylimidazolium bromide. After pretreatment, we separated solubilised sugars from residual solids. The residual solids were saccharified using green solvent-stable glycosidases that were isolated from a newly identified strain of the ascomycetous fungus, Penicillium oxalicum. The factors affecting this saccharification were quantified from the response surfaces of a Box-Behnken design. Finally, the sugars extracted from Ulva biomass were fermented into bioethanol using a dual yeast culture. We obtained higher bioethanol yields from Ulva biomass with consolidated processing in deep eutectic solvents, compared to lower yields from Ulva biomass with other solvents or two-stage processing.

ANNUAL CONFERENCE MONTPELLIER 2022

P33 IDENTIFICATION OF A KEY REGULATOR CONTROLLING CUTICULAR WAX IN BARLEY Wednesday 6th July 2022

15:05

Trisha McAllister, University of Dundee Co-authors: Chiara Campoli, University of Dundee, Mhmoud Eskan, University of Dundee, Linsan Liu, University of Dundee, Sarah M. McKim, University of Dundee

SCIENCE ACROSS BOUNDARIES ABSTRACTS 16

two-hybrid library of quiescent ovaries with the SlAGL6 full-length protein resulted in the identification of eight MADS-box transcription factors as candidate partners that complex with SlAGL6. CRISPR knockout of corresponding genes revealed that one mutant exhibited a parthenocarpy syndrome that closely resembled that of slagl6CRsg1. This includes the absence of a typical endothelium in mutant ovules and the precocious post-fertilization reprogramming of their integument. Taken together, our results suggest that a protein complex containing SlAGL6 acts from within the ovule integument to inhibit ovary growth beyond anthesis. That by suppressing components of the fertilization-induced ovule reprogramming underlying fruit set.

ANNUAL CONFERENCE MONTPELLIER 2022

temperature fluctuates, it is equally significant for plants to be able to recover following warm acclimation. The purpose of this paper is to understand the flexibility of plant dynamic acclimation towards periods of high temperature. Fully developed plants of Arabidopsis Col-0 were acclimated to high temperature at 30C for 7 days after grown at control condition (20C day/ 16C) for 8 weeks. Afterwards, these plants were returned to growth condition for another week to recover from warm treatment. In this paper, the consequences of these treatments on their morphological changes were observed. Following that, photosynthetic capacity was measured and total starch content of leaves in these treatments was also determined.

p.a.mcallister@dundee.ac.uk Land plants cover their epidermis with a specialised protective layer called the cuticle, a feature which is crucial for surviving the perils of a terrestrial environment, including desiccation, UV damage and pathogen attack, dangers which may worsen with our escalating climate crisis. Several cereal staples such as barley and wheat show further epidermal specialisation with a distinctive, glaucous wax bloom on reproductive stage tissues, a feature associated with improved drought tolerance. Understanding the mechanisms underpinning wax bloom development may help breed more climate resilient varieties.

To date, studies on barley eceriferum mutants have identified several enzymes involved in cuticular wax biosynthesis. However, little is known about the upstream regulation of this process. My research addresses this knowledge gap by exploiting genetic resources to identify a key regulatory player in barley cuticle development. Here, I will discuss how I used high density genotyping, comparative gene expression and wax compositional analyses to identify a gene essential for wax bloom formation and the expression of cuticular metabolic genes in barley.

P38 HOW TO SET A PERFECT PARTHENOCARPIC FRUIT? Wednesday 6th July 2022

09:45

Tzahi Arazi, ARO - Volcani Center.

Co-authors:Suresh Kumar Gupta, ARO - Volcani Center, Hawi Deressa Kenea, Jimma University, Oscar Castañeda Mendez, Michigan State University, Victoria Kwarteng, ARO - Volcani Center, Rivka Barg, ARO - Volcani Center, Erich Grotewold, Michigan State University

P44 PLANTS ACTIN’ UP – AUTOMATIC CYTOSKELETON EXTRACTION IN ARABIDOPSIS Wednesday 6th July 2022

11:45

Jordan Hembrow, University of Exeter Co-authors: David Richards, University of Exeter, Mike Deeks, University of Exeter jmh253@exeter.ac.uk The actin cytoskeleton has numerous roles in plant cells, from transporting vesicles and organelles, to transducing external physical stimuli, to enabling cytoplasmic streaming over the entire cell length.

The network is constantly remodelled and is adapted for each cell type and tissue. The ability to measure and quantify the actin network is key to understanding cell function and response to external stimuli.

Further, there is currently a lack of an automatic method that can reliably and objectively quantify actin network properties. Here, I will introduce such a method that we have recently developed, including how we have validated this on Arabidopsis hypocotyl and leaf cells. I will then present our findings that this method has enabled into the differences between the actin network in various tissue types and mutants. Finally, I will discuss how the actin network in plant cells is remodelled in response to Barley powdery mildew, a fungal disease that costs £300M in fungicides to combat it.

POSTER SESSIONS

tarazi@agri.gov.il Fruit set, the switch from quiescent ovary to developing fruit, is a crucial developmental landmark that is normally established during and soon after fertilization of the ovules inside the quiescent ovary. Despite the progress made, its molecular mechanism is not fully understood.

We previously showed that the tomato AGAMOUS-like-6 (SlAGL6) loss-of-function mutant (slagl6CR-sg1) is capable of fertilizationindependent setting of normal, yet seedless (parthenocarpic) fruit. We show that slagl6CR-sg1 ovules are enlarged due to integument overproliferation and fail to differentiate an endothelium, the integument's innermost layer, upon maturation. A causal relation between this abnormal phenotype and slagl6 loss-of-function is inferred from the observation that SlAGL6 is predominantly expressed in the immature ovule integument and upon ovule maturation its expression shifts to its innermost layer the endothelium. RNA-Seq analysis of unfertilized slagl6CR-sg1 ovules indicated that their transcriptome underwent reprogramming that resembles the transcriptional changes occurring in wild-type ovules following fertilization. Screening yeast

P4 ACCLIMATION AND RECOVERY RESPONSES OF HIGH TEMPERATURE IN ARABIDOPSIS Thursday 7th July 2022

POSTER SESSION

Norazreen Abd-Rahman, The University of Manchester, Co-author: Giles N. Johnson, The University of Manchester norazreen.bintiabdrahman@postgrad.manchester.ac.uk Temperature plays an important role in controlling growth and development; however, plants are almost always exposed to nonoptimal temperature at times during their life cycle. Plants possess mechanisms to acclimate to high temperature, nevertheless, as ambient

P5 PLASTID TERMINAL OXIDASE (PTOX) IS INVOLVED IN HIGH LIGHT ACCLIMATION IN EUTREMA SALSUGINEUM Wednesday 6th July 2022

POSTER SESSION

Pablo Calzadilla, The University of Manchester Co-authors: Junliang Song, The University of Manchester, Giles N. Johnson, The University of Manchester pablo.calzadilla@manchester.ac.uk Light is essential for photosynthetic organisms, which harvest solar energy for the synthesis of organic carbon molecules. However, extreme environmental conditions can lead to imbalances between the light energy capture and their utilization, inducing cell damage and photoinhibition. Previous work in our lab demonstrated that the plastid terminal oxidase (PTOX) can act as a safety valve for photosynthesis under such conditions, particularly salt stress. In the present study, we aimed to determine PTOX participation in high light acclimation of Eutrema salsugineum. Six-week-old plants were subjected to high light (HL, 800 μmol.m-2.s-1) or control conditions (Ct, 100 μmol.m-2.s-1) for 12 d. Acclimation to HL increased Pmax and ΦPSII values, when compared to Ct plants, resulting in a 3-fold higher fresh and dry weight accumulation. To determine PTOX activity, electron transport rates (ETR) were measured in the presence and absence of oxygen (21 and 1 % O2, respectively). Absence of oxygen inhibits ETR by 23 % in HL plants, and after 10 d of treatment, while no oxygen dependence electron transport was observed in Ct plants.

PTOX activity was further confirmed by infiltrating 10 d leaves of HL and Ct-treated plants with n-propyl-gallate (nPG, PTOX inhibitor). nPG inhibited electron transport to the same extent as 1 % O2, and only in the HL-treated leaves, supporting PTOX involvement in high light acclimation of E. salsugineum plants. Currently, further experiments are being performed to understand PTOX activation mechanism, which could potentially be used to increase tolerance to environmental stresses in other plants species.

SCIENCE ACROSS BOUNDARIES ABSTRACTS 17

CP6 FLAVINS AND FLOWERING: THE EFFECTS OF ALTERED COFACTOR METABOLISM Thursday 7th July 2022

POSTER SESSION

Skylar Johnson, Washington State University skylar.johnson@wsu.edu Flavins, a class of small molecules used as redox cofactors, are essential for all life forms. Catalytically active flavins include Flavin Adenine Dinucleotide (FAD) and Flavin MonoNucleotide (FMN), both of which are derived from the parent molecule riboflavin. These cofactors are utilized in a wide variety of metabolic pathways, from electron transport chains to fatty acid oxidation, signaling, and ROS generation. Current literature evaluates the effects of altered flavin contents on plant responses to biotic stresses with exogenously applied flavins. This project aimed to break new ground and uncover the wider effects of overexpressed flavin biosynthetic enzymes in the model plant Arabidopsis thaliana.

An RNAseq experiment uncovered a link between flavins and iron homeostasis, and physiological measurements unveiled a connection between flavins and flowering times. While cofactor engineering is popular and well-documented in microorganisms, this study provides further evidence that it may also be a useful approach in multicellular lifeforms such as plants.

C12 OPTICAL SUPER-RESOLUTION IMAGING OF TISSUES AND TOBACCO MOSAIC VIRUS (TMV) USING MICROSPHERE TECHNOLOGY Thursday 7th July 2022

POSTER SESSION

Sorin Laurentiu Stanescu, LIG Nanowise Ltd Co-authors: Sebastien Vilain, LIG Nanowise Ltd, Francesco Valente, LIG Nanowise Ltd, Lin Li, LIG Nanowise Ltd sorin.stanescu@lig-nanowise.com Microsphere super-resolution microscopy has recently received a lot of attention due to its simplicity and its capability to resolve features beyond the diffraction limit for living systems, in real time, without being invasive. Current systems which are able to image small biological structures are destructive, invasive (they use fluorescent dyes) or they provide reconstructed images (i.e. not a real time imaging of living organisms). The authors designed and built a bio-microscope tailored around the SMAL® (Super-Resolution Microsphere Amplifying Lens) objective lens which overcomes these drawbacks. The novelty of the setup is the ability to study cell’s structures and viruses which previously were not possible to be imaged using conventional white light microscopy. In this work, along various plant cells, label-free tobacco mosaic virus was employed for imaging in this work due to its stability, reliability, and its dimensions beyond the diffraction limit.

The results were compared with images obtained using an X100/1.40 NA oil immersion objective lens fitted onto a white light microscope, in the same location. Microsphere assisted microscopy is a novel type of optical microscopy with great potential for high resolution imaging of in vivo biological structures and pathogens.

ANNUAL CONFERENCE MONTPELLIER 2022

P12 THE ROLE OF PLASTID TERMINAL OXIDASE (PTOX) IN BARLEY UNDER STRESS Thursday 7th July 2022

morphological markers on the growing pitcher bud and linked these to a timeline of internal peristome development. This will allow us to target specific stages of surface patterning with confidence, which is crucial for investigating gene expression patterns and gene function during development.

POSTER SESSION

Junliang Song, The University of Manchester Co-authors: Giles N. Johnson, The University of Manchester, Pablo Ignacio Calzadilla, The University of Manchester junliang.song@postgrad.manchester.ac.uk Photosynthesis is one of the most important physiological processes in plants. However, this process can be affected by abiotic stresses, the frequency of which has been increasing due to global climate change.

Plastid terminal oxidase (PTOX) has previously been found to play a positive role in plant stress tolerance, acting as a sink for electron transport for PSII. Through PTOX, electrons are transferred to oxygen and produce water. In this study, we explored PTOX activity in Barley (Hordeum vulgare) under salt stress. 10-days old barley plants were exposed to different concentrations of salt (150mM, 200mM, 250mM) for 7 and 10 days. The results showed that the PSII efficiency (PSII) of salt stress plants was significantly higher than control plants. To test for PTOX activity, electron transport rate (ETR) was measured under two different O2 concentrations (21%, 1%). We found that ETR dropped nearly 30% in salt stress plants under 1% O2. This drop was not observed in control plants, implying that salt stress induces PTOX activity. PTOX protein increased after 7-days of salt treatment, suggesting an induced expression of this protein as an acclimation response to stress. Further experiments are being carried out to investigate the PTOX mechanism in barley under abiotic stresses.

C13 NEPENTHES PITCHER PLANTS RECOMBINE COMMON PATTERNING PROCESSES TO CREATE A COMPLEX HIERARCHICAL EPIDERMIS STRUCTURE Wednesday 6th July 2022

SCIENCE ACROSS BOUNDARIES ABSTRACTS 18

POSTER SESSION

Oona Lessware, University of Bristol Co-author: Ulrike Bauer, University of Bristol

CP14 THE UPS AND DOWNS OF BEING AN OUTDOOR PLANT Thursday 7th July 2022

POSTER SESSION

Robyn Emmerson, University of Essex (currently University of Birmingham) Co-authors: Tracy Lawson, University of Essex, Nicolae Radu Zabet, Queen Mary University of London, Ulrike Bechtold, Durham University r.emmerson@bham.ac.uk Plants must cope with the highly dynamic nature of light to survive and thrive, a process referred to as acclimation. Although acclimation to different light intensities has been well studied, there has been little research into the effects of dynamic lighting regimes on this process.

Natural fluctuating light in field grown crops, can limit photosynthesis through slow stomatal opening in response to increasing light, whilst slow stomatal closure can erode water use efficiency (McAusland et al, 2016). It has been reported that both biochemical and stomata limitation on photosynthesis can lead to wheat yield losses of upto 21% (Taylor and Long, 2017).Previously dynamic growth light has been shown to effect the photosynthetic abilities of Arabidopsis thaliana, reducing maximum photosynthetic capacity and light absorption and altering light use efficiency along with changes in photoprotection (Vialet-Chabrand et al., 2017). To understand changes in gene expression resulting from acclimation to fluctuating light, Whole Genome Bisulfite Sequencing (WGBS) was utilised to examine changes in DNA methylation. Genome-wide changes were noted, with differentially methylated regions observed across a range of protein coding genes, transposable elements, and non-coding RNAs, as well as multiple regulatory sequences. RNAseq analysis demonstrated that some of these genes with changed methylation state impacted transcription, although many more changes in transcript levels were noted beyond the WGBS data. This could provide a new set of gene targets for improved photosynthetic efficiency and ultimately crop yield, which could be incorporated into on-going crop breeding programmes.

oonana@hotmail.co.uk The epidermis serves as a multifunctional interface between plants and their environment.

The leaf surfaces of carnivorous plants such as the Nepenthes pitcher rim (peristome) are highly specialised. The structure of the peristome is unique, holding a hierarchical pattern of radial ridges, grooves, and overlapping steps, that render it highly wettable and slippery to insects when wet. Virtually nothing is known about how the peristome's characteristic microtopography forms inside the hollow, developing pitcher bud. We used SEM imaging to document this process for the first time. We found that a sequence of distinct epidermal patterning events (cell organisation, conical cell formation, papillate cell outgrowth, and cell elongation) governs peristome development. All of these individual processes are common and conserved in leaf epidermal patterning across plant lineages. We hypothesise that Nepenthes co-opted these processes for peristome development and combined them in a novel way. In order to probe the genetic underpinnings of the sequential epidermal patterning events, we identified external

P14 RUBISCO SUBSTITUTIONS PREDICTED TO ENHANCE CROP PERFORMANCE THROUGH CARBON UPTAKE MODELLING Thursday 7th July 2022

POSTER SESSION

Wasim Iqbal, Newcastle University Co-author: Maxim Kapralov, Newcastle University W.Iqbal@ncl.ac.uk Improving the performance of the CO2-fixing enzyme Rubisco is among targets for increasing crop yields. Here, Earth system models (ESM) of

ANNUAL CONFERENCE MONTPELLIER 2022

canopy C3 and C4 photosynthesis were combined with species-specific Rubisco parameters to quantify the consequences of bioengineering foreign Rubiscos into C3 and C4 crops under field conditions. The sunlit/ shaded model for canopy photosynthesis was used together with species-specific Rubisco kinetics parameters including maximum rate (Kcat), Michaelis-Menten constant for CO2 (Kc21%O2), specificity for CO2 to O2 (Sc/o), and associated heat activation (Ha) values. Canopy scale consequences of replacing native Rubiscos in wheat, maize and sugar beet with foreign enzymes from 27 species were modelled using data from Ameriflux and Fluxnet databases. Variation among the included Rubisco kinetics differentially affected modelled carbon uptake rates, and Rubiscos from several species of C4 grasses showed the greatest potential of over 50% carbon uptake improvement in wheat, and over 25% improvement in sugar beet and maize.

P16 MANIPULATING PHOTORESPIRATION PROTECTS GROWTH AND PRODUCTIVITY AT ELEVATED TEMPERATURES IN A MODEL CROP Thursday 7th July 2022

POSTER SESSION

Amanda Cavanagh, University of Essex Co-authors: Paul South, Louisiana State University, Carl Bernacchi, United States Department of Agriculture, Agricultural Research Service (USDA-ARS), Donald Ort, University of Illinois at Urbana-Champaign a.cavanagh@essex.ac.uk Adapting crops to warmer growing season temperatures is a major challenge in mitigating the impacts of climate change on crop production. Warming temperatures drive greater evaporative demand and can directly interfere with both reproductive and vegetative physiological processes. Most of the world’s crop species have C3 photosynthetic metabolism for which increasing temperature means higher rates of photorespiration, wherein the enzyme responsible for fixing CO2 fixes O2 instead followed by an energetically costly recycling pathway that spans several cell compartments. In C3 crops like wheat, rice and soybean, photorespiration translates into large yield losses that are predicted to increase as global temperature warms. Engineering less energy-intensive alternative photorespiratory pathways into crop chloroplasts drives increases in C3 biomass production under agricultural field conditions, but the efficacy of these pathways in mitigating the impact of warmer growing temperatures has not been tested. We grew tobacco plants expressing an alternative photorespiratory pathway under current and elevated temperatures (+5 °C) in agricultural field conditions. Engineered plants exhibited higher photosynthetic quantum efficiency under heated conditions than the control plants, and produced 26% (between 16% and 37%) more total biomass than WT plants under heated conditions, compared to 11% (between 5% and 17%) under ambient conditions. That is, engineered plants sustained 19% (between 11% and 21%) less yield loss under heated conditions compared to non-engineered plants.

These results support the theoretical predictions of temperature impacts on photorespiratory losses and provide insight toward the optimisation strategies required to help sustain or improve C3 crop yields in a warming climate.

SCIENCE ACROSS BOUNDARIES ABSTRACTS 19

P18 MECHANISMS UNDERLYING HOLM OAK RECOVERY AFTER WATER STRESS: IS THE CARBON RESERVES CONSUMPTION UNAVOIDABLE TO MAINTAIN XYLEM HYDRAULIC FUNCTIONALITY? Thursday 7th July 2022

POSTER SESSION

Antonella Gori, Department of Agriculture, Food, Environment and Forestry (DAGRI), University of Florence Co-authors: Cecilia Brunetti, CNR, Institute for Sustainable Plant Protection, Barbara Baesso Moura, The Institute of Research on Terrestrial Ecosystems (IRET) of the CNR, Fabiano Sillo, CNR, Institute for Sustainable Plant Protection, Dalila Pasquini, University of Florence, Francesca Alderotti, Department of Agriculture, Food, Environment and Forestry (DAGRI), University of Florence, Raffaella Balestrini, CNR, Institute for Sustainable Plant Protection, Francesco Ferrini, Department of Agriculture, Food, Environment and Forestry (DAGRI), University of Florence, Mauro Centritto, CNR, Institute for Sustainable Plant Protection antonella.gori@unifi.it Quercus ilex dieback was observed in Mediterranean forests after drought events. We investigated the physiological and molecular mechanisms linked to embolism formation and depletion of carbon reserves in Q. ilex seedlings exposed to severe water stress and rewatering. Coordinated measurements of gas exchange, water relations, non-structural carbohydrates, drought-related genes expression and anatomical changes in wood parenchyma were assessed. Under water stress, stem midday water potential of - 4.6 MPa, corresponding to ~ 50% loss of hydraulic conductivity, and prolonged stomatal closure led to the depletion of carbon reserves.

Carbohydrates consumption, resulting from the upregulation of a β-amylase gene (BAM3) and the downregulation of glucose (GPT1) and sucrose (SUC27) transport genes, suggested glucose utilization to sustain cellular metabolism. After rewatering, the partial recovery of photosynthesis allowed the storage of carbohydrates in the wood parenchyma and the formation of new vessels. Changes in cell wall composition of fibers were also observed, probably helping regulate water storage in stem tissues. Our results show that, under severe water stress, Q. ilex preserve xylem functionality at the expense of wood carbon reserves. This may expose this species to the risk of carbon starvation, compromising its survival in Mediterranean environments exposed to recurrent drought spells.

P20 PLANTS COLD RESPONSE AND HOW IT IS AFFECTED

BY NITROGEN AVAILABILITY Thursday 7th July 2022

POSTER SESSION

Armida Gjindali, The University of Manchester Co-authors: Giles N. Johnson, The University of Manchester, Patrick Gallois, The University of Manchester, Marina Semchenko, The University of Manchester armida.gjindali@manchester.ac.uk

ANNUAL CONFERENCE MONTPELLIER 2022

To cope with a sustained drop in temperature plants need to adjust their photosynthesis to better suit the prevailing conditions. Fully developed leaves with fixed morphology alter their protein content by upregulating limiting factors. This dynamic response is called dynamic acclimation and requires days to be completed. For acclimation to be completed energy and elements need to be invested in de novo protein synthesis. A limitation to soil nitrogen availability can hinder this response and affect plant survival after cold exposure. To test this hypothesis, we grew Arabidopsis thaliana plants in three different N soil availabilities and exposed them to cold for 7 days. Plants were grown in sand and fertilized with nutrient solution containing 2.5mM, 5mM and 15mM total N at 20°C day/ 18°C night. After 8 weeks when the first fully developed leaves immerged plants were transferred at 5°C for 7 days before acclimation was assessed. Our results indicate that N availability plays a pivot role in plant response to cold stress. Only plants grown at the highest N availability were able to upregulate their maximum photosynthetic capacity while plants grown at the lowest N availability were unable to cope with the temperature shift and as a result had lower photosynthetic capacity after cold exposure. Plants grown in 5mM total N were able to maintain the same photosynthetic capacity after cold exposure.

P23 SUMO PROTEASE OTS1 CONTROLS LATERAL ROOT HYDROPATTERNING THROUGH RE-ACTIVATION OF ARF7 Wednesday 6th July 2022

POSTER SESSION

Jason Banda, University of Nottingham Co-authors: Nicky Leftley, University of Nottingham, Anthony Bishopp, University of Nottingham, Ari Sadanandom, Durham University, Malcolm Bennett, University of Nottingham jason.banda2@nottingham.ac.uk Root system architecture is crucial for foraging for heterogeneously distributed resources such as water. To acquire this water, roots preferentially branch when in direct contact with moist soil. This root adaptive response is called lateral root hydropatterning (Bao et al, 2014) and is dependent on the activity of AUXIN RESPONSE FACTOR7 (ARF7) creating a gradient of expression of LR regulator LBD16 (OrosaPuente et al, 2018). During a hydropatterning response, ARF7 activity is controlled through post-translational modification with Small Ubiquitin-like Modifier (SUMO). SUMOylation has a negative effect on ARF7 transcriptional activity by increasing binding with SHY2/ IAA3 repressor protein. Our work focusses on the role of the SUMO protease OVERLY TOLERANT TO SALT1 (OTS1), which re-activates ARF7 transcriptional activity by removing SUMO. A double mutant lacking OTS1 and its close ortholog OTS2 exhibits a defect in hydropatterning.

A functional OTS1-VENUS translational reporter revealed that the SUMO protease has a similar expression pattern to DR5 driven auxin response reporter lines, including in the lateral root-related basal meristem and pericycle tissues. However, in contrast to LBD16, no asymmetric spatial expression pattern for gOTS1-VENUS was observed when exposed to a hydropatterning stimulus. We propose that regulation of OTS1 protease activity (rather than stability) controls LR hydropatterning.

SCIENCE ACROSS BOUNDARIES ABSTRACTS 20

P24 A ROLE FOR MITOCHONDRIA DURING HIGH LIGHT STRESS IN CHLAMYDOMONAS REINHARDTII Thursday 7th July 2022

expression. Following that, Virus like particle (VLP) generation will be tested and then animal studied to validate immunogenicity. Through this, it is expected that the development of PCV2d vaccine, a new genotype virus that is spreading worldwide, will be able to contribute to the green vaccine against livestock diseases market.

POSTER SESSION

Josef Oliver, The University of Manchester josef.oliver@manchester.ac.uk So called ‘drop-in’ Biofuels produced from plants are becoming increasingly important for the aviation and shipping industries, which urgently need to move away from fossil fuels in order to limit their impact on the climate. Algae farms provide a number of benefits over traditional biofuel crops, such as sugar cane, by alleviating competition for arable land. When exposed to high light, the green alga Chlamydomonas reinhardtii produces triacylglycerols (TAGs) which can be converted to drop-in biodiesel. Excess light results in the over-reduction of the photosynthetic electron transport chain, and it has been suggested that the production of TAGs is in response to this redox imbalance. A deeper understanding, therefore, of how Chlamydomonas cells address redox imbalance will help to inform future work aiming to maximise TAG production in these conditions.

Our work has highlighted a potential role for the phenomenon known as light enhanced respiration (LER) in responding to redox stress induced by high light. We show that presence of acetate in the growth media may allow cells to better acclimate to high light by increasing the capacity of the cells for LER. Autotrophic cells (cells grown without acetate) appear to be more susceptible to photodamage than mixotrophic (grown with acetate) when grown in high light. Our results display the complexity of the high light response and provide preliminary evidence for the potential of the mitochondria as a tool for addressing redox imbalance.

P26 RESEARCH ON PRODUCTION OF GREEN VACCINE AGAINST LIVESTOCK DISEASES Thursday 7th July 2022

ANNUAL CONFERENCE MONTPELLIER 2022

POSTER SESSION

Seon-Kyeong Lee, National Institute of Agricultural Sciences, Rural Development Administration

P27 EFFECTIVE DETECTION OF SPOILAGE BIOMARKERS IN TOMATOES Wednesday 6th July 2022

POSTER SESSION

Miranda Burke, Lancaster University Co-authors: Martin McAinsh, Lancaster University, Mike Roberts, Lancaster University, Francis Martin, Biocel Ltd m.burke1@lancaster.ac.uk Food waste is a global issue with 1/3 of all food lost or wasted annually.

Tomato is a culturally important fruit that provides nutrition to a global market but is highly perishable and requires carefully controlled storage and transportation to maintain shelf life. Losses occur throughout the entire supply chain as often the symptoms of spoilage are detected too late for effective repurposing. There are existing methods that are used in a commercial environment for detecting spoilage, however, these methods are often slow, destructive, and expensive. It is important that a non-destructive, high-throughput and cheap technology becomes readily available that can used throughout the supply chain to detect spoilage biomarkers for effective repurposing of produce. This study investigates the use of attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy as a rapid, quantitative method for detecting decay in surface tissue of tomato fruit. Spectra was analysed using chemometric multivariate analysis of the fingerprint region (400 cm-1 to 1500 cm-1). In a time-series from harvest to spoilage, we identified differences between the time points in the series demonstrating the molecular changes in the fruit surface through the ripening and decaying period. Distinct chemical peaks were detected which represent potential biomarkers for spoilage and were associated with specific time points. Notable fruit properties associated with these peaks include the changes in levels of phenolic compounds, cell wall polysaccharide modifications including pectin and cellulose.

ATR-FTIR provides a low-cost method for in vivo detection of spoilage biomarkers and biochemical changes.

lsk220@korea.kr Green vaccine is a bio-vaccine produced based on plants such as tobacco and strawberry or plant cells. Plant-based vaccines have the advantage of reducing production costs and producing them quickly compared to traditional vaccine using egg-based vaccine or animal cell culture.

In addition, since there are few common infectious pathogens due to the distance between human-evolutionary system, it is attracting attention as a new vaccine production platform with high stability.

Porcine circovirus (PCV2) is the smallest DNA virus that causes porcine circovirus associated diseases (PCVAD), which is causing massive economic losses in the pig industry worldwide. In order to develop a green vaccine against PCV2d, a vector for expression of capsid protein was constructed by synthesized PCV2d gene between the cauliflower mosaic virus (CaMV) 35S double promoter and the NOS terminator.

Plant expression vectors were transformed into tobacco (Nicotiana benthamiana, Nicotiana tabacum) in order to achieve stable expression of the antigen protein. Generation development is underway through molecular biological analysis of transformants, particularly determines, whether or not a gene has been introduced and the pattern of gene

P28 ROOT ANGLE IN CEREALS IS CONTROLLED BY A NOVEL ANTIGRAVITROPIC MECHANISM Thursday 7th July 2022

POSTER SESSION

Marco Lombardi, Università Campus Bio-Medico di Roma Co-authors: Riccardo Fusi, University of Nottingham, Aneesh Lale, University of Nottingham, Francesco Loreto, University Federico II, Laura De Gara, Campus Bio-Medico, Rahul Bhosale, University of Nottingham, Malcolm Bennett, University of Nottingham, Silvio Salvi, University of Bologna m.lombardi@unicampus.it

SCIENCE ACROSS BOUNDARIES ABSTRACTS 21

Root angle in crops represents a key trait for efficient capture of soil resources. Root angle is determined by competing gravitropic versus anti-gravitropic offset (AGO) mechanisms. Here we report a new root angle regulatory gene termed ENHANCED GRAVITROPISM1 (EGT1) that encodes a putative AGO component. Mutations in barley and wheat EGT1 genes confer a striking root phenotype, where every root class adopts a steeper growth angle. EGT1 encodes a F-box and Tubby domain containing protein which is highly conserved across plant species.

Haplotype analysis found that natural allelic variation at the barley EGT1 locus impacts root angle. Gravitropic assays indicated that Hvegt1 roots bend more rapidly than wildtype. Transcript profiling revealed Hvegt1 roots deregulate cell wall-loosening enzymes and ROS cofactors. In situ analysis identified that HvEGT1 is highly expressed in inner root tissues, which are distinct from known root gravitropic perception and response tissues in the columella and epidermis, respectively. Atomic Force Microscopy measurements revealed that elongating cell walls in Hvegt1 mutant roots are significantly less stiff than wildtype. Hence EGT1 appears to control root angle by regulating cell wall stiffness in elongating root tissues, counteracting the gravitropic machinery’s known ability to bend the root via its outermost tissues. We conclude that root angle is controlled by EGT1 in cereal crops employing a novel anti-gravitropic mechanism.

P30 CHARACTERISING THE PROTEOLYTIC NETWORK OF PLANT CATHEPSIN B Thursday 7th July 2022

POSTER SESSION

Marianna Coppola, The University of Manchester Co-authors: Beata Czajkowska, The University of Manchester, Patrick Gallois, The University of Manchester marianna.coppola@postgrad.manchester.ac.uk Programmed cell death (PCD) is a genetically managed biological process that results in the targeted sacrifice of unwanted or diseased cells. Plants use PCD for various purposes such as development, defence against pathogens, response to abiotic stress caused by UV radiation or heat shock. Several proteinases are involved in the PCD process; among them, cathepsin B (CathB) which plays an important role in pathogen defence, plant development, germination, senescence, microspore embryogenesis and abiotic stress response. A greater understanding of the molecular mechanisms underlying the processes downstream of CathB is the next important step for new discoveries in cell biology and applications in biotechnology. To achieve this goal, it is important to discover and test substrates cleaved by plant CathB. Up to 13 substrates for CathB were identified in animal cells, and we found orthologous genes in Arabidopsis thaliana for eight of them.

Among these, we are testing some candidate substrates for CathB. To experimentally validate the cleavage site, we used leaf agro-infiltration to co-expressed substrate GFP-fusion and CathB in tobacco cells and carried out cleavage assays. in vivo and in vitro results will be presented.

ANNUAL CONFERENCE MONTPELLIER 2022

P31 STRATEGIES FOR PROTECTING POTATO TUBER YIELD UNDER CONDITIONS OF ENVIRONMENTAL STRESS Wednesday 6th July 2022

POSTER SESSION

Mark Taylor, The James Hutton Institute mark.taylor@hutton.ac.uk For many commercial potato cultivars, tuber yield is optimal at average day temperatures in the range of 14-22˚C. Further rises in temperature can reduce or completely inhibit potato tuber production. Although most potato genotypes are sensitive to elevated temperature, heat tolerance has been noted in some wild relatives, land races and varieties. We have deployed forward genetic screens to identify allelic variants of genes associated with both heat tolerance and genes that impact on the tuber life-cycle.

For heat tolerance, a candidate gene encoding HSc70 was identified within one of the three QTL intervals in a diploid potato population (06H1). Transgenic expression of the HSc70 allelic variant in potato resulted in enhanced HSc70 expression at elevated temperatures and improved yield under elevated temperature. In a wide range of potato wild relatives, potato diploids and tetraploid varieties, we identify HSc70 expression level as a factor influencing yield stability under elevated temperature.

Further genetic studies identified a member of the TERMINAL FLOWER 1 gene family as a key regulator of the tuber life cycle that impacts on both tuber initiation and tuber sprouting in storage. Our data have enabled us to develop a model that add to our knowledge about how tuberization and sprouting are regulated. The results suggest strategies that will be developed to accelerate the rate of potato tuber formation and confer resilience to elevated temperature.

P32 EXPLORING GENETIC DIVERSITY IN ORYZA GLABERRIMA FOR BETTER NITROGEN RECYCLING AND HEAT STRESS TOLERANCE Thursday 7th July 2022

POSTER SESSION

Md Tanvir Ahammed, University of Nottingham Co-authors: Sigrid Heuer, National Institute of Agricultural Botany (NIAB), Erik H. Murchie, University of Nottingham, Maria Oszvald, Rothamsted Research md.ahammed@nottingham.ac.uk Nitrogen assimilation under heat stress is not well understood. Due to its principal role in nitrogen metabolism and abiotic stress tolerance, glutamine synthetase (GS) has been a major focus area in plant research.

In this study, we investigated the GS activity under heat stress in 154 Oryza glaberrima accessions and showed its activity is modulated by heat stress but varies among the genotypes. We also detected comparatively higher level of superoxide dismutase (SOD) and catalase (CAT) activity corresponding to a lower level of lipid peroxidation in putatively heat tolerant genotypes compared to the sensitive ones.

Moreover, putatively tolerant genotypes possessed higher stomatal conductance and transpiration rate under heat stress compared to the sensitive genotypes suggesting a temperature regulation

SCIENCE ACROSS BOUNDARIES ABSTRACTS 22

function. An extensive RNAseq study pinpointed the potential genes and metabolic pathways related to the heat tolerance and showed a distinct genomic differentiation between Oryza glaberrima and Oryza sativa. An metabolomic study are currently being conducted to investigate the metabolome related to the heat tolerance.

P34 WHOLE GENOME DUPLICATION SHOWS SPECIES-SPECIFIC MORPHOLOGICAL CHANGES IN NEOAUTOPOLYPLOIDS Thursday 7th July 2022

POSTER SESSION

Praveen Kumar Oraon, University of Delhi Co-authors: Priyanka Yadav, University of Delhi, Rama Rao Satyawada, North-Eastern Hill University, Surekha Katiyar-Agarwal, University of Delhi, Arun Jagannath, University of Delhi, Manu Agarwal, University of Delhi, Shailendra Goel, University of Delhi, praveenkumaroraon@gmail.com praveenkumaroraon@gmail.com Polyploids are of common occurrence among the plants. Several studies have been conducted to understand the impact of polyploidy on the evolution of plant genome. Natural polyploids do occur in the wild, but it is difficult to decipher which changes are due to polyploidy as the plants accumulate variation over the history of their existence.

It is important to study the impact of polyploidy away from natural variation. Therefore, we generated synthetic neoautopolyploids in two species of Vigna L. using colchicine-based cotton swab method. The polyploids were screened via flowcytometry and confirmed polyploids were taken to the field to study biological parameters. The two species were found to be behaving differently based on various parameters like photosynthetic efficiency, cell density, stomatal count, cell size and nucleus size. We will be studying inheritance pattern of these traits in subsequent generations. Our study provides a proof that polyploidy does not always have a positive scaling effect on plants at various biological parameters and the changes are species specific. We will be studying genomic changes in future and will correlate them with morphological changes observed.

Keywords: Polyploids, WGD, Autopolyploid, Flowcytometry, morphometery

P37 PHYSIOLOGICAL, AGRONOMICAL, AND PROTEOMIC STUDIES DIVULGE CRUCIAL PLAYERS IN RICE NITROGEN USE EFFICIENCY UNDER LOW NITROGEN SUPPLY Wednesday 6th July 2022

POSTER SESSION

Aadil Yousuf Tantray, Aligarh Muslim University Co-author:Altaf Ahmad, Aligarh Muslim University tantrayadil313@gmail.com Excessive use of nitrogenous fertilizers for enhancing rice productivity has become a major source of environmental nitrogen (N) pollution and

ANNUAL CONFERENCE MONTPELLIER 2022

reduced sustainable agriculture. However, little information is available about the physiology of different growth stages and agronomic traits and associated genetic bases of N use efficiency (NUE) at low N supply.

Two rice (Oryza sativa L.) cultivars were grown in the field with optimum and low N supply. Six growth stages were used to measure the growth and physiological traits, and differential proteomic analysis of the rice cultivars. Cultivar Panvel outclassed Nagina 22 at low N supply and exhibited improved growth and physiology at most of the growth stages and agronomic efficiency due to higher N uptake and utilization at low N supply. On average, photosynthetic rate, chlorophyll content, plant biomass, leaf N content, and grain yield were more decreased in cultivar Nagina 22 than Panvel were 8%, 11%, 21%, 19%, and 22%, respectively under low N supply. Further, proteome analyses revealed that many proteins were up- and down-regulated at the different growth stages under low N supply are associated with N and carbon metabolism and other physiological processes. This supports the genetic cultivar differences in photosynthesis, N assimilation, energy stabilization, and rice protein yield. Overall, our study determines that enhancing NUE at low N supply demands distinct modifications in N metabolism and physiological assimilation. The NUE may be regulated by identified key differentially expressed proteins and are suggesting targets for improving crop NUE at low N supply.

P40 THE BIOLOGICAL SIGNIFICANCE OF GENETIC VARIATION IN ARBUSCULAR MYCORRHIZAL COLONISATION IN RICE Thursday 7th July 2022

POSTER SESSION

Adam Price, University of Aberdeen Co-authors: Mari Sumayli, University of Aberdeen, Stephen Woodward, University of Aberdeen m.sumayli.19@abdn.ac.uk Numerous crops including rice cultivars, are colonised by arbuscular mycorrhizal fungi (AMF), which are capable of efficiently absorbing nutrients such as phosphate from the soil. Using mycorrhizal symbioses in agricultural systems is one of the most promising approaches to building resource-efficient and environmentally friendly agricultural systems. AMF colonisation with rice tend to be low under flooding regimes due to the domination by anaerobic processes. However, understanding rice-AMF interaction under non-flooded conditions, is of key importance for improving nutrient and water use efficiency.

AMF colonisation rates by Rhizophagus irregularis in rice shows a wide range of genetic diversity. This work seeks to determine the biological significance of that variation. Five cultivars were selected because of consistent differences in colonisation. By using three pots with different mesh exclusion systems, AMF (R. irregularis) and rice roots were orientated to the supply of phosphate, where calcium hydrogen phosphate (CaHPO4) was either inaccessible (no mesh), accessible only to the AMF (20 μm mesh) or accessible to both the AMF and rice roots (2 mm mesh). We found significant differences in plant heights, tillers, biomass, and AMF colonisation rates across all our pot systems.

There was big genetic difference in colonisation rates. Colonisation rates were limited in 2mm mesh compared to control and 2mm mesh.

A massive increased of P uptake in 20 μm mesh demonstrates AMFdriven P acquisition. Samples of roots were also taken for RNAseq analysis, and the results will be presented here.

SCIENCE ACROSS BOUNDARIES ABSTRACTS 23

P41 ROOT DEVELOPMENTAL AND HYDRAULICS RESPONSES TO BENEFICIAL CHLORIDE NUTRITION AND ITS EFFECTS DURING WATER DEFICIT Wednesday 6th July 2022

POSTER SESSION

Miguel A. Rosales, IRNAS-CSIC Co-authors: Marta Lucas, IRNAS-CSIC, Ana Pérez-Álvarez, IRNAS-CSIC, Adriana Garay-Arroyo, Universidad Nacional Autónoma de México, Christophe Maurel, IPSiM-CNRS, Philippe Nacry, IPSiM-INRAE, José M. Colmenero-Flores, IRNAS-CSIC, mrosales@irnas.csic.es mrosales@irnas.csic.es Chloride (Cl-) is known to participate in key physiological processes in plants such as photosynthesis and osmotic regulation. Recently, we defined Cl- as a beneficial macronutrient with specific functions that result in a more efficient use of water, nitrogen and CO2 in plants. When accumulated in leaves at macronutrient levels, Cl- improves growth promoting leaf morphological and cellular changes including bigger cells and higher turgor. Roots are crucial in the search for water and nutrients for plant growth and development, especially during water scarcity periods. Although some anion transporters regulating Cl− homeostasis have been reported to affect root cell elongation, little is known about the effect of Cl− nutrition on root developmental and hydraulic processes. With this aim, Arabidopsis and tomato seeds were sown in Agar vertical plates and hydroponics conditions containing a basal nutrient solution supplemented with mixtures of 5 mM Cl− salts (CL), and sulphate+phosphate salts (SP) used as a control. Seedlings were collected at different developmental stages (6-21 days) and roots were used for the analysis of biomass, development (root tip meristem size and stem-cell patterning), architecture (primary root length, number and length of lateral roots) and hydraulic conductivity. Results showed that Cl− promoted bigger plants with longer primary roots but shorter lateral roots in both species. These effects are consistent with a higher number of bigger cells in the primary root tip, especially in the elongation zone. The effect of Cl- on different Arabidopsis mutants with altered root development and during water deficit are also discussed.

P43 TRAFFICKING SNARE SYP132 CONTRIBUTES TO AQUAPORIN ENDOCYTOSIS DURING OSMOTIC STRESS IN ARABIDOPSIS Wednesday 6th July 2022

POSTER SESSION

Guillermo Baena, University of Glasgow, Guillermo.

Co-authors: Rucha Anil Karnik, University of Glasgow, Lingfeng Xia, University of Glasgow, Sakharam Waghmare, University of Glasgow Baena@glasgow.ac.uk Aquaporins are the central regulation target for water transport and cell homeostasis in plants. The plasma membrane intrinsic protein (PIP) family of aquaporins account for most of hydraulic conductivity in Arabidopsis. In response to osmotic stress, density of some PIP isoforms

ANNUAL CONFERENCE MONTPELLIER 2022

is modulated at the plasma membrane through both transcriptional control and rapid endocytic traffic.

Soluble N-ethylmaleimide-sensitive factor protein attachment protein receptors (SNAREs) are membrane trafficking proteins. The syntaxin of plants 121 (SYP121) is involved in the delivery of some aquaporin isoforms to the PM. However, although the rapid endocytosis of PIP proteins during osmotic stress has been widely reported, the binding partner that drives this endocytosis has not been described yet.

Syntaxin of plants 132 (SYP132) is a low abundant PM SNARE whose expression is modulated by hormones for plant growth and stress responses. Although it was generally thought to be a secretory SNARE, recent discoveries have shown that SYP132 interacts and drives the endocytosis of the PM H+-ATPase 1, which is also directly involved in cell homeostasis by energizing the osmotic ion uptake through secondary transporters and ion channels to generate a water potential gradient.

SCIENCE ACROSS BOUNDARIES ABSTRACTS 24

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Our results show that SYP132 is involved in PIP endocytosis during osmotic stress in Arabidopsis, through a direct interaction between the SNARE and the aquaporins. These findings reveal for the first time an endocytic binding partner of aquaporins in SYP132, which could be used in the future to control the plant response to environmental stresses.

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P60 CONTRASTING IMPACT OF SALINITY ON NUTRITIONAL VALUE OF STAPLE ROOT CROPS: IMPLICATIONS FOR FOOD SECURITY IN PACIFIC ISLAND COUNTRIES Thursday 7th July 2022

POSTER SESSION

Roslyn Gleadow, Monash University ros.gleadow@monash.edu Many crops increase in toxicity, especially the concentration of cyanogenic glucosides, in response to stress. Cassava and taro are both widely grown in the Pacific and elsewhere. Cassava is severely impacted by moderate salinity and increases in the amount of hydrogen cyanide, posing risks to human health. Taro is able to grow at higher concentrations of salt, and there is little increase in secondary metabolites or calcium oxalate. The different metabolite systems in these two crops appear to regulate their ability to tolerate salt. In the future cassava will be better adapted to dry regions (although will be more toxic) and taro better in areas increasingly subject to coastal inundation.

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SCIENCE ACROSS BOUNDARIES ABSTRACTS 28

A3 - INDIVIDUAL VARIATION IN INFECTION-INDUCED PHENOTYPES IN ANIMAL HOSTS: MECHANISMS AND IMPLICATIONS FROM INDIVIDUALS TO ECOSYSTEMS ORGANISED BY: SIMON POPPINGA (TECHNICAL UNIVERSITY OF DARMSTADT) A133 UNLOCKING THE EVOLUTIONARY STORY OF COCKLE CONTAGIOUS METASTASES Friday 8th July 2022

11:45am-12:00pm

Alicia L. Bruzos, Universidade de Santiago de Compostela, Co-authors: Jose M.C. Tubío, Universidade de Santiago de Compostela, Seila Díaz, Universidade de Santiago de Compostela, Martín Santamarina, Universidade de Santiago de Compostela, Sara Rocha, Universidade de Vigo, Iago Otero, Universidade de Santiago de Compostela, Jorge Zamora, Universidade de Santiago de Compostela, David Posada, Universidade de Santiago de Compostela albruzos@gmail.com Contagious cancers are somatic cell lineages that are transmitted between individuals via the transfer of living tumour cells, meaning that they can survive beyond the host that spawned them. In other words: they are tumours that metastasize across different hosts. For this reason, they represent an interesting and unique model to illuminate insights into the general mechanisms of cancer development and metastasis. Since 2016, we have collected 6,300 common cockles from 33 locations covering all the Atlantic Coast of Europe, from Morocco to Russia. 342 cockles (5.4%, 350/6,300) from 5 different countries were diagnosed with cancer by cytological and histological methods. The contagious nature of these cancer samples was assessed with sequencing data as it has been previously done in dogs and Tasmanian devils that also suffer from contagious cancers. Phylogenetic analyses based on variants from mitochondrial DNA revealed nine paraphyletic clonal cancer lineages, some with a distribution extending over thousands of miles. The analysis of nuclear structural variants, however, does not reveal nine cancer lineages, seeming to suggest a maximum of two independent origins of the disease. Multiple captures of the mitochondria from the host cells by the cancer lineages, throughout the long-term evolution of these two cancer lineages, may explain these contradicting observations. This work represents the most comprehensive analysis of a marine contagious cancer performed to date and reveals that mitochondrial and nuclear DNA of cockle transmissible cancers tell slightly different evolutionary stories that are part of the same book.

A134 ASSESSING HOST–PARASITE INTERACTIONS USING EXPERIMENTAL INFECTIONS Friday 8th July 2022

10:15am-10:30am

Lauren E. Nadler, Nova Southeastern University, Hannah Bauman, Nova Southeastern University, Laura D. Nicolas, Nova Southeastern University, Bennett Perry, Nova Southeastern University, Kelly L. Weinersmith, Rice University, Nancy F. Smith, Eckerd College, Christopher A. Blanar, Nova Southeastern University lnadler@nova.edu Host-parasite interactions can be difficult to disentangle using exclusively naturally infected hosts. Wild hosts may have also been exposed to and infected by multiple parasite species that can interact to alter host phenotypes. These interactions make connecting a particular phenotypic modification to a specific parasite species difficult. Experimental infections enable researchers to expose uninfected individuals to a specific species of parasite in controlled numbers to uncover drivers of phenotypic changes, which aids in resolving questions about the cause-and-effect of parasite-induced changes in host behavior, morphology, and physiology. However, developing ecologically-relevant parasite infections is logistically challenging, as it requires multiple hosts in the parasite’s lifecycle to be maintained in the lab and often necessitates several sequential parasite exposures to develop natural infection intensities. Here, we describe an experimental infection protocol for the trematode Euhaplorchis sp. A and two species that are known to act as second intermediate hosts, the Gulf killifish Fundulus grandis and the longnose killifish F. similis. Infectious parasites (known as cercariae) were shed from this parasite’s first intermediate host, the ladder hornsnail Cerithideopsis scalariformis. This parasite is known to alter the behavior of its fish host, in theory, to promote trophic transmission to the parasite’s final host and one of these small-bodied fishes’ primary predators, a range of piscivorous marsh birds. This protocol has the potential to be adapted to other host-parasite systems to create a better understanding of why parasites modify or manipulate their host’s phenotypes and the mechanisms that drive these changes.

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A135 STUDIES OF WILD ANIMAL PERFORMANCE FAIL TO TAKE PARASITE INFECTION INTO ACCOUNT Friday 8th July 2022

parasite infection. Such collaboration will help overcome current limits to our understanding of how migration and parasites interact, and allow us to predict how these critical ecological processes will change in the future. This poster is based on an article published in Biological Reviews in 2022 (https://doi.org/10.1111/brv.12835).

09:45am-10:00am

Emmanuelle Chrétien, Institut national de la recherche scientifique (INRS), Jérémy de Bonville, Université de Montréal, Joëlle Guitard, Université du Québec à Rimouski (UQAR), Sandra A. Binning, Université de Montréal, Marie Barou-Dagues, CNRS manuchretien@gmail.com Wild animals have parasites. This inconvenient truth has far-reaching implications for experimental biologists measuring performance in wild animals: infection with parasites can alter host behaviour and physiology in profound and sometimes counterintuitive ways. Yet, to what extent do studies on wild animals take individual infection status into account? We performed a systematic review of 8 journals publishing experimental and observational studies on animal behaviour and physiology over a 5-year period. We assessed the proportion of studies on animals observed or collected in the wild that considered, accounted for, or controlled for parasite infection in their study design and analyses. Of the 683 filtered articles, we found that only 151 studies (22.1%) considered the potential effects of parasites on wholeorganism performance, regardless of taxa or performance traits studied.

Of this subset, few studies accounted for or controlled for parasites in their design (24.5%) or statistical analyses (25.1%). We argue that scientists should consider individual infection status when assessing wild animal performance, as parasites can modulate effects of other stressors on host behaviour and physiology. We suggest ways that experimental biologists can implement such practices in their study design. Accounting for the natural variation among individuals due to parasite infection can help reduce bias and/or errors in interpretation of results on wild animal performance.

A136 HOW TO STUDY PARASITES AND HOST MIGRATION: A ROADMAP FOR EMPIRICISTS Friday 8th July 2022

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12:15pm-12:30pm

Sandra A. Binning, Université de Montréal, Meggan E. Craft, University of Minnesota, Marlene Zuk, University of Minnesota, Allison K. Shaw, University of Minnesota sandra.ann.binning@umontreal.ca Animal migration (round-trip, predictable movements) takes individuals across space and time, bringing them into contact with new communities of organisms. In particular, migratory movements shape (and are shaped by) the costs and risk of parasite transmission.

This poster first synthesizes the conceptual frameworks that developed to understand interactions between migration and parasites (e.g. migratory exposure, escape, allopatry, recovery, culling, separation, stalling and relapse). We also highlight current challenges to studying migration and parasites empirically. Finally, we provide a guide to overcoming these challenges in empirical studies, using comparative, observational and experimental approaches. Beyond guiding future empirical work, we aim to inspire stronger collaboration between empiricists and theorists studying the intersection of migration and

A137 MICROBIAL COMMUNITIES FROM THE GILLS AND CARAPACE SURFACE OF VENT CRABS (XENOGRAPSUS TESTUDINATUS) SURROUNDING SHALLOW-WATER HYDROTHERMAL VENTS OFF KUEISHAN ISLAND, TAIWAN Friday 8th July 2022

12:00pm-12:15pm

Ling Chiu, Marine Research Station, Institute of Cellular and Organismic Biology, Academia Sinica, Yung-Che Tseng, Marine Research Station, Institute of Cellular and Organismic Biology, Academia Sinica, Min-Chen Wang, Marine Research Station, Institute of Cellular and Organismic Biology, Academia Sinica ken860531@gmail.com There are considerable documents showing that microbes would survive in extremotolerant animals through performing a microbehost symbiont to supply metabolic energy as autotrophs. Of late, there has been a surge in studying the structure of microbial communities that are mainly shaped by extreme environmental conditions.

The brachyuran crab Xenograpsus testudinatus is endemic to the shallow-water hydrothermal vent system off Guisahn Island located at northeastern Taiwan, the southeastern rifting end of Okinawa trough.

This system was ever reported as one of the world’s most acidic and sulfur-rich marine environments. The strong ion- and acid-base regulatory ability and detoxification machinery in the gills enable X. testudinatus to thrive under the extreme conditions. However, the holobiont features underlying acidic- and sulfidic- tolerance are still unclear. The present study utilized a novel sequencing technique, LoopSeq long reads based on full-length 16S rRNA gene, to identify microbial communities collected from the gills and carapace surface of X. testudinatus. LoopSeq sequencing coupled with FISH (fluorescence in situ hybridization) images revealed the significance of dominant symbiotic microbes mainly related to sulfur oxidation and energy metabolism mechanisms, which showed the importance of symbiotic microbes in extremotolerant animals under a harsh environment.

A138 PARASITE-INDUCED VARIATION OF INDIVIDUAL AND GROUP BEHAVIOUR IN GUPPIES Friday 8th July 2022

14:45pm-15:30pm

Angela Albi, Max Planck Institute of Animal Behavior, Iain Couzin, Max Planck Institute of Animal Behavior, Jacob Davidson, Max Planck Institute of Animal Behavior, Sandra A. Binning, Université de Montréal, Jessica Stephenson, University of Pittsburgh aalbi@ab.mpg.de

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In the ecology of fish, parasite infections often induce multidimensional changes and can affect a host by altering morphology, physiology, and movement abilities. However, the details of how parasites affect behavior, and how infected individuals interact with other conspecifics in a group, is not fully understood.

In our study, we look at how both individual and social behaviour of guppies are affected by the ectoparasite Gyrodactylus. At the individual level, we compare swimming kinematics and metabolic costs of uninfected to infected guppies. We find that parasites do not induce unidirectional changes on the host’s physiology or locomotion ability across different flow regimes. However, a minority of the parasitized individuals show increased critical swimming speeds, and this increase might be explained by higher rates of pectoral fin use at low flow speeds.

In the social behaviour context, we find that infected guppies spend more time swimming in isolation, have increased nearest-neighbor distance and are mostly found in the periphery of big groups. Moreover, after a group fission, parasitized fish are more likely to be found in smaller groups compared to uninfected conspecifics. These results are partly explained by changes in swimming speed relative to the group mean, but it remains unclear whether the changes are also due to an active avoidance mechanism, or if they are a consequence of active or passive self-isolation. Overall, with this study we show how physiological and behavioural measures can be used in the context of sickness behaviour research to better understand the role of disease transmission for group living organisms.

A139 PHYSIOLOGICAL CONDITION OF COD INFECTED WITH THE PARASITIC NEMATODE CONTRACAECUM OSCULATUM – CAUSALITIES AND THE CHICKEN OR THE EGG Friday 8th July 2022

11:00am-11:45am

Jane W. Behrens, National Institute of Aquatic Resources (DTU Aqua), Technical University of Denmark jabeh@aqua.dtu.dk Parasitism is one of the most common animal lifestyles, yet the potential effects of parasites on ecosystem food-web stability, interaction strength and energy flow often remains ignored. At the level of the individual, parasites can have adverse effects on the performance of the host. For trophically transmitted parasites, such effects on transport hosts can make the host more vulnerable to predators, increasing the probability of the parasite to reach its final host. Yet, disentangling effects of parasites in wild animals from effects of other drivers is challenging. For nutritional status of infected hosts, the conundrum arises: Does high parasite load reduce nutritional condition? Or does poor nutritional status increase susceptibility to parasites? The chicken or the egg. Combining results from laboratory experiments, field investigations and historical data on the parasite– host system between cods liver worm Contracaecum osculatum and the Eastern Baltic cod Gadus morhua, I elucidate how parasite load may relate to the physiological performance and nutritional condition of a transport host. The Eastern Baltic cod is in distress, with historically low nutritional condition, disappearance of the larger fish, high natural mortality and no signs of recovery of the population, and a heated debate exists amongst scientists, NGOs, fishers and managers on which factors drive this misery. Åland cod in adjacent waters are large and in good nutritional state – but do they have liver worm? Is it possible to monitor liver worm load at a broad spatio-temporal scale? I will present a parasite-monitoring program, which is at its infancy.

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A140 FUNCTIONAL DISRUPTION VARIES WITH INFECTION INTENSITY IN AN AMPHIBIAN FUNGAL PANZOOTIC Friday 8th July 2022

15:30pm-16:15pm

Nicholas Wu, Western Sydney University

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stickleback-Schistocephalus host-parasite model, investigating how temperature, host size at exposure, the availability of food resources pre- and post-infection and chemical pollutants impact the infection phenotypes associated with Schistocephalus parasitism. I will discuss the results of these studies – which typically investigate one ecological factor in isolation – in the context of the complex, multi-factorial ecological perturbations that are more commonly encountered in impacted ecosystems, and relate them to observed population variation in infection phenotypes.

nicholas.wu.nz@gmail.com The development of infectious disease depends on the intensity of pathogen infection. However, the sensitivity of a host’s phenotype or functional trait related to the fitness such as behaviour, physiology, and reproduction may differ to infection intensity. Determining commonalities in trait sensitivity to pathogen infection across species can provide insight to the pathogenesis of emerging infectious diseases.

Here, I systematically conducted a phylogenetically controlled metaanalysis to test how infection intensity affects different functional traits (e.g., behaviour, physiology, morphology, reproduction) and the survival in amphibians infected with a globally impacting cutaneous fungal pathogen, Batrachochytrium dendrobatidis (Bd). There was a strong effect of Bd infection on energy metabolism, and the overall effect was more pronounced for species classified as ‘susceptible’. On average, ‘resilient’ and ‘tolerant’ species did not show considerable changes in functional response to infection intensity compared to susceptible species. Mortality was better predicted by life stage than resistance type, where juvenile mortality showed a negative relationship between infection intensity and exposure duration, while adult mortality was depended on infection intensity only. Importantly, there were strong biases for studies on immune response, body condition, and survival, while traits such as locomotor capacity, energy metabolism, and cardiovascular traits were lacking. This study suggests quantifying pathogen load can predict functional disruption for susceptible species and can help inform management strategies on pathogen thresholds before the onset of irreversible damage and mortality. Hence, infection intensity mediates functional disruption in amphibians, but study bias currently limits generalised implications.

A141 HOST–PARASITE INTERACTIONS IN A CHANGING WORLD: USING THE STICKLEBACK–SCHISTOCEPHALUS MODEL TO INVESTIGATE ECOLOGICAL VARIATION IN INFECTION PHENOTYPES Friday 8th July 2022

09:00am-09:45pm

Iain Barber, Nottingham Trent University iain.barber@ntu.ac.uk Environmental degradation, along with global changes in climate – and their consequent ecological impacts – have the potential to profoundly influence the interactions of parasites and hosts. For example, changes in the abundance, temporal availability or distribution of food resources might differentially alter the reproductive, growth and development cycles of hosts and/or their parasites, disrupting established patterns of infection, with implications for both the parasite’s impact on the host and for parasite development. Experimental studies, undertaken under controlled laboratory conditions, allow us to begin to understand some of these effects and make predictions about how host-parasite interactions might be affected in a changing world. In this talk I will present the results of a suite of recent experimental studies using the

A153 INFECTION ALTERS HOST SURVIVAL FOLLOWING AN ACUTE THERMAL CHALLENGE IN FISH Friday 8th July 2022

10:00am-10:15am

Jérémy De Bonville, Université de Montréal, Sandra A. Binning, Université de Montréal jeremy.debonville@gmail.com Extreme heat waves are predicted to become more frequent, more intense and longer-lasting in the coming years. One consequence of climate change is that parasites, such as helminths, are expected to thrive, posing a concomitant stress to hosts including ectotherms like fishes. For instance, parasites may impose increased oxygen demands on hosts, thus decreasing host thermal tolerance. Studies exploring how increasing mean temperatures and extreme heat events influence thermal tolerance and survival in natural fish populations often fail to consider parasites. The limited studies exploring these questions have not explicitly looked at the combined effects of parasites and acclimation temperature on thermal tolerance and survival following acute heating or cooling events. We conducted a series of experiments on naturally infected pumpkinseed sunfish (Lepomis gibbosus), acclimated to five temperatures (10, 15, 20, 25 & 30°C) for three weeks. We estimated critical thermal maximum (CTmax) and minimum (CTmin) as proxies of thermal tolerance, recorded survival rates one week post-test, and quantified parasite load. Although we did not find a relationship between overall parasite load and thermal tolerance, fish infected by yellow grub trematode parasites showed lower survival rates in the days following CTmax trials, especially for fish acclimated at warmer temperatures. This suggests that the combination of parasite infection and high prolonged summer temperatures as during heat waves can act as concomitant stressors affecting fish survival, emphasizing the need to account for parasites while conducting studies on natural populations in order to better understand how infection and host physiology interact in nature.

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ANNUAL CONFERENCE MONTPELLIER 2022

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A4 - MUSCLES AND MOTORS: ORGANISMAL BIOINSPIRED ROBOTICS

Wednesday 6th July 2022

17:35pm-17:50pm

Letizia Zullo, Istituto Italiano di Tecnologia, Alessio Di Clemente, Istituto Italiano di Tecnologia, Irene Bornia, Istituto Italiano di Tecnologia letizia.zullo@iit.it The Octopus vulgaris arm is a ‘one of a kind’ soft limb, with a high maneuverability, vast range of motions and extraordinary sensing abilities. It is composed of an array of muscles and intramuscular connective tissue, allowing force and shape production, controlled by a rather autonomous peripheral nervous system. Two rows of suckers are disposed in the ventral arm surface and works as both mechanical and chemical ‘devices’ in various tasks. Suckers allow the arm to probe the environment but also to reconfigure in vertebrate-like structures through the integration of sensory feedback with central motor commands.

These features are particularly relevant in the bio-robotics field as an increasing number of researchers are currently aiming at designing and constructing bio-inspired soft-robotic manipulators capable of semi-autonomous functions.

We will show how the octopus arm motor performances emerge from the tight interaction of at least three players: the muscle control and biomechanics, the arm structural design and the sucker sensory feedback. Each of this player may offer solutions for an efficient and energetic advantageous artificial control strategy. The physiology and biomechanics of the Octopus vulgaris arm can be a valid source of bioinspiration and biomimetics as it allows for the implementation not only of the structural design but also of material and control properties underlying soft limb performance.

A12 BIARTICULAR TOE-FLEXOR TENDON AND ITS FUNCTION DEPENDING ON LOCOMOTION SPEED Thursday 7th July 2022

A74 DEVELOPING A BIOPHYSICAL SIMULATOR CHARACTERIZING THE MECHANICS OF AVIAN LUMBOSACRAL INTRASPINAL MECHANOSENSING Thursday 7th July 2022

11:45am-12:00pm

An Mo, Max Planck Institute for Intelligent Systems, Viktoriia Kamska, Max Planck Institute for Intelligent Systems, Fernanda Bribiesca Contreras, Max Planck Institute for Intelligent Systems, Janet Hauptmann, Max Planck Institute for Intelligent Systems, Monica A. Daley, University of California, Irvine, Alexander Badri-Spröwitz, Max Planck Institute for Intelligent Systems

ORGANISED BY: ARIEL CAMP (UNIVERSITY OF LIVERPOOL), BROOKE FLAMMANG (RUTGERS UNIVERSITY) A10 HOW TO GRASP AND SENSE WITH NO JOINTS: THE OCTOPUS AS A MODEL FOR SOFT-ROBOTICS

ANNUAL CONFERENCE MONTPELLIER 2022

09:30am-09:45am

Alborz Aghamaleki Sarvestani, Max Planck Institute for Intelligent Systems, Alexander Badri-Spröwitz, Max Planck Institute for Intelligent System sarvestani@is.mpg.de Inspired by avians, BirdBot legged robot utilizes mechanical intelligence, physically embedded in its leg structure and control. BirdBot features mechanical joint coupling to coordinate joint movements and power.

Networks of overlapping spring tendons act as joint flexors and extensors, and complex functions are achieved. BirdBot shows robust, agile, and energy-efficient locomotion with surprisingly little control effort. In stance, a spring-tendon network is engaged and acts on all leg joints with joint extending torques. The orientation of the toe segment purely mechanically engages this spring-tendon network.

In the swing phase, the leg is slack, with no or minimal joint torques acting. During the swing, a knee motor flexes the slack knee joint.

The remaining, slack joints follow the motion coordinated by the robot's tendon network. Both modes are designed to provide the leg's stance and swing phase functions, reduce energy consumption, reduce control effort, and increase the robot leg's performance. In this work, we closely observe the function of the robot's distal toe-flexor spring-tendon, which spans the two most-distal joints. The toe-flexor spring-tendon continuously charges in the stance phase, accumulating energy. At the stance-swing transition, the tendon collapses the TMP joint. This action rapidly switches the leg from its loadable stance phase to its slack swing mode and also pushes the toe segment into a digital-flexed posture. Hence, besides its main function as a clutch trigger, the toe flexor-tendon also recuperates mechanical energy back in the leg. Energy stored in stance is released and supports rapidly flexing and leg protraction.

mo@is.mpg.de The lumbosacral organ (LSO) is a unique morphology located in birds' lower spine. Over a century after the discovery of a glycogen body and a spinal canal enlargement, the functionality of the unusual soft tissues and morphologies remain unknown. Recent studies hypothesize that the LSO is a locomotion sensor organ that relies on spinal soft tissue motion, induced by external movements and accelerations. Intra-spinal mechanosensing would present a major evolutionary step towards rapid mechanosensing, avoiding long signal paths of the peripheral nervous system. However, in-vivo observations of the spinal soft tissue motion have been so far unsuccessful, due to the dense, bony spinal canal structure. Here we develop a biophysical model that mimics the lumbosacral organ, and quantify the time and frequency response of artificial spinal soft tissue motion under locomotion. Our model incorporates key morphologies and physical properties of its biological reference. We tested several LSO configurations to study the impact of individual features, by mounting it to a locomotion simulator. Our findings support the hypothesis that the lumbosacral organ soft tissue could be entrained by external oscillations.

A79 THE CATAPULT IN HUMANOID ROBOT WALKING: THE ROLE OF SOLEUS AND GASTROCNEMIUS MUSCLES DURING ANKLE PUSH-OFF Thursday 7th July 2022

09:45am-10:00am

Bernadett Kiss, Max Planck Institute for Intelligent Systems, Emre Cemal Gönen, Max Planck Institute for Intelligent Systems, An Mo, Max Planck Institute for Intelligent Systems, Alexandra Buchmann, Technical University of Munich, Daniel Renjewski, Technical University of Munich, Alexander BadriSpröwitz, Max Planck Institute for Intelligent Systems kiss@is.mpg.de Fundamental gaps remain in our understanding of human locomotion, its underlying biomechanical principles and control. The high efficiency of human gait has not yet been reproduced by technical devices such as state-of-the-art lower limb prostheses or humanoid robots. One mechanism potentially contributing to the high efficiency of human walking is the impulsive ankle push-off. During stance, the ankle plantar flexor muscle tendon units are slowly loaded, storing elastic energy that is rapidly released during push-off, catapulting the trailing leg into swing (Hof, 1983). The catapult's function, especially its catch and release mechanism, is hard to identify due to the complex

SCIENCE ACROSS BOUNDARIES ABSTRACTS 33

interplay between the thigh-shank-foot segment chain and multiple redundant muscle-tendon structures. We developed a small (2.2kg) anthropomorphic bipedal robot with soleus and gastrocnemius muscle-tendon-units represented by linear springs, acting as monoand biarticular elasticities around the robot's ankle and knee joints.

The robot’s hip and knee joints are actively driven by an open-loop central pattern generator. We tested the influence of three soleus and gastrocnemius spring-tendon configurations on the ankle joint power, on the synchronization of ankle and knee joint movements, on the total cost of transport, and on walking speed. We found that the soleus spring supports the robot's speed and energy efficiency, while the gastrocnemius spring facilitates the synchronization between knee and ankle joints during push-off. A deeper understanding of the swing leg catapult will help to increase the efficiency of legged robots and to improve gait rehabilitation devices toward a more natural gait pattern.

A194 EFFECT OF MASS DISTRIBUTION ON EFFORT-OPTIMIZING GAIT IN A 3D MODEL Wednesday 6th July 2022

15:20pm-15:35pm

Delyle Polet, Royal Veterinary College, James R. Usherwood, Royal Veterinary College, John R. Hutchinson, Royal Veterinary College dpolet@rvc.ac.uk The lateral sequence walk is a widespread gait among mammals, but certain groups, such as adult primates and aardvarks, instead employ a diagonal sequence gait. It may be that caudally-shifted centers of mass and large whole-body moments of inertia in the latter groups make diagonal sequence gaits energetically favourable. To test this, we built a simple model of a generalized quadruped in OpenSim, consisting of two-link, four degree-of-freedom legs, and a two-link trunk with a spinal joint. We generate gaits to minimize various measures of effort cost, including torque-rate squared and joint work, by employing recent advances in trajectory optimization with algorithmic differentiation.

We show how mass distribution affects gait choice in three dimensions, and compare these results to the gaits of various mammalian groups.

A195 EVOLUTIONARY CO-OPTIMISATION OF ROBOT MORPHOLOGY AND CONTROL: TOWARD A SEAHORSE-TAIL INSPIRED ROBOTIC MANIPULATOR Wednesday 6th July 2022

15:05pm-15:20pm

Dries Marzougui, Ghent University, Dominique Adriaens, Ghent University, Francis wyffels, Ghent University dries.marzougui@ugent.be The design of robotic manipulators is confronted with a seemingly unavoidable trade-off between the level of flexibility versus strength.

Unsurprisingly, nature has already come up with a solution and encapsulated it in a particular group of organisms: the seahorses. A seahorse’s body is completely enclosed in a highly articulated body armour, made of similar and modular bony plates. Yet, the combination of regional variation in this skeletal anatomy and the soft tissue interconnecting the skeletal units provides a rigid, yet controllable

ANNUAL CONFERENCE MONTPELLIER 2022

and flexible tail. A seahorse tail thereby intriguingly integrates these two seemingly mutually exclusive properties. Although the seahorse can serve as a bio-inspired foundation for designing a novel type of robotic manipulator, its actual design is far from intuitive and hard to do manually. This raises the need for automated design methodologies.

One domain, named Evolutionary Robotics, applies evolution as an optimisation technique to provide a holistic perspective to automated robot design. Evolutionary Robotics has already shown its potential in conventional rigid robotics and provided the necessary backbone for the optimisation of more recent alternatives such as soft robotics. Our work lies at the intersection of biology and robotics, as we aim to create a generic evolutionary brain-body co-optimisation framework. Using this framework, we pursue the automated design of a seahorse-tail inspired robotic manipulator. From there on, the framework maintains applicability to other biomimetic experiments, next to providing a testbed for in-silico evolutionary experiments in biology.

A197 WHAT CAN MUSCLES TEACH US ABOUT ENGINEERED ACTUATORS? Wednesday 6th July 2022

15:35pm-15:50pm

Thomas Roberts, Brown University, Jarrod Petersen, Brown University, Kaelan Yao, Brown University thomas_roberts@brown.edu The intersection of animal biomechanics and robotics has proven particularly productive. An understanding of how animals move informs robot design, and the challenges and successes of robot designers fuel new questions in organismal biomechanics. The same principle can apply in the study of the actuators that power robot and animal movement. The highly context-dependent, three-dimensional (3D) nature of muscle contraction is essential to how animals move, but stands in contrast to engineered systems for actuation, where simple single axis torque and motion generation dominates. Can the complex, multi-scale, three-dimensional nature of muscle actuation inform the design of engineered actuators? We have been exploring this question with physical models that reproduce features of muscle contraction at multiple scales. Simple physical models suggest that the 3D interaction of muscle contractile elements, intramuscular connective tissues, and fluid forces influences both passive and active muscle force production. Models based on features of muscle architecture, such as pennation angle, reproduce variable gearing and other muscle behaviors that could be advantageous in engineered systems. A central principle of muscle function, that precise control is achieved through the activation of many independent actuation units (motor units), may be an example of a biological solution that does not translate to engineered systems. Such an actuation strategy might be the result of the constraints of evolutionary history and biological organization (e.g., maximum cell size), but it is worth exploring whether there is a wisdom in nature’s solution that might be applied to the design of robot actuators.

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A198 REVERSE-ENGINEERING THE LOCOMOTION OF A STEM AMNIOTE – INSIGHTS FROM A MULTIDISCIPLINARY APPROACH Thursday 7th July 2022

09:00am-09:30am

John Nyakatura, Humboldt University of Berlin john.nyakatura@hu-berlin.de Reconstructing the locomotor mechanics of key vertebrate fossil specimens offers insights into their paleobiology and helps to conceptualize major transitions in vertebrate evolution. A unique combination of an articulated nearly complete early land-living vertebrate fossil specimen and fossilized trackways was the starting point for an in-depth reconstruction of the locomotion based on the integration of image-based analyses with engineering techniques.

The reconstruction involved experimental as well as computer-aided modelling approaches (‘virtual paleontology’). Starting from a large space of potential solutions, unlikely postures and gaits were stepwise excluded based on quantitative data. Research into the fossil’s anatomy, the fossil’s potential joint mobility and simulated potential movements within fossil tracks, a comparative analysis of modern animal locomotor biomechanics using x-ray motion analysis, and finally into a bio-informed dynamic walking machine (OroBOT) will be summarized. The locomotor reconstruction demonstrates that Orobates exhibited more advanced locomotion than has been assumed for earlier species, which suggests that advanced terrestrial locomotion preceded the diversification of crown amniotes. The study leverages constraintbased exclusion of unlikely scenarios and deals with uncertainty.

A199 USING A BIOLOGICALLY MIMICKING CLIMBING ROBOT TO EXPLORE THE PERFORMANCE LANDSCAPE OF CLIMBING IN LIZARDS Wednesday 6th July 2022

14:35pm-15:05pm

Christofer Clemente, University of the Sunshine Coast, Johanna T. Schultz, University of the Sunshine Coast, Hendrik Beck, Imperial College London cclement@usc.edu.au Locomotion is a key aspect associated with ecologically relevant tasks for many organisms, therefore, survival often depends on their ability to perform well at these tasks. Despite this significance, we have little idea how different performance tasks are weighted when increased performance in one task comes at the cost of decreased performance in another. Additionally, the ability for natural systems to become optimized to perform a specific task can be limited by structural, historic or functional constraints. Climbing lizards provide a good example of these constraints as climbing ability likely requires the optimization of tasks which may conflict with one another such as increasing speed, avoiding falls and reducing the cost of transport (COT). Understanding how modifications to the lizard bauplan can influence these tasks may allow us to understand the relative weighting of different performance objectives among species. Here, we reconstruct multiple performance landscapes of climbing locomotion using a 10 d.f. robot based upon the lizard bauplan, including an actuated spine, shoulders and feet,

ANNUAL CONFERENCE MONTPELLIER 2022

the latter which interlock with the surface via claws. This design allows us to independently vary speed, foot angles and range of motion (ROM), while simultaneously collecting data on climbed distance, stability and efficiency. We first demonstrate a trade-off between speed and stability, with high speeds resulting in decreased stability and low speeds an increased COT. By varying foot orientation of fore- and hindfeet independently, we found geckos converge on a narrow optimum of foot angles (fore 20°, hind 100°) for both speed and stability, but avoid a secondary wider optimum (fore −20°, hind −50°) highlighting a possible constraint. Modifying the spine and limb ROM revealed a gradient in performance. Evolutionary modifications in movement among extant species over time appear to follow this gradient towards areas which promote speed and efficiency.

A200 NAVIGATING BIOLOGICAL SPACE: ESSENTIALS OF BIOLOGY FOR BIOINSPIRED DESIGN Wednesday 6th July 2022

17:05pm-17:35pm

Emilie C. Snell-Rood, University of Minnesota, Dimitri Smirnoff, University of Minnesota, dimitris@umn.edu emilies@umn.edu There is growing interest in the use of biomimetic approaches in fields from chemistry to robotics. Such interdisciplinary research is hampered by divisions across fields that make collaboration challenging. Here, we give an overview of conceptual tools for moving between biology and bio-inspired design. We review the concept of function as a bridge between fields, and key insights from ecology and evolution for exploring biological diversity for inspiration. For example, in determining which systems to focus on for a given application, designers should consider the evolutionary context of biological trait function, as this can clarify potential trade-offs and systems that may be more promising for an application. We argue that core concepts from evolutionary and organismal biology, such as co-option, integration, convergence, and independent origins can increase the breadth and power of biomimetic approaches. In this work, we aim to build a series of educational modules to serve as a companion to engineers and designers taking a bio-inspired approach, while also facilitating more active collaboration and crosstalk with biology.

A201 NEUROMUSCULAR ACTUATORS FOR BIOHYBRID SOFT ROBOTS Thursday 7th July 2022

11:00am-11:30am

Ritu Raman, Massachusetts Institute of Technology ritur@mit.edu Human beings and other biological creatures navigate unpredictable and dynamic environments by combining compliant mechanical actuators with neural control and sensory feedback. The field of soft robotics has made significant advances in mimicking biological systems by creating compliant actuators capable of multiple degrees of freedom of motion. These abiotic actuators have yet to match their biological counterparts, however, in their ability to autonomously sense and adapt their form and function to changing environments.

Skeletal muscle drives movement in our bodies and can generate

SCIENCE ACROSS BOUNDARIES ABSTRACTS 35

large forces from small volumes with form, flexibility, and adaptive function that is unmatched by abiotic actuators. A complex feedback loop of sensory and motor neuron signaling, moreover, enables precise responsive control of muscle compliance and contractility.

Optimizing for an actuator that has a high power-to-weight ratio, uses a compact sustainable energy source, has integrated feedback control, and is robustly resilient to damage and fatigue makes neuromuscular actuators a compelling choice for powering engineered machines. We have shown that engineered skeletal muscle actuators, controlled by neuronal networks, can generate force and power functional behaviors such as walking and pumping in a range of untethered robots. These muscle-powered robots are dynamically responsive to mechanical stimuli and are capable of complex functional behaviors that have not been replicated in fully abiotic machines, such as exercise-mediated strengthening and healing in response to damage. This work sets the stage for leveraging biological sensing, processing, and actuation to build the next generation of dynamically adaptive machines.

A279 FUNCTIONAL CONSEQUENCES OF THE FORCE–VELOCITY RELATIONSHIP ON SIMULATED MUSCULOSKELETAL DYNAMICS Thursday 7th July 2022

10:00am-10:15am

Roger Kissane, University of Liverpool, James P. Charles, Royal Veterinary College, Graham N. Askew, University of Leeds r.kissane@liverpool.ac.uk Biomechanical computational models have been comprehensively used to evaluate the physiology of locomotion within various extinct and extant vertebrate species. Such models offer enormous potential to explore parameters which would otherwise require invasive procedures to measure experimentally, however, it is currently unknown which functional inputs are integral to developing physiologically and biomechanically accurate models. Amongst the most important models inputs, though often ignored, are the force-velocity characteristics of the muscle actuators, which describe the relationship between force-generating capacity during shortening and lengthening. While the shortening velocity of muscles has been extensively studied, fibre behaviour during lengthening is less well understood, and as such are not included in many muscle driven simulations of vertebrate movement. Here, we aim to use the ‘fast’ extensor digitorum longus and ‘slow’ soleus from the mouse to explore if there exist phenotypic differences in the lengthening portion of the force-velocity relationship and explore the functional implications these parameters have on the outputs of a biomechanical simulation of mouse trotting. Using in-vitro isovelocity contractions that span ±5% of optimum fibre length on the force-length relationship, we show that several aspects of the force-velocity relationship differ significantly between the muscles. Applying these muscle-specific force-velocity curves to the musculoskeletal model, we show that the predicted lengthening and activation parameters were highly sensitive to these input parameters, as was muscle power. These data highlight the importance of accurately representing the force-velocity relationship of muscles for the generation of physiologically valid musculoskeletal models.

ANNUAL CONFERENCE MONTPELLIER 2022

A342 MULTIBODY SIMULATION OF A STARFISH SKELETON Wednesday 6th July 2022

17:50pm-18:05pm

Raman Chaudhary, Biomimetics-Innovation-Centre, Hochschule Bremen – City University of Applied Sciences, Susanna Labisch, Biomimetics-Innovation-Centre, Hochschule Bremen – City University of Applied Sciences, Jan-Henning Dirks, Biomimetics-Innovation-Centre, Hochschule Bremen – City University of Applied Sciences raman.raman@hs-bremen.de Starfish possess a unique and complex endoskeleton which allows them to remain in the same body posture for a prolonged period of time whilst using only very little energy. This endoskeleton is formed by many intricate bone-like structures (ossicles) embedded in a collagenous matrix. Neuronal control of the matrix fibers allows the starfish to selectively control the stiffness of the arms and the body. To actively move the arms, different types of highly specialized ossicles are each attached to several groups of small muscle fibers. Selective contraction of these muscles fibers leads to a controlled deformation of the ossicle network with multiple degrees of freedom. To understand the detailed biomechanics of Asterias rubens skeleton and the interaction of the ossicles during locomotion, we have performed a multibody simulation of single rays. Using 3D microCT, geometry and relative alignment of the different ossicles were obtained, and a simplified CAD model was made. In the 3D model, forces on the different sets of ossicles were applied, corresponding to the forces arising due to the attached muscle contraction, and the resulted motion was observed. Based upon the results, the structure-motion relationship of the ossicles network is discussed for some of the starfish ray motions.

A347 THE IMPACT OF MUSCLE ACTIVATION DYNAMICS AND OTHER INTRINSIC PROPERTIES ON REACHING MOVEMENTS: A SIMULATION STUDY Thursday 7th July 2022

11:30am-11:45am

Tiina Murtola, Royal Veterinary College, Christopher T. Richards, Royal Veterinary College tmurtola@rvc.ac.uk Limb movements and their control are widely studied using musculoskeletal models, but the results of biomechanical simulations can be heavily influenced by the choice of muscle model. In order to investigate how reaching movements are affected by intrinsic muscle properties, we have implemented a simple upper limb model with three joints, each controlled by an antagonistic muscle pair. By varying the characteristics of the muscles in the model, we have studied the consequences of using a simple activation dynamics model compared to a more realistic, higher-order activation model, and we have also investigated how activation dynamics interact with the muscles’ force-length-velocity characteristics to affect reaching outcomes.

Our simulations suggest that accurate reaching movements can be achieved with a variety of muscle models, but compared to simple activation models, higher-order activation dynamics requires longer prediction from a forward model and gives rise to a higher level of unplanned co-contraction of antagonistic muscle pairs. In line with

SCIENCE ACROSS BOUNDARIES ABSTRACTS 36

prior work, the force-length-velocity properties of muscles were observed to enable stabilisation and smoothing of limb movements in simulations as well as to promote accurate reaching performance with the high-order activation model. Overall, our simulation results support the use of simple muscle models when only the behavioural outcome is of interest. However, the choice of muscle model can become critical when addressing questions related to neuromuscular control, as models capable of capturing realistic muscle behaviour may also affect key features of the control problem.

POSTER SESSION A193 AN INVESTIGATION OF MUSCULOSKELETAL CONTROL OF UNDERWATER WALKING USING XROMM AND BIOINSPIRED ROBOTICS Wednesday 6th July 2022

POSTER SESSION

Ariel Camp, University of Liverpool, Haley Amplo, New Jersey Institute of Technology/Rutgers University – Newark, Brooke E. Flammang, New Jersey Institute of Technology ariel.camp@liverpool.ac.uk Frogfish offer a unique opportunity to study underwater walking over rough terrain and develop new bioinspired robotic technologies to explore this ability. However, biologically relevant robotic models require information on how the bones and muscles are moving, which is often impossible to directly observe in living animals. We show how 3D skeletal motion can be combined with anatomical and behavioural data to develop a robotic model of the musculoskeletal system of the frogfish fin. The 3D anatomy of the fin muscles and bones was reconstructed from computed-tomography (CT scans). Underwater light cameras recorded the motion of the fin during natural behaviours in live frogfish. Finally, we used X-ray reconstruction of moving morphology (XROMM) to measure the range of motion and 3D kinematics of the fin bones. Morphological analysis showed that the fin skeleton consists of three radial bones and 11 fin rays that form the hand-like surface that interacts with the substrate; the limb is articulated with the pectoral girdle via ball-and-socket joints. During locomotion, the fin occupied a broad range of positions relative to the body depending on the type and orientation of substrate. XROMM animations demonstrated the radials are capable of both circumduction and long-axis rotation relative to the pectoral girdle. Based on this, we designed a simplified fin model with a single radial, ball-and-socket articulation, and a flexible foil as the fin rays. The bioinspired robotic model is validated by matching its kinematics output with the range of motion observed in frogfish.

ANNUAL CONFERENCE MONTPELLIER 2022

SCIENCE ACROSS BOUNDARIES ABSTRACTS 37

A5 - TO MAKE THE ENDS MEET: INSTRINSIC AND EXTRINSIC DETERMINANTS OF INTERINDIVIDUAL VARIATION IN TELOMERE DYNAMICS IN NON-MODEL SPECIES ORGANISED BY: SOPHIE REICHERT (UNIVERSITY OF TURKU), TIIA KӒRKKӒINEN (UNIVERSITY OF TURKU) AC3 LOWER MUSCLE MITOCHONDRIAL EFFICIENCY RESULTS IN MORE RAPID SHORTENING OF TELOMERES IN ECTOTHERMS AT HIGH AND FLUCTUATING TEMPERATURES Tuesday 5th July 2022

09:45am-10:00am

Neal Dawson, Institute of Biodiversity Animal Health & Comparative Medicine, University of Glasgow, Caroline Millet, University of Glasgow, Colin Selman, University of Glasgow, Neil B. Metcalfe, University of Glasgow neal.dawson@glasgow.ac.uk Recent cross-sectional comparisons of telomere lengths, a hallmark of ageing, suggest that high temperatures may increase the rate of senescence in ectotherms. Telomeres shorten as a result of exposure to ROS produced by the mitochondria. Given that the rate of ROS production varies with mitochondrial efficiency, there may be a link between an individual’s mitochondrial efficiency and its telomere dynamics, which may be more acute at high temperatures. We tested this hypothesis by examining the relationship between telomere length and mitochondrial function from white muscle and liver of brown trout Salmo trutta of similar age and size, fed ad libitum, and acclimated to high-constant (19.5°C), high-variable (19.5 ± 2.5°C, daily cycle), or ideal (12°C) temperature regimes. Fish under high-constant and high-variable temperature regimes had greater higher average rates of telomere attrition, mitochondrial oxygen consumption rates, and ROS release rates along with lower mitochondrial phosphorylation efficiencies when compared to 12°C acclimated fish. However, telomere changes were positively correlated with mitochondrial phosphorylation efficiency in muscle, but not liver, in fish from the high-constant and high-variable temperature regimes: telomeres shortened in the least efficient individuals but increased in length in the most efficient fish.

No relationship was observed in fish acclimated to 12°C. Therefore, individual diversity in muscle mitochondrial efficiency seems to cause variation in cellular senescence, where less efficient individuals have a more rapid shortening of telomeres. This may ultimately suggest

that less efficient individuals will have shorter lifespans in warming and fluctuating environments.

A392 DO LIFE HISTORY STRATEGIES AFFECT WITHIN-BODY MOSAICS OF AGEING? Tuesday 5th July 2022

14:30pm-14:45pm

Ana A. Romero-Haro, University of Exeter, Barbara Tschirren, University of Exeter, Simon Verhulst, University of Groningen, Ellis Mulder, University of Groningen a.romero-haro@exeter.ac.uk The disposable soma theory predicts that ageing is a consequence of the investment in reproduction at the expense of self-maintenance.

Depending on their pace of life (POL), individuals prioritise either reproduction (fast POL) or self-maintenance (slow POL). A fast POL is associated with a rapid accumulation of physiological damage and early death, and vice versa for a slow POL. To date, especially in vertebrates, it is unclear if physiological damage accumulates uniformly across the entire body, or if there are within-body mosaics of ageing.

Here, we quantified telomere length (TL) by TRF in blood, spleen and reproductive tissue in Japanese quail (Coturnix japonica) artificially selected for high (fast POL) or low (slow POL) reproductive investment to test for POL-dependent within-body mosaics of ageing. We found that TL differed across reproductive and non-reproductive tissues in a sex-specific way, but found no indication that these within-body mosaics of TL were affected by an individual’s POL. In females telomeres were longer in oviduct than in blood or spleen, whereas in males TL in testes was not different from TL in non-reproductive tissues, but telomeres in spleen were longer than telomeres in blood. Our study provides evidence for sex-specific within-body mosaic of ageing, which are, however, independent of an individual’s life history strategy.

ANNUAL CONFERENCE MONTPELLIER 2022

A393 FROM CLIMATE WARMING TO ACCELERATED CELLULAR AGEING: INSIGHTS FROM TWO EXPERIMENTAL STUDIES IN WILD PASSERINE BIRDS Tuesday 5th July 2022

10:15am-10:30am

Antoine Stier, Université Lyon 1 – LEHNA, Bin-Yan Hsu, University of Turku, Suvi Ruuskanen, University of Turku antoine.stier@gmail.com Climate change is increasing both the average ambient temperature and the frequency and severity of heat waves. While direct mortality induced by heat waves is increasingly reported, sub-lethal effects are also likely to impact population dynamics and persistence. We hypothesized that accelerated cellular ageing could be a cost of being exposed to higher ambient temperature. We tested this hypothesis in two common European passerine species by experimentally increasing nest box temperature by ca. 2°C during postnatal growth and measuring telomere length as a biomarker of ageing. In great tits, we also estimated the impact on medium-term survival and measured a large set of physiological markers including thyroid hormones, glucocorticoid signaling, oxidative stress, mitochondrial density and telomere maintenance mechanisms. We show that in both species, increasing early-life temperature does not affect growth or survival to fledging, but leads to an acceleration in the shortening of telomeres.

In great tits, such shortening of telomeres was not explained by increased oxidative stress levels, but more likely by an increase in energy demand (i.e. higher thyroid hormones levels, increased expression of glucocorticoid receptor, increased mitochondrial density) leading to a reduction in telomere maintenance mechanisms (i.e. decrease in the gene expression of telomerase and protective shelterin). Additionally, medium-term survival was reduced from 34% in control nests to 19% in heated nests. Our results thus suggest that climate warming might affect cellular ageing in wild passerine populations, with potential impact on population dynamics and persistence.

A394 UNDERSTANDING HOW PERSISTENT ORGANIC POLLUTANTS DETERMINE INTERINDIVIDUAL TELOMERE DYNAMICS IN A EUROPEAN MIGRATORY BIRD, THE ALPINE SWIFT (TACHYMARPTIS MELBA): NOVEL INSIGHTS IN A LONG-TERM PERSPECTIVE Tuesday 5th July 2022

10:00am-10:15am

Roger Colominas-Ciuró, Institut Pluridisciplinaire Hubert Curien, UMR 7178, Université de Strasbourg, CNRS, François Criscuolo, Institut Pluridisciplinaire Hubert Curien, UMR 7178, Université de Strasbourg, CNRS, Sandrine Zahn, Institut Pluridisciplinaire Hubert Curien, UMR 7178, Université de Strasbourg, CNRS, Sylvie Massemin, Institut Pluridisciplinaire Hubert Curien, UMR 7178, Université de Strasbourg, CNRS, Christoph M. Meier, Swiss Ornithological Institute, Pierre Bize, Swiss Ornithological Institute colominasciuro@gmail.com

SCIENCE ACROSS BOUNDARIES ABSTRACTS 38

Human activities are imposing major environmental alterations in natural populations and ecosystems. One of them is pollution, which is the introduction in natural environments of contaminants that can alter the health, reproduction, and survival of free-living organisms.

Persistent organic pollutants (POPs) are known to remain in the environment and to bioaccumulate through the lifetime of organisms, as well as to increase in concentration with each successive step in the food chain (biomagnification). Therefore, top predators as birds are used as bioindicators. Virtually, all bird species studied so far were found to be exposed to POPs, and there is growing evidence for their negative effects on reproduction or adult survival. However, there are large discrepancies among studies on the fitness consequences since (i) many are reporting no or little effects of POPs on reproduction, and (ii) the consequences of POPs on survival are rarely reported because most studies are relying on short rather than long-term monitoring. Therefore, our aim is to provide novel insights in a longterm perspective (2017-2021) on how POPs shape telomere dynamics in a European migratory bird species (the Alpine swift, Tachymarptis melba) to understand interindividual consequences on fitness, survival and, ultimately, life-history trajectories.

A395 OXYGEN AND TELOMERES: EXPERIMENTAL ELUCIDATION OF OXIDATIVE STRESS EFFECTS IN EARLY LIFE Tuesday 5th July 2022

09:30am-09:45am

Elisa Perez Badas, University of Groningen e.perezbadas@gmail.com Oxidative stress -the imbalance between antioxidants and reactive oxygen species (ROS) generated during aerobic respiration- has often been hypothesized to play a central role in disease and life history evolution, including ageing. However, whether oxidative stress modulates patterns of growth, ageing or survival is still an enigma, largely because the high reactivity of ROS makes oxidative stress difficult to measure. In addition to this, the experimental manipulation of oxidative stress levels without toxic side effects has also proven difficult. To avoid such caveats, I used a novel non-invasive experimental approach that bypasses the side effects of pharmacological approaches and successfully increases oxidative stress. Nestling zebra finches were exposed to hyperoxic air in a specially designed cabinet for 30 days during growth, when telomere shortening is highest. This was combined with the subcutaneous administration of antioxidants in a 2x2 design, to verify that the observed effects of hyperoxia can be attributed to oxidative stress. I will present the effects of this manipulation on markers of oxidative stress, telomere attrition, sexual ornamentation and survival. These results will shed light on the conundrum of the roles of oxidative stress in life history evolution and telomere dynamics. I will discuss the long-standing question whether the effect of oxidative stress in vitro is also observed in vivo, at physiological oxidative stress levels.

ANNUAL CONFERENCE MONTPELLIER 2022

A397 HERITABILITY OF TELOMERE LENGTH: A META-ANALYSIS Tuesday 5th July 2022

10:30am-11:00am

Hannah L. Dugdale, University of Groningen, Heung Ying Janet Chik, University of Groningen, Alexandra M. Sparks, University of Sheffield, Julia Schroeder, Imperial College London h.l.dugdale@rug.nl Individual variation in telomere length has been linked with health, survival and senescence. Individual variation in telomere length is due to environmental and genetic effects, which can be partitioned into their relative variance components. Estimating the ratio of additive genetic variance to the total phenotypic variance of telomere length, known as the heritability of telomere length, then facilitates understanding of the evolutionary potential of telomere length.

However, telomere length heritability estimates vary greatly, and there is a limited understanding of why this is. To fill this knowledge gap, we conducted a systematic review and meta-analysis. We extracted 104 estimates from 43 studies and 18 species to test whether variation in telomere length heritability estimates is due to: phylogeny, species, environmental setting, age at sampling, laboratory methods, statistical methods, and individual repeated measurements. Overall, we found a moderate heritability of 45% (95% CI: 25% – 65%), and significant phylogenetic and species-specific effects, suggesting differential selection pressures on telomere length across taxa. Twin-based and SNP-based estimates were lower than correlation-based or pedigree-based estimates. Furthermore, we detected a publication bias, where small studies with low or non-significant heritability were under-represented. Our results demonstrate an overall heritable basis of telomere length, and the need for careful selection of statistical methods. Specifically, we recommend variance-partitioning methods with relatedness or SNP data over correlation methods to minimize bias.

We also recommend future research to expand into a wider range of taxa, and to explore and validate the use of genome-wide correlation data in calculating quantitative genetic metrics.

A398 MANIPULATED PARENTAL EFFORT, TELOMERE DYNAMICS AND TELOMERE LENGTH ACROSS LIFE IN JACKDAWS Tuesday 5th July 2022

14:00pm-14:30pm

Christina Bauch, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Jelle J. Boonekamp, University of Groningen, University of Glasgow, Ellis Mulder, University of Groningen, Simon Verhulst, University of Groningen christinabauch@gmx.de Where resources are limited, life-history theory predicts that the allocation of resources towards reproduction comes at the expense of somatic maintenance. The underlying mechanisms remain poorly understood. Telomere dynamics and telomere length are candidate biomarkers as they predict survival in many species (including jackdaws). We consistently enlarged or reduced brood size over life in jackdaw parents, finding that individuals with an experimentally increased reproductive effort suffered an increased rate of actuarial

SCIENCE ACROSS BOUNDARIES ABSTRACTS 39

senescence. Our subsequent aim was to test if telomere dynamics mediate or reflect this trade-off between reproduction and lifespan and how telomere dynamics affect telomere length. Individual-based data on reproduction and blood samples for telomere analysis were collected during every breeding season since 2005 from adults and offspring. We find that telomere attrition rate was higher early than later in life and did not differ between parents raising enlarged or reduced broods, but the relationship between telomere length and survival was affected by reproductive effort. While we found no relationship between telomere length and survival in the group of parents raising reduced broods, in the group of parents raising enlarged broods only individuals with the longest telomeres survived. Telomere length tracking over life revealed that telomere shortening did not affect telomere length ranking of individual jackdaws. Our findings are in agreement with the growing realization that individual differences in (endothermic) vertebrate telomere length are largely already determined early in life and that the telomere length – fitness association originates there.

A399 TELOMERES IN THE OCEAN: HOW PRE- AND POSTNATAL FACTORS SHAPE TELOMERE DYNAMICS IN A COLONIAL LONG-LIVED SEABIRD Tuesday 5th July 2022

09:00am-09:30am

José C. Noguera Amoros, Universidade de Vigo josec.noguera.amoros@gmail.com It is well established that conditions experienced during prenatal development affect postnatal telomere length and dynamics in humans and laboratory animal models. However, we still know little about how prenatal environmental and social conditions shape telomere dynamics in wild animal populations. In the last years, we have performed several experimental studies to elucidate the role played by maternal glucocorticoids and the exposure to prenatal social stressors (e.g. exposure to predator cues) on postnatal telomere length and dynamics in a long-lived seabird species, the Yellow-legged gull (Larus michahellis). The results of these studies show that in contrast to previously thought, mothers may promote longer telomeres in their offspring by mildly increasing the allocation of glucocorticoids into their eggs (i.e. corticosterone). However, the effect of glucocorticoids hormones seems to differ depending on their intensity, origin and duration. Indeed, when late-stage embryos are repeatedly exposed to predator cues, they show increased secretion of glucocorticoids soon after hatching, an effect that was accompanied by a loss of telomere length during the early postnatal development. Together, our results show that embryos are not passive agents against their developmental environment, as their telomere dynamics are influenced by the maternal phenotype and the social cues they are able to integrate during their development.

ANNUAL CONFERENCE MONTPELLIER 2022

A400 ACROSS THE GREAT DIVIDE: TELOMERE DYNAMICS THROUGH METAMORPHOSIS IN AMPHIBIANS 14:45pm-15:00pm

Tuesday 5th July 2022

Pablo Burraco, University of Glasgow and Doñana Biological Station, Neil B. Metcalfe, University of Glasgow, Pat Monaghan, University of Glasgow, Miguel Hernández-González, University of Glasgow pablo.burraco@glasgow.ac.uk Despite ~80% of all animal species undergoing metamorphosis, the effect of this dramatic developmental process on telomere dynamics is unknown. Given that the rate of telomere shortening has been shown in non-metamorphosing species to be influenced by environmental harshness, the question arises as to whether the re-modelling of tissues that occurs during metamorphosis allows an individual to re-set its telomeres and so leave behind this legacy of past environments. This issue is pertinent to amphibians, a group likely to be heavily impacted in the larval stage (i.e., before metamorphosis) by environmental events such as global warming. We will first briefly discuss the current knowledge gaps in the study of amphibian telomeres, then present new data on telomere length across different tissues and developmental stages (from larva to adulthood) in the frog Xenopus laevis. We will also examine the impact of warming conditions before and after metamorphosis on amphibian telomeres and telomerase. Our results show that telomere length is affected not only by the rate of somatic growth, but also by the degree of metamorphic transformation experienced by particular tissues: during metamorphosis, telomere length can either decline, remain stable or dramatically increase.

Furthermore, this life history transition seems to be able to buffer the impact on telomeres of harsh conditions in early life. This leads us to suggest directions for future research on telomere dynamics in Recent cross-sectional comparisons.

POSTER SESSION A396 TELOMERE LENGTH, IMMUNITY AND REPRODUCTIVE INVESTMENT IN A FREE-LIVING MAMMAL POPULATION Thursday 7th July 2022

SCIENCE ACROSS BOUNDARIES ABSTRACTS 40

studies have found investment in these traits to be associated with shorter TL and higher rates of telomere attrition suggesting a cost.

TL has also been shown to reflect overall phenotypic quality in some studies with high-quality individuals having longer telomeres and also investing in reproduction and immunity. Here, we investigated the associations among maternal reproduction, chronic nematode infection, and mounting an antibody-mediated immune response on leukocyte TL in a free-living population of Soay sheep. We found that females that gave birth to lambs had shorter TL compared to females who did not breed in a given year. However, females whose offspring survived the neonatal period (and thus invested fully in lactation) had longer TL than those whose offspring died neonatally.

In both male and female Soay sheep, we also found helminth parasite burdens to be associated with longer TLs but no association between helminth-specific antibody levels and TL. Using multivariate mixedeffects models, we demonstrated that within-individual processes were driving the associations between TL, reproduction and parasite burden. Although the effect sizes were small, this suggests that TL may reflect some aspect of variation in overall physiological condition.

This can vary depending on the aspect of reproduction and immunity under investigation and suggests that TL may be associated with some aspects of resource investment and condition but not others.

ANNUAL CONFERENCE MONTPELLIER 2022

A6 - THE EFFECTS OF PARENTAL AGE AT TIME OF CONCEPTION ON OFFSPRING PERFORMANCE AND FITNESS ORGANISED BY: NEIL B. METCALFE (UNIVERSITY OF GLASGOW), PAT MONAGHAN (UNIVERSITY OF GLASGOW) A299 AGE-DEPENDENT REPRODUCTIVE ALLOCATION IN A VIVIPAROUS FLY Friday 8th July 2022

09:00am-09:30am

Sinead English, University of Bristol sinead.english@bristol.ac.uk Across diverse taxa, maternal allocation to offspring tends to increase until mothers reach a prime, before declining in later life. Offspring born to very young or old mothers thus are of lower quality, as measured for example in size at birth, and potentially experience reduced lifespan.

Here, I describe how we can gain new insights into the evolutionary causes of this age-dependent allocation by studying the tsetse fly: a relatively long-lived fly which gives birth to single offspring the same size as the mother. We experimentally test whether the decline in offspring quality produced by older females in the laboratory is exacerbated by nutritional stress, or mitigated by alleviating costs of reproduction. Using state-dependent models, we explore the evolutionary conditions favouring hump-shaped allocation with age, and how this is affected by physiological constraints and environmental uncertainty. Such models also shed light on why the senescence that we find in laboratory flies seems absent in field conditions, where flies have limited access to food and higher mortality. Finally, I discuss the implications for understanding age-dependent maternal allocation not just for considering offspring longevity, but for population processes and disease transmission.

POSTER SESSION

Sanjana Ravindran, University of Edinburgh, Hannah Froy, University of Edinburgh, Sarah Underwood, University of Edinburgh, Jennifer Dorrens, University of Edinburgh, Luise Seeker, University of Edinburgh, Kathryn Watt, University of Edinburgh, Rachael Wilbourn, University of Edinburgh, Daniel Nussey, University of Edinburgh sanjana.ravindran@ed.ac.uk Telomere length (TL) has been linked with individual physiological state and may act as a potential mediator of life-history tradeoffs. In the context of life-history traits such as reproduction and immunity,

SCIENCE ACROSS BOUNDARIES ABSTRACTS 41

A364 THE DISTRIBUTION OF THE LANSING EFFECT ACROSS ANIMAL SPECIES Friday 8th July 2022

11:45am-12:00pm

Edward Ivimey-Cook, University of Glasgow, Sharema Shorr, University of Edinburgh, Jacob Moorad, University of Edinburgh edward.ivimey-cook@glasgow.ac.uk

The Lansing Effect (LE) is the observation of decreased offspring longevity with increasing maternal age at birth. Whilst there appears to be much awareness of this phenomenon, actual support for a LE is mixed, with various studies reporting positive, negative, or no effects of maternal age on lifespan. We performed a meta-analytic review of published studies with two goals: 1) to determine if there exists a tendency across all studies species to express a LE, and 2) identify factors that might related to the severity (or presence) of the effect.

We derived 74 relevant estimates from 20 published studies of 14 species. Our analysis revealed a tendency across all studied animal species to exhibit a LE, but this appeared to be driven by estimates from insect and rotifer species, which were the most heavily studied and presented the most consistent LEs. We found no clear tendency from studies of bird or mammal species, but these were severly understudied. These results emphasize both the need to expand the taxonomic breadth of LE studies beyond laboratory model organisms and to develop new evolutionary theory that might help us understand this among-species variation.

A364 NATURAL SELECTION AND THE EVOLUTION OF MATERNAL AGE EFFECTS Friday 8th July 2022

09:30am-09:45am

Jacob Moorad, University of Edinburgh, jacob.moorad@ed.ac.uk Maternal age at birth has been demonstrated to affect offspring performance in aspects associated with fitness, including juvenile survival, lifespan, and fitness. A tendency appears to exist for such maternal age effects to be deleterious (‘maternal senescence’).

However, there also appears to be much variation in the degree (and even in the direction) of these effects. Why should maternal senescence evolve and where should we expect it to be strongest (or weakest)? The clearest and most general way to explore this question theoretically is to expand William Hamilton’s models of the evolution of ageing to age-specific maternal genetic effects for vital rates. This approach has been applied specifically only to juvenile survival, but it has yielded results that show: 1) that selection always favours the evolution of this manifestation of maternal senescence; 2) that the evolved rate of senescence will differ from actuarial and reproductive senescence; and 3) exactly how selection drives the age-of-onset of maternal senescence. Here I will discuss how this model of maternal genetic effects can be adapted to all other vital rates, and through these, to

ANNUAL CONFERENCE MONTPELLIER 2022

explain how natural selection can favour other aspects of maternal senescence, such as the Lansing Effect and reduced offspring fitness caused by advancing maternal age.

A366 GRANDMATERNAL AGE AT REPRODUCTION AFFECTS GRANDOFFSPRING BODY CONDITION, REPRODUCTION AND SURVIVAL IN A WILD POPULATION OF LIZARDS Friday 8th July 2022

11:30am-11:45am

Josefa Bleu, Institut Pluridisciplinaire Hubert Curien, Sandrine Meylan, Institut d’Ecologie et des Sciences de l’Environnement de Paris, Jean Clobert, Centre National de la Recherche Scientifique, Manuel Massot, Institut d’Ecologie et des Sciences de l’Environnement de Paris josefa.bleu@iphc.cnrs.fr Age at reproduction can influence the survival and future reproduction of an individual as well as that of their offspring. Remarkably, it has been shown that grandmaternal age at reproduction can also affect the characteristics of grandoffspring in humans and in laboratory or semi-captive animals. However, currently we do not know whether grandmaternal age effects exist in wild populations. We gathered data on female age at reproduction, offspring and grandoffspring characteristics using a 16-year long-term survey of a natural population of the common lizard, Zootoca vivipara. The dataset contains 579 grandoffspring from 135 litters. Body size at birth was not correlated with grandmaternal age at reproduction. However, grandoffspring body condition at birth, grandoffspring survival and reproductive performance of granddaughters were dependent on grandmaternal age. These relationships were independent of maternal age. An agestructured model showed that the global effect of grandmaternal age was non-linear and was largely driven by its effect on grandoffspring survival. Fitness was higher for granddaughters produced by grandmothers of intermediate ages. The study shows that age can shape life-history traits for more than one generation, documenting the importance that grandmaternal age can have in wild populations.

A367 PARENTAL AGE EFFECTS ON OFFSPRING PERFORMANCE EXACERBATE REPRODUCTIVE SENESCENCE IN FEMALE, BUT NOT MALE, EUROPEAN BADGERS Friday 8th July 2022

09:45am-10:00am

Melanie Weedon, University of Exeter, Paula Marjamaki, University of Exeter, Robbie McDonald, University of Exeter, Alastair Wilson, University of Exeter, Richard Delahay, Animal Plant Health Agency, Andrew Young, University of Exeter mw577@exeter.ac.uk Reproductive senescence is an age related decline in reproductive performance, and is commonly studied in terms of age-related patterns

SCIENCE ACROSS BOUNDARIES ABSTRACTS 42

of offspring production. However, parental fitness arises via offspring performance as well as production, so both components require attention to gain a more complete understanding of the trajectory and fitness consequences of reproductive senescence. Here we utilise a longitudinal dataset from a long-term study of European badgers (Meles meles) to investigate maternal and paternal reproductive senescence, and quantify how both offspring production and lifetime performance vary with parental age. First, we show that badgers of both sexes experience a senescent decline in annual offspring production, which occurs with a similar age of onset in the two sexes. Second, we show evidence of deleterious maternal age effects on offspring performance; offspring mortality risk increases and offspring lifespan and life-time reproductive success decreases with within-mother increases in maternal age. Crucially, the maternal ages of onset of these declines in offspring performance are significantly earlier than those for offspring production, such that failure to account for them would lead to underestimation of the severity (in terms of timing and fitness consequences) of maternal reproductive senescence. Finally, we found no evidence of paternal age effects on offspring mortality, lifespan or life-time reproductive success. Overall, our findings illustrate the potential importance of attending to parental age-related changes in offspring performance as well as production, and the potential for sex differences in the relative contributions of these two components to the overall fitness consequences of reproductive senescence.

A368 HERITABILITY AND PARENTAL AGE EFFECTS IN TELOMERE LENGTH IN A COLOUR POLYMORPHIC BIRD Friday 8th July 2022

10:00am-10:15am

Patrik Karell, Novia University of Applied Sciences, Chiara Morosinotto, Novia University of Applied Sciences/ Lund University , Staffan Bensch, Lund University, Maja Tarka, Lund University

ANNUAL CONFERENCE MONTPELLIER 2022

A370 BLAME IT ON THE PARENTS? PARENTAL AGE EFFECTS ON OFFSPRING FITNESS IN THE SEYCHELLES WARBLER Friday 8th July 2022

11:00am-11:30am

Alexandra M. Sparks, University of Leeds (currently University of Sheffield), Martijn Hammers, University of Groningen, Aeres University of Applied Sciences, Jan Komdeur, University of Groningen, Terry Burke, University of Sheffield, David S. Richardson, Nature Seychelles, University of East Anglia, Hannah L. Dugdale, University of Leeds, University of Groningen a.sparks@sheffield.ac.uk In virtually all animals an individual’s health and condition deteriorate with age in a process known as senescence, which impacts their survival and the number of offspring they produce in later life. Importantly, the quality of offspring produced, as measured through their own physiological condition, survival, and reproductive success, may also be impacted by the age of their parents. These parental age effects may have considerable health and evolutionary implications.

However, the evidence for parental age effects on offspring fitness in wild populations is limited and mixed. Furthermore, it remains unclear whether parental age effects are sex-specific or whether they might be dependent on early-life environmental conditions. In this talk, I will summarise general patterns observed in wild populations, and describe specifically the patterns of parental age effects observed in a population of Seychelles warblers (Acrocephalus sechellensis) that are the subject of a long-term individual-based study. In this population there is evidence that parental age effects on offspring lifespan and lifetime reproductive success depend on both the sex of the parent and the sex of the offspring. Finally, I will discuss the role of telomeres as a potential mechanism underlying parental age effects in this population, as well as the evolutionary implications of these sex-dependent parental age effects.

patrik.karell@novia.fi Investigating heritability as well as parental effects and rearing environment can highlight the factors affecting offspring telomere length. Moreover, how phenotypic parental traits linked with fitness affect offspring telomere dynamics is still unclear. A phenotypic marker closely associated with physiological traits and fitness is melanin-based colour polymorphism. In tawny owl (Strix aluco) this polymorphism is highly heritable and strongly associated with both adult telomere shortening and survival. We studied narrow-sense heritability (h2) of telomere length (RTL), as well as the impact of colour morph and parental age and their combined effects on offspring telomere length.

Offspring RTL was strongly positively correlated with both mother and father RTL measured at breeding. Offspring RTL was also negatively associated with father age, suggesting that older fathers sired offspring with shorter telomeres, while there was no association with mother age. Parental colour morph was not clearly associated to offspring telomere length and there were no interactive effects of parental morph and age, despite previously documented morph-specific senescence patterns. Our results suggest that telomere length is highly heritable and affected by paternal age, but not related to colour polymorphism.

Thus, either morph-specific telomere shortening as adult does not result in significantly shorter telomeres in their gametes, or parents compensate morph-specific senescence via parental care. Morphspecific patterns of telomere dynamics in polymorphic species may thus be driven by different life-history strategies adopted in adulthood.

A371 PATERNAL AGE IMPACTS BOTH EARLY AND LATE LIFE OFFSPRING PERFORMANCE Friday 8th July 2022

12:00pm-12:30pm

Pauline Vuarin, Laboratoire de Biométrie et Biologie Évolutive UMR CNRS 5558, Loïc Lesobre, Reneco International Wildlife Consultants LLC, Gwènaëlle Levêque, Emirates Center for Wildlife Propagation, Michel Saint Jalme, National Museum of Natural History, Centre d’Ecologie et des Sciences de la Conservation, UMR 7204 CNRS, Frédéric Lacroix, Reneco International Wildlife Consultants LLC, Yves Hingrat, Reneco International Wildlife Consultants LLC, Gabriele Sorci, University of Bourgogne Franche-Comté, Biogéosciences, UMR 6282, CNRS pauline.vuarin@univ-lyon1.fr It is now widely acknowledged that parental age has profound implications for offspring phenotype. We investigated both short and long-term effects of parental age on offspring performance in a promiscuous bird from a conservation breeding program, the houbara bustard. Using an experimental approach, we first aimed at testing

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whether male age impinges on fertilization success, offspring growth and survival. We inseminated females with mixed semen composed of sperm from two males of either contrasted (3-6 versus 12-16 years old) or similar ages (control groups). We collected the first 5 eggs laid after insemination, and we monitored chick growth and survival in captivity and then in the wild following release, using satellite transmitters. Paternity analyses revealed that young males fertilized 66% of the eggs. Although there was no difference in either body size or mass at hatching, chicks sired by young males were in better body condition throughout their first 3 months. Finally, once in the wild, female offspring sired by young males had higher survival 3 months post-release. Then, we took advantage of a longitudinal dataset on ejaculate attributes to test parental age effects on sperm senescence in male offspring. Using data from 1708 males produced by dams and sires of varying ages, we investigated whether maternal and paternal ages affected the rate at which sperm quantity and quality of the progeny senesce. We found that offspring sired by old fathers produced far less sperm, particularly during their first year of life, but also throughout their entire lifetime. However, maternal age had no effect on the production of male gametes nor on their senescence rate.

Overall, our results support that paternal age impacts early life offspring performance and fitness, and that it has very long-lasting effects on offspring phenotype, accelerating their reproductive senescence.

A372 MATERNAL AGE EFFECTS ON OFFSPRING LIFESPAN AND FITNESS Friday 8th July 2022

14:45pm-15:15pm

Kristin Gribble, Marine Biological Laboratory kgribble@mbl.edu Phenotypic plasticity occurs not only within individuals, but also across generations. Intergenerational plasticity in which maternal physiology or maternal environment causes a change in offspring phenotype without a change in the genome is known as a “maternal effect.” To understand the role of maternal effects in aging, we examined the influence of maternal age, maternal diet, and offspring diet on offspring lifespan, health, fecundity, mitochondrial phenotype, and response to environmental conditions in the rotifer Brachionus manjavacas. Rotifers are aquatic invertebrate animals with many advantages as models in research on aging and maternal effects, including a short lifespan of two weeks, enabling high replication and rapid experimentation; asexual and sexual reproduction, allowing both clonal culture and outcrossing; a transparent body, permitting imaging of morphology and cellular processes; extremely large reproductive investment in individual offspring; direct development of offspring; and no postnatal maternal care. We found that offspring lifespan, fecundity, and stress resistance decline significantly with increasing maternal age, though the magnitude of these effects is genotype specific. The decreased fitness of old-mother offspring is associated with significant changes mitochondrial homeostasis and function, including altered mtDNA content, decreased mitochondrial inner membrane folding, lower ATP levels, changes in ROS, and increased protein carbonylation, suggesting that deleterious maternal age effects may be mediated via inherited mitochondrial dysfunction. Interestingly, old-mother offspring appear to be more responsive to interventions to aging such as caloric restriction. Our results suggest that maternal age effects may be an important source of interindividual variability in lifespan, reproductive success, and health.

ANNUAL CONFERENCE MONTPELLIER 2022

A407 MATERNAL AGE INTERACTS WITH ENVIRONMENTAL CONDITIONS IN SHAPING OF OFFSPRING PHENOTYPE IN AN ANNUAL FISH SPECIES Friday 8th July 2022

10:15am-10:30am

Agnieszka Magierecka, University of Glasgow

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talk I will outline the potential routes whereby a Lansing effect can occur, and discuss how these might be teased apart through carefully designed experimental studies. I will stress that parental age effects such as the Lansing effect can arise via routes that have nothing to do with biological ageing of the parents or their offspring, since there can be indirect effects of parental age such as changes in investment patterns by their mates. We also need to be aware that there may be compensatory responses by the offspring themselves that obscure the underlying effects of parental age. Consideration of these issues should reveal why phenomena such as the Lansing effect are seen in some contexts and not others.

agnieszka.magierecka@glasgow.ac.uk Annual populations of animals express all of their reproductive effort in a single year only, with some of them producing offspring across a series of reproductive attempts (e.g. clutches) within the same breeding season. In such organisms, the timing of a reproductive attempt correlates with maternal age (so that offspring produced late in the breeding season are mothered by older females), and thus the phenotype of the offspring may differ between reproductive attempts of the same female. Moreover, environmental conditions experienced by the mother during that breeding season may further modify the phenotypic effects of maternal age. In this study, I investigated the effects of the interaction between maternal age and maternal environment on offspring phenotype using an annual population of three-spined stickleback (Gasterosteus aculeatus). I compared the phenotype of offspring from the early, mid- and late clutches of females, half of which were exposed to environmental stressors across their breeding season. Older females produced heavier eggs and fry that were larger at hatching, regardless of environmental stressors.

Offspring of both stressed and non-stressed older mothers showed increased hormonal response to an acute stressor, but their survival patterns showed a complex relationship with both maternal age and stress exposure. Moreover, I observed a positive effect of maternal age on their daughters’ reproductive investment, but only if the mothers experienced stressful conditions during the breeding season.

I thus show that annual females nearing the end of their reproductive lifespan increase their reproductive investment, with a potentially intergenerational effect. In addition, maternal age influences offspring phenotype, but this influence is moderated by the environmental conditions the mothers experience during the reproductive period.

A418 WHAT ARE THE POTENTIAL MECHANISMS UNDERLYING EFFECTS OF PARENTAL AGE ON OFFSPRING PHENOTYPE? Friday 8th July 2022

15:30pm-15:45pm

Neil B. Metcalfe, University of Glasgow neil.metcalfe@glasgow.ac.uk It is clear that the age of parents at the time of conception can affect the phenotype of the next generation. The most commonly observed adverse trend is for old parents to produce offspring that have a shorter lifespan (the Lansing effect). Effects such as this are important to our understanding of the selective forces shaping life history evolution, yet we rarely understand the underlying mechanisms, nor whether they actually reduce offspring fitness. For instance, is a shorter lifespan due to greater frailty ( = greater likelihood of dying, even at younger ages) or an earlier onset of senescence, and is it offset (or even caused by) a greater investment by the offspring in early reproduction? In this

A410 EFFECTS OF MATERNAL AND GRANDMATERNAL AGE AT BREEDING ON A BIOMARKER OF AGEING Friday 8th July 2022

15:15pm-15:30pm

Pat Monaghan, University of Glasgow pat.monaghan@glasgow.ac.uk There are several pre- and post-natal routes whereby the adverse effect of parental age on offspring longevity (the Lansing effect) could occur, and the nature and magnitude of the effects could also be influenced by environmental factors that affect parent or offspring state. Furthermore, we know little about the extent to which any such effects persist beyond the first generation. In this talk we will describe experiments in which female zebra finches lived in a mildly stressful environment other when they were not breeding. In both young and old age these females bred with young males, thereby controlling for effects of old father age. The telomere length of their offspring at 30 days after hatching was compared with those produced by females that always lived in a benign environment. When the mothers were young, those that had lived in the more stressful environment had sons (but not daughters) with significantly shorter telomere lengths than those of mothers living in the benign environment. Offspring of both sexes had substantially shorter telomere lengths when the mother was old than when she was young. This effect of maternal age on F1 offspring persisted into the F2 generation, with grandmother (F0) age at the time of producing the mother (F1) having a substantial effect on telomere length in the F2 offspring. In contrast, no effect of grandmother environment was evident in the F2 generation. Such maternal and grand-maternal age effects on early life telomere length could underpin the Lansing effect.

ANNUAL CONFERENCE MONTPELLIER 2022

SCIENCE ACROSS BOUNDARIES ABSTRACTS 45

POSTER SESSION

Here, we take advantage of a unique multigenerational demographic dataset on a natural population of Alpine swifts intensively monitored in Switzerland to investigate both maternal and paternal age effects on offspring life-histories by testing for relationships between parental age and offspring condition, age-specific reproductive success and lifespan. We expect that that offspring born to older parents display reduced overall performance. By investigating substantial fitness costs of late reproduction, our study will help better understand which factors contribute to the variation in ageing rates and fitness among individuals.

A363 DEVELOPMENT OF A FRAILTY INDEX IN THE ZEBRAFINCH, TAENIOPYGIA GUTTATA Wednesday 6th July 2022

POSTER SESSION

Eugenio Carlon, University of Glasgow, Edward Ivimey-Cook, University of Glasgow, Winnie Bonner, University of Glasgow, Cara Cochrane, University of Glasgow, Neil B. Metcalfe, University of Glasgow, Colin Selman, University of Glasgow, Pat Monaghan, University of Glasgow 2330865C@student.gla.ac.uk Frailty, the variation in age-related risk of death, is commonly associated with the phenotypic state of an individual. As such, various measures of phenotypic performance are often used as indices to understand how age-related phenotypic change varies among individuals and species.

Whilst traditionally used in humans and mammalian model species, there is a general need to expand the use of frailty measures in the study of the comparative biology of ageing. An important step is identifying appropriate traits to use in developing frailty indices. In a laboratory population of zebra finches, Taeniopygia guttata, we are examining various phenotypic indices in individuals of different chronological age, including locomotory performance, foraging preferences and responses to novel situations, together with morphological features.

Development of such frailty indices have the potential for widespread use in evaluating individual variation in ageing rate.

A369 EFFECTS OF PARENTAL AGE ON OFFSPRING LIFE HISTORY TRAJECTORIES IN THE ALPINE SWIFTS Wednesday 6th July 2022

POSTER SESSION

Sophie Reichert, University of Turku, Héloïse Moullec, University of Turku, Pierre Bize, University of Aberdeen reichert.sophie@gmail.com Parental age at conception effects are a crucial driver of offspring phenotype, with effects on offspring survival or reproduction. Parental age at conception can significantly influence the phenotype of their offspring independently of the genes they passed on to them. These non-genetic parental effects can carry over to the next generation to influence offspring performance with important ecological and evolutionary consequences. Most studies linking parental age to offspring life histories have been conducted on humans, model systems and insects. Only rare studies are focusing on natural populations, usually only considering maternal age effects, and presenting a “snapshot” of an individual’s lifetime. Seldom have there been studies looking at the effects of both parents’ age over an offspring’s entire lifetime. Because of this limitation, effects of parental age on fitness in the next generation are poorly understood in wild vertebrates.

ANNUAL CONFERENCE MONTPELLIER 2022

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A7 - LIMITS TO THERMAL PERFORMANCE IN ECOTOTHERMS: THE INTERPLAY BETWEEN PHYSICAL CONSTRAINTS ORGANISED BY: WILCO C.E.P. VERBERK (RADBOUD UNIVERSITY), ENRICO L. REZENDE (PONTIFICIA UNIVERSIDAD CATÓLICA DE CHILE), IGNACIO PERALTA-MARAVER (UNIVERSITY OF GRANADA A20 THE ROLE OF CELL SIZE IN SHAPING RESPONSES TO OXYGEN AND TEMPERATURE IN FRUIT FLIES Thursday 7th July 2022

09:45am-10:00am

Félix Leiva, Radboud University, Jeroen G.J. Boerrigter, Radboud University, Wilco C.E.P. Verberk, Radboud University felixpleiva@gmail.com The body size of an animal is a key driver of ecological traits such as fecundity, mortality and growth. Ectotherms mature at smaller body sizes in warmer conditions and under low oxygen availability (hypoxia).

Whether these size reductions are driven by a decrease in cell size or cell number (which together determine body size) and how such cellular responses may help ectotherms cope with thermal challenges and hypoxia is poorly understood. The theory of optimal cell size postulates that cell size impacts metabolic costs and the capacity of cells to take up oxygen via differences in surface-to-volume ratio. In this way, cell size has consequences for growth rate and body size. Here, using inbred lines of fruit flies Drosophila melanogaster, which exhibits differences in cell size, we investigate how body size reductions due to warming or hypoxia are modulated by and result from differences in cell size.

Temperature-size responses were stronger under hypoxia and in lines of flies exhibiting large cell sizes, supporting the idea that larger cells constrain organismal growth by their inherently lower capacity for oxygen uptake. Reductions in body size were driven by reductions in cell size, whereas cell number increased to compensate partially. Thus, a cellular perspective offers a complete understanding of changes in body size in response to temperature and oxygen.

A21 CELL SIZE PREDICTS THERMAL SENSITIVITY AND GEOGRAPHIC DISTRIBUTION IN AN ECTOTHERM Thursday 7th July 2022

09:30am-09:45am

France Dufresne, Université du Québec à Rimouski (UQAR), Sarah-Béatrice Bernier, Université du Québec à Rimouski

ANNUAL CONFERENCE MONTPELLIER 2022

satisfying explanations for both findings given a limited understanding of what ultimately determines an organism’s heat limit. Here, we propose that the amount of heating an ectotherm can tolerate should scale with temperature’s influence on biological rates and therefore the effective duration of biological processes. We tested this hypothesis by analyzing heating tolerances of diverse ectothermic taxa acclimated to different temperatures, and rescaling the duration of heating events to account for the non-linear influence of temperature on biological rates and thus, on the way organisms experience time. This rescaling reveals that the rate-corrected heating tolerance of an organism is in fact remarkably constant across any acclimation temperature, enabling highprecision estimates of how their heat limits will vary under different thermal regimes. We also find that faster heating rates consistently reduce rate-corrected heating tolerances, which helps further explain why heat limits seem so variable. Existing paradigms are that heating tolerances and heat limits are constrained by evolutionary conservatism or index failure of systems such as membrane function; our data provide a different perspective and show that an organism’s heat limit emerges from expenditure of rate-corrected heating tolerance, which is an approximately-fixed property of a species.

france_dufresne@uqar.ca The negative relationship between body size and temperature has been documented in numerous ectotherms and has been termed the temperature size rule. Smaller body sizes have been associated with greater temperature tolerances (often measured as Ctmax) though reasons underlying this are not entirely clear. As smaller bodies are often composed of small cells with a greater membrane surface area, relative to volume than larger cells, they may support a greater capacity for oxygen transport and explain the greater temperature tolerance of small organisms. In this study, we examine the consequence of increased cell size on Ctmax. We measured Ctmax (critical thermal maximum) in 17 triploid and diploid clones of the water flea Daphnia pulex raised under 16°C, 20°C and 24°C for several generations. Diamond-shaped prints on the carapace were used as proxy of epidermal cell size. Cell size varied significantly with body size, acclimation temperature, and ploidy. Daphnia had significantly larger cells when raised at 16°C than under higher temperatures. Triploid clones had larger cells than diploids under all temperatures. Ctmax increased with acclimation temperature and was negatively correlated to both cell size and body size. Our results suggest that cell size is an important factor underlying the temperature size rule. Lower thermal tolerance due to increased cell size could restrict the distribution of polyploid clones to higher latitudes.

A142 HEATING TOLERANCE OF AN ECTOTHERM DOES NOT VARY WHEN TEMPERATURE’S INFLUENCE ON BIOLOGICAL RATES IS ACCOUNTED FOR Thursday 7th July 2022

11:30am-11:45am

Nicholas Payne, Trinity College Dublin, Jacinta Kong, Trinity College Dublin, Jean-François Arnoldi, CNRS, Andrew L. Jackson, Trinity College Dublin, Amanda Bates, Memorial University, Simon Morley, British Antarctic Survey, James Smith, NOAA paynen@tcd.ie The capacity of ectotherms to adjust their heat limits through evolution or acclimation seems relatively modest and highly variable, and we lack

A143 LOCAL ADAPTATION IN THE PLASTICITY OF COLD TOLERANCE IN THE EASTERN SPRUCE BUDWORM Thursday 7th July 2022

11:45am-12:00pm

Katie Marshall, University of British Columbia, Amanda D. Roe, Canadian Forest Service kmarshall@zoology.ubc.ca Temperature affects many aspects of spruce budworm (SBW) fitness, including survival and development; therefore, we hypothesized there would be strong selection for local adaptation of cold tolerance and the capacity to increase it. We know that regional populations are capable of plastic responses to stressful low temperature conditions, however we have limited knowledge of the biochemical mechanisms underlying these responses. Cold tolerance is closely tied to glycerol production as glycerol is the most prevalent cryoprotectant in SBW. Yet glycerol synthesis must come at the cost of glycogen reserves, which also form the only overwintering energy store. We hypothesized that local adaptation for increased glycerol synthesis has occurred in SBW, and predicted that fluctuating temperatures (which increase glycerol synthesis) would induce increased enzyme activity in the pathway responsible for glycerol synthesis, and that more northerly populations would have higher enzyme activity than more southerly populations.

We developed enzyme activity assays for three key enzymes in the SBW glycerol synthesis pathway: glucose-6-phosphate dehydrogenase (G6PDH), phosphoglucoisomerase (PGI) and phosphofructokinase (PFK). We then assayed the activity of these enzymes in SBW from five populations (NWT, Alberta, New Brunswick, Quebec, and IPQL) reared in common garden conditions and then following fluctuating cold exposure to assess enzymatic reaction rate (Vmax) and enzyme substrate affinity (Km) to characterize changes in potential glycerol synthesis. Here we show that Km was not changed by either population origin or experimental conditions, but Vmax is frequently affected by both, illuminating a mechanism of adaptation to extreme temperatures.

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A146 EVOLUTIONARY TRADE-OFFS BETWEEN THERMOREGULATORY BEHAVIOR AND THERMAL PHYSIOLOGY IN AN ASSEMBLAGE OF SONORAN DESERT LIZARDS Thursday 7th July 2022

10:15am-10:30am

Donald Miles, Ohio University, Anthony L. Gilbert, Auburn University urosaurus@gmail.com Predicting the responses of organisms to environmental change requires understanding the correlation between behavioral and physiological traits so as to avoid overheating without compromising performance. The concept of coadaptation, i.e., the correlation between thermoregulatory behavior and thermal physiology, is a foundational principle in evolutionary physiology. Yet, phylogenetic comparative analyses provide mixed support for coadaptation or evolutionary tradeoffs. Few analyses of coadaptation between behavior and physiology include both a phylogenetic and an environmental context. Evidence for trade-offs maybe scarce, because the covariation between traits may be constrained by responses to local environmental conditions. Here we quantify how constraints in core thermal and behavioral trait may modulate patterns of coadaptation. We estimated thermoregulatory behavior and thermal physiology for 12 species of Phrynosomatid lizards inhabiting the Sonoran desert. We found low phylogenetic signal in traits associated with behavioral thermoregulation. Yes, behavioral traits have rates of evolution 3x higher than physiological traits associated with locomotor performance and temperature tolerance.

When we modeled state-dependent shifts in thermal physiology as a function of thermoregulatory behavior, we found that thermoregulatory behavior did not influence the rate of evolution in thermal physiology.

As environmental change may favor new combinations of behavioral and physiological traits, evolutionary mismatches between these traits can become exaggerated and result in novel phenotypic trajectories and result in a breakdown of thermal coadaptation. Our study revealed partial coadaptation and limited evidence for tradeoffs between thermoregulation and thermal physiology, which could be the default evolutionary pattern in the evolution of these traits, which has major implications for studying thermal coadaptation as environments change worldwide.

A150 INTERACTIVE EFFECTS OF TEMPERATURE AND OXYGEN AVAILABILITY ON PERFORMANCE AND THERMAL LIMITS IN THE LIZARD PODARCIS MURALIS Thursday 7th July 2022

10:00am-10:15am

Eric Gangloff, Ohio Wesleyan University, Rory S. Telemeco, California State University Fresno, G. Antonio Cordero, University of Lisbon, Essie Rodgers, University of Canterbury, Fabien Aubret, Station d’Ecologie Théorique et Expérimentale du CNRS ejgangloff@owu.edu

ANNUAL CONFERENCE MONTPELLIER 2022

Decades of research on the physiology of amphibians and non-avian reptiles suggest that both subcellular and organ system mechanisms are important in determining thermal tolerance limits, with hierarchical effects. We propose an integrated framework, which we call Hierarchical Mechanisms of Thermal Limitation (HMTL), which combines ideas from the thermal performance curve paradigm, oxygen limitation hypothesis, and marginal stability hypothesis. This unified framework can explain how processes interact to limit performance and set tolerance limits at high temperatures. We tested this framework in experiments with the upslope-colonizing lizard, Podarcis muralis. In line with the predictions of the HMTL hypothesis, the critical thermal maximum and anaerobically-fueled sprint speed are unaffected by acute mild hypoxia, while both the maximum aerobic scope and the optimal temperature for aerobic scope are reduced. We then developed a mathematical framework, which we call Temperature-Oxygen Performance Surfaces (TOPS), that provides sensitivity parameters which quantify how performance traits vary in response to oxygen availability or capacity. This novel framework is transferable across traits and levels of organization to allow predictions for how ectotherms will respond to novel combinations of temperature and other abiotic factors, an essential tool in a time of rapidly changing environmental conditions.

A157 THE ROLE OF MICROCLIMATE AT FINE SCALES IN DRIVING EXPOSURE OF ECTOTHERMS TO CLIMATE CHANGE: INTEGRATING BIOPHYSICS, PHYSIOLOGY AND ECOLOGY Thursday 7th July 2022

09:00am-09:30am

Sylvain Pincebourde, Université de Tours, CNRS sylvain.pincebourde@univ-tours.fr The surface of pant leaves hosts a huge diversity of interacting ectotherms. The ecophysiology of these tiny organisms, as well as the rate of biotic interactions, depends on the leaf surface temperature.

Most of these organisms are tiny enough to be totally submerged within the leaf boundary layer, making them largely under the influence of the leaf functioning. The temperature of a leaf surface can deviate from air temperature sometimes quite strongly. In this presentation, I will detail the biophysical mechanisms determining the microclimate of arthropods living at the leaf surface. A comprehensive understanding of the leaf-air temperature deviations as well as the temperature heterogeneity at the within-leaf surface scale, is important to identify the extent to which ectotherms can exploit these thermal patterns to thermoregulate. Then, arthropod herbivore can fundamentally modify the functioning of the leaf when feeding on it; these changes have cascading effects on the leaf microclimate. These cascading effects can help explain the patterns of thermal adaptation among arthropod herbivores and predict the consequences of competitive interactions. These approaches needs to be cross-scales since the finescale microclimate is embedded into another microclimate at larger scale. Finally, the leaf microclimate can be placed in the context of climate change impacts: will the leaf surface provide ectotherms with a buffer of extreme heat or by contrast will it magnify the atmospheric changes? This knowledge of the leaf microclimate helps us determining the vulnerability of arthropods to warming.

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A158 LONG-TERM FORECAST OF THERMAL MORTALITY WITH CLIMATE WARMING IN AMPHIPODS FROM A TEMPERATE RIVER Thursday 7th July 2022

12:00pm-12:15pm

Ignacio Peralta-Maraver, University of Granada, Wilco C.E.P. Verberk, Institute for Water and Wetland Research, Radboud University, Enrico L. Rezende, Universidad Católica de Chile, K. Natan Hoefnagel, Institute for Water and Wetland Research, Radboud University peraltamaraver@ugr.es Forecasting the long-time consequences of global warming requires knowledge not just on thermal mortality but also how heat stress interacts with other environmental stressors1,2. Here we describe an analytical framework that combines laboratory measurements and high resolution field temperature records to forecast mortality risks over the next century. As a proof of concept, we study amphipods Dikerogammarus villosus and Echinogammarus trichiatus from river Waal, Netherlands, acclimated to different temperatures and oxygen levels. We predicted daily and annual heat mortality in the river under different oxygen levels for current temperatures and for 1 ºC and 2 ºC warming . Given the projected increases in summer temperatures, annual mortality is forecasted to increase substantially during the next decades, varying with acclimation status and water oxygenation. Both acclimation to elevated water temperatures and adequate oxygenation are crucial for persistence under current temperatures. However, even in the best case scenario, mortality in D. villosus is expected to approach 100 % by 2100, while E. trichiatus appears to be less vulnerable. Overall, this framework generates forecasts in unprecedented detail on short- and long-term temporal impacts of rising temperatures in ecological communities, and also the contribution of other environmental stressors.

A411 LIFE IN FLUCTUATING ENVIRONMENTS Thursday 7th July 2022

11:00am-11:30am

Joey Bernhardt, University of British Columbia joey.bernhardt@biodiversity.ubc.ca Variability in the environment defines the structure and dynamics of all living systems, from cells to organisms to ecosystems. Species have evolved traits and strategies that allow them to detect, exploit and predict the changing environment. These traits allow organisms to maintain steady internal conditions required for physiological functioning through feedback mechanisms that allow internal conditions to remain at or near a set point despite a fluctuating environment. In addition to feedback, many organisms have evolved feedforward processes, which allow them to adjust in anticipation of an expected future state of the environment. Here I provide a framework describing how feedback and feedforward mechanisms operating within organisms can generate effects across scales of biological organization, and how they allow living systems to persist in fluctuating environments. I demonstrate how daily, seasonal and multiyear cycles provide cues that organisms use to anticipate changes in physiologically-relevant environmental conditions. Using feedforward

ANNUAL CONFERENCE MONTPELLIER 2022

mechanisms, organisms can exploit correlations in environmental variables to prepare for anticipated future changes. Strategies to obtain, store and act on information about the conditional nature of future events are advantageous and are evidenced in widespread phenotypes such as circadian clocks, social behaviour, diapause, and migrations. Finally, I show how humans are altering the ways in which the environment fluctuates, causing correlations between environmental variables to become decoupled, decreasing the reliability of cues. Human-induced environmental change is also altering sensory environments and the ability of organisms to detect cues. Recognizing that living systems combine feedback and feedforward processes is essential to understanding their responses to current and future regimes of environmental fluctuations.

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A19 CLIMATE CHANGE DRIVES UPSLOPE MIGRATION OF WALL LIZARDS IN THE PYRENEES: EFFECTS ON BODY SIZE AND BODY TEMPERATURE Wednesday 6th July 2022

POSTER SESSION

Constant Perry, CNRS – Station d’Ecologie Théorique et Expérimentale, Fabien Aubret, CNRS - Station d’Ecologie Théorique et Expérimentale, Eric J. Gangloff, Ohio Wesleyan University constant.perry.contact@gmail.com

POSTER SESSION A18 DIFFERENTIAL METABOLIC RESPONSES OF JUVENILE ANTARCTIC FISHES TO CLIMATE CHANGE STRESSORS Thursday 7th July 2022

POSTER SESSION

Amanda Frazier, University of California, Davis, Milica Mandic, University of California, Davis, Andrew W. Naslund, University of California, San Diego, Kenneth W. Zillig, University of California, Davis, Anne E. Todgham, University of California, Davis ajfrazier@ucdavis.edu Due to uncurbed anthropogenic CO2 emissions, polar oceans are experiencing ocean warming and ocean acidification at among the fastest rates on Earth. Polar species cannot migrate to colder habitats and must rely on existing physiological plasticity to cope with rapid warming. Antarctic species may be especially unprepared for rapid changes, as they evolved in extremely stable and isolated environments. Elucidating differential interspecific capacities to cope with climate change is critical to inform our predictions of potential Antarctic ecosystem shifts and adaptive management decisions. In the marine Antarctic, benthic fishes play an especially important role in the ecosystem, yet niche differentiation among benthic trematomids is not well defined. Some evidence suggests that adult Trematomus bernacchii and Trematomus pennellii may have different physiological capacities when exposed to stressors, which may contribute to their niche differentiation. The aim of this study was to evaluate if differential performance under stress is seen at juvenile life stages in T. bernacchii and T. pennellii, as young animals are thought to be more vulnerable to anthropogenic stressors. Specifically, we examined the resting metabolic rate (RMR) of juvenile T. bernacchii and T. pennellii in response to acidification and warming exposures over a five-week acclimation period. T. pennellii demonstrated lower RMR in all treatments than T. bernacchii, suggesting that T. pennellii may have a greater capacity to cope with climate change stressors than T. bernacchii. This is significant, as T. bernacchii have a higher abundance in the ecosystem and may be at risk of niche compression under climate change.

Mountain ecological landscapes are characterised by altitudinal zonation, where organisms tend to be adapted to a relatively narrow range of environmental conditions along the altitudinal gradient. The effects of climate change are consequently particularly pronounced in mountainous regions as shifts in the altitudinal climate envelope are generated. In the context, organisms may adapt, migrate, or go extinct.

Up-slope range shift have been widely observed as a result of climate change, and can be associated with shifts in ectotherms body size, presumably because the conditions encountered are sub-optimal.

One can expect these factors to influence many life history traits at the forefront of colonisation, including growth rates, reproductive output and survival.

We sought to test this hypothesis in a montane colonizer: The Wall lizard, Podarcis muralis. Yet, climate change has allowed these organisms to colonize mountain slope, such as the Pyrenees. In the summer of 2021, we measured Wall lizards along 4 transects from 400 m to 2400 m ASL in the Pyrenees. Our results indicate that male body size decreases with altitude, while this trend was not observed in females. Furthermore, as altitude increases, mean body temp moves away from their preferred temp.

This preliminary study suggests that (1) body size at the colonisation front may be limited by resource availability and a shorter activity period at high altitude, (2) conditions are still sub optimal and (3) further warming will benefit the lizards and favour upslope migration. This will potentially increase pressure on high altitude relict populations of Iberolacerta sps.

A22 EFFECTS OF ACCLIMATION TEMPERATURE AND ACUTE TEMPERATURE SHIFTS ON THE SOCIABILITY OF INDIVIDUAL EUROPEAN MINNOWS Thursday 7th July 2022

POSTER SESSION

Isabelle Valiulis, University of Glasgow, Amelia Munson, University of Glasgow, Daphne Cortese, University of Glasgow, Shaun S. Killen, University of Glasgow bvaliulis@gmail.com Social behaviour is widespread among animal species. Individuals face a tradeoff between the benefits of group living (predation protection, mate availability, foraging opportunities) and the costs (foraging competition, exposure to pathogens). While it is known that individuals consistently vary in their level of sociability, less is known about how

ANNUAL CONFERENCE MONTPELLIER 2022

environmental factors alter the relative costs and benefits of grouping.

We examined whether acclimation temperature and acute temperature changes can modulate the sociability of individual European minnow Phoxinus phoxinus. Minnows (n = 240) were acclimated to one of three temperature treatments (14°, 17° or 20°C) and then were exposed to an acute temperature shift. During the acute temperature shift, individual minnow sociability was measured at 14°, 17° and 20°C using a standard binary choice test. Acclimation temperature did not affect the sociability or spontaneous activity of individuals. Activity increased as the acute temperature shift increased, but this temperature shift had little effect on sociability. Individual social behaviour and activity were highly repeatable across temperature shifts, indicating that variation in sociability and activity was consistent in response to acute temperature changes. These results indicate that the sociability of individual European minnows is largely unaffected by the acclimation temperatures and acute temperature changes examined in this study.

Further work will examine the effects of temperature on group-level behaviours, including group activity level, cohesion, and coordination.

A23 WARMING TOLERANCE IS OXYGENLIMITED IN COLD-ACCLIMATED BUT NOT WARM-ACCLIMATED ZEBRAFISH Wednesday 6th July 2022

POSTER SESSION

Lorena Silva Garay, Norwegian University of Science and Technology (NTNU), Fredrik Jutfelt, Norwegian University of Science and Technology (NTNU), Anna H. Andreassen, Norwegian University of Science and Technology (NTNU), Rasmus Ern, Norwegian University of Science and Technology (NTNU), Marie Reiersen, Norwegian University of Science and Technology (NTNU) lorena.silvagaray@gmail.com The physiological mechanisms responsible for setting the upper thermal limits in fishes have been subject to much debate. Some studies show tissue oxygenation limits thermal tolerance, while others do not, even within species. We hypothesized that some of this discrepancy stems from the temperature the fish are acclimated to. We, therefore, investigated if thermal acclimation affects the mechanism underlying the upper thermal limits (critical thermal maximum, CTmax) of zebrafish (Danio rerio). Zebrafish (N=207) were acclimated to three temperature treatments (20°, 28°, and 34°C) and their CT max was tested at three water oxygen levels (30%, 100%, and 200% air saturation). Predictably, the acclimation temperature strongly affected CTmax. Furthermore, hypoxia reduced the CTmax at all acclimation temperatures. Hyperoxia increased CTmax in cold-acclimated fish but did not affect CTmax at other acclimation temperatures. In a follow-up experiment on only cold-acclimated zebrafish (20°C; N=113), we measured metabolic rates and CTmax at four oxygen saturations (50%, 100%, 150%, and 250% air saturation). Aerobic scope increased with increasing oxygen saturation, suggesting higher tissue oxygenation in hyperoxic water, whereas CTmax increased with oxygen saturation until reaching a plateau at 150%, before declining at 250%. Our results suggest that tissue oxygenation limits the acute thermal tolerance of cold-acclimated zebrafish, but not of warm-acclimated fish. Therefore, acclimation temperature is an important factor to include when investigating the mechanisms limiting upper thermal tolerance in fishes.

SCIENCE ACROSS BOUNDARIES ABSTRACTS 50

A24 FIT MUMS, FIT JUVENILES? MATERNAL EFFECTS OF EXERCISE SWIMMING TRAINING ON THERMAL TOLERANCE IN BROWN TROUT OFFSPRING Thursday 7th July 2022

POSTER SESSION

Luca Pettinau, University of Turku, Tytti Uurasmaa, University of Turku, Jenni M. Prokkola, University of Helsinki, Amélie Crespel, University of Turku, Eila Seppänen, Natural Resources Institute Finland (Luke), Katja Anttila, University of Turku lupett@utu.fi Farming fish for stocking is the most common conservation tool for brown trout (Salmo trutta). However, hatchery fish have often difficulties coping with natural conditions having low survival in the wild. In addition, with the current context of global warming, there is an urgent need to improve the stocking programmes to enhance fish survival.

For example, current brood-stock rearing conditions do not allow fish to display their normal swimming behaviour which negatively affect their cardiorespiratory physiology. As cardiac functions are strongly related to the capacity of fish to handle high temperatures, hatchery reared fish might be especially vulnerable to heat waves, reducing their survival prospects even more. Recent studies have shown that aerobic exercise training can improve cardiac function and cardiac thermal tolerance in farmed fish. However, it is unknown whether the benefits of exercise training might be transmitted to the next generation. Therefore, our aim was to investigate the effects of training on cardiac thermal performance of adult brown trout and test for the occurrence of transgenerational inheritance. We trained the dams with two different water flow conditions: a control program (0.2 bl/s) and exercise training program (0.7 bl/s for 6h per day), and assessed their cardiac thermal performance and reproductive success. Thereafter we examined the survival rate of the offspring at different life stages, as well as the genetic and non-genetic inheritance of thermal tolerance.

By combining these different approaches, this project is providing new insights on the determinants of fish thermal tolerance.

A25 EFFECTS OF ACUTE WARMING ON REPRODUCING AND NON-REPRODUCING POLAR COD (BOREOGADUS SAIDA) Wednesday 6th July 2022

POSTER SESSION

Nicole Vogt, Alfred-Wegener-Institut, Daniela Storch, Alfred-Wegener-Institut, Felizitas C. Wermter, University of Bremen, Hans-Otto Pörtner, Alfred-Wegener-Institut, Christian Bock, Alfred-Wegener-Institut nicole.vogt@awi.de Climate change is causing rapid warming of Arctic regions. The impact of temperature rise on the survival of Arctic marine species such as the keystone species polar cod (Boreogadus saida) depends on the potential acclimatory or evolutionary adjustments of thermal limits in their most sensitive life stages. According to literature data on acute thermal limits differences in thermal preferences suggest

ANNUAL CONFERENCE MONTPELLIER 2022

that reproducing adults are more vulnerable than non-reproducing adults or juveniles, however a cause-and-effect understanding is lacking. An in vivo approach of magnetic resonance imaging (MRI) was used to compare the physiological performance of unanaesthetised, reproducing and non-reproducing polar cod during acute warming.

Individual fish were placed in the MR scanner that was continuously perfused with aerated seawater. Inside the MR scanner, 0°C acclimated polar cod were exposed to acute warming from 0°C to 8,5°C at a rate of 1.5 °C every two hours. A set of specialized MRI techniques was applied to measure physiological performance parameters such as heart rate and monitor the energy status at different temperatures.

At the end of the experiment fish were sacrificed and blood and tissue samples were taken for further analyses.

SCIENCE ACROSS BOUNDARIES ABSTRACTS 51

A27 PREDICTING EMBRYONIC DEVELOPMENT OF A LIZARD IN TROPICAL MOUNTAIN AREAS Wednesday 6th July 2022

POSTER SESSION

Shu-Ping Huang, National Sun Yat-sen University, Jia-Wei Chen, National Sun Yat-sen University, Hao-Chun Fan, National Sun Yat-sen University, Yue-lin Cai, National Sun Yat-sen University, Romain Richard, National Sun Yat-sen University sphuang0711@gmail.com

A26 DIFFERENTIAL EFFECTS OF TEMPERATURE ON THE LIFE HISTORY OF TWO SUBTROPICAL AQUATIC SPECIES FROM DIFFERENT ELEVATIONS IN TAIWAN Thursday 7th July 2022

POSTER SESSION

Romain Richard, National Sun Yat-sen University rrichard03@gmail.com Organisms from different elevations usually have different sensitivity and tolerance to temperature, but these effects may be multifaceted.

For example, different aspects of an individual performance - such as survival and metabolism - may not be equally sensitive, which may affect in a subtle way the life history expressed by individuals and their overall ecological performance. Evaluating the consequences for the ecology of these species requires studying and integrating these effects over the whole lifetime of individuals.

In this study, we used two Daphnia species from different elevations: Daphnia similis, which was collected from lowland, where mean monthly temperatures vary from 18°C to 30°C, and D. sinensis, which was collected at high elevation (2250 m), where temperature varies from 5°C to 16°C. We quantified each species’ lifetime patterns of growth, fecundity and survival at 9 different temperatures, ranging from 10°C to 32°C. Surprisingly, the highest temperature at which each species can achieve reproductive success (i.e. reproduce enough to ensure population persistence) was similar in both species, about 34°C. However, D. sinensis showed clear signs of thermal stress at much lower temperatures (≥ 23°C) than D. similis (≥ 30°C).

Therefore, although persistence of D. sinensis is, in principle, possible for a large range of temperatures, various aspects of this species’ ecology may become impaired before reaching the temperature threshold for persistence. In contrast, increasing temperatures would have lesser consequences for the normal ecological functioning of D. similis, until approaching the persistence boundary. Ultimately, these results suggest that the lowland species D. similis may be more threatened than the high-elevation D. sinensis, as currently experienced temperatures are already much closer to their persistence boundary.

Mountain climate affects reptiles’ physiology and behaviors profoundly, yet how it interacts with vegetation pattern to affect nesting distribution of oviparous lizards is understudied. In order to assess how these variables affect hatching success, we used a combination of laboratory experiments and model simulations to predict the embryo developmental rate of a high-altitude lizard, Takydromus hsuehshanensis, in the field. Data on developmental times of embryos maintained in the laboratory under different fluctuating temperature treatments were used to parameterize a thermal performance curve.

Simulations were then performed with a biophysical NicheMapR model, in order to predict developmental time in various field settings. These simulations predict that potential nesting sites are all located to open, grasslands sites of high elevations, just as observed in the field. The widespread forested areas in our study region are too cold for embryos to develop. Other climatic factors (such as precipitation and fog formation) also play an important role in determining hatching success.

These results suggest that the elevation range of this high-elevation reptile is tightly linked to the temperature landscape associated with vegetation patterns and topography, and have implications for assessing the ecological consequences of climate change and forest alteration.

A144 THE IMPACT OF ACUTE WARMING ON THE RESPIRATORY SYSTEM OF FISH – A COMPARISON OF EELPOUTS FROM ANTARCTICA AND TEMPERATE ZONES Thursday 7th July 2022

POSTER SESSION

Nina Krebs, Alfred-Wegener-Institut, Hans-Otto Pörtner, Alfred-Wegener-Institute, Jan Tebben, Alfred-Wegener-Institute, Felix C. Mark, Alfred-Wegener-Institute, Magnus Lucassen, Alfred-Wegener-Institute, Gisela Lannig, Alfred-Wegener-Institute, Christian Bock, Alfred-Wegener-Institute Nina.krebs@awi.de Testing how evolutionary cold adaptation affects metabolism and performance of fish we compared the acute responses to warming of the stenothermal Antarctic eelpout Pachycara brachycephalum and of the eurythermal common eelpout Zoarces viviparus from the North Sea. We investigated whole animal oxygen consumption rate and ammonia excretion. As excretion of ammonia via the gills reflects whole animal metabolic patterns, especially nitrogen and amino acid metabolism, we also investigated the temperature dependent protein synthesis rate of gills in vivo and connected it to respiration and ammonia excretion.

ANNUAL CONFERENCE MONTPELLIER 2022

Both species were exposed to temperature changes within their species-specific thermal window: P. brachycephalum -acclimated to 0°C- at a rate of 2°C day-1 until 10°C, and Z. viviparus - acclimated to 4°C - at a rate of 3°C day-1 until 22°C. Once temperature stabilized (within 12 hours), oxygen consumption rates were measured repeatedly and water samples were taken to determine the ammonia excretion of each fish individually. In a parallel experiment, we investigated the temperature dependent protein synthesis rate (Ks) of gills after intraperitoneal injections of 13C-labeled phenylalanine. The gill tissue was sampled 1.5 and 3 hours after the injection.

All measured parameters followed an exponential increase with warming for both species, however, with different Q10 values (e.g.

Q10 protein synthesis rate P. brachycephalum 4.2 vs. 2.8 Z. viviparus).

Protein synthesis rates at the same temperatures were similar in both species (P. brachycephalum vs. Z. viviparus: 4°C Ks= 2.5 vs. 2.6 % day-1; 10°C Ks= 4.5 vs. 4.3% day-1) indicating no cold compensation regarding protein synthesis in gills of the Antarctic eelpout. It will be discussed how these results are related to oxygen uptake and ammonia excretion.

A148 SOCIAL NETWORK ANALYSIS ON THE EFFECTS OF TEMPERATURE ON THE SOCIAL DYNAMICS OF CORYDORAS AENEUS Thursday 7th July 2022

POSTER SESSION

Adrienne Amri, University of Glasgow, Shaun Killen, University of Glasgow, Nicola Herlihy, University of Glasgow, Daphne Cortese, University of Glasgow, Amelia Munson, University of Glasgow adrienne.amri@gmail.com For group-living species, the benefits of being in a group are often not shared equally among group members, sometimes causing non-random assortment within the aggregation. Networks of social interactions among group members can vary depending on individual phenotypes and environmental conditions. In the wild, many ectothermic species live in groups and experience temperature fluctuations, yet we still lack knowledge of how temperature affects social networks in ectotherms.

We studied how temperature affects social network structure in groups of bronze Corydoras Corydoras aeneus, an Amazonian armoured catfish that lives in groups and displays various forms of complex social behaviour. Groups of 30 fish were held in large mesocosms at either 24°C and 28°C ambient temperature. Individuals were tagged for identification and observed for social interactions and social network structure. Groups at the cooler temperature showed increased levels of interactions among individual group mates and altered centrality relative to groups at the warmer temperature. These findings indicate temperature is an important abiotic factor driving social network structure in this species. Reduced group cohesion in warmer water temperatures may lead to altered group dynamics, causing cascading effects on predation, disease, and information transfer.

A149 DEVELOPMENTAL RESPONSES TO THERMAL STRESS IN THE STARLET SEA ANEMONE

SCIENCE ACROSS BOUNDARIES ABSTRACTS 52

Wednesday 6th July 2022

POSTER SESSION

Diego Yusta Belsham, Queen’s University, Alexander G. Little, Queen’s University dayusta@gmail.com Many ectotherms can optimize their physiology during development to match current or future environments (developmental plasticity) and there is often variation in the capacity for plasticity between individuals and populations. However, the degree to which developmental stochasticity contributes to this variation is not well understood. This is important because developmental instability may limit an individual’s ability to match their physiology to the environment. Here, I cloned 18 genotypes of the model organism Nematostella vectensis (starlet sea anemone) to test variation in developmentally plastic phenotypes both within and between individuals. Specifically, I analyzed the repeatability of developmentally plastic phenotypes by developing three clones per genotype (N=18) at each of three developmental temperatures (13°C, 21°C, and 29°C); 162 clones total. I hypothesized that genotypes would vary in their capacity for plasticity and that more plastic genotypes would have greater developmental stability at the thermal extremes.

Our results suggest that within-individual variation in developmental rate is low at 29°C and high at 13° and 21°C — especially relative to inter-individual variation. Our preliminary results also suggest that metabolic rate it is a more repeatable trait than developmental rate.

This variation is interesting because it may represent limitations in regulatory processes during development or variation in ecological strategies to overcome environmental stress (e.g., diversified bethedging). Further analyses will leverage this dataset to test for potential costs or trade-offs associated with plasticity.

A151 HYPOXIA LOWERS CARDIAC THERMAL LIMITS IN A MARINE TELEOST (GIRELLA NIGRICANS) Wednesday 6th July 2022

POSTER SESSION

Gail Schwieterman, University of California, Santa Barbara, Emily A. Hardison, University of California, Santa Barbara, Georgina K. Cox, Washington State University, Jacey Van Wert, University of California Santa Barbara, Kim Birnie-Gauvin, National Institute of Aquatic Resources, Technical University of Denmark, Erika J. Eliason, University of California, Santa Barbara gschwiet1@gmail.com Understanding the mechanisms determining these limits is, therefore, essential in our general understanding of thermal tolerance of ectotherms. It has been put forth that oxygen limits cardiac performance at high temperatures, although this has rarely been explicitly or thoroughly tested. It has also been suggested that hyperkalemia may negatively impact cardiac function under elevated temperatures.

We hypothesized that low environmental oxygen and elevated blood [K+] would reduce the upper thermal limits of the heart in a marine teleost (Girella nigricans). Using the Arrhenius Breakpoint Temperature Test, we assessed fish (n=12 per treatment) under hyperoxic (200% air saturation), normoxic (100% air saturation), and hypoxic (20% air saturation) conditions under a range of plasma [K+]. We also measured ventricle lactate content and venous blood oxygen pressure (PO2) to determine if there were common critical points in these metrics driving cardiac collapse. We found significant differences in cardiac

ANNUAL CONFERENCE MONTPELLIER 2022

upper thermal limits (Arrhenius breakpoint temperature [TABT], peak maximum heart rate (peak fHmax], temperature of peak heart rate [Tpeak], and temperature at which the heart becomes arrhythmic [TARR]) in fish exposed to hypoxia during the trial compared to those exposed to normoxia or hyperoxia. We also found significantly higher ventricular lactate content in fish exposed to hypoxia. Elevated [K+] may be correlated with decreases in TABT, but there were no other significant correlations. These results suggest that oxygen limitation can drive cardiac collapse at high temperatures.

A152 EFFECTS OF TEMPERATURE ACCLIMATION ON THERMAL PERFORMANCE FOR SEA LAMPREY LARVAE Thursday 7th July 2022

POSTER SESSION

Hugo Flávio, Wilfrid Laurier University, Milica Koledin, Wilfrid Laurier University, Michael Wilkie, Wilfrid Laurier University

SCIENCE ACROSS BOUNDARIES ABSTRACTS 53

function caused by a spreading depolarization (SD) event which is characterized by a rapid surge in extracellular K+ concentration. This neurophysiological limit to performance is, however, not static and most insects are capable of altering the SD-inducing temperature through acclimation. Here we use Drosophila melanogaster to investigate how acclimation alters the temperature leading to cold-induced SD and whether this plasticity relates to expression voltage-gated K+ channels in the brain. After confirming that cold-acclimated flies experience SD at lower temperatures, we investigated the role of voltage-gated K+ channels in driving the difference between acclimation groups by injecting the inhibitor 4-aminopyridine and compared this to the effect of a general K+ channel inhibitor (tetraethylammonium).

Blocking voltage-gated K+ channels increased the SD temperature in both cold- and warm-acclimated flies. This effect was smaller in warm-acclimated flies, but in both groups it represented a large proportion of the effect of general K+ channel blockade, indicating that the acclimation-induced differences in SD temperature were largely related to voltage-gated channels. This is supported by a UASGal4-mediated glial knock-down screen showing that knockdown of channels encoded by the seizure and shaw genes had similar, albeit smaller, effects compared to the pharmacological blockade. Thus, differential expression of voltage-gated K+ channels represents a key mechanism by which flies are able to alter their thermal tolerance to match the environment.

hflavio@wlu.ca Sea lamprey (Petromyzon marinus) invaded the Laurentian Great Lakes in the early 20th century and remain a threat to fisheries in the largest freshwater ecosystem of the world. Nowadays, population growth is restrained by a highly successful control program that mainly relies on the application of the lampricide 3-trifluoromethyl-4’-nitrophenol (TFM) to streams infested with larval sea lamprey. Recent work shows that the effectiveness of TFM is affected by temperature, with the toxicity to larval sea lamprey decreasing with increasing temperature.

As such, we set out to unveil the thermal breadth of larval sea lamprey using intermittent-flow respirometry. To do so, we calculated thermal performance curves for this life stage using two approaches: First, we acclimated larvae to 7, 13, 18, 21, 25 and 28°C and tested their aerobic scope at the respective acclimation temperature. Second, we acclimated larvae to 6, 13 and 21°C and subsequently performed acute exposure tests (6, 10, 13, 15, 18, 21, 25, 28 and 31°C), with a temperature increase/decrease rate of approx. 0.1°C/min. Our results show a wide thermal tolerance, consistent with the plasticity required to become a successful invasive species. Further, sea lamprey larvae show a thermal optimum nearing 28°C, indicating that their tolerance to TFM will likely continue to increase as water temperatures in the Great Lakes continue to rise due to climate change.

A154 GLIAL EXPRESSION OF VOLTAGEGATED K+ CHANNELS MODULATES THE DROSOPHILA CRITICAL THERMAL MINIMUM Thursday 7th July 2022

POSTER SESSION

Mads Kuhlmann Andersen, Carleton University, Heath MacMillan, Carleton University mads.andersen@carleton.ca At the critical thermal limits, animals experience a general loss of function which often manifests as a paralytic or coma-like phenotype.

In insects, this has been attributed to a loss of central nervous

A156 INVESTIGATION INTO THE EFFECT OF TEMPERATURE ON SOCIAL FORAGING IN CORYDORAS AENEUS Thursday 7th July 2022

POSTER SESSION

Nicola Herlihy, University of Glasgow, Adrienne Amri, University of Glasgow, Daphne Cortese, University of Glasgow, Amelia Munson, University of Glasgow, Shaun Killen, University of Glasgow nicola_herlihy@hotmail.co.uk While group-living can increase foraging efficiency and feeding consistency, individual variation in behaviour can cause disparity in food intake among groupmates. For example, bolder individuals may secure more food if they are more exploratory or are willing to take risks to obtain food items. Temperature variation may further modulate phenotypic variation among groupmates and alter levels of feeding disparity within groups.

We examined the effects of ambient temperature on group foraging in a social catfish, the bronze corydoras (Corydoras aeneus). Groups of 30 fish were placed within large mesocosms and were observed for feeding behaviour at both of 24°C or 28°C, with at least two weeks acclimation to each temperature. Feeding behaviour among individuals within groups was highly repeatably, with the same individuals being consistently first to feed when presented with food items, even when the same groups were tested across temperatures (R = 0.467). Temperature increased group activity and feeding rate, with groups finding food quicker at the warmer temperature, even though groups were more cohesive (individuals closer together) at the cooler temperature. Together, these data highlight individual variation within a group foraging context, whereby specific individuals are more successful at securing food than their groupmates. This will have implications for the relative costs and benefits of group membership for individuals.

ANNUAL CONFERENCE MONTPELLIER 2022

SCIENCE ACROSS BOUNDARIES ABSTRACTS 54

A9 - ANIMAL PERFORMANCE IN RESPONSE TO VARYING DIET QUALITY AND QUANTITY: TRADEOFFS BETWEEN EFFICIENCY AND CAPACITY

ANNUAL CONFERENCE MONTPELLIER 2022

A65 FASTING IN WINTER-DORMANT FISH IS A BEHAVIOURAL RESPONSE RATHER THAN A CONSEQUENCE OF CONSTRAINTS OF COLD ON DIGESTION AND GROWTH Tuesday 5th July 2022

10:15am-10:30am

Lauren Rowsey, University of New Brunswick Saint John, Melina Watson, University of New Brunswick, Saint John, Ben Speers-Roesch, University of New Brunswick, Saint John lrowsey@unb.ca

ORGANISED BY: RACHAEL L. MORGAN (UNIVERSITY OF BERGEN), DARRYL MCLENNAN (UNIVERSITY OF GLASGOW), NEAL DAWSON (UNIVERSITY OF GLASGOW), AGNIESZKA MAGIERECKA (UNIVERSITY OF GLASGOW) A62 DIET EFFECTS ON ACCLIMATION RATE AND CAPACITY FOR MAXIMUM HEART RATE IN A TEMPERATE FISH (GIRELLA NIGRICANS) Tuesday 5th July 2022

A63 ENERGY ASSIMILATION AND ALLOCATION BY YOUNG-OF-YEAR LAKE STURGEON Tuesday 5th July 2022

14:30pm-14:45pm

09:30am-09:45am

Emily Hardison, University of California, Santa Barbara, Gail D. Schwieterman, University of California, Santa Barbara, Erika J. Eliason, University of California, Santa Barbara emilyhardison@ucsb.edu Thermal acclimation is a mechanism that ectotherms use to maintain performance across a range of temperatures. In variable environments, acclimating quickly may be as important as acclimation capacity.

The phenotypic changes comprising acclimation require energy and nutrients that ectotherms obtain from their diet. Thus, diet may be a critical factor determining acclimation rate and capacity. Using a temperate omnivorous fish, opaleye (Girella nigricans), we tested the hypotheses that diet can impact thermal acclimation rate and capacity for cardiac performance. We offered juvenile opaleye an ad-lib herbivorous (algae), carnivorous (shrimp), or omnivorous (algae and shrimp) diet for two weeks at 12°C and measured the thermal performance curve (TPC) for maximum heart rate (fHmax) and cardiac thermal limits. Next, we raised the temperature in the holding tanks from 12 to 20ºC, mimicking an abrupt heatwave, and independently sampled fish on days 1, 3, 7, and 14 post-temperature change using the same cardiac test. Acclimation capacity for fHmax was sensitive to diet, with the herbivorous treatment displaying the smallest change in fHmax. However, acclimation rate and all cardiac thermal limits were insensitive to diet, with >60% of acclimation capacity occurring in the first 3 days at 20°C. Our results indicate that for generalist species, like opaleye, variation in diet is an important determinant of thermal performance on environmentally relevant timescales. Our findings also add to growing evidence that it is essential to integrate acclimation time into our predictions of species responses to temperature change.

Janet Genz, University of West Georgia, Rachael Hicks, University of West Georgia, Afroza Naznin, The Ohio State University jgenz@westga.edu Lake sturgeon (Acipenser fulvescens) were used as a model organism in recent studies to investigate how diet utilization is related to increased ambient temperature or ionoregulatory burden in youngof-year juveniles. Shifts in metabolism and available nutrition during stocking are hypothesized to impact the survival of hatchery-reared fingerlings, and the potential for reintroduction and conservation of this species. While temperature did not influence overall growth following initiation of exogenous feeding, more subtle changes in energy use were detected in juveniles. Compared to 15℃, fingerlings at 21℃ demonstrated a reduction in energy stores (triglycerides) and condition factor, indicating increased acute energy demand to maintain higher metabolic rates. Furthermore, rearing at higher temperatures results in less resilience to acute thermal stress in stocking-size juveniles.

Larval growth was reduced in response to the decreased availability of [Ca2+] and increased [Na+], [Mg2+], and [Zn2+] in natural river water. Juvenile sturgeon exposed to river water for 3 weeks displayed no differences in growth, but did have more efficient FCR at 10 and 21 days post- transfer. Differences in nutrient absorption in response to ionic composition of the ambient water suggests that environmental ion availability influences intestinal function. Older juveniles absorb nutrients similarly to fingerlings, but the composition of wild diets may impact overall energetic status post-stocking. Physiological changes to nutritional absorption and energy allocation in lake sturgeon at the time of stocking, paired with shifts in nutrient availability, may have impacts on survival and thus the effectiveness of stocking programs for population recovery.

The cold of temperate winters slows, and may constrain, ectotherm physiology. Yet many fish species remain active in the winter, with continued performance facilitated by physiological compensation.

Conversely, certain species (e.g., cunner, Tautogolabrus adspersus) enter winter dormancy – an energy-savings strategy characterized by inactivity, fasting, and slow metabolism – which allows them to endure frigid, food-poor winters and persist at poleward latitudes.

We hypothesized that winter dormancy is a consequence of severe constraints on digestion and growth in the cold, which make it inefficient to remain active and feeding. Cunner become dormant below ~7.5°C, so we predicted negative growth and zero feeding below ~7.5°C even when provided food. In voluntarily feeding fish acclimated to 15, 9, or 3°C, daily food consumption and specific growth rates decreased significantly with declining temperature, and dormant fish at 3°C had near-zero feeding rates with negative growth.

We then repeated this experiment with force-feeding 1% body weight every third day of acclimation to determine if fasting and weight loss results from physiological constraints of cold on digestion and growth processes. Contrary to our hypothesis, force-fed cunner showed positive growth at 3°C, indicating that the fasting, inactive, and non-foraging phenotype characteristic of dormancy is a behavioural response rather than a consequence of intrinsic physiological constraints. We are currently analyzing specific dynamic action. Our findings are consistent with an overarching conclusion emerging from our work on cunner: physiological performance is not severely constrained by cold in winter-dormant fishes, and ecological factors are more likely to be driving winter dormancy.

A67 RELATION BETWEEN FATTY ACID PROFILE, GROWTH RATE AND CONDITION FACTOR USING A NONLETHAL SAMPLING METHOD IN EUROPEAN SEA BASS Tuesday 5th July 2022

10:00am-10:15am

Mickaël Peron, Université de Bretagne Occidentale, JeanBaptiste Quéméneur, Ifremer, Victor Simon, Ifremer, Romain Gonzalvez, Université de Bretagne Occidentale, Fabienne Le Grand, Université de Bretagne Occidentale, David Mazurais, Ifremer, Philippe Soudant, CNRS, Marie Vagner, CNRS mickael.peron@univ-brest.fr In several organisms including fish, lipids are the most efficient source of energy compared to other nutrients. Some fatty acids (e.g. oleic acid, palmitic acid) are known to be preferentially used by organisms to

SCIENCE ACROSS BOUNDARIES ABSTRACTS 55

create or to store energy. Here, we aimed to understand the relationship between FA profile, individual growth performance and well-being of European sea bass (Dicentrarchus labrax). For that, we coupled the measurements of growth rate and Fulton’s condition factor (K), both widely used to estimate growth and the well-being of a fish, to an innovative non-lethal sampling method for FA analysis that allows us to measure the evolution of the fatty acid profile individually.

Eighteen tagged sea bass juveniles were reared during 130 days in the same food and temperature conditions, in triplicate. White muscle subcutaneous biopsy was carried out on each fish at day 0 and day 130 for FA analysis. Fish were weighted and measured to calculate growth rate (Thermal Growth Coefficient, TGC) and K at d0 and d130. The fatty acid profiles of the three best and lowest performing fish (TGC related) were compared. The two biopsies performed over the 130 days induced no mortality. All the fish had positive TGC and showed an increase in K (1.01 ±0.15 at d0; 1.20 ±0.12 at d130). The results will be discussed trying to establish a link between FA, TGC and K, on an individual scale.

A68 WHY SOME FISH GROW FASTER THAN OTHERS: EXAMINING THE INTERPLAY BETWEEN METABOLIC PHENOTYPE, PREDATOR THREAT AND GROWTH PERFORMANCE Tuesday 5th July 2022

09:45am-10:00am

Timothy Clark, Deakin University timothy.clark.mail@gmail.com All animals must acquire food for energy, but there is a vast diversity in how different species and even different individuals approach this task.

Individuals within a species appear to fall along a bold-shy continuum, whereby some fish acquire food aggressively and with seemingly high risk, while others appear more opportunistic and cautious. Greater food consumption generally results in faster growth, but only if the energy acquired through food is more than enough to compensate for heightened metabolism associated with a more active lifestyle. Fastgrowing phenotypes also tend to have elevated baseline metabolism – at least when food is plentiful – which further complicates the link between food consumption and growth. The net energy gained from a meal (as calculated from the specific dynamic action (SDA) coefficient) is optimised with larger meal sizes, but the digestion of large meals can erode the aerobic metabolic scope available for other critical activities such as predator avoidance. Thus, it is expected that fish in predator-rich habitats should regulate meal sizes to maximise growth efficiency without dangerously compromising aerobic capacity, and this balance may differ between individual metabolic phenotypes.

This presentation will discuss these complicated interplays with a goal to better understand what drives intraspecific differences in growth performance.

ANNUAL CONFERENCE MONTPELLIER 2022

A69 FLIGHT TESTING NATURAL DOPING: INFLUENCE OF DIETARY N-3 LONG CHAIN POLYUNSATURATED FATTY ACIDS ON MIGRATORY PERFORMANCE IN WESTERN SANDPIPERS Tuesday 5th July 2022

14:45pm-15:15pm

Morag Dick, Western University, Sara Lupi, Western University, Kevin G. Young, Western University, Keith Hobson, Western University, Christopher G. Guglielmo, Western University mdick23@uwo.ca Migratory flight requires birds to sustain high levels of energy expenditure, fueled almost exclusively by fat, for prolonged periods of time. Beyond fueling flight, the types of dietary fatty acids may influence performance. The natural doping hypothesis proposes that shorebirds feed on diets rich in essential n-3 long chain polyunsaturated fatty acids (LCPUFA), which help prime the flight muscles for endurance flight by enhancing membrane fludity, promoting rapid fatty acid transport, and activating cellular signalling pathways to increase aerobic and fatty acid oxidation capacity. We fed western sandpipers (Calidris mauri) formulated diets low or high in n-3 LCPUFA (EPA and DHA) and flew them for up to 8 hours in a wind tunnel to assess endurance flight performance. We found that a diet high in n-3 LCPUFA decreased flight energy expenditure by 12%. Activities of key oxidative enzymes, citrate synthase and carnitine palmitoyl transferase were significantly greater in the flight muscles of birds fed the n-3 LCPUFA enriched diet, and we are investigating further effects on the regulation of lipid metabolism and oxidative capacity. In addition, we present evidence for limited capacity for endogenous synthesis of n-3 LCPUFA from precursor fatty acids, suggesting an essential dietary requirement for n-3 LCPUFA. These findings support the natural doping hypothesis by demonstrating performance-enhancing effects at the biochemical and whole animal level, and they indicate a critical role of dietary n-3 LCPUFA during migration for shorebirds.

A70 MITOCHONDRIAL RESPONSES TO VARYING DIET QUALITY AND QUANTITY: SHIFT IN METABOLIC EFFICIENCY AND CAPACITY Tuesday 5th July 2022

09:00am-09:30am

Karine Salin, IFREMER, Sonya K. Auer, Williams College, Margaux Mathieu-Resuge, IFREMER, Neil B. Metcalfe, University of Glasgow, Marie Vagner, CNRS karine.salin@ifremer.fr Many animals experience periods of reduction in food quality and quantity. Metabolic responses of animals to periods of reduction in crucial nutrient and food deprivation may have positive and negative impacts on the animal performance. I will present results on the mitochondrial responses to reduction in omega-3 dietary availability in a marine fish, golden grey mullet (Chelon auratus) and naturallyoccurring periods of food deprivation in brown trout (Salmo trutta).

We show that mitochondria of fish fed on the low omega 3 highly

SCIENCE ACROSS BOUNDARIES ABSTRACTS 56

unsaturated fatty acids (n-3 HUFA) diet had higher mitochondrial efficiency than those of fish maintained on the high n-3 HUFA diet. Yet, mitochondrial efficiency varied up about 2-fold among individuals on the same dietary treatment, resulting in some fish consuming half the oxygen and energy substrate to produce the similar amount of ATP than conspecific on similar diet.

In another study, after a 2-week period of fasting, brown trout increased their oxidative phosphorylation (OXPHOS) respiration and decreased proton leakage (LEAK) respiration, suggesting a selective increase in the capacity to produce ATP without a concomitant increase in energy dissipated through proton leakage. However, this was associated with an almost two-fold increase in mitochondrial H2O2 levels.

Our results emphasize that (i) shift in energy metabolism in response to food change may help preserve limited resources but potentially come at a cost of increased oxidative stress; (ii) individual variation in mitochondrial efficiency may explain intraspecific variation in response to food changes.

A71 WHEN NUTRIENTS ARE ABLE TO PREVENT GLUCOCORTICOID-INDUCED TELOMERE ATTRITION Tuesday 5th July 2022

10:30am-11:00am

Stefania Casagrande, Max Planck Institute for Ornithology Biological Intelligence, scasagrande@orn.mpg.de Telomeres are chromosome protections that can shorten at each cell replication and in stressful conditions. Developing individuals are particularly exposed to telomere erosion when growth rate is fast and resources are limited. This is crucial because the rate of telomere attrition in early life is linked to health condition and life span. Telomeres can respond - and be part - of metabolic adjustments triggered by biochemical signals. Among these signals are glucocorticoids, hormones secreted in energetically stressful conditions. They promote catabolic processes that often run at the expense of telomere maintenance. A contrasting signalling function can be played by specific nutrients that are known to promote anabolic states. How telomere dynamics is regulated in the presence of two contrasting signals, one promoting telomere maintenance and the other attrition, has not been specifically addressed, while it could clarify the context-dependent telomere shortening effect of stress exposure. During the talk I will present what found in nestlings of a rapidly developing free-living passerine that received glucocorticoids or a mixture of glucocorticoids and specific nutrients. By measuring mitochondria aerobic metabolism, gene expression of telomere-related pathways and oxidative stress, I will discuss the physiological processes that could explain why nestlings treated only with glucocorticoids showed telomere attrition, while birds treated also with nutrients, did not, highlighting determinants of telomere maintenance in stressful conditions.

ANNUAL CONFERENCE MONTPELLIER 2022

A72 EFFECTS OF FEEDING ON THE ENERGETICS OF TORPOR IN HIBERNATING SPECIES 14:00pm-14:30pm

Tuesday 5th July 2022

Sylvain Giroud, Research Institute of Wildlife Ecology sylvain.giroud@vetmeduni.ac.at Torpor is a state of active metabolic depression associated with a decrease of body temperature that enables individuals to save energy to cope with environmental fluctuations. Heterothermic species can use short, daily bouts of torpor during the active season, e.g., for young individuals to sustain processes of growth, development and pre-hibernation fattening. Hibernators can also employ torpor bouts lasting several days, weeks or months, called hibernation, to survive long winters with no or little food available. Feeding can affect the use of torpor and the seasonal expression of hibernation. For instance, reduced food availability facilitates the use of torpor, which in turn can increase nutrient assimilation during euthermic phases. Also, various proportions of omega fatty acids modulate hibernation onset and impacts hibernation performances, notably the duration and depth of torpor bouts, during the winter. Saturated fatty acids ensure the optimal fuelling of hibernation, while some unsaturated fatty acids regulate oxidative and metabolic functions including the proper functioning of the heart, a key organ to maintain the activity during deep torpor.

Further, contrasted torpor and hibernating patterns, resulting from feeding regimes that differ in terms of food quantity and/or quality, can lead to contrasted life-history strategies and impacts on somatic maintenance, survival and longevity. In this talk, I will present evidence for effects of feeding on the seasonal regulations of the expression of torpor and hibernation as strategies affecting the survival and lifehistory traits of individuals from hibernating species.

POSTER SESSION A59 PHYSIOLOGY AND FEEDING STRATEGIES OF BERGHIA STEPHANIEAE (NUDIBRANCHIA: AEOLIDIODEA) Wednesday 6th July 2022

POSTER SESSION

Eléa Giraud, Institute of Marine Sciences, University of Portsmouth, Simon Cragg, University of Portsmouth elea.giraud@port.ac.uk Berghia stephanieae is a small nudibranch of th e aeolid family, known to feed voraciously on the anemone Aiptasia pallida, a common pest in tropical aquaria. Berghia is sold in the aquarium trade for anemone density control. Though well documented in the aquarium context, studies on Berghia-Aipatsia interactions in the natural environment are more scarce. Being a specialised predator (as are most nudibranchs) that feeds exclusively on A. pallida, it is unclear how both species can coexist in the natural environment without B. stephanieae causing local extirpation of its prey. Building on the discovery of kleptopredation

SCIENCE ACROSS BOUNDARIES ABSTRACTS 57

in 2017 in the aeolid nudibranch Cratena peregrina, the current research investigates the possibility of this mechanism being used by other nudibranch species, here B. stephanieae. C. peregrina is a highly specialised predator known to feed exclusively on hydroid E. racemosum polyp, yet half of their diet was found to consist of planktonic prey acquired through kleptopredation. The current research investigates the feeding strategy of B. stephanieae, and the possibility of kleptopredation. B. stephanieae were reared and fed in the laboratory with either kleptopredation treatment (recently-fed anemones) or control diet treatment (unfed anemones). Their physiology was studied over time under each treatment conditions, to assess the possible benefits of kleptopredation on the energy budget. Preliminary results suggest kleptopredation is exhibited by Berghia stephanieae. Growth, spawning, and respiration measurements show that this feeding strategy could provide energetic benefit to the nudibranch predator by allowing more energy to be invested in growth and reproduction.

A60 PERFORMANCE OF SCORPION VENOM SECRETION IN RESPONSE TO DIFFERENT CAPTIVE CONDITIONS: DIET, TEMPERATURE AND HUMIDITY ON DIFFERENT GENERA OF SCORPIONS Thursday 7th July 2022

POSTER SESSION

Mouad Mkamel, Hassan II University of Casablanca contact@mkamelmouad.com Scorpion venoms contain different types of proteins, peptides, and molecules that can be used against predators or to immobilize prey.

Toxins of venom are used for pharmaceutical purposes that require maintaining scorpions in captivity as long as possible for venom extraction purposes.

In this survey, four scorpion species from four genera; Androctonus, Buthus, Hottentotta, and Scorpio, were put in environments that vary in three variables: Diet, Temperature, Humidity. And it Was conducted to discover the influence of the captivity conditions on the venom quantity. During this research, we aim to explore these interactions, to optimize captivity conditions for more venom secretion efficiency.

In the Light of this study, the results are very promising. This proves the huge impact of the environment on the scorpions. It could be the main key to studying other species or other venomous animals.

A64 EFFECTS OF EARLY-LIFE CONDITIONS ON AGE-RELATED FLIGHT PERFORMANCE IN NICROPHORUS VESPILLOIDES Thursday 7th July 2022

POSTER SESSION

Kynan Delaney, University of Edinburgh, Jacob Moorad, Institute of Evolutionary Biology, University of Edinburgh kynan.delaney@ed.ac.uk Early-life conditions are important in shaping variation in individual quality and rates of ageing. Our understanding of this relationship

ANNUAL CONFERENCE MONTPELLIER 2022

between early-life conditions and late-life outcomes is particularly lacking in the context of age-related functional declines, which are often overlooked in favour of age-specific mortality and reproduction.

Flight is a metabolically costly trait in insects and is closely associated with fitness in wild burying beetle populations, including Nicrophorus vespilloides. Therefore, flight represents an interesting avenue along which to examine ageing in an expensive functional trait that is closely related to fitness. We manipulated early-life environments through adjusting food availability to explore the role early-life-environments play in shaping lifespan and ageing in flight. Preliminary results find that individuals from higher quality early-life environments (abundance of food) exhibited superior peak flight-speed that was maintained across all assayed ages (10-99 days old). Peak flight speed was seen to decline only in the oldest-aged beetles (90+ days old), an age-range which exceeds that of most studies of ageing performed on this species .

However, poorer-quality early-life environments (dearth of food) was associated with increased survival in later life. Beetles displayed a decreased propensity to fly at increasing ages, but no accompanying decrease in time spent in flight was detected . We show that highquality early-life environments can contribute to improved measures of peak flight performance but have a less pronounced role in shaping patterns of age-related declines in flight. Furthermore, these early-life benefits may also be associated with reduced adult lifespan.

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A66 EFFECTS OF DIFFERENT SIZES AND QUANTITIES OF FOOD ON THE N-3 HIGHLY UNSATURATED FATTY ACID CONTENT OF SARDINE MUSCLE Thursday 7th July 2022

POSTER SESSION

Mathilde Bertrand, Université de Bretagne Occidentale, Quentin Queiros, Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Fabienne Le Grand, Laboratoire Environnement Marin (LEMAR), UMR 6539 IFREMER, Université de Bretagne Occidentale, CNRS, IRD, Claire Saraux, Institut Pluridisciplinaire Hubert Curien (IPHC), UMR 7178, CNRSUDS, Philippe Soudant, Laboratoire Environnement Marin (LEMAR), UMR 6539 IFREMER, Université de Bretagne Occidentale, CNRS, IRD , Marie Vagner, Laboratoire Environnement Marin (LEMAR), UMR 6539 IFREMER, Université de Bretagne Occidentale, CNRS, IRD Mathilde.Bertrand@univ-brest.fr Small pelagic fish play important ecological and economic roles.

However, a reduction in the size and body condition index of sardines (Sardina pilchardus) has been recorded in the Gulf of Lions since 2008 and in the Bay of Biscay since 2012. A recent experiment showed that the growth and body condition of sardines were (i) an immediate response to food quantity and pellet size and (ii) optimal when sardines consumed large amount of large pellets. Knowing that sardines' prey are rich in n-3 highly unsaturated fatty acids (n-3 HUFA), we hypothesise that small pellets and/or small quantities of food would not meet the n-3 HUFA requirements for an optimal growth of sardines. The objective is to investigate food size/quantity effects on n-3 HUFA’ thresholds.

For this, we measured n-3 HUFA content, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in muscle from sardines (n=30 individuals/condition) previously conditioned for seven months to four different feeding conditions: small or large pellets (0.1 vs.

1.2 mm) in small or large quantities (0.3 vs. 0.6% of fish mass). A preferential retention of DHA and EPA seems to take place in polar lipids whatever the diet, unlike neutral lipids. In neutral lipids, sardines fed with small pellets in small quantities have the highest DHA/EPA ratio and DHA percentage over total fatty acids, while those fed with large pellets in large quantities have the lowest values. Fatty acid analysis will ultimately contribute to better estimate the impacts of prey quantity and quality on the population dynamics.

ANNUAL CONFERENCE MONTPELLIER 2022

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A10 - THE EVOLUTIONARY SIGNIFICANCE OF VARIATION IN METABOLIC RATE ORGANISED BY: AMANDA K. PETTERSEN (THE UNIVERSITY OF SYDNEY) A374 THE EVOLUTIONARY IMPACT OF HARVESTING SELECTION AND POPULATION DENSITY ON FISH METABOLIC RATE AND ASSOCIATED TRAITS Wednesday 6th July 2022

09:30am-09:45am

Amélie Crespel, University of Turku, Shaun S. Killen, University of Glasgow, Anita Rácz, University of Glasgow, Kevin Parsons, University of Glasgow, Jan Lindström, University of Glasgow amelie.crespel@gmail.com The selective harvest of individuals from wild populations constitutes one of the strongest and most widespread human-induced evolutionary pressures for natural populations. In addition to imposing strong selection on potentially heritable fitness traits, intensive harvest could also cause environmental changes in targeted population, such as a reduction in the population density, which could in turn affect the evolutionary potential of the traits in the populations. As metabolic rate is related to many of the biological functions in animals, interacting with growth, movements, and behaviour, selection on this trait could have important repercussions for wild populations. Using wild zebrafish as model species reared at two densities, and simulated trawling fishing pressure as selective harvest, we investigated the potential for harvestinduced evolution on metabolic rate and associated traits (growth, swimming, risk taking behaviour). We showed consistent capture of fish with lower metabolic rate, slower growth and slower swimming, regardless of density. As these traits had significant heritability, such harvest could lead to evolution of the populations over time. However, even though metabolic rate was phenotypically correlated to the other traits, no genetic correlations were observed between metabolic rate and either growth or swimming. Therefore, selection on metabolic rate is unlikely to induce indirect selection on the other traits and vice versa. The potential evolution of metabolic rate, growth and swimming under harvest would thus be more the result of independent direct selection on each trait rather than correlated selection.

A377 INTERINDIVIDUAL VARIATION IN MAXIMUM AEROBIC METABOLISM VARIES WITH GILL MORPHOLOGY AND MYOCARDIAL BIOENERGETICS Wednesday 6th July 2022

10:15am-10:30am

Bernard Rees, University of New Orleans, Jessica E. Reemeyer, McGill University, Brian A. Irving, Louisiana State University brees@uno.edu This study asked whether interindividual variation in maximum and standard aerobic metabolic rates of the Gulf killifish, Fundulus grandis, held under common garden conditions correlate with gill morphology and cardiac mitochondrial bioenergetics, traits reflecting critical steps in the oxygen-supply cascade from the environment to the tissues.

Maximum metabolic rate (MMR) was positively related to body mass, total gill filament length, and myocardial oxygen consumption during maximum oxidative phosphorylation (multiple R2 = 0.82). Standard metabolic rate (SMR) was positively related to body mass, total gill filament length, and myocardial oxygen consumption during maximum electron transport system activity (multiple R2 = 0.69). After controlling for body mass, individuals with longer gill filaments, summed over all filaments, or greater cardiac respiratory capacity had higher wholeanimal metabolic rates. The overall model fit and the explanatory power of individual predictor variables were better for MMR than for SMR, suggesting that gill morphology and myocardial bioenergetics are more important in determining maximum rather than resting metabolism. Heart ventricle mass was not related to mass-independent variation in MMR or SMR, indicating that the quality of the heart (i.e., the capacity for mitochondrial metabolism) was more influential than heart size. Finally, myocardial oxygen consumption required to offset the dissipation of the transmembrane proton gradient in the absence of ATP synthesis was not correlated with either MMR or SMR. The results support the idea that interindividual variation in aerobic metabolism, particularly maximum metabolic rate, is explained, in part, by variation in specific steps in the oxygen-supply cascade.

ANNUAL CONFERENCE MONTPELLIER 2022

A378 THE EVOLUTION OF RESTING BODY TEMPERATURES IN MAMMALS Wednesday 6th July 2022

10:00am-10:15am

Danielle L. Levesque, University of Maine, Eric Brown, University of Maine, Ana M. Breit, University of Maine danielle.l.levesque@maine.edu Basal metabolic rate is often likened to the idling speed of mammals.

Measured during rest in non-reproductive, mature, fasted animals, it has become a gold standard for use in interspecific studies. Recent evolutionary analyses have shown a decoupling between basal metabolism and body temperature in endotherms. However, these studies were based on body temperature datasets that ignored the inherent variability in this trait and consisted of non-comparable temperatures (for example comparing that of a resting animal during the active phase of its activity cycle to an active animal in its rest phase). Using a new dataset of standardised resting body temperatures in mammals, we explore the relationship between basal metabolism and body temperature as well as the evolutionary history of these two traits. We discuss the implications of correcting, or not, for body temperature in studies on metabolic scaling and discuss

A379 MACROEVOLUTIONARY PATTERNS IN METABOLISM AND DEVELOPMENT Wednesday 6th July 2022

11:45am-12:00pm

George C. Jarvis, Monash University, Craig White, Monash University, Dustin Marshall, Monash University george.jarvis@monash.edu While some traits such as body size are well known predictors of metabolism, the covariance between metabolism and other traits remains poorly resolved. There are good reasons to suspect that developmental mode (direct or indirect development) should covary with metabolic rate but this covariance has not been explored. We compiled published data for adult metabolic rates and developmental mode for 705 species of marine invertebrates across 13 phyla. Using a phylogenetically-controlled analysis, we found that adult metabolism is shaped by developmental mode – species with planktonic larvae have higher metabolic rates than those with aplanktonic development. This pattern is unaffected by adult size. We also found support for differential temperature-dependence of metabolic rate among developmental modes. Overall, our results suggest developmental mode shapes the physiology of marine organisms in ways that have gone largely unanticipated by theory.

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A380 INSIGHTS INTO GENETIC ASSOCIATIONS OF LIFE-HISTORY AND METABOLIC RATE VIA LARGE-EFFECT LOCI IN ATLANTIC SALMON Wednesday 6th July 2022

11:30am-11:45am

Jenni M. Prokkola, University of Helsinki, Eirik R. Åsheim, University of Helsinki, Sergey Morozov, University of Helsinki, Craig R. Primmer, University of Helsinki, Tutku Aykanat, University of Helsinki jenni.prokkola@helsinki.fi

Topt for swimming speed, metabolic rate, activity and boldness), which was consistent across latitudes and rearing temperatures. This trade-off, potentially driven by the energetically costly maintenance of a fast pace-of-life, may be an alternative mechanism contributing to the maintenance of variation in pace-of-life within populations.

A385 VARIATION IN FIELD METABOLIC RATES OF WILD MARINE FISHES: THERMAL, ONTOGENETIC, PHYLOGENETIC AND MACROECOLOGICAL DRIVERS Wednesday 6th July 2022

Life-history variation emerges due to trade-offs in energy allocation, suggesting energetics shapes life-history evolution. The Atlantic salmon (Salmo salar) exhibits high diversity in the age-at-maturity trait, which is largely controlled by two genomic regions, vgll3 and six6.

This simple genetic control of age-at-maturity enables implementing genomic prediction methods to test potential genetic correlations, and subsequent co-evolution, between age-at-maturity and physiological traits. Here, we tested how variation in these life-history genomic regions affect the central metabolic phenotypes: standard and maximum metabolic rates, and aerobic scope in juvenile Atlantic salmon. We found no evidence for covariation between standard metabolic rate and the two life-history loci. However, we found that one of the life-history loci affected the maximum metabolic rate and aerobic scope, and that the two loci showed physiological epistasis in the control of maximum metabolic rate. We then measured proxies of aerobic and anaerobic capacities from four tissues to study how tissuespecific energetics can mediate genetic variation in life-history. The results help us to better understand the mechanistic basis of life-history variation as well as metabolic constraints on life-history evolution.

A383 A TRADE-OFF BETWEEN FAST PACE-OF-LIFE AND THERMAL PERFORMANCE IN A DAMSELFLY Wednesday 6th July 2022

ANNUAL CONFERENCE MONTPELLIER 2022

12:00pm-12:15pm

12:15pm-12:30pm

Clive Trueman, University of Southampton, Sarah Alewijnse, University of Southampton, Joseph Jones, University of Southampton, Natalie Cooper, Natural History Museum

The integration of life-history, behavioural and physiological traits into a ‘pace-of-life syndrome’ (POLS) is a powerful concept in understanding trait variation in nature. Yet, mechanisms maintaining variation in ‘pace-of-life’ are not well understood. We tested whether decreased thermal performance is an energetic cost of a faster pace-of-life. We characterized the pace-of-life of larvae of the damselfly Ischnura elegans from high-latitude and low-latitude regions when reared at 20°C or 24°C in a common-garden experiment, and estimated thermal performances curves (TPCs) for a set of behavioural, physiological and performance traits. Our results confirm a faster pace-of-life (i.e. faster growth and metabolic rate, more active and bold behaviour) in the low-latitude and in warm-reared larvae, and reveal increased maximum performance, Rmax, but not thermal optimum Topt, in low-latitude larvae. Besides a clear POLS integration at the individual level, larvae also aligned along a ‘cold-hot’ axis. Importantly, a faster pace-of-life correlated negatively with a high thermal performance (i.e. higher

of-life differences, we use the honeybee colony as an experimental model to understand how interindividual variation in metabolic rate may influence the performance of individuals and thereby impact group-level traits. By measuring a large number of behavioral, lifehistory, and physiological traits in individual bees, we show that variation in metabolic rate plays a fundamental proximate role in driving the covariance among various behavioral and life history traits that characterize the pace of life axis. Following this with breeding genetic lines of bees with low and high metabolic rate and creating experimental groups with different phenotypic compositions, we quantified the effect of diversity in metabolic rate on group level performance traits. Contrary to the predictions of an individual-based model that we developed that suggested metabolically diverse groups would outperform metabolically homogenous groups, we found the impact of metabolic rate heterogeneity to be much more complex and specific to different performance measures. We discuss the importance of these findings in the context of how interindividual variation in metabolic rate may drive the phenotype at a group level and the functional role metabolic rate might play in shaping division of labor and social evolution.

trueman@soton.ac.uk Reproductive success (and therefore selection) is ultimately related to how well an organism performs in the context of its environment.

Performance reflects the interactive trade-off between physiological traits, behaviour, resource availability and mortality. Time-integrated field metabolic rate (FMR) captures the realised energetic cost of performing in a natural setting, accounting for multi-generational acclimation to the environmental and ecological context. In-situ measurements of FMR may be needed to fully appreciate the evolutionary significance of variation in metabolic traits.

Here we draw on data compiled using a new emerging proxy capable of providing estimates of individual-level FMR together with experienced temperature and growth rate derived from the otoliths of marine fishes. We quantify the extent and nature of among- and within-species variation in FMR observed so far in marine fishes. Among other patterns we show that in most observed populations operating within their natural thermal range, realised FMR is relatively insensitive to temperature, with no clear relationship between individual-level variation in FMR and growth rate. However, temperature has a stronger effect on realised FMR during early juvenile life stages (including in the same individuals), implying that in fishes, thermal effects on selection may be stronger during early juvenile life history stages.

Nedim Tüzün, Leibniz Institute of Freshwater Ecology and Inland Fisheries, Robby Stoks, KU Leuven ndmtzn@gmail.com

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A389 HOW DOES INTERINDIVIDUAL VARIABILITY IN METABOLIC RATE SHAPE THE PERFORMANCE OF A SOCIAL GROUP? Wednesday 6th July 2022

09:45am-10:00am

Dhruba Naug, Colorado State University, dhruba@colostate.edu Interindividual variation within a species has recently attracted a lot of theoretical and empirical interest but how such variation affects the collective performance of a social group has not been a major part of this discussion. Using the pace-of-life as a theoretical framework and assuming metabolic rate to be a key driver of pace-

A390 THE PHYSIOLOGICAL EFFECTS OF EXPERIMENTAL EVOLUTION OF AEROBIC EXERCISE PERFORMANCE IN BANK VOLES Wednesday 6th July 2022

11:00am-11:30am

Edyta T. Sadowska, Institute of Environmental Sciences, Jagiellonian University, edyta.sadowska@uj.edu.pl The rate at which animals acquire and use energy is an important factor that affects many aspects of animal performance, including reproductive output and thermoregulatory capabilities. Therefore, understanding the factors limiting energy budgets has remained one of the central issues in ecological and evolutionary physiology. We used a unique experimental evolution model – lines of bank voles (Myodes glareolus) selected for high rate of swim-induced aerobic metabolism (VO2swim, A-lines), which evolved a 70% higher VO2swim than that observed in unselected control (C) lines – and asked how the BMR, reproductive output, and thermoregulatory capabilities evolved in response to the selection. After 25 generations, animals from the A-lines achieve over 30% higher forced running maximum metabolic rate than those from unselected, control (C) lines. The selection has also increased the forced running maximum metabolic rate by about 30%37. Voles from the A-lines spend more time on active swimming, and, unlike the C-line voles, during the swimming trial work up to their physiological performance limit they achieve during running. In these lines the animals have developed an increased metabolic capacity, and we tried to understand the mechanism behind it.

ANNUAL CONFERENCE MONTPELLIER 2022

A391 INDIVIDUAL VARIATION IN METABOLIC RATE AND ECTOTHERM RESPONSES TO ENVIRONMENTAL CHANGE Wednesday 6th July 2022

09:00am-09:30am

Lumír Gvoždík, Institute of Vertebrate Biology, Czech Academy of Sciences gvozdik@brno.cas.cz Impacts of changing environment on fitness are mediated by changes in energy acquisition and allocation within an organism. Maintenance energy costs constitute a substantial part of individual's energy budget. Therefore, individual variation in standard metabolic rate plays an important role in understanding how ectotherms adapt to environmental changes. Despite considerable efforts in this area, many issues remain unresolved. In this talk, I (1) introduce the theoretical framework for the link between environmental change, individual metabolic variation and fitness, (2) present the latest findings in this field, and (3) highlight priorities for future research.

POSTER SESSION A373 SUSTAINED SWIMMING PERFORMANCE IS INDEPENDENT OF ORGANISM-LEVEL AND MITOCHONDRIALLEVEL METABOLISM IN EUROPEAN MINNOWS Wednesday 6th July 2022

POSTER SESSION

Agnieszka Magierecka, University of Glasgow, Darryl McLennan, University of Glasgow, Neal Dawson, University of Glasgow< Caroline Millet, University of Glasgow, Neil B. Metcalfe, University of Glasgow agnieszka.magierecka@glasgow.ac.uk Metabolic rate is a fundamental trait that influences and constraints the behaviour and performance of animals. However, conventional measures of metabolic rate, based on whole-animal oxygen consumption, often fail to show the predicted relationships with measures of animal performance since it is unclear what proportion of consumed oxygen is associated with ATP production. Thus the efficiency with which the mitochondria convert oxygen into ATP can be a better determinant of an animal performance capacity. In this study we examined whether mitochondrial efficiency predicts sustained swimming performance in the European minnow (Phoxinus phoxinus), a riverine fish. We measured individual critical swimming speed (Ucrit) followed by a measurement of maximum metabolic rate (MMR), standard metabolic rate (SMR) and mitochondrial function, predicting that measures of mitochondrial performance such as the ATP produced per molecule O2 consumed will be positively related to Ucrit and that the variation in Ucrit explained by mitochondrial function will be greater than any explained by MMR and SMR. Maximal rates of oxidative phosphorylation at the mitochondrial level were positively correlated with maximal oxidative metabolism of the whole fish.

SCIENCE ACROSS BOUNDARIES ABSTRACTS 62

However, contrary to our predictions, swimming performance was unrelated to both organism-level and our measures of mitochondrial level metabolism, with Ucrit, MMR and SMR being influenced by individual body mass only. This suggests that, while mitochondrial function predicts whole-animal metabolism, it does not necessarily constrain animal locomotor performance, and the maximum sustained swimming speed is not determined by energy or oxygen supply. Further research is needed to determine the limits to physical performance.

A382 ENERGY METABOLISM, LONGEVITY AND MITOCHONDRIAL DNA EVOLUTION IN ENDOTHERMS: WHAT DIFFERENCES BETWEEN MAMMALS AND BIRDS? Thursday 7th July 2022

POSTER SESSION

Mathieu Mortz, Université du Québec à Rimouski, Pierre Ulrich Blier, Université du Québec à Rimouski mathieu.mortz@gmail.com Understanding the mechanisms that influence aging has been a major challenge for several decades. It has been known since then that longevity is positively correlated to body size and negatively correlated to energy metabolism, putting forward Harman's theory linking the life expectancy of an animal to aerobic metabolism. These relationships, even if they are found in all classes of animals, differ according to the taxonomic group. For example, birds usually have a greater longevity than mammals of the same size, demonstrating a greater capacity to manage the deleterious effects of energy expenditure.

Since mitochondria have their own DNA that codes for subunits of the respiratory chain, it can be assumed that its evolution may be related to aging, and that there may be notable differences when comparing mammals to birds. A negative relationship between the rate of substitution of mitochondrial DNA (mtDNA) and the longevity of animals has already been demonstrated in these animals, always separately and by studying the mtDNA in its entirety. Here, we wanted to push the analysis further by distinguishing the 13 mitochondrial protein coding genes (mtPCGs) individually to study the existing relationships between their evolution and those of 3 biological parameters: size, longevity and energy metabolism, and by making a comparative study between mammals and birds. Our results confirm the demonstrated negative correlation between longevity and substitution rate for each of the mtPCGs in mammals and birds. We also find a positive correlation between energetic metabolism and the substitution rate of COX genes, which is more important in mammals than in birds.

This higher conservation of COX genes despite variations in energy metabolism in birds may be an interesting avenue to explain their better management of metabolic deleterious effects.

A384 NO EVIDENCE FOR A SIGNAL IN MAMMALIAN BASAL METABOLIC RATE ASSOCIATED WITH A FOSSORIAL LIFESTYLE Thursday 7th July 2022

POSTER SESSION

Hana Merchant, Royal Holloway University of London PHBA013@live.rhul.ac.uk

ANNUAL CONFERENCE MONTPELLIER 2022

Basal metabolic rate (BMR) – the rate of energy use needed to perform basic, life-sustaining functions – is a universal measure of metabolic rate allowing for comparisons of energy expenditure between species.

Many animals inhabit a vast array of challenging environments, an example being living in confined spaces where oxygen levels are likely to be low. Previously it has been shown that species can exhibit both genoand phenotypic adaptations in metabolic rate to exploit such unique niches. Living for extended periods of time within an enclosed space – in a burrow, den or crevice – will likely require certain physiological and morphological adaptations, and thus influence the biology of the species that occupy them. In this study we are taking a global look at the mammalian kingdom to understand the relationship between BMR and burrow use (fossoriality) in mammals. In particular, we aimed to determine if there was a trait within BMR associated with fossoriality, versus species which live above ground. We used pre-existing data for mammalian BMR and body mass, and 24-life history traits. To account for variation in body size, residual BMR was used (RBMR), controlling for any phylogenetic trends through a phylogenetic least squares model (PGLS) and an MCMCglmm, to account for inter- and intra-specific variation. Overall, mammalian metabolic rate is dictated primarily by environmental temperature. Only aquatic mammals had a detectable trait in RBMR and there was no significant differences in RBMR of terrestrial, fossorial and subterranean mammals, suggesting that species occupying a subterranean niche do not pay any baseline metabolic costs on account of their burrowing lifestyle. This may possibly explain why certain species can live above ground whilst also occupying an underground shelter at night or during other periods of the day. Aquatic mammals, however, had a significantly higher RBMR to all other groups apart from flying mammals. This significantly high BMR may also be due to the energetically demanding thermoregulatory need to maintaining a constant body temperature in cold water, particularly the Arctic/Antarctic waters that the large aquatic mammals in the study will be visiting seasonally, if not occupying year-round. This study has shown that environmental temperature is an important factor when exploring differences in mammalian BMR. Temperature can be used to predict BMR and therefore strongly infers whether a mammal is physiologically suited to living in a particular place or habitat. Changes to the environmental temperatures that these species are experiencing are likely to have knock on effects and alter population spread and change, as well as persistence of populations in certain areas. This highlights the importance of climate change and the largescale effects that small changes in environmental temperature may have on the diversity and distribution of mammalian species on the planet.

A386 METABOLIC SCALING IS UNAFFECTED BY HABITAT ARIDITY IN GECKOS Thursday 7th July 2022

POSTER SESSION

Zuzana Starostová, Charles University, Martin Hlubeň, Charles University, Tereza Myslíková, Charles University, Lumír Gvoždík, Institute of Vertebrate Biology, Czech Academy of Sciences, Lukáš Kratochvíl, Charles University zuzana.starostova@natur.cuni.cz Species from arid environments, mainly mammals and birds, often have lower metabolic rates than species from mesic environments.

To test whether squamate reptiles, a group that mastered life in arid environments, follow the same trend, we compared intra- and interspecific scaling of metabolic rate in two independent lineages the eyelid geckos, family Eublepharidae, and the geckos of the genus

SCIENCE ACROSS BOUNDARIES ABSTRACTS 63

Paroedura, family Gekkonidae. Representatives of both groups live in habitats with considerable temperature and humidity gradients, ranging from deserts to tropical rainforests. Both lineages highly diversified in body size and exhibit negative relationship between habitat aridity and total evaporative water loss. Our phylogenetically informed analyses reveal that in both groups metabolic rate scales closely with body mass and the intra- and interspecific scaling in metabolic rate is nearly the same. Differences in habitat aridity and total evaporative water loss do not explain the slight departures from the conserved scaling in metabolic rate. In contrast to mammals and birds, these results rule out the possibility that changes in metabolic rate, and thus water loss via respiration, drive adaptive changes in total evaporative water loss in geckos.

A388 BRAIN SIZE, GUT SIZE AND COGNITIVE ABILITIES: THE ENERGY TRADE-OFFS TESTED IN AN ARTIFICIAL SELECTION EXPERIMENT Thursday 7th July 2022

POSTER SESSION

Anna Goncerzewicz, Nencki Institute of Experimental Biology a.goncerzewicz@nencki.edu.pl The enlarged brains of homeotherms bring behavioural advantages, but also incur high energy expenditures. The ‘expensive brain’ (EB) hypothesis posits that the energetic costs of the enlarged brain and the resulting increased cognitive abilities (CA) were met by either increased energy turnover or reduced allocation to other expensive organs, such as the gut. We tested the EB hypothesis by analysing correlated responses to selection in an experimental evolution model system, which comprises line types of laboratory mice selected for high or low basal metabolic rate (BMR), maximum (VO2max) metabolic rates and random-bred (unselected) lines. The traits are implicated in the evolution of homeothermy, having been pre-requisites for the encephalization and exceptional CA of mammals, including humans.

High-BMR mice had bigger guts, but not brains, than mice of other line types. Yet, they were superior in the cognitive tasks carried out in both reward and avoidance learning contexts and had higher neuronal plasticity (indexed as the long-term potentiation) than their counterparts. Our data indicate that the evolutionary increase of CA in mammals was initially associated with increased BMR and brain plasticity. It was also fuelled by an enlarged gut, which was not traded off for brain size.

ANNUAL CONFERENCE MONTPELLIER 2022

SCIENCE ACROSS BOUNDARIES ABSTRACTS 64

A11 - ENDOCRINE-MEDIATED RESPONSES TO ENVIRONMENTAL VARIABILITY ORGANISED BY: FRANK SEEBACHER (THE UNIVERSITY OF SYDNEY), ALEXANDER G. LITTLE (QUEEN’S UNIVERSITY, CANADA) A87 BISPHENOL S EXPOSURE REDUCES LOCOMOTOR FUNCTION BY AFFECTING MUSCLE FUNCTION BUT NOT MITOCHONDRIA Friday 8th July 2022

09:30am-09:45am

Alexander Rubin, The University of Sydney, Tiana Pelaia, The University of Sydney, Frank Seebacher, The University of Sydney alexander.rubin@sydney.edu.au Bisphenols enter the environment from the production and degradation of plastics, and are ubiquitous pollutants with endocrine disrupting effects. Thyroid hormones are key regulators of vertebrate metabolism and muscle function, and represent one of many endocrine targets disrupted by bisphenol S (BPS). Our aim was to test whether BPS disrupts locomotor performance in zebrafish in a thyroid-dependent manner. First, we established that BPS at an environmentally relevant concentration impaired swimming performance (Ucrit). We then conducted two subsequent but separate, fully factorial experiments using BPS exposure (present and absent) and induced hypothyroidism (hypo- and normo- thyroid) as factors to assess mitochondrial function and muscle protein composition as potential mechanisms by which BPS could disrupt locomotor performance. Hypothyroidism but not BPS exposure reduced maximal substrate oxidation and proton leak. Metrics of mitochondrial efficiency were not impact by BPS exposure but were altered by both temperature and hypothyroidism. BPS exposure decreased AMPK activity (pAMPK/AMPKtotal) in skeletal muscle but increased fast myosin heavy chain (MHC) proteins. BPS exposure did not strongly impact slow MHC or myosin enhancer factor 2 (MEF2).

Hypothyroidism decreased AMPK activity, and increased fast and slow MHC and MEF2 so that BPS and hypothyroidism affected muscle in the same direction. Since AMPK activity is important to sustained exercise, the BPS-induced decrease in AMPK activity could explain the observed decrease in swimming performance.

A89 GLUCAGON AND ADRENALINE: TWO MODULATORS OF NOCTURNIN EXPRESSION IN GOLDFISH? Friday 8th July 2022

11:30am-11:45am

Diego Madera, Complutense University of Madrid, Aitana Alonso-Gómez, Complutense University of Madrid, Ana Isabel Valenciano, Complutense University of Madrid, María Jesús Delgado, Complutense University of Madrid, Ángel Luis Alonso-Gómez, Complutense University of Madrid dmadera@ucm.es

A88 ESTRADIOL EFFECTS ON EARLY SKELETOGENESIS IN THE EUROPEAN SEA BASS DICENTRARCHUS LABRAX Friday 8th July 2022

ANNUAL CONFERENCE MONTPELLIER 2022

10:00am-10:15am

Camille Martinand-Mari, University of Montpellier, CNRS, IRD, Emilie Farcy, UMR MARBEC, Eric Potier, UMR MARBEC, Clarence Bourdy, UMR MARBEC, Eric Gassett, UMR MARBEC, Gilbert Dutto, UMR MARBEC, Nicolas Leurs, University of Montpellier, Mélanie Debiais-Thibaud, ISEM camille.martinand-mari@umontpellier.fr First identified as sexual hormones, estrogens were shown to have a key role in the development of gonads but also to be involved in the skeleton development and homeostasis. In mammals, cytosolic estrogen receptors (ERa and ERb) are expressed in osteoblasts, osteoclasts, osteocytes as well as chondrocytes and chondroblasts, regulating their activity to build up and maintain cartilage and bone.

To expand our knowledge of estrogen signaling in skeletal development outside of mammals, we used the European sea bass Dicentrarchus labrax, to test the impact of two concentrations of the natural estrogen 17b estradiol (E2, 0.4 and 40 ng/L) on 6-to-23-day old post-hatching larvae.

We evaluated the effects of E2 on the morphological characteristics of the larvae as well as on the mineralization of the cranium, vertebrae and fins using alizarin red staining. In addition, qPCR measurements were performed to analyze the expression of various genes known to be involved in the formation of cartilage and bone in vertebrates.

We showed that the effect of estrogens varied depending on the developmental stage of the larvae and the state of mineralization of their skeleton at the time of treatment, and that these effects were dose-dependent.

Nocturnin (NOC) is a phosphatase involved in the transformation of NADP(H) to NAD(H), performing a key role in the regulation of metabolism. In mammals, it has been purposed that nocturnin expression is induced by E-box element activation. However, nothing is known about the possible elements that modulate its expression in fish.

Our aim was to undertake the study of the possible endocrine regulation and the intracellular pathways involved in the gene expression of three noc paralogs (noc-a1, noc-a2 and noc-b1) expressed in goldfish (Carassius auratus). For this purpose, we studied the effect of glucagon, adrenaline and different activators and inhibitors of protein kinase A (PKA) and protein kinase C (PKC) pathways on noc paralogs expression in hepatopancreas organotypic cultures. We found a concentrationdependent induction of noc-a1 expression by both glucagon and adrenaline at 2 and 6-h incubation time. Forskolin, an adenylyl cyclase activator, induced a 5-fold increase of the relative abundance of this paralog, meanwhile a 2-fold increase was obtained in the presence of phorbol 12-myristate 13-acetate, a PKC activator. The effects of glucagon and forskolin were fully blocked by a PKA inhibitor (H89), and partially by a PKC inhibitor (chelerythrine) and by a PLC inhibitor (U73122), suggesting a possible interaction between PKA and PKC pathways in the intracellular signaling of glucagon on noc-a1 expression.

Regarding noc-a2 mRNA expression, our results show an induction by adrenaline at 2 and 6-h incubation time but not by glucagon, forskolin or phorbol 12-myristate 13-acetate. Then, noc-b1 seems to be insensitive to both hormones, and to PKA and PKC activators. Altogether, these results suggest a possible functional specialization of noc paralogs in hepatopancreas and aim to investigate the possible role of other metabolic regulators in the control of noc expression in goldfish.

Supported by the Spanish MICINN (PID2019-103969RB-C32). D.M and A.A-G are predoctoral fellows, UCM (CT42/18-CT43/18) and FPI (BES-2017-081398), respectively.

A90 BISPHENOL A-INDUCED DECREASES IN ENERGETIC GROWTH EFFICIENCY ARE MEDITATED BY DNA METHYLTRANSFERASE 3A Friday 8th July 2022

09:45am-10:00am

Frank Seebacher, The University of Sydney, Stephanie M. Bamford, The University of Sydney frank.seebacher@sydney.edu.au Energetic cost of growth determines how much food-derived energy is needed to produce a given amount of new biomass, and thereby influences energy transduction between trophic levels. Growth and development are regulated by hormones and are therefore sensitive

SCIENCE ACROSS BOUNDARIES ABSTRACTS 65

to changes in environmental endocrine disruption. Here we show that the endocrine disruptor bisphenol A at an environmentally relevant concentration (BPA; 10 µg l⁻¹) increased metabolic rate during development and thereby energetic cost of growth in zebrafish (Danio rerio) at 24 and 30°C. At 200 days post fertilization, BPA-exposed fish had significantly lower locomotor performance.

Mechanistically, BPA-induced physiological changes were mediated

by DNA methyltransferase 3a enzyme. These results indicate that differential DNA methylation could transmit the effects of BPA exposure to subsequent generations. We are in the process of conducting experiments to test this hypothesis. The BPA-mediated physiological effects can impact animal performance and growth efficiency, and hence the dynamics and resilience of animal populations and the services these provide.

A91 PHYSIOLOGY OF SOMATIC GROWTH: INSULIN-LIKE GROWTH FACTOR 1 AND ITS VARIABILITY IN PASSERINE SPECIES WITH DIFFERENT LIFEHISTORY Friday 8th July 2022

11:45am-12:00pm

Jaanis Lodjak, University of Tartu, Simon Verhulst, University of Groningen jaanis.lodjak@ut.ee How limited resources are physiologically directed towards somatic growth is a simple question, but poorly understood. The hormone insulin-like growth factor 1 (IGF-1) - is an evolutionarily conserved hepatic peptide that is one of the more important hormones of growth regulation. For example, administration of IGF-1 to the nestlings of the pied flycatcher (Ficedula hypoleuca) induced growth to bigger pre-fledging body size. Moreover, administrating an IGF-1 receptor inhibitor (OSI-906) resulted in reduced growth. The growth rate is age-dependent and we investigated how IGF-1 levels changed with age and growth conditions in nestlings of two passerine species – great tits (Parus major) and jackdaws (Corvus monedula) – with different life histories. We showed experimentally in both species that levels of IGF-1 change positively with the improving food availability, both when observed in the short- (within 1h) and long-term (during the nestling phase). However, the effects of nestling age on IGF-1 levels as well as IGF-1 growth associations contrasted strongly between these species.

Thus, IGF-1 appears to respond to environmental cues uniformly across species, but the timing of IGF-1 mediated investments into growth is dependent on the particular growth strategy. These findings together show that IGF-1 variability provides a promising avenue for studies of animals’ growth, of which the exploration has only just begun.

ANNUAL CONFERENCE MONTPELLIER 2022

A92 OXYTOCIN CENTRALLY REGULATES TEMPERATURE-DEPENDENT METABOLISM IN FISH Friday 8th July 2022

15:15pm-15:30pm

Avner Cnaani, Agricultural Research Organization, Jakob Biran, Agricultural Research Organization Adi Segev-Hadar, Agricultural Research Organization, Anouk M. Olthof, University of Connecticut, Rahul Kanadia, University of Connecticut jakob@agri.gov.il As poikilotherms, fish exposed to environmental extremes temperatures experience a stressful metabolic challenge, which elicits physiological responses required to maintain cellular homeostasis. These responses include modified glucose or lipid metabolism, altered gene expression and alternative splicing, and endocrine and immune system activity.

Additionally, heat seeking may not resolve the homeostatic needs of tropical poikilotherms under unpredictable extreme cold events, which occur frequently due to global climate changes. In spite of the physiological responses that occur in poikilothermic vertebrates, the prevailing notion is that their reduction in metabolic rate is passive.

Here, we explored molecular hypothalamic and physiological responses to cold stress in the tropical cichlid, Nile tilapia (Oreochromis niloticus).

When exposed to low temperatures, tilapia exhibited complex homeostatic responses, including increased plasma glucose and cortisol concomitant with reduced plasma lactate and metabolic rate.

Hypothalamic transcriptome analysis revealed increased oxytocin expression. Blockage of oxytocin signaling using zebrafish CRISPRknockout lines for oxytocin or its receptors, and pharmacological antagonist in tilapia, further affected temperature-dependent metabolic rate in two cold-exposed tropical fish species. This indicates that oxytocin, a known thermoregulator in homeotherms, actively regulates temperature-related homeostasis in fish. Overall, our findings show that the fish brain actively responds to cold temperature by regulating metabolic physiology. Moreover, we identify oxytocin signaling as an adaptive and evolutionarily conserved metabolic regulator of temperature-related homeostasis.

A93 PRENATAL ACOUSTIC SIGNALS AND POSTNATAL HEAT SHAPE NESTLING STRESS PHYSIOLOGY Friday 8th July 2022

15:30pm-15:45pm

Eve Udino, Deakin University Mylene Mariette, Deakin University, Doñana Biological Station EBD-CSIC, Anaïs Pessato, Deakin University,. BriAnne Addison, Deakin University, Ondi L. Crino, Deakin University, Australian National University, Katherine L. Buchanan, Deakin University udinoe@deakin.edu.au Animals respond to environmental challenges with a suite of physiological responses – the stress response. As high temperatures become more frequent and intense globally, determining whether and how individuals vary in their stress response to heat is urgent. While there is an emerging interest in understanding avian stress response to heat, very often, only glucocorticoids are quantified. Here, we tested whether early-life conditions affect multiple traits of nestling

SCIENCE ACROSS BOUNDARIES ABSTRACTS 66

stress physiology in response to heat. In the arid-adapted zebra finch, parents emit “heat-calls” when incubating under high temperatures, which adaptively alter offspring growth. We exposed nestlings to prenatal heat-calls or control-calls, and manipulated postnatal nest temperatures. At 13-day old, we collected blood samples in two experiments: under undisturbed “in-nest” conditions, or following a 2.5-hour heat-challenge. As biomarkers of acute, cellular and chronic stress, we measured, respectively, levels of corticosterone (CORT), constitutive heat-shock cognate 70 (HSC70) and stress-inducible heat-shock protein 90a (HSP90a), and, the heterophil to lymphocyte (H/L) ratio. We found that none of the stress biomarkers co-varied in either experiment, likely due to distinct time-courses. After the heatchallenge, only the H/L ratio was higher than in the in-nest experiment.

Furthermore, in the in-nest experiment, control-call nestlings had a marginally higher H/L ratio than heat-calls nestlings, and both HSPs increased with nest temperatures, in control-call individuals only.

These results suggest a higher sensitivity of control-calls nestlings to summer nest temperatures. Overall, our study shows for the first time that a prenatal acoustic signal for heat affects physiological stress responses to postnatal thermal conditions.

A94 EFFECTS OF NUTRITIONAL STATUS AND ENVIRONMENTAL FACTORS ON THE ENDOCRINE REGULATION OF FEEDING IN TELEOST FISH Friday 8th July 2022

phenotypes precisely adjusted to the environment. Yet the mechanisms underlying developmental plasticity are not fully understood yet.

Determining how plastic developmental changes that occur in response to environmental conditions are coordinated at the physiological, cellular, and molecular levels is a challenge that must combine ecology with developmental biology. The mechanisms that underlie the development of alternative phenotypes are still unclear for many systems and is one major goal of ecological developmental biology or Eco-Evo-Devo. We observed that clownfish (Amphiprion percula) young juveniles have a different rate of white bar formation depending on the sea anemone species, their obligate symbiotic partner, in which they are recruited: white bars develop more rapidly when fish are recruited in Stichodactyla gigantea than in Heteractis magnifica.

Because the sister species A. ocellaris acquire their adult color pattern during metamorphosis under thyroid hormone (TH) control, we asked whether developmental plasticity in bar formation was associated with alteration in TH status as these are the main hormones triggering metamorphosis in vertebrates. We found that thyroid hormones regulate white bar formation and that a shift in hormone levels, associated with ecological differences, results in divergent color patterns in different sea anemone species in which the young fish is recruited. Taken together our results suggest that TH control the timing of adult color pattern formation and that shifts in gene expression and TH levels are associated with ecological differences resulting in divergent ontogenetic trajectories in color pattern development.

We recently observed that the phenotypic change observed not only concerns pigmentation but also energy metabolism. The evolutionary implications of these observations will be discussed

11:00am-11:30am

Hélène Volkoff, Memorial University of Newfoundland hvolkoff@mun.ca In fish, food intake is ultimately regulated by feeding centers of the brain, which receive and process information from endocrine signals from both brain and peripheral tissues such as the gastrointestinal tract. These endocrine signals induce (orexigenic) or inhibit (anorexigenic) food intake, and interact with each other to maintain energy homeostasis.

Feeding habits, environmental conditions (e.g. temperature) as well as nutritional status and levels of energy stores influence feeding and the expression of endocrine appetite regulators. This review provides an overview of hormones known to regulate food intake in fish, and how feeding, fasting, diet composition and environmental changes might affect these endocrine networks in selected temperate water and tropical freshwater teleost fish.

A95 PHENOTYPIC PLASTICITY IN ANEMONEFISHES: AN ECO-EVO-DEVO ANALYSIS Friday 8th July 2022

ANNUAL CONFERENCE MONTPELLIER 2022

14:45pm-15:15pmv

Vincent Laudet, Okinawa Institute of Science and Technology (OIST) vincent.laudet@oist.jp Determining how plasticity of developmental traits respond to environmental conditions is a challenge that must combine evolutionary sciences, ecology and developmental biology. Developmental plasticity is defined as the ability of an organism to adjust its development depending on environmental signals, thus producing alternative

A408 TRANSGENERATIONAL ENDOCRINE DISRUPTION – A POTENTIAL MECHANISM FOR LEGACY EFFECTS OF ANTHROPOGENIC DISTURBANCE Friday 8th July 2022

10:15am-10:30am

Suvi Ruuskanen, University of Jyväskylä, suvi.k.ruuskanen@jyu.fi Anthropogenic changes in the environment are ubiquitous and affect organisms in many ways. Flexibility of the endocrine system may help organisms to response to those changes. However, disruption in the female endocrine function may lead to altered transfer of hormones in eggs or embryos, ie. transgenerational endocrine disruption, which can have long-lasting effects on offspring. Maternally derived thyroid hormones (THs) are essential for development, but poorly studied, especially in wild birds. Here, we provide three case examples of studies on transgenerational TH disruption. First, we studied how parental exposure to metal pollution, using repeated sampling of polluted and control areas across Europe, influenced egg TH levels in a passerine bird, the great tit. Second, we studied how long-term experimental parental herbicide exposure influenced egg THs and offspring traits in Japanese quails. Third, we studied experimentally how limitation of iodine, a key element of the TH molecule, influenced parental and egg THs in rock pigeons. We found no overall effect of parental metal exposure on egg THs, but the effect was dependent on calcium availability. Parental herbicide exposure did not influence egg THs, but affected hatchability and embryo traits. Parental iodine availability did not influence parental or egg TH levels, but decreased egg laying rate. Results of these case examples suggest that transgenerational endocrine disruption is a complex phenomena and should be further studied, as such legacy effects can delay adapting to environmental changes.

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A409 FREE-LIVING GREAT TITS DIFFER IN GLUCOCORTICOID PLASTICITY IN RESPONSE TO ENVIRONMENTAL TEMPERATURE – IMPLICATIONS FOR VARIABLE ENVIRONMENTS AND GLOBAL WARMING Friday 8th July 2022

12:00pm-12:30pm

Michaela Hau, University of Konstanz mhau@orn.mpg.de Fluctuations in environmental temperature affect energy availability and usage of endotherms, requiring plastic changes in behavioral and physiological traits. Hormones like glucocorticoids underpin environmentally-induced phenotypic plasticity, with changes in circulating glucocorticoids concentrations orchestrating plastic changes in diverse traits. Climate change is predicted to alter temperature variation globally; increasing the urgency to evaluate how free-living populations may cope. Individual variation is one prerequisite for evolution by natural selection; we therefore quantified individual differences in glucocorticoid responses to environmental temperature in a great tit (Parus major) population. Using a reaction norm approach, we repeatedly sampled adults for circulating glucocorticoid concentrations across five years during reproduction. Baseline and stress-induced glucocorticoid concentrations increased with lower ambient temperatures at the population and within-individual level. Moreover, we found unique evidence that individuals differ significantly in plastic responses to temperature variation for both glucocorticoid traits, with some displaying greater plasticity than others. Average concentrations and degree of plasticity covaried for baseline glucocorticoids, indicating that these two reaction norm components are linked. Hence, individual variation in glucocorticoid plasticity to a key environmental factor exists in a wild population, representing a crucial step to assess the adaptive potential of vertebrates to endure temperature fluctuations.

We now aim at elucidating the mechanisms underlying individual differences in glucocorticoid plasticity, for example the contributions of genetic, early environmental or direct environmental effects.

Furthermore, we are quantifying phenotypic implications like behavior and mitochondrial metabolism. Finally, we are analyzing whether an individual’s glucocorticoid plasticity covaries with plasticity in behavioral and physiological traits.

A410 ENDOCRINE DISRUPTION IN AQUATIC VERTEBRATES IS MEDIATED

BY ANTHROPOGENIC AND NATURAL ENVIRONMENTAL FACTORS Friday 8th July 2022

09:00am-09:30am

Werner Kloas, Leibniz-Institute of Freshwater Ecology and Inland Fisheries werner.kloas@igb-berlin.de Environmental factors are known to interfere with endocrine systems of wildlife and humans. Most emphasis has been given in developed countries to chemical compounds of anthropogenic origin affecting reproduction and development without causing remarkable toxicity.

The main sink of such endocrine disrupting compounds (EDC),

ANNUAL CONFERENCE MONTPELLIER 2022

are surface waters and thus, aquatic vertebrates, such as fish and amphibians, are most endangered, which makes them good sentinels for endocrine disruption. EDC can adversely affect reproductive biology, behavior, and the thyroid system and it seems also probable that they interfere with stress axis and metabolism. However, there is also evidence that natural sources, such as parasites and decomposition of leaves, or disruption of natural circadian light rhythm by artificial light at night (ALAN) also can act as endocrine disrupting factors in fish and amphibians. Next to well known (anti)estrogenic and (anti) androgenic EDC, progestins are also candidates to impair reproduction but surprisingly one substance, levonorgestrel, also disrupts the thyroid system drastically in amphibians by impairing metamorphosis. More recently microplastics have been discussed as potential endocrine mediating factor for freshwater systems. Recent results demonstrate that microplastics per se (except their leaching plasticizers) might not interfere directly as EDC rather than indirectly by adsorptive effects to already present EDC and thus enhancing or diminishing bioaccumulation of these EDC for aquatic organisms. For instance, co-exposure of microplastic and the estrogenic EDC, ethinylestradiol, enhanced the estrogenic response in tadpoles of Xenopus laevis. However, despite endocrine disruption can be caused also by natural factors such as leaf decomposition and parasites, such natural variabilities occurred since ages and did not cause a general loss of biodiversity and thus anthropogenic impacts, EDC including microplastics or ALAN, should become minimized or avoided in order to address the main drivers for endocrine disruption in the environment. .

SCIENCE ACROSS BOUNDARIES ABSTRACTS 68

A413 ENDOCRINE DISRUPTION IN THE CONTEXT OF CLIMATE CHANGE: UNDERSTANDING RESPONSES IN FISH Friday 8th July 2022

15:45pm-16:15pm

Susanne Brander, Oregon State University

ANNUAL CONFERENCE MONTPELLIER 2022

SCIENCE ACROSS BOUNDARIES ABSTRACTS 69

A12 - BIOINSPIRATION, BIOMIMETICS AND BIOREPLICATION

branders@oregonstate.edu Many pesticides are endocrine-active, even if the intended mechanism of action is not specified to directly interfere with outcomes such as development, reproduction, or sex determination. Pyrethroid pesticides, which are commonly used in both North America and the European Union, are based on toxins naturally produced by the chrysanthemum plant, but are chemically enhanced to increase persistence and toxicity to target organisms. These modifications make pyrethroids more likely to interact with endocrine targets such as the nuclear and membrane estrogen receptors, to modify downstream responses like the activity of steroidogenic enzymes, and to ultimately induce organismal responses indicative of endocrine disruption in fish (e.g. changes in gonad size, sex ratio). Previous work from our group confirmed these interactions for specific pyrethroid types, demonstrating that early life exposure can result in impacts that span multiple generations, and that increased temperature can exacerbate these effects. Recent findings indicate that other abiotic factors, such as salinity, can influence the direction and degree of endocrine-related responses, likely due to a combination of osmoregulatory modulation and differential chemical behavior that is dependent upon aqueous salinity. These observations are highly relevant in terms of predicted changes in temperature and salinity regimes over the coming decades, and our findings underscore the importance of understanding responses to endocrine-active compounds in the context of altered environmental conditions.

ORGANISED BY: THOMAS NEIL (UNIVERSITY OF BRISTOL), MARC HOLDERIED (UNIVERSITY OF BRISTOL) A11 WETTING OF HIERARCHICALLY MICRO-PATTERNED TRAPPING SURFACES OF CARNIVOROUS PITCHER PLANTS Thursday 7th July 2022

15:20pm-15:35pm

Michal Golos, University of Bristol, Andrea E.L. Attipoe, Imperial College London, David Labonte, Imperial College London, Ulrike Bauer, University of Bristol michal.golos@bristol.ac.uk Nepenthes pitcher plants trap insects in cup-shaped leaves lined with slippery surfaces. One such surface, the collar-like pitcher rim (peristome), has gained increasing attention from engineers as a valuable source of biomimetic inspiration. The peristome is only slippery when wet, and – in contrast to most plant surfaces – it is fully wettable. Water spreads rapidly on the surface and forms a thin film which remains stable under insect feet and causes them to slip. These phenomena have been attributed to the peristome’s microstructure, formed by regularly spaced, superimposed ridges on two distinct length scales; we can therefore expect functional constraints on ridge dimensions and aspect ratios. Using scanning electron and light microscopy, we investigated the characteristic surface pattern of more than 80 Nepenthes species. We found pronounced interspecific variation in ridge shape, frequency and amplitude on the macroscopic but not on the microscopic scale. In order to explore the effect of surface topography on water spreading further, we quantified ridge dimensions and aspect ratios for more than 30 species, and filmed water spreading on the peristomes of these species in a greenhouse.

Ongoing experiments employ artificial ridged epoxy surfaces with varying levels of intrinsic hydrophilicity to separate the effects of surface chemistry and topography, and to identify topographical limits of wetting. Our work elucidates the necessary and sufficient conditions for water film stabilisation on the Nepenthes peristome and can inform the development of biomedical and technological innovations such as micro-scale fluid transport systems or self-cleaning surfaces.

A13 MECHANICAL JOINT COUPLING IN AN AVIAN INSPIRED LEGGED ROBOT Thursday 7th July 2022

17:50pm-18:05pm

Alexander Badri-Spröwitz, Max Planck Institute for Intelligent Systems, Alborz Aghamaleki Sarvestani, Max Planck Institute for Intelligent Systems, Monica A. Daley, University of California, Irvine, Metin Sitti, Max Planck Institute for Intelligent Systems sprowitz@is.mpg.de Animal-legged locomotion is the result of tight interaction of biomechanics and neural control. Special focus has been set on multiarticulate coupling mechanisms; muscle-tendon networks that act simultaneously at multiple joints. Multi-articulate mechanisms are associated with joint movement coordination, reduction of forces and metabolic cost of transport, and even power amplification. Yet most multi-articulate configurations remain without sufficient functional explanation. In this presentation I will describe our latest projects in human- and bird-like locomotion, where we develop mechanical models (legged robots) featuring complex multi-articulate mechanisms. Our robots allow us to test the interaction of a complex leg design, with integrated neuromuscular-inspired control, and while locomotion in the physical world. Robots allow collecting rich biomechanical data from within: we measure joint angles, forces and torques, and electrical power consumption of motors. Already with simple control (feedforward) and a high degree of under-actuation (spring-tendon based function), we observe the emergence of natural-looking gaits.

Specifically, our bird-inspired robot demonstrates a self-engaging and disengaging parallel leg elasticity that is switched through foot-ground contact. This is the first available proof where mechanical coupling between joint kinematics and function replaces neural coupling, to a large amount. We show that complex leg trajectories and leg function (stance leg, swing leg, and transitions) are established almost entirely through multi-articulate mechanical coupling, and with base-line control that mimics muscles isometric mode. We also show that our leg mechanism is theoretically scalable to dynamic loads and sizes of the largest animals ever roaming this world.

ANNUAL CONFERENCE MONTPELLIER 2022

A14 MECHANICS AND UNDERLYING STRUCTURE OF PLANT MOTION: INSPIRATION FOR NOVEL BIOMIMETIC SOFT MACHINES Thursday 7th July 2022

14:50pm-15:05pm

Thomas Speck, Plant Biomechanics Group & Botanic Garden of the University of Freiburg and Cluster of Excellence livMatS @ FIT, Simon Poppinga, Technical University Darmstadt and Cluster of Excellence livMatS @ FIT, Tiffany Cheng, Cluster of Excellence IntCDC, Yasaman Tahouni, Cluster of Excellence IntCDC, Achim Menges, Cluster of Excellence IntCDC, Marc Thielen, Cluster of Excellence livMatS @ FIT, Jürgen Rühe, University of Freiburg thomas.speck@biologie.uni-freiburg.de During the last decades, biomimetics has attracted increasing attention from basic and applied research, especially in the fields of soft robotics and soft machines. The huge number of organisms with the specific structures and functions they have developed during evolution in adaptation to differing environments represents the basis for all biomimetic projects. Biomimetics has a high innovation potential and offers the possibility for the development of sustainable technical products.

Animals with their fascinating movement processes have long attracted interest in biomimetics. More recently, however, plants have also been recognized as valuable concept generators for biomimetic soft machines, as their movement is typically based on elastic deformation and lacks mechanically highly loaded localized joints. The potential of plant-inspired materials development for soft robots and soft machines is demonstrated by several recent research projects executed in collaboration of the Clusters of Excellence livMatS and IntCDC. Examples include (1) bioinspired 4D-printed hygromorphic selflocking soft machines with architected mesostructure and differential hygro-responsiveness inspired by the bracts of the silver thistle, (2) self-adaptive hygroscopic building hulls and envelopes inspired by the movement of the scales of pine cones, and (3) computationally designed self-adjusting 4D-printed wearable orthotic devices with motion mechanisms inspired by winding lianas. Special emphasis in these studies is laid on embodied energy and embodied intelligence found in moving plant organs, which offer a huge potential for a new generation of materials systems for soft robots, sustainable architecture and technical applications in general.

A15 FROM FISH TO FILTER: DEVELOPMENT OF A BIO-INSPIRED FILTER MODULE TO REDUCE MICROPLASTIC EMISSIONS FROM WASHING MACHINES Thursday 7th July 2022

15:50pm-16:05pm

Leandra Hamann, Institute of Evolutionary Biology and Ecology, University of Bonn, Alexander Blanke, Institute of Evolutionary Biology and Ecology, University of Bonn lhamann@evolution.uni-bonn.de Plastic particles smaller than 5 mm, so-called microplastics, are constantly released into the environment through everyday behaviours.

SCIENCE ACROSS BOUNDARIES ABSTRACTS 70

Besides emissions from tyre wear, cosmetics, or artificial turfs, microplastic fibres from washing machines have a high share of microplastic emissions in Europe, with around 20 to 220 g per person and year. To identify innovative filtration mechanisms that lay beyond conventional engineered solutions, 35 particle separation mechanisms of suspension feeders were reviewed for their potential to develop a bio-inspired filter module for washing machines. Ram-feeding fishes were selected for detailed analysis based on their ability to use cross-flow filtration, process large volumes of water, retain particles in a similar size range, and have an inherent cleaning mechanism.

The gill arch system of five species (Clupeiformes, Scombriformes), in which elongated gill rakers with denticles retain particles, was studied using optical microscopy, µCT, and videography to determine relevant filtration parameters. The results show differences in gill raker morphology, filtration area, and mesh size, indicating two cross-flow filtration variations: Scomber scombrus and Rastrelliger kanagurta (Scombriformes) use surface structures and mucus as adhesive material to increase particle retention, whereas Clupea harengus, Sardina pilchardus, and Engraulis encrasicolus (Clupeiformes) use a purely mechanical separation mechanism. The morphological traits of the clupeid filters were abstracted into parametric models to study fluid dynamics and determine the filtration efficiency in numerical and experimental experiments. Through an iterative process, the models are currently optimised to fit the requirements of washing machines and retain microplastic fibres.

A16 EFFECTS OF FLEXIBLE OWL-INSPIRED SERRATIONS ON AERODYNAMIC PERFORMANCE AND NOISE REDUCTION Thursday 7th July 2022

17:20pm-17:35pm

Jianwei Sun, Chiba University, Koichi Yonezawa, Central Research Institute of Electrical Power Industry, Liu Hao, Chiba University sunjianwei@chiba-u.jp Owls are a master to achieve silent flight in stealthy hunting or prey detection owing to their featured wing morphologies of leadingedge serrations, trail-edge fringes, and velvet-like surfaces. While the aeroacoustic characteristics of the owl-inspired leading-edge serrations has been a hot topic in terms of aerodynamic performance and noise suppression, their effects of serration-flexibility and passive deformation remain yet poorly studied. We have recently investigated experimentally the aerodynamic and acoustic performance of the propeller blades with both flexible and rigid serration-like appendages attached onto the blade tip. We utilized a high-speed camera system to measure the dynamic deformations of the serration-like structures and examined the aeroacoustic features of the various blades. Using three propeller blade models with the leading-edge (LE) serrations, we found that the flexible LE-serrated blade displays an optimal aeroacoustic performance with the high-frequency broadband noise suppressed remarkedly. Our results indicate that the flexible serrations with appropriate stiffness enable a pronounced sound reduction at high frequencies while sustaining the aerodynamic performance comparable to that of the non-serrated blades.

ANNUAL CONFERENCE MONTPELLIER 2022

A17 BIOMECHANICS OF CONTROLLABLE ATTACHMENT IN CLIMBING ANIMALS Thursday 7th July 2022

14:20pm-14:50pm

David Labonte, Imperial College London d.labonte@imperial.ac.uk Many small vertebrates and arthropods are able to run with sticky feet, and must hence be able to rapidly switch between strong attachment and effortless detachment. The timescale over which contacts are formed and broken precludes chemical control. Instead, terrestrial climbing animals appear to rely on mechanical `switches’. Recently, strong evidence has emerged that at least some of these switches are universal: Whether adhesive pads are `hairy’, `smooth’, `wet’ or `dry’ pads, there appears to exist a linear relationship between the shear force, applied in parallel to the surface, and the adhesive force, normal to the surface, required to detach them. This ‘shear-sensitivity’ provides a rapid mechanical switch, enables larger animals to maintain approximately constant safety factors despite smaller surface-tovolume ratios, and has implications for optimal step coordination patterns during climbing on vertical and inverted substrates. The control of adhesion via shear forces is deeply integrated with the anatomy and locomotion of climbing animals, and involves both active neuro-muscular control, and rapid passive responses. The resulting dynamic adhesive systems are robust, reliable, versatile and nevertheless remarkably simple. They may thus serve as suitable inspiration for the design of climbing robots.

A73 SUBWAVELENGTH BIOINSPIRED ACOUSTIC PANELS Thursday 7th July 2022

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A75 DRAG REDUCTION EFFECT OF PENGUIN-FEATHER-MIMETIC RIBLETS UNDER VARIATION IN FLOW DIRECTION Thursday 7th July 2022

15:35pm-15:50pm

Ryosuke Saito, Tokyo Institute of Technology, Takeshi Yamasaki, Yamashina Institute for Ornithology, Hiroto Tanaka, Tokyo Institute of Technology saito.r.ag@m.titech.ac.jp Since penguins swim underwater to forage in the sea, their body surface presumably evolved to minimize fluid friction drag. The barbs of their body feathers are longitudinally oriented and form a group of micro ribs. Here, we hypothesized that the barbs on the surface work as riblets to reduce friction drag. Additionally, considering the various maneuvers of penguins, the drag reduction effect of the barbs could be robust to change in the flow direction. To test these hypotheses, we designed trapezoidal riblets based on the spacing and cross-sectional shape of the barbs, followed by fabrication of polyimide-film riblets by ultraviolet laser scanning ablation. The drag of flat plates with the fabricated riblets was measured in a water tunnel with a load cell. Four different cross-sectional shapes of the riblets were compared. One was a small-scale riblet. The other three were at-scale riblets with three different widths of the rib ridge. Flow angles of 0° to 45° were tested with the at-scale riblets. As a result, the small-scale riblet reduced drag by around 1% at the flow speed corresponding to cruising swimming of 1.4 m/s. The at-scale riblets with medium ridge, which is the most penguin-like cross-sectional shape, also reduced drag by around 0.5% at the flow speed corresponding to high-speed swimming up to 3.79 m/s. The at-scale riblet with medium ridge showed the best robustness to flow direction, where drag was reduced to 15° flow angle. Additionally, we will investigate the drag reduction effect for a 3-D spindle body model.

17:35pm-17:50pm

James Gaffney, University of Bristol, Hernaldo Mendoza Nava, University of Bristol, Marc Holderied, University of Bristol james.a.gaffney@bristol.ac.uk Deaf moths evade bat predation by reducing the amplitude of their echo signature. This has been achieved by evolving repeating structures on their wings which strongly absorb sound. The thickness of the wings are much thinner than the wavelengths they absorb, up to 1%, due to this subwavelength property moth wings can be classified as metamaterials.

The purpose of this work is to profiteer from the bat-moth arms race and scale-up the metamaterial mechanism from ultrasound to audible frequencies. We design, build and test a moth-inspired acoustic absorbing panel which is tuned to within the human-hearing range that is extremely thin. In doing so, we also show that the biological mechanism can work at audible frequencies. As the target frequencies drop, the wavelengths increase, therefore the dimensions of the proposed metamaterial absorbing panel also increases. However, the proposed biomimetic absorbing panel (containing the moth-like repeating structure) is still extremely thin compared to the target frequency. This biomimetic sound absorber has the advantage of being as efficient as existing acoustic sound absorber panels but is significantly less thick.

A76 NANO-BIOMIMETICS – THE NEXT STEP IN BIO-INSPIRED RESEARCH?!

Thursday 7th July 2022

16:50pm-17:20pm

Jan-Henning Dirks, Hochschule Bremen - City University of Applied Sciences Bremen jan-henning.dirks@hs-bremen.de Like most research fields, biomimetic research has changed notably over the past centuries. However, successful biomimetic research has always been limited by available methods. Successful technological transfer of bio-inspired principles in aero- and hydrodynamics, materials sciences and structural and civil engineering involved traditional machining conventional manufacturing techniques. Only with recent developments in 3D printing, these fields have gained additional biomimetic interest. Improved and more affordable computational power have also increased computer based additional biomimetic research fields, such as bio-inspired neuronal networks and machine learning. In the past decades there have also been significant advances in the field of micro- and nanostructuring. Self-organizing surface modifications now allow to mass produce bio-inspired optical structures and other miniature topological features. The most recent advances in manufacturing technology however now start to push this limit even further and allow the full control of molecular assemblies of highly complex structures. The ability to assemble complex molecules might

ANNUAL CONFERENCE MONTPELLIER 2022

bring biomimetics to a whole new level - nano-biomimetics. This talk will discuss the possible role of nano-biomimetics and highlight how this exciting research field might allow to transfer biological principles from protein structures, molecular motors, cellular membranes and even extracellular matrixes into truly bio-inspired technological applications.

A425 TOWARDS MOTH WING INSPIRED SOUND ABSORBING MATERIALS Thursday 7th July 2022

15:05pm-15:20pm

Thomas Neil, University of Bristol, Zhiyuan Shen, IMEC Marc W. Holderied, University of Bristol t.r.neil@bristol.ac.uk The 65 million year acoustic arms race between moths and bats has led to the evolution of numerous different defence strategies amongst moths against bat echolocation. Some moths have evolved passive defences such as ultrasound absorbing scales, which diminish the strength of a moth generated echo returning to a bat. The scales work by resonant mechanisms and are much smaller than the wavelength of the sound which they absorb. This unique architecture opens avenues for bioinspired sound insulation solution that are much smaller than current technical sound absorbers. Previous works have looked at sound absorption by moth scales in free space, but to determine their effectiveness as a sound insulating solution for buildings, their performance must be measured when resting on a hard substrate.

Here, we measure the potential for moth wings to act as a sound absorbing surface coating for acoustically reflective substrates. Moth wings were found to be efficient sound absorbers, reducing reflection from an acoustically hard surface by up to 87% despite a thickness to wavelength ratio of up to 1/50 at the lowest frequency tested (20 kHz). Remarkably, after removal of the scales from the dorsal surface the wing’s orientation on the surface changed its absorptive performance: absorption remains high when the bald wing membrane faces the sound but breaks down almost completely in the reverse orientation. The finding that moth wings can act as a sound absorbing surface opens the door to the creation of biomimetic light-weight noise mitigation materials.

POSTER SESSION A9 BIRD GUST SOARING MANOEUVRE IDENTIFICATION FOR ENERGY EFFICIENT URBAN FLIGHT Wednesday 6th July 2022

POSTER SESSION

Freddie Turner, University of Bristol, Shane P. Windsor, University of Bristol, Luca Giuggioli, University of Bristol freddie.turner@bristol.ac.uk In addition to riding thermals and updrafts, birds can gain energy by flying through nonuniform wind fields. This has been widely studied in the context of dynamic soaring, where birds such as albatross

SCIENCE ACROSS BOUNDARIES ABSTRACTS 72

exploit large-scale wind gradients above the ocean surface to fly long distances with minimal energy expenditure. The same principles of energy extraction can in theory be applied to small scale spatial and temporal gradients (gusts), commonly found in urban environments as wind shear and turbulence. Although birds can be seen to perform complex interactions with the wind, measurement of the local airflow makes it difficult to attribute particular motions with energy gain. This makes it challenging to quantify such ‘gust soaring’ manoeuvres. We avoid issues of airflow measurement by utilising companion data sets of real and simulated urban bird flight trajectories, the former from GPS and IMU ‘backpacks’ carried by lesser black-backed gulls and the latter generated by a wind-aware path planner optimising for energy gain. Analysis of the two data sets using statistical machine learning techniques allows us to derive estimates for the prevalence of gust soaring in bird flight and analyse the manoeuvres being performed to gain energy. Further to its contributions in behavioural ecology, this research promises to benefit the design of flight control systems for future small uncrewed aerial vehicles, whose range and endurance are restricted by power constraints.

A77 TOWARDS MOTH WING INSPIRED SOUND ABSORBING MATERIALS Wednesday 6th July 2022

POSTER SESSION

Thomas Neil, University of Bristol, Zhiyuan Shen, IMEC, Marc W. Holderied, University of Bristol t.r.neil@bristol.ac.uk The 65 million year acoustic arms race between moths and bats has lead to the evolution of numerous different defence strategies amongst moths against bat echolocation. Some moths have evolved passive defences such as ultrasound absorbing scales, which diminish the strength of a moth generated echo returning to a bat. The scales work by resonant mechanisms and are much smaller than the wavelength of the sound which they absorb. This unique architecture opens avenues for bioinspired sound insulation solution that are much smaller than current technical sound absorbers. Previous works have looked at sound absorption by moth scales in free space, but to determine their effectiveness as a sound insulating solution for buildings, their performance must be measured when resting on a hard substrate.

Here, we measure the potential for moth wings to act as a sound absorbing surface coating for acoustically reflective substrates. Moth wings were found to be efficient sound absorbers, reducing reflection from an acoustically hard surface by up to 87% despite a thickness to wavelength ratio of up to 1/50 at the lowest frequency tested (20 kHz). Remarkably, after removal of the scales from the dorsal surface the wing’s orientation on the surface changed its absorptive performance: absorption remains high when the bald wing membrane faces the sound but breaks down almost completely in the reverse orientation. The finding that moth wings can act as a sound absorbing surface opens the door to the creation of biomimetic light-weight noise mitigation materials.

ANNUAL CONFERENCE MONTPELLIER 2022

SCIENCE ACROSS BOUNDARIES ABSTRACTS 73

A13 - ENVIRONMENTAL AND EVOLUTIONARY INFLUENCES ON PERFORMANCE CAPACITY AND ENVIRONMENTAL TOLERANCE ORGANISED BY: OLIVER H. WEARING (MCMASTER UNIVERSITY), JUSTIN CONNER (UNIVERSITY OF NEVADA) A96 EFFECTS OF CHANGING TEMPERATURES ON SOCIAL BEHAVIOR VIA EFFECTS TO METABOLISM IN THE COMMON MINNOW (PHOXINUS PHOXINUS) Thursday 7th July 2022

15:35pm-15:50pm

Amelia Munson, University of Glasgow, Daphne Cortese, University of Glasgow, Belle Valiulis, University of Glasgow, Shaun Killen, University of Glasgow amelia.munson@glasgow.ac.uk Social behavior is an important part of the life of many animals with consequences for foraging and predator avoidance. In many species, individuals consistently vary in how social they are, which has consequences for group level dynamics. Recent work has found that individuals with a higher metabolic rate are less social, likely because they prioritize finding food over avoiding predators. In ectothermic animals like fish, temperature influences metabolic activity with higher temperatures leading to an increase in metabolic rate. As an individual fish moves through its environment, it is exposed to temporally and spatially different temperatures which could alter the individual motivation to engage in social behavior. Warming temperatures caused by climate change could also lead to reductions in social behavior and changes in overall group cohesion via effects on metabolic rate. However, the speed by which changes in metabolic rate affect expressed social behavior is not well understood. To test this, we acclimated common minnows (Phoxinus phoxinus) to three different temperatures (14, 17 and 20˚C) over 4 weeks. We then measured maximum metabolic rate, standard metabolic rate and aerobic scope at acclimation temperature. In addition, we measured the routine metabolic rate, individual social behavior and group cohesiveness over a gradient of ramping temperatures (up to 23˚C). The results of this study will shed light into the effects of environmental change not only on an individual’s physiology and behavior but also on group behavior, which is essential to better predict the capacity of species to cope with climate change.

A99 DO FISHERIES INFLUENCE ADAPTATION TO CLIMATE CHANGE? Thursday 7th July 2022

17:20pm-17:35pm

Daniel Sadler, University of Jyväskylä, Stephan van Dijk, University of Jyväskylä, Phillip Watts, University of Jyväskylä, Silva Uusi-Heikkilä, University of Jyväskylä daniel.e.sadler@jyu.fi Overfishing may be the biggest threat to aquatic ecosystems; indeed, the extremely high mortality rates and distinct size selectivity can cause evolutionary change in exploited populations. Consequently, fished populations may become more vulnerable to other anthropogenic stressors due to reduced genetic variation and selection towards certain life-history strategies. We utilise three populations exposed to size selective harvesting: large-selected (removing 75% of the smallest individuals from the population, leaving the largest individuals), smallselected (removing 75% of largest individuals from the population, leaving the smallest individuals, mimicking fisheries), and randomselected (removing 75% of a population at random). Five generations of size-selective harvesting induced numerous phenotypic changes in exploited populations together with large-scale genetic changes.

These populations have now recovered from harvesting stress for nine generations. To determine the vulnerability to thermal stress of size-selectively exploited fish populations, we exposed individuals to three temperature treatments (34°C; 28°C; 22°C). We assessed differences among the selection lines in life history traits (growth and reproduction), physiological traits (metabolic rate and CTmax), behavioural traits (activity and feeding behaviour), and genetic traits.

We found that selection lines showed different responses to the thermal stressors, with particularly strong responses at 34°C, showing large alterations in life history traits. Furthermore, our control line (randomselected) showed greater resilience to thermal stress, particularly in relation to growth and metabolism suggesting fisheries-induced selection can erode adaptive potential. Our results allow for a greater understanding of synergistic stressors on fish populations under future climatic scenarios.

ANNUAL CONFERENCE MONTPELLIER 2022

A100 DOES GEOGRAPHIC ORIGIN MATTER? WHOLE-ORGANISM AND CELLULAR RESPONSES OF THE NORTHERN SHRIMP TO OCEAN WARMING AND ACIDIFICATION Thursday 7th July 2022

17:35pm-17:50pm

Ella Guscelli, Université du Québec à Rimouski, Denis Chabot, Institut Maurice-Lamontagne, Fisheries and Oceans Canada, Fanny Noisette, Institut des Sciences de la Mer, Université du Québec à Rimouski, Pierre U. Blier, Université du Québec à Rimouski, Piero Calosi, Université du Québec à Rimouski ella.guscelli@uqar.ca Species with a wide distribution can experience regionally and/or locally a wide range of environmental conditions, and potentially be acclimatized or adapted to them. Consequently, when defining species sensitivity to future global change scenarios it is to be considered that the geographical origin of an organism can influence its response to combined global change drivers. This study aimed at determining the physiological responses of the Northern shrimp, Pandalus borealis, from different locations along the latitudinal gradient of eastern Canada under future isolated and combined ocean warming and acidification.

Shrimp from the St. Lawrence Estuary, the Scotian Shelf, Esquiman Channel and the Northeast Newfoundland Coast were exposed under laboratory conditions for 30 days to a combination of three temperatures and two pH levels. Survival rates, aerobic performance, cellular capacity, and metabolomics profiles were assessed for each treatment and origin investigated. Our results show that shrimp survival is negatively affected by the increase in temperature and decrease in pH, regardless of shrimp origin. Additionally, shrimp from different origins show overall similar aerobic performances, aerobic scope increasing with increasing temperature and decreasing with decreasing pH. The maintenance of aerobic metabolism appears to be related to cellular adjustments specific to the shrimp origin, as confirmed by the lack of change in ATP concentration among shrimp from different origins. Overall, shrimp from all geographic origin investigated show similar responses, suggesting that sensitivity of this specie would not be defined by local environmental conditions. Nonetheless, costly cellular adjustments could redefine local sensitivities.

A107 FUEL THE BURN: MECHANISMS OF LIPID OXIDATION IN THERMOREGULATING HIGHALTITUDE DEER MICE (PEROMYSCUS MANICULATUS) Thursday 7th July 2022

15:20pm-15:35pm

Sulayman Lyons, McMaster University, Grant B. McClelland, McMaster University lyonssa@mcmaster.ca Deer mice (Peromyscus maniculatus) native to high altitude (HA) must sustain stable body temperatures by performing the metabolically demanding process of thermogenesis (heat production) in the face of constant cold and low oxygen availability. During maximal cold challenge in hypoxia (cold-induced VO2max), HA deer mice have been

SCIENCE ACROSS BOUNDARIES ABSTRACTS 74

observed to have higher capacities for lipid oxidation compared to their low-altitude (LA) conspecifics. The objective of this work was to determine the mechanisms that have enabled HA deer mice to have higher thermogenic rates of lipid oxidation compared to LA deer mice.

Using whole animal and biochemical techniques to assess fat oxidation, we assessed the various components of the lipid metabolic pathway and hypothesized that HA deer mice have increased their capacity to mobilize and transport fats to thermo-effector tissues. HA and LA deer mice were kept in either warm normoxia (WN) conditions or simulated high altitude (cold hypoxia; CH) conditions. We found that HA mice acclimated to CH have whole animal lipid oxidation rates greater than WN HA mice, and both WN and CH LA mice (p<0.05). CH HA deer mice also have higher circulatory delivery rates of non-esterified fatty acids and triglycerides (p<0.05). Tracer studies reveal that during VO2max, fat uptake occurred primarily by skeletal muscles in WN HA mice (p<0.05), but brown adipose tissue predominated fat uptake following CH acclimation (p<0.05). These results signify the high fat use by HA deer mice for heat production relies on rapid circulatory delivery to, and uptake by, thermo-effector tissues.

A110 PRENATAL ACOUSTIC COMMUNICATION AFFECTS THERMOREGULATION CAPACITIES IN AN ARID-ADAPTED BIRD Thursday 7th July 2022

15:05pm-15:20pm

Anaïs Pessato, Centre for Integrative Ecology, Andrew E. McKechnie, University of Pretoria, Mylene M. Mariette, Deakin University pessato.anais@gmail.com In birds, embryos use acoustic signals to synchronize hatching, learn calls or even solicit parental care. In zebra finches (Taeniopygia guttata), parents produce a peculiar “heat-call” during incubation at high ambient temperatures, which results in reduced nestling growth, in a temperature-dependent manner. Whilst being smaller may facilitate heat dissipation, we do not know whether being exposed to heat-calls prenatally affects thermoregulatory capacities and heat tolerance, and whether these effects persist into adulthood. Here, we tested the effects of experimentally delivered prenatal playback of heat-calls on thermoregulation at high temperatures at adulthood.

We used a respirometry system to measure individuals’ metabolic rate and evaporative water loss at air temperatures (Ta) gradually increasing from 25°C to 44°C, while simultaneously monitoring their body temperature. Remarkably, prenatal exposure to heat-calls affected heat tolerance at adulthood, with individuals exposed to heat-calls as embryos more likely to reach the highest Ta in morning trials. This was despite higher metabolic rate and evaporative water loss in heat-call individuals, partly driven by a stronger metabolic effect of moderate activity. At low Ta, however, heat-call exposed individuals had greater relative water economy, as predicted if heatcalls improve offspring thermoregulatory capacities. These results provide the first evidence that prenatal sound can have long-term effect on thermoregulation. Moreover, our findings point to a novel mechanism underlying developmental plasticity of thermal tolerance.

ANNUAL CONFERENCE MONTPELLIER 2022

A112 MECHANOTRANSDUCTION AND THE REGULATION OF COLLAGEN DEPOSITION

BY TROUT CARDIAC FIBROBLASTS DURING THERMAL ACCLIMATION Thursday 7th July 2022

17:50pm-18:05pm

Todd Gillis, University of Guelph, Leo G. Nataprawira, University of Guelph, Elizabeth F. Johnston, University of Guelph tgillis@uoguelph.ca Thermal acclimation of some temperate fish species can stimulate changes in the physiological capacity of the heart. This is due to modifications to the active and passive properties of the myocardium.

These modifications include changes in the Ca2+ sensitivity of the contractile element and to the amount and composition of myocardial collagen. Interestingly, this response is sex specific. Using cultured cardiac fibroblasts, from male and female trout, we have been working to determine how a change in physiological temperature leads to a change in deposited collagen. This work has integrated experiments examining the effect of biomechanical stretch, TGF-B, testosterone, angiotensin II, and microRNAs on the cell signalling pathways that regulate collagen deposition and turnover. We propose that increased biomechanical stimulation of the heart, caused by an increase in vascular resistance and blood viscosity, triggered by a decrease in physiological temperature, activates mitogen-activated protein kinase signalling pathways through stimulation of mechanosensitive membrane proteins and the release of TGF-B. The end result is changes in the expression of gene transcripts and cellular proteins that support an increase in collagen deposition including matrix metalloproteinases, and collagen monomers. It was also found that cellular pathways associated with the deposition of collagen are stimulated by physiologically relevant levels of testosterone, and that these can be reversed through the expression of microRNA-29b.

These studies suggest that the phenotypic response of the heart to a change in environmental temperature is under complex regulatory control that is sex specific.

A114 COOL RUNNING: EVOLVED REDUCTIONS IN BODY TEMPERATURE AND THE METABOLIC COSTS OF THERMOREGULATION IN DEER MICE NATIVE TO HIGH ALTITUDE Thursday 7th July 2022

SCIENCE ACROSS BOUNDARIES ABSTRACTS 75

ancestry were held in warm normoxia (WN) or CH for 6 weeks, and then surgically instrumented with physiological telemeters. Mice in CH had significantly higher fH than mice in WN, underlain by reduced vagal tone and increased bbeta1-adrenergic tone on the heart, reflecting the metabolic challenges of CH. CH exposure led to marked reductions in Tb (~2˚C) in both lowlanders and highlanders. However, overlaid upon this plastic response to CH, highlanders had consistently lower Tb (~1˚C) than lowlanders. The combined effects of these plastic and evolved reductions in Tb were estimated to reduce metabolic demands by ~20%, based on theoretical expectations of Q10 effects and empirical measurements of the relationship between Tb and O2 consumption rate in these mice. Our results suggest that plastic and evolved reductions in Tb are important for overcoming the challenges at high altitudes, and provide a relatively rare example of evolved changes in Tb setpoint in a non-hibernating endotherm to cope with extreme environmental conditions.

A115 UNIVERSAL METABOLIC CONSTRAINTS SHAPE THE EVOLUTIONARY ECOLOGY OF DIVING IN ANIMALS Thursday 7th July 2022

14:50pm-15:05pm

Wilco Verberk, Radboud Universiteit, Piero Calosi, Université du Québec à Rimouski, François Brischoux, CNRS - La Rochelle Université, John Spicer, Plymouth University, Theodore Garland Jr, University of California Riverside, David T. Bilton, Plymouth University wilco@aquaticecology.nl Diving as a lifestyle has evolved on multiple occasions when airbreathing terrestrial animals invaded the aquatic realm, and diving performance shapes the ecology and behaviour of all air-breathing aquatic taxa, from small insects to great whales. Using the largest dataset yet assembled, we show that maximum dive duration increases predictably with body mass in both ectotherms and endotherms.

Compared to endotherms, ectotherms can remain submerged for longer, but the mass scaling relationship for dive duration is much steeper in endotherms than in ectotherms. These differences in diving allometry can be fully explained by inherent differences between the two groups in their metabolic rate and how metabolism scales with body mass and temperature. We therefore suggest that similar constraints on oxygen storage and usage have shaped the evolutionary ecology of diving in all air-breathing animals, irrespective of their evolutionary history and metabolic mode.

15:50pm-16:05pm

Oliver Wearing, McMaster University, Graham R. Scott, McMaster University wearingo@mcmaster.ca The evolution of endothermy was instrumental to the diversification of birds and mammals, and enabled colonization of previously uninhabitable niches around the globe. However, in extreme environments such as high altitude, with extremely cold temperatures and limited O2 and food availability, the significant energetic demands of maintaining high body temperature (Tb) could offset the advantages of endothermy. We hypothesised that evolved reductions in Tb help overcome the metabolic challenges of cold hypoxia (CH) in deer mice native to high altitude. Deer mice with lowland or highland

A116 PHYSIOLOGICAL PLASTICITY AND THE EVOLUTION OF ENVIRONMENTAL TOLERANCE IN THE COMMON TENREC Thursday 7th July 2022

16:50pm-17:20pm

Frank van Breukelen, University of Nevada, Las Vegas frank.vanbreukelen@unlv.edu We all assume that physiological plasticity is advantageous because it allows organisms to respond to diverse or changing conditions.

However, can being too plastic actually be detrimental? Malagasy common tenrecs, Tenrec ecaudatus, have many plesiomorphic traits

ANNUAL CONFERENCE MONTPELLIER 2022

and may represent an ancestral placental mammal. The physiology of these tenrecs is extraordinary. Tenrec body temperature (Tb) may approximate ambient temperature to as low as 12°C even when tenrecs are fully active. Conversely, tenrecs can hibernate with Tb of 28°C. During the active season, resting oxygen consumption may vary 25fold with little or no change in Tb. We found that tenrecs essentially place homeostatic processes like kidney function on hold when metabolism is low much like a hibernator. In contrast to Boreoeutherian hibernators like ground squirrels, tenrecs are surprisingly intolerant of extremes in ambient temperature (<8 or >34°C). While plasticity may confer numerous energetic advantages in consistently moderate environments, environmental extremes may have limited the success and distribution of plastic basal mammals.

A117 BABY ANIMALS ARE NOT SMALL ADULTS! PROXIMATE AND ULTIMATE MECHANISMS OF BROWN ADIPOSE TISSUE EVOLUTION IN THE NORTH AMERICAN DEER MOUSE Thursday 7th July 2022

14:20pm-14:50pm

Cayleih Robertson, McMaster University, Colin Nurse, McMaster University, Grant B. McClelland, McMaster University roberceg@mcmaster.ca For small, winter active endotherms living in cold ecosystems, thermal performance is critical for survival. Its unsurprising that populations of deer mice (Peromyscus maniculatus) adapted to high altitude, where ambient temperature is consistently lower than at sea level, have evolved an enhanced thermoregulatory capacity. As adults, these animals rely on an evolved, oxidative skeletal muscle phenotype to perform high rates of shivering thermogenesis. However, like most altricial mammals, the muscles of newborn deer mice are immature and unable to shiver. What happens when young animals face the same environmental challenges without the physiological tools as adults?

In this talk I will discuss my recent work on the evolution of brown adipose tissue (BAT) and whole animal thermal performance in young Peromyscus mice. I have shown that during postnatal development, high altitude deer mice have evolved to suppress thermogenesis by impeding BAT function. I will discuss both the proximate and ultimate mechanisms we hypothesize are driving this phenomenon, including how BAT acts as an endocrine organ and may help program adult metabolic phenotype. These data will highlight how selection can act differently on the same physiological system depending on life stage.

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Thursday 7th July 2022

Priyanka Yadav, University of Delhi, Manisha Jhajhariya, University of Delhi, Praveen Kumar Oraon, University of Delhi, Rajesh Tandon, University of Delhi, Ratul Baishya, University of Delhi, Shailendra Goel, University of Delhi, Mukunda Dev Behera, Indian Institute of Technology, Arun Chettri, Sikkim University, Tanvir Dar, Baba Ghulam Shah Badshah University priyanka994mh@gmail.com The genus Primula L. (Primulaceae) represents approximately 430 species, distributed all over the Northern Hemisphere in temperate to alpine regions. It is an important floristic element of the Himalayan flora and is considered an ecological indicator of the high-altitude vegetation. Many Primula species show two morphs (pin and thrum) based on style length. The stigma of pin plants is positioned at the entrance of the flower, exhibiting a long style, while in thrum flowers, the style is much shorter, leaving the stigma around halfway up the floral tube. Among these species, Primula denticulata exhibits a large extent of occurrence in a broad altitudinal range (2096-3700 m). A study was undertaken to understand the frequency, morphological and phenological variations between two morphs of the species along an altitudinal gradient in the Western Himalayas. We recorded the numbers of pin and thrum flower morphs at three different elevations (2337m, 3000m, and 3700m) during 2021 and 2022. Our results indicate variation in morph frequency at middle elevation i.e., 3000m, while at lower and higher elevations, both the morphs have an equal frequency. A delay was observed in the onset of phenological events with increasing elevation. We observed more numbers of floral visitors at lower and middle elevations than at higher elevations. The stigmatic surface of pin and thrum morphs were found to be different under Scanning Electron Microscope (SEM). Along with these morphological and phenological observations, genetic diversity analysis of P. denticulata is underway with 290 samples collected from different populations along the altitudinal gradient and 100 primer pairs designed from Simple Sequence Repeats (SSRs). As a result of this study, the correlation of morphological and phenological studies with genetic variation existing along the altitudinal gradient can be observed. The study will show the impact of changing environmental conditions on the diversity of the plant along the altitudinal gradient.

P6 EFFECT OF MORPHOLOGICAL, PHENOLOGICAL VARIATIONS AND MORPH FREQUENCIES ON POPULATION GENETIC DIVERSITY ALONG AN ALTITUDINAL GRADIENT IN HETEROSTYLOUS PRIMULA DENTICULATA

food provisioning and regular emersion can enhance or limit acclimation capacities of marine organisms. Here we investigate the physiological response of young Pacific oyster Crassostrea gigas exposed for 3 months to ambient and future (+3°C, -0.3 pH unit) climate scenarios under two food regimes (ad libitum vs restricted) and two tidal levels (subtidal vs intertidal, emersion twice daily) under laboratory conditions. Oysters were sampled for biometric and physiological rate measurements (respiration and food intake), biochemistry (energetic reserves and enzyme assay) and histology to evaluate their reproductive status. At the end of the experiment, oysters were further challenged with a viral disease to investigate the physiological cost of acclimation to these conditions and their immune response. Preliminary analyses suggest that food level was the most influential factor, followed by climate scenario and tidal level. We indeed found that growth, food intake, reproduction and disease resistance of oysters were negatively affected by food restriction. Future conditions enhanced oyster physiological rates and sexual maturation, particularly at high food levels. Finally, tidal level had no major effect on these variables, suggesting physiological compensatory mechanisms during emersion. Our study suggests that the oyster is robust to future climatic conditions, even when feeding was restricted. A detailed analysis of the results will be presented at the conference.

A101 EFFECT OF PHOTOPERIOD MANIPULATION IN FRESHWATER ON ACID-BASE REGULATION, SUBSEQUENT SEAWATER TRANSFER AND HYPOXIA TOLERANCE IN ATLANTIC SALMON (SALMON SALAR) Wednesday 6th July 2022

POSTER SESSION

Gam Le, University of British Columbia, Daniel Montgomery, University of British Columbia, Rachael Mackinnon, University of British Columbia, Daniel Laronde, University of British Columbia, Jeffrey Richards, University of British Columbia, Colin Brauner, University of British Columbia gamle@zoology.ubc.ca

A98 PHYSIOLOGICAL AND IMMUNE RESPONSE OF OYSTERS TO CLIMATE CHANGE AS A FUNCTION OF DIET AND TIDAL REGIME Thursday 7th July 2022

POSTER SESSION

POSTER SESSION

ANNUAL CONFERENCE MONTPELLIER 2022

POSTER SESSION

Coline Caillon, IFREMER, LEMAR UMR 6539, Fabrice Pernet, IFREMER, LEMAR UMR 6539, Elodie Fleury, IFREMER, LEMAR UMR 6539, Charlotte Corporeau, IFREMER, LEMAR UMR 6539 coline.caillon@ifremer.fr Ocean acidification and warming caused by increased anthropogenic carbon dioxide emissions poses a tremendous challenge to marine calcifiers such as intertidal bivalves. The approach to studying acclimation potential or adaptation to climate change are often conducted under artificial conditions where food is provided ad libitum and do not consider tidal emersion. These limitations present problems for extrapolating results to natural ecosystems. For instance,

Smolts are transferred into marine net-pens for a 2 year grow-out phase to yield market-sized fish. A major industry goal is to produce larger, more robust smolts with higher marine net-pen growth rates and survival, ultimately reducing the time farmed Atlantic salmon spend in the marine environment. Large smolts can be generated

by PT in recirculating aquaculture systems (RAS), but little is known about how this procedure affects susceptibility to elevated CO2 and hypoxia. To address this, Atlantic salmon were reared from hatch in freshwater (FW) 3ppt under continuous light (24:00) with or without photoperiod manipulation (PT) when fish reached one of three different sizes (230g, 580g of 1200g). The PT consisted of an 8 week exposure to (12:12 light:dark) followed by 4 week return 24:00, a treatment used in industry to induce smoltification. PT and non-PT fish were then exposed to 0 or 1.5% CO2 (hypercapnia) for 96h in FW (where blood and red blood cell pH was significantly reduced with no effect of PT) and then transferred to air equilibrated seawater (SW, 35ppt) for 7 days. Fish were sampled at 24h and 7 days in SW for measurement of blood ion/acid-base status, muscle water content and gill and kidney Na+/K+ ATPase activity. Blood pH, plasma Na+, Cl- and osmolality increased significantly from FW to SW but were stable at 7 days in SW in all treatments and fish sizes. Overall, there were no negative effects of elevated CO2 in FW RAS to ion and acid-base regulation following

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SW transfer. Fish exposed to 0% CO2 in FW were also transferred to SW for measurement of hypoxia tolerance. Interestingly hypoxia tolerance of the PT fish was higher than non-PT fish following 7 days in SW at 230g, but this was reversed when fish reached larger sizes, and hypoxia tolerance was lowest at fish 1200g.

A102 TOO COLD AND TOO HOT TEMPERATURES INCREASE PESTICIDE TOXICITY Thursday 7th July 2022

POSTER SESSION

Julie Verheyen, KU Leuven, Kiani Cuypers, KU Leuven, Robby Stoks, KU Leuven julie.verheyen@kuleuven.be Most studies on pesticide and temperature interactions only considered few temperatures, typically including an intermediate and a high temperature, thereby ignoring colder and extreme high temperatures, and daily temperature fluctuations (DTF), which can be perceived as stressful in natural populations. To predict organismal responses to warming, thermal performance curves (TPCs) can be used. These TPCs may also improve our insights in the fate of populations to warming in a polluted world, yet such studies are rare. We tested the effects of pesticide exposure and DTF on latitude-specific TPCs of Ischnura elegans damselfly larvae. While chlorpyrifos did not affect the life history traits at the intermediate temperatures (20, 24 °C), chlorpyrifos became toxic (reduced survival and growth) at the warmer temperatures (≥ 28 °C), and also (reduced growth) at the colder temperatures (12, 16 °C). At the extreme warm temperatures, acetylcholinesterase activity showed the strongest chlorpyrifos-induced inhibition, which contributed to the observed toxicity patterns in life history. Overall, pesticide exposure resulted in more concave-shaped TPCs compared to the solvent control. By taking a thermal performance curve perspective, our study could identify different toxicity patterns at low, intermediate and high-to-extreme temperatures. Our results indicate that making predictions on the fate of populations under warming based on TPCs may be biased when ignoring pesticide exposure. This highlights the importance of studying pesticide toxicity across a range of temperatures to make more realistic predictions about the impact of (i) pesticides in a warming world and (ii) warming in a polluted world.

A103 DILUTED SEAWATER AND AMMONIA-N TOLERANCE OF TWO MANGROVE CRAB SPECIES: INSIGHTS TO UNDERSTAND PHYSIOLOGICAL PLASTICITY IN CONTRASTED AND CHANGING ENVIRONMENTS Wednesday 6th July 2022

POSTER SESSION

Laura Mégevand, Centre Universitaire de Formation et de Recherche de Mayotte, Dimitri Theuerkauff, STARES, Claire l’Épine, Université de La Rochelle, Sophie Hermet, Université de Montpellier, Jehan-Hervé Lignot, Université de Montpellier, Elliott Sucré, Centre Universitaire de Formation et de Recherche de Mayotte

ANNUAL CONFERENCE MONTPELLIER 2022

laura.megevand@umontpellier.fr Studying the environmental tolerance of certain key species provides a better understanding of the pressures and variations experienced by certain ecosystems. For example, mangrove crabs, considered to be ecosystem engineers, are animals that show physiological adaptations and acclimations to constantly changing environments that are the receptacle of anthropogenic pollution. Through an ecophysiological approach, we studied two crab species inhabiting mangroves with opposite environmental parameters: (i) in the uninhabited island of Europa (Mozambique Channel), considered as a pristine ecosystem, and, (ii) on the island of Mayotte, facing chronic domestic wastewater discharges. The effects of diluted seawater (DSW) and increased ammonia-N were studied for two fiddler crab species: Gelasimus tetragonon (GT) on the island of Europa and Paraleptuca chlorophthalmus (PC) on the island of Mayotte. Osmoregulation curves and osmoregulatory capacity were determined along with O2 consumption rates after a 96-h exposure period. Histological analyses were carried out on two key metabolic organs: the hepatopancreas and the posterior gills. Results indicate that both crab species are good hyper-hypo-osmoregulators but only PC maintains a stable osmoregulatory capacity when exposed to ammonia-N. Oxygen consumption is increased in GT after 96 h of exposure to ammonia-N but this does not occur in PC. Finally, a thickening of the gill osmoregulatory epithelium was observed after 96 h in PC when exposed to ammonia-N but not in GT. Therefore, the two species do not have the same tolerance to DSW and increased ammonia-N. PC seems to develop physiological acclimation capacities in order to better manage nitrogenous enrichments. GT did not show the same physiological plasticity when exposed to ammonia-N and could be more at risk by this kind of stress. These different short-term physiological responses raise further questions of interspecific physiological plasticity (environmental adaptation or acclimation) for both changing natural environments and those under anthropogenic pressure.

A104 THE EFFECT OF PROGRESSIVE HYPOXIA ON SWIMMING MODE AND OXYGEN CONSUMPTION IN THE PILE PERCH, RHACOCHILUS VACCA Thursday 7th July 2022

POSTER SESSION

LeeAnn Frank, University of Miami: Rosenstiel School of Marine and Atmospheric Science, Leteisha Prescott, James Cook University, Molly Scott, James Cook University, Paolo Domenici, Institute for Biophysics-National Research Council (IBF-CNR), Jacob Johansen, Hawaii Institute of Marine Biology , John Steffensen, University of Copenhagen lcf51@miami.edu Hypoxia, an increasingly common stressor in coastal environments, lowers the capacity for aerobic activity such as sustained swimming.

This study examines the effect of self-depleting, progressive hypoxia on swimming performance and oxygen consumption of the pile perch, Rhacochilus vacca, at their optimal speed (1.9 body lengths·s-1). R. vacca is a labriform, median-paired fin swimmer that exhibits a clear gate transition from oxidative muscle-powered pectoral fin swimming to anaerobic muscle-powered burst swimming using the caudal fin. Using a closed-system swimming respirometer, R. vacca maintained strictly pectoral fin swimming at a consistent frequency and metabolic rate until reaching a critical oxygen saturation (Pcrit)

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of 38.6% air saturation (O2sat). Below Pcrit, R. vacca significantly increased pectoral fin beat frequency, followed by a transition to caudal bursting at 33.7% O2sat. The activation of burst swimming allowed R. vacca to swim for 44.4 minutes beyond Pcrit until reaching 29.2% O2sat. Excess post hypoxia oxygen consumption (EPHOC), lead to a significant increase in metabolic rate during recovery which took 1.89 h to return to original levels. Time to recovery and EPHOC did not differ from that accrued after exhaustive exercise, suggesting that this species has an anaerobic energy reserve that does not differ when stressed during hypoxia or exercise. This study that demonstrates in hypoxia, the modulation of swimming mode to glycolytic, caudal fin-based locomotion allows the maintenance of swimming well below Pcrit, provides a fundamental understanding of the physiological basis of sustained swimming in hypoxia.

A105 SEASONAL VARIABILITY IN METABOLIC RESILIENCE TO ENVIRONMENTAL STRESS IN A HAWAIIAN REEF FISH Wednesday 6th July 2022

POSTER SESSION

Leon Tran, Hawaii Institute of Marine Biology, Jacob L. Johansen, University of Hawaii at Manoa - Hawaii Institute of Marine Biology leontran@hawaii.edu The increasing frequency and intensity of marine heatwaves (MHW) and simultaneous water deoxygenation (i.e., hypoxia) resulting from anthropogenic climate change is increasingly affecting marine organisms worldwide. These stressors occur throughout the year, and marine organisms may be differentially vulnerable to these events across seasons. While most climate change projections highlight summer maximum temperatures as the greatest threat to coral reef organisms, this prediction has never been tested.

After characterizing local MHWs in Kāneʻohe Bay, HI, we compared the capacity of representative Hawaiian reef fish of commercial importance—the convict tang (Acanthurus triostegus; manini) —to tolerate the combined effects of acute thermal stress and reduced oxygen availability that occur during MHWs between seasons.

While marine heatwaves did not significantly differ in heating rate, duration, or warming anomaly (i.e., temperature increase above the seasonally varying threshold) between summer and winter, the metabolic response of A. triostegus significantly varied between seasons. We found that MHWs had a stronger effect on thermal sensitivity of standard and maximum metabolic rates with higher Q10 coefficients (i.e., an indicator of thermal stress) during winter MHWs. Hypoxia tolerance did not significantly vary between seasons, but winter MHWs caused a greater reduction in hypoxia tolerance compared to summer, despite the greater absolute temperatures of summer. We discuss the importance of clarifying climate change impacts year-round.

ANNUAL CONFERENCE MONTPELLIER 2022

A108 OXYGEN DELIVERY TO THE AVASCULAR RETINA OF BIRDS AND REPTILES Thursday 7th July 2022

POSTER SESSION

Mia Viuf Skøtt, Aarhus University, Christian Damsgaard, Aarhus University, Henrik Lauridsen, Aarhus University, Catherine J. Williams, Aarhus University, Nina Kerting Iversen, Aarhus University, Hans Malte, Aarhus University, Tobias Wang, Aarhus University, Jens Randel Nyengaard, Aarhus University Hospital mia.viuf.skoett@bio.au.dk The light-absorbing retina within the eye is one of the most energetically active tissues in vertebrates. Yet, the retinas of birds and reptiles lack internal blood vessels that would otherwise blur vision, questioning how their retinas can function without an efficient oxygen supply. To study this, we measured the PO2 through the entire eye of anesthetized birds, crocodiles, turtles, and lizards.

We show that all species primarily supply O2 to the retina from the choroid, a capillary network behind the retina. Additionally, birds supply O2 from a vascular structure within the eyeball, the pecten oculi, but this mode of O2 supply was not found in any of the reptiles. Furthermore, we found that some parts of the bird retina are anoxic, showing these parts of the bird retina function anaerobically.

These findings show that the dual presence of the pecten oculi and mechanisms for retinal anoxia tolerance likely originated in the crown group of birds. These respiratory mechanisms may have supported the development of thicker retinas in birds with more photoreceptors and ganglion cells and provided the morphological basis for the evolution of sharp vision in birds.

A109 THE INFLUENCE OF ENVIRONMENTAL AND ENDOCRINE FACTORS ON COLLAGEN REGULATORY PATHWAYS IN RAINBOW TROUT (ONCORHYNCHUS MYKISS) CARDIAC FIBROBLASTS Wednesday 6th July 2022

POSTER SESSION

Leo Nataprawira, University of Guelph, Todd Gillis, University of Guelph natapral@uoguelph.ca Cold acclimation induces cardiac remodelling in rainbow trout.

This remodeling can include changes in contractile function, cardiac hypertrophy as well as an increase in collagen content. To understand how collagen is regulated in the trout heart we have been studying the function of cultured trout cardiac fibroblasts, the cells responsible for collagen turnover. We have previously found that exposure of these cells to cyclical stretch and transforming growth factor beta 1 (TGF-β1) activate cellular signalling pathways involved in collagen deposition and increase collagen deposition.

In the current study, we have examined the influence of different levels of cyclical stretch, testosterone, and angiotensin II (ANG II), on the cell signalling pathways that regulate collagen deposition.

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We also examined how low temperature and TGF-β1 affected these responses. We found that the effect of cyclical stretch on collagen related signalling pathways is frequency and magnitude dependent.

In addition, testosterone treatment led to changes in gene expression that would support an increase in collagen deposition regardless of temperature. This includes changes in the expression of the gene transcripts for matrix metalloproteinase-9, collagen type 1 alpha, and tissue inhibitor of metalloproteinases 2. We also found that 1 µM of ANG II had no effect on collagen-associated gene expression. Our results also suggest that the effect of TGF-β1 on collagen deposition is temperature dependent. The results of this work provide mechanistic insight into the regulation of collagen deposition in the trout heart and how this is affected by temperature change. This research is funded by NSERC.

A111 A UNIQUE MACHINERY OF AMMONIA PRODUCTION AND EXCRETION IN AMMONOTELIC TELEOSTS UNDER AN ACIDIC ENVIRONMENT Wednesday 6th July 2022

POSTER SESSION

Hsin-Ju Chuang, Institute of Cellular and Organismic Biology (ICOB), Academia Sinica, Pung-Pung Hwang, Institute of Cellular and Organismic Biology (ICOB), Academia Sinica ruby840504@gmail.com Climate changes and anthropogenic activities cause environmental acidification in fresh water as in marine. Excreting ammonia as the main proportion of net acid secretion is a conserved physiological trait in both ureotelic mammals and ammonotelic teleosts. Teleosts generally excrete a much higher rate of ammonia in the gills than that in human kidney, and teleosts are more tolerant to acid as well. It is reasonable to hypothesize that ammonotelic teleosts may have developed unique mechanisms for ammonia production and excretion in the gills, which are different from that in mammalian kidney. Ammonia excretion and the mRNA expressions of ammonia transporters (nhe3, rhbg, and rhcg2) and glutaminase (GLS, gls) were activated in the gills by acidic acclimation. We identified a novel gill cell type (GLS cells), which are rich of GLS and mostly adjacent to the ammonia-excreting ionocytes (NHE cells). In the time-course experiments, ammonia excretion, GLS expressions and the number of GLS and NHE cells were simultaneously increased by several hours after acidic stress, suggesting that GLS cells play a triggering role in ammonia production/excretion to cope with acidic stress. Ammonotelic teleosts developed the trait of labor division between GLS cell (for ammonia production) and NHE cell (for ammonia excretion) in the gills, which may efficiently and timely trigger ammonia production/excretion for fish to overcome acidic environment during vertebrate evolution.

ANNUAL CONFERENCE MONTPELLIER 2022

SCIENCE ACROSS BOUNDARIES ABSTRACTS 80

A14 - MITOCHONDRIAL PLASTICITY AND ADAPTATION: PROXIMATE DETERMINANTS AND ULTIMATE CONSEQUENCES FOR ADJUSTMENTS TO ENVIRONMENTAL CONDITIONS ORGANISED BY: ANTOINE STIER (UNIVERSITY OF TURKU), KARINE SALIN (IFREMER),NICOLAS PICHAUD (UNIVERSITÉ DE MONCTON), LISA BJERREGAARD JØRGENSEN (AARHUS UNIVERSITY) C19 THE UNDERESTIMATED PROTEIN CODING POTENTIAL OF THE MITOCHONDRIAL GENOM Wednesday 6th July 2022

11:00am-11:30am

Sophie Breton, University of Montreal, Laura Kienzle, University of Montreal, Stefano Bettinazzi, University of Montreal, Marie Brunet, University of Sherbrooke, Christian Landry, Laval University, Xavier Roucou, University of Sherbrooke, Annie Angers, University of Montreal, Thierry Choquette, University of Montreal, Hajar Hosseini Khorami, University of Montreal s.breton@umontreal.ca Mitochondria possess a genome, a vestige of their bacterial ancestor.

Over the course of evolution, most of the genes of the ancestor have been lost or transferred to the nucleus. In humans, the mtDNA is limited to 37 genes, with little room for evolutionary novelties. This is radically different from bacterial genomes, which are much larger, and in which we can find genes inside other genes. These sequences are called alternatives open reading frames or altORFs, and they have key functions. By ignoring altORFS, have we underestimated the coding potential of the mitogenome? We found a downstream alternative ATG initiation codon in the +3 reading frame of the human mitochondrial nd4 gene. This newly characterized mitochondrial altORF encodes a 99-amino acids long polypeptide termed MTALTND4 with a completely different amino acid sequence from ND4. MTALTND4 is localized in mitochondria and is also found in the plasma, and it impacts mitochondrial physiology. These findings indicate that mitochondrial genes in humans (and other species) have gone unnoticed. This calls into question the evolution of the mitochondrial genome as well as the selection pressures exerted on the mitochondria and the mechanisms allowing the translation of these alternative proteins. We anticipate that more studies on the alternative mitochondrial proteome will expedite the discovery of new mitochondrial genes with key biological roles.

A163 FISH METABOLIC RESPONSE TO FRESHWATER HYPOXIA: PLASTICITY AND ADAPTATION Thursday 7th July 2022

15:35pm-15:50pm

Amélie Crespel, University of Turku, Katja Anttila, University of Turku, Tiphaine Menguy, University of Turku, Diego Blanco, University of Turku, Elina Chiesa, University of Turku amelie.crespel@gmail.com While hypoxia (i.e. low dissolved oxygen level in water) events occur naturally, global change and human activities have exacerbated their strength and temporal fluctuations. As populations may not be able to escape the hypoxic conditions, especially in freshwater ponds, it is crucial to understand how organisms can adjust and adapt to these fluctuating environments. When directly exposed, individuals may be able to adjust their phenotypes through plasticity, but continued exposure to hypoxia over generations may require adaptation and evolution. As the mitochondrial metabolism is the key component that fuel aerobic functions, the individual capacity to respond to the environmental change in oxygen availability is likely to rely on mitochondrial functions. Using two populations of wild three-spined sticklebacks (Gasterosteus aculeatus) exposed to different levels of hypoxia conditions in their natural habitats and experimentally exposed to fluctuating hypoxia (20% air saturation during the night and 100% during the day), we investigated the fish metabolic plastic and evolutionary response. We showed adaptation in fish growth and metabolic rate, fish exposed to hypoxia in their natural habitats possessing higher metabolic capacity, but limited evidence for plasticity to the experimental conditions. These responses were supported by the muscle mitochondrial metabolism, for which similar adaptation were observed. However, no differences were observed in the brain mitochondrial metabolism, suggesting tissue specific response to environmental changes. Overall, these results highlight the capacity

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of fish to adapt environmental changes across generations, relying on mitochondrial adaptation.

A164 HALF-OPENING THE MITOCHONDRIAL BLACK BOX: GENETIC, PRENATAL AND POSTNATAL ENVIRONMENTAL DETERMINANTS OF MITOCHONDRIAL AEROBIC METABOLISM IN THE WILD Wednesday 6th July 2022

09:45am-10:00am

Antoine Stier, Université Lyon 1, Coline Marciau, Institute for Marine and Antarctic Studies, University of Tasmania, BinYan Hsu, University of Turku, Suvi Ruuskanen, University of Jyväskylä antoine.stier@gmail.com Mitochondrial aerobic metabolism is suggested to play a central role in ecology and evolution by influencing animal performance, as well as acclimation and adaptation to environmental conditions through its impact on ATP, ROS and heat production. While mitochondrial aerobic metabolism is highly plastic, recent evidence suggests that consistent inter-individual differences through time do exist. Understanding the origin (e.g. genetic differences, early-life programming) of these consistent inter-individual differences is a key step to further understand how mitochondrial aerobic metabolism is shaping animal’s life and performance. We explored this question in a wild bird species (i.e. the pied flycatcher) by experimentally manipulating egg levels of thyroid hormones (i.e. prenatal environment), switching half of the chicks between nests after hatching (i.e. partial cross-fostering) and manipulating postnatal ambient temperature. By measuring mitochondrial aerobic metabolism of blood cells, we were able to show that the prenatal hormonal environment only had mild and sexspecific effects on mitochondrial aerobic metabolism. While variation in mitochondrial traits was only weakly explained by the nest of origin (i.e. genetic + prenatal effects: 10.8 ± 2.4%), the postnatal environment (i.e. nest of rearing) explained a large amount of variance (41.6 ± 6.2%).

Yet, postnatal nest cooling had no clear effect on mitochondrial aerobic metabolism, thereby suggesting that other postnatal environmental factors such as food availability or quality must be more important. Our results highlight that while genetic and prenatal factors likely contribute to inter-individual variation in mitochondrial aerobic metabolism, postnatal environmental factors are probably its main drivers.

A165 HIBERNATION IS SUPER COMPLEX: DYNAMICS OF ELECTRON TRANSPORT CHAIN SUPERCOMPLEXES Wednesday 6th July 2022

11:45am-12:00pm

Amalie Hutchinson, The University of Western Ontario, Brynne M. Duffy, The University of Western Ontario, James Staples, The University of Western Ontario asaab4@uwo.ca Complexes of the electron transport system can associate with each other to form supercomplexes (SCs) within mitochondrial membranes,

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perhaps increasing respiratory capacity or reducing reactive oxygen species production. In this study, we determined the abundance, composition, and stability of SCs in a mammalian hibernator, in which both whole-animal and mitochondria metabolism change greatly throughout winter. We isolated mitochondria from thirteen-lined ground squirrels (Ictidomys tridecemlineatus, TLGS) in different hibernation states, as well as from rats (Rattus norvegicus), and measured mitochondrial respiration. We also extracted mitochondrial proteins using two non-ionic detergents of different strengths, and quantified SC abundance using two-dimensional gel electrophoresis and immunoblotting. Rat heart and liver had fewer SCs than TLGS. Within TLGS, SCs are dynamic, changing among hibernation states within a matter of hours. In brown adipose tissue, Complex III composition in different SCs differed between the torpid and interbout euthermic phase of a hibernation bout. In heart and liver, complex III composition changed between seasons. Despite the dynamics of SCs, we found no correlation between SC abundance and mitochondrial respiration in liver and heart. We also evaluated the stability of liver SCs using a stronger detergent and found that the stability of SCs differed: torpor SCs were more stable than the SCs of ground squirrels in other states and rats. This study is the first report of SC changes during hibernation, and the first to demonstrate their dynamics on a short timescale.

A166 CHRONIC HYPOXIA TRIGGERS METABOLIC PLASTICITY IN THE BRAIN CORTEX OF MICE Wednesday 6th July 2022

11:30am-11:45am

Christian Arias Reyes, Université Laval, Fernanda Aliaga Raduán, Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Jorge Soliz, Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Vincent Joseph, Institut Universitaire de Cardiologie et de Pneumologie de Québec Université Laval christian.arias@gmail.com Species adapted to life in hypoxia have physiological mechanisms to optimize the oxygen use for energy production. Contrastingly, when exposed to chronic hypoxia, non-adapted organisms may see their health and biological fitness endangered. Specifically, due to its high energy demand and dependance on the aerobic metabolism, the brain is susceptible to be affected. In this scenario, the ability to modulate the functioning of aerobic and anaerobic metabolic pathways at cellular level (metabolic plasticity) may be key for successfully acclimatizing to hypoxia. Considering that FVB mice and SD rats show divergent phenotypes under chronic hypoxia, in this work we used high-resolution respirometry (OROBOROS) and spectrophotometric methods to investigate the metabolic adjustments occurring at mitochondrial and cellular levels in the brain cortex of male FVB mice and SD rats during acclimatization to hypoxia (0, 1, 7, 21 days -12%O2). The mitochondrial oxygen consumption (OCR), and the activity of enzymes representative of the glycolytic (hexokinase–HK), aerobic (pyruvate dehydrogenase– PDH), and anaerobic (lactate dehydrogenase–LDH) metabolism were measured. In mice we found an increase in the anaerobic metabolism (HK+LDH) during the first week of hypoxia followed by a later decrease (21 days) in the mitochondrial OCR. In rats, a late increase (day 21) in glycolysis (HK) occurs without further changes at mitochondrial or enzymatic levels. These findings suggest that chronic hypoxia triggers the metabolic plasticity in the brain cortex of mice. These mechanisms are not present in rats, which could explain, at least in part, the absence of common rats in high-altitude environments.

ANNUAL CONFERENCE MONTPELLIER 2022

A168 MITONUCLEAR INTERACTIONS MODULATE NUTRITIONAL PREFERENCE Thursday 7th July 2022

11:30am-11:45am

Florencia Camus, University College London, Sahutchai Inwongwan, University College London f.camus@ucl.ac.uk In nature, organisms are faced with constant nutritional options which fuel key life-history traits. Studies have shown that species can actively make nutritional decisions based on internal and external cues.

Metabolism itself is underpinned by complex genomic interactions involving components from both nuclear and mitochondrial genomes.

Products from these two genomes must coordinate how nutrients are extracted, used, and recycled. Given the complicated nature of metabolism, it is not well understood how nutritional choices are affected by mitonuclear interactions. This is under the rationale that changes in genomic interactions will affect metabolic flux and change physiological requirements. To this end we used a large Drosophila mitonuclear genetic panel, comprising 9 isogenic nuclear genomes coupled to 9 mitochondrial haplotypes, giving a total of 81 different mitonuclear genotypes. We use a capillary-based feeding assay to screen this panel for dietary preference between carbohydrate or protein. We find strong levels of sexual dimorphism for this trait, with females consuming a lot more protein than males. Furthermore, we find significant mitonuclear interactions modulating nutritional choices.

This work gives us deeper insights on how key metabolic interactions can have large implications on behaviour.

A169 ACCLIMATION CAPACITY AND THERMAL SENSITIVITY OF NOTOTHENIOID ENERGY METABOLISM Thursday 7th July 2022

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A170 LONGITUDINAL STUDY AND MITOCHONDRIAL METABOLIC TRAITS: A WAY TO MEASURE MITOCHONDRIA PLASTICITY OVER TIME Wednesday 6th July 2022

17:50pm-18:05pm

Jean-Baptiste Quéméneur, IFREMER, Karine Salin, IFREMER, Sophie Collet, IFREMER Jean.Baptiste.Quemeneur@ifremer.fr The challenge of coping with climate changes will depend in part on individual's ability to sustain energy production. Mitochondria play an important role by being plastic and supporting 90% of ATP production, which is essential for organism performance. However, although mitochondria are well studied, less is known about the evolution of mitochondria over time in the same individual. The aims of this study were to evaluate mitochondrial metabolic traits from the same individuals over time and especially their response after the exposition of animals to a reduction in oxygen level. Using a nonlethal biopsy, mitochondria from the red muscle of European sea bass (Dicentrarchus labrax, n=40) were measured monthly in three trials.

Following the second trial, oxygen level in fish tank dropped from 100% to 50% saturation. Metabolic traits of red muscle mitochondria were assessed as respiration rates (OXPHOS respiration, LEAK respiration), ATP production and cytochrome c oxidase (COX) activity, an estimate of mitochondrial density. For each mitochondrial metabolic traits, no difference was found at one month interval when fish were maintained at 100% oxygen saturation. COX activity responded to the oxygen drop: COX activity increased after a 4 week exposition of the fish to 50% oxygen saturation. Our results provide evidence of acclimatisation of individuals to changing environmental conditions. This study offers an insight into the potential of using longitudinal studies to understand mitochondrial plasticity by measuring the same individuals over time.

15:50pm-16:05pm

Felix Mark, Helmholtz Center for Polar and Marine Research, Felix.Christopher.Mark@awi.de Antarctic fish of the suborder Notothenioidei display remarkable metabolic adaptations to life in the Southern Ocean. These comprise very low, energy saving metabolic rates, higher mitochondrial densities, cold adapted enzymes, anti-freeze proteins and last but not least, the loss of hemoglobin in the icefishes (family Channichthyidae). Yet, those adaptations come at a premium and render Antarctic notothenioids especially vulnerable to a warming ocean. As the central players in aerobic energy metabolism, mitochondria and their acclimatory plasticity play an important role in buffering the effects of climate change and much depends on their thermal stability and acclimatory capacity.

I will present an overview of recent studies on notothenioid mitochondrial and whole animal respiration under acute and chronic thermal exposure and explore the differences in thermal reaction norms, leak rates and thermal stability of the individual respiratory complexes in Antarctic nototheniids (N. rossii, N. coriiceps), trematomids (T. eulepidotus, T. loennbergii) and the haemoglobinless channichthyids (C. hamatus, C. wilsoni).

A172 ARE CARDIAC MUSCLE PERFORMANCE AND MITOCHONDRIAL FUNCTION RELATED IN ATLANTIC SALMON (SALMO SALAR) AT HIGH TEMPERATURES? Thursday 7th July 2022

10:00am-10:15am

Julie Nati, Memorial University, Kathy A. Clow, Memorial University Doug Syme, University of Calgary, A. Kurt Gamperl, Memorial University julienati3@gmail.com Mitochondrial function [e.g., respiration, respiratory coupling ratio (RCR) and reactive oxygen species (ROS) production] is negatively impacted by high temperatures, and may limit fish cardiac performance and upper thermal tolerance. Nevertheless, direct evidence of this is lacking, and testing at different levels of organization will be critical to establishing whether this construct has validity. We acclimated salmon to 10 and 20°C for at least 2 weeks and then: used strips from half of the ventricle to simultaneously measure muscle work and O2 consumption (and thus efficiency) at 20 and 26°C; and the other half to obtain myocardial homogenates and isolated mitochondria so that

ANNUAL CONFERENCE MONTPELLIER 2022

mitochondrial functional parameters could be measured at the same temperatures. State 4 respiration for isolated mitochondria and State 2 respiration for homogenates, and absolute ROS production during these states, were positively correlated with resting muscle O2 consumption in fish acclimated to both temperatures. In contrast, we were unable to consistently identify relationships between mitochondrial parameters and O2 consumption/efficiency while the muscle was working. For example, the P:O ratio (Complex I) and RCR (Complex I+II) for these preparations were not related to the absolute efficiency of shortening work. Further, while total CI+CII ROS production was negatively correlated with the efficiency of shortening work in 20°C acclimated salmon, this relationship was not evident for 10°C acclimated fish. These results are consistent with previous data showing that warm acclimation improves cardiac mitochondrial function at high temperatures; but only provide a tenuous link between heart and mitochondrial performance in salmon under such conditions.

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A174 TISSUE AND SUBSTRATEDEPENDENT MITOCHONDRIAL RESPONSES TO HYPOXIA/ REOXYGENATION STRESS IN MARINE BIVALVE CRASSOSTREA GIGAS (THUNBERG, 1793) Wednesday 6th July 2022

09:30am-09:45am

Linda Adzigbli, Institute for Biological Sciences, University of Rostock, Inna Sokolova, Institute for Biological Sciences, University of Rostock, Eugene P. Sokolov, University of Rostock, Siriluck Ponsuksili, Research Institute for Farm Animal Biology (FBN), Institute of Genome Biology linda.adzigbli@uni-rostock.de

A173 MITOCHONDRIAL (DYS)FUNCTION AT HIGH AND LOW TEMPERATURE EXTREMES – COMPLEX I AS A COMMON CULPRIT? Wednesday 6th July 2022

10:00am-10:15am

Lisa Bjerregaard Jørgensen, Aarhus University, Andrea Milena Hansen, Aarhus University, Nicolas Pichaud, Université de Moncton, Johannes Overgaard, Aarhus University lbj@bio.au.dk Temperature is among the most important factors shaping the biogeographical distribution of ectotherm species. Thermal constraints on aerobic metabolism have been observed in several phyla at both high and low temperature and thermal adaptations of mitochondrial function are believed to play an important role for the variable thermal performance of ectothermic animals. Using a comparative system of Drosophila species with different thermal tolerance, we examined the thermal sensitivity of mitochondrial function at both high and low temperature extremes to explore a potential relation to organismal thermal tolerance. Mitochondrial function was measured in permeabilised thoraces using a substrate-uncoupler-inhibitor-titration protocol to sequentially stimulate components of the electron transport system. Preliminary results show that complex-I-driven respiration is severely challenged at both high and low temperature. Specifically, complex-I-driven respiration fails at a species-specific temperature that correlates strongly with minimal and maximal tolerance (CTmin and CTmax). However, for all species and at all temperatures, it was possible to restore a stable total oxygen consumption across temperatures when alternative substrates were provided (proline, succinate and glycerol3-phosphate). These observations suggest that loss of neuromuscular function and mortality at temperature extremes are more associated with failure of complex-I-driven respiration, rather than rates of fully stimulated respiration. Ongoing investigations are now examining if/how failure of complex-I-driven respiration could be associated with lowered energetic P:O ratios and/or increased production of reactive oxygen species, as these responses could explain the apparent connection to organismal failure.

Hypoxia is a major stressor for aquatic organisms. In organisms like the intertidal oyster Crassostrea gigas, adaptations to frequent fluctuations in oxygen levels require metabolic plasticity to maintain mitochondrial function and adjust to shifts in substrate availability.

This study investigated the effects of acute and long term hypoxiareoxygenation (H/R) stress (15 min and 90 min at ~0% O2 for acute and long term exposures, respectively, and 10 min reoxygenation) on respiration (Mo2) and reactive oxygen species (ROS) generation in the gill and digestive gland mitochondria of C. gigas respiring on different substrates (pyruvate, succinate, and palmitate). Oyster mitochondria showed high capacity for succinate oxidation under normoxia in both studied tissues. Mitochondrial responses to H/R stress strongly depended on the oxidized substrate, the activity state of mitochondria and the type of hypoxia exposure. In both tissues, oxidizing exposure to both H/R stress suppressed Mo2 and ROS generation in the resting (LEAK state) mitochondria oxidizing NADH-linked substrates (palmitate/pyruvate). However, after acute H/R stress, mitochondria in ADP-stimulated (OXPHOS) state increased ROS production despite suppressed oxygen consumption. In mitochondria oxidizing FADH2–linked substrate (succinate), acute H/R exposure strongly increased Mo2 and ROS in LEAK and OXPHOS states, whereas; ROS production after long term H/R exposure was similar to normoxic conditions despite Mo2 suppression. Suppressed ability to oxidize NADH-linked substrates indicates that mitochondrial Complex I might be the key target of H/R induced injury in oyster mitochondria, which can be partially offset by robust succinate oxidation capacity to support ATP production during frequent oxygen fluctuations.

A176 PRENATAL ACOUSTIC PROGRAMMING OF MITOCHONDRIAL FUNCTION FOR HIGH TEMPERATURES IN AN ARID-ADAPTED BIRD Thursday 7th July 2022

15:20pm-15:35pm

Mylene Mariette, CSIC, Eve Udino, Deakin University, Julia M. George, Clemson University, Matthew McKenzie, Deakin University, Anaïs Pessato, Deakin University, Ondi L. Crino, Deakin University, Katherine L. Buchanan, Deakin University m.mariette@deakin.edu.au Developmental programming is a major source of inter-individual variation that can tailor phenotypes to environmental conditions, including thermal conditions. While the underlying mechanisms

ANNUAL CONFERENCE MONTPELLIER 2022

of developmental plasticity are mostly unknown, there is growing evidence for the involvement of mitochondria in this process. Here, we investigate whether prenatal sound – increasingly recognised as an essential source of information for embryos – can program mitochondrial metabolism. In the arid-adapted zebra finch, prenatal exposure to “heat-calls”, produced by parents incubating at high temperatures, adaptively alters nestling growth in the heat. To test whether mitochondrial programming underlies this adaptive pattern, we measured red blood cell mitochondrial function in nestlings, exposed prenatally to either heat-calls or control-calls, and reared in contrasting thermal environments post-hatch. Exposure to high temperatures always reduced mitochondrial ATP production efficiency.

However, as expected to reduce heat production and improve growth, prenatal exposure to heat-calls improved mitochondrial efficiency under mild heat conditions. By contrast, when exposed to an acute heat-challenge, LEAK respiration was higher in heat-call nestlings.

Consistent with its role in reducing oxidative damage, LEAK under extreme heat was also higher in fast growing nestlings. These changes in mitochondrial function are consistent with the differential growth pattern induced by prenatal heat-calls. Our study therefore provides the first demonstration of mitochondrial acoustic sensitivity, and brings us closer to understanding the underpinning of acoustic developmental programming and avian strategies for heat adaptation.

A177 WHAT ANTS TELL US ABOUT METABOLIC AGEING Thursday 7th July 2022

09:30am-09:45am

Maïly Kervella, CNRS, François Criscuolo, CNRS, Frédéric Bouillaud, Institut Cochin (U1016) maily.kervella@iphc.cnrs.fr Theories on ageing emphasise the importance of metabolic rate and oxidative stress to determine longevity. Mitochondria being at the crossroads of energy metabolism and ROS, they would bring information on both at the same time. Social insect workers and queens share the same maternally inherited mitochondria through the germline, but are characterized by remarkable disparity in lifespan i.e. months vs. decades. The aim of our work was therefore to establish the first step in energetic profiles of the different ant castes of black garden ant, Lasius niger. We conducted our analyses on different scales, from the individual to the mitochondria. Ants from different castes were placed into respiration chambers, to establish their metabolic rate (oxygen consumption reported to the mass). Our results matched the rate of living theory predictions, with values in long-lived queens that are 5 to 6 times lower than for oldest workers (foragers) that showed the highest metabolic rates. To progress in understanding the cellular basis of this large difference in metabolic rate: higher density of mitochondria or higher recruitment of existing mitochondria, we undertook quantitation of mtDNA by QPCR, evaluation of mitochondrial density in different tissues by electron microscopy and mitochondrial enzymatic equipment from measurement of citrate synthase activity (first step of TCA cycle). We also evaluated antioxidant defence with catalase activity, and oxidative stress markers (glutathione, aconitase/ fumarase ratio).

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A180 DO NATURAL UCP1 VARIANTS PREDICT ECOPHYSIOLOGICAL AND THERMOREGULATORY CONSTRAINTS IN MAMMALS? Wednesday 6th July 2022

15:50pm-16:05pm

Martin Jastroch, The Wenner-Gren Institute, Stockholm University, Michael James Gaudry, The Wenner-Gren Institute, Stockholm University martin.jastroch@su.se Thermogenesis has been of paramount importance for the diversification and survival of many animal species, as it allows the maintenance of metabolism and biological function independent of external heat sources. In nature, we find many different forms of thermogenesis, ranging from facultative heat production to sustained elevated body temperatures in many birds and mammals. Yet, the interplay between thermogenesis and physiology/ecophysiology, as well as the underlying molecular mechanisms, are still debated. Here, we investigate how ecophysiological constraints have shaped the function of the mitochondrial uncoupling protein 1 (UCP1), which is the main thermogenic effector of mammalian brown adipose tissue. UCP1 resides in the inner mitochondrial membrane where, upon functional induction by free fatty acids, it catalyzes mitochondrial proton leak, collapsing the proton gradient that stores oxidation energy. The ensuing futile cycling of protons increases substrate oxidation and thus heat production. Central questions remain regarding the exact mechanism by which UCP1 facilitates proton leak, largely stemming from the lack of a crystal structure of the protein. We adopt a comparative approach, targeting species with extreme ecophysiological characteristics expected to culminate in drastic differences in thermoregulatory demands and thus UCP1 function, to provide insights into protein structure-function relationships. We compared key UCP1 variants by ectopically expressing them in HEK293 cells and assessing their function using plate-based respirometry techniques. I will focus on UCP1 of marsupials, representing a sister clade of modern eutherians, of tenrecs, representing the early diverged Afrotherian clade, and of naked mole rats, is well-suited to survive in hypoxic burrows that exhibit high year-round temperatures (30-34°C). Our data give insights on the evolution of UCP1 thermogenic function, a deeper understanding of structure-function relationships and the adjustments in response to specific ecophysiological constraints.

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Nina Cossin-Sevrin, University of Turku, Antoine Stier, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR 5023 LEHNA, Mikaela Hukkanen, Institute for Molecular Medicine Finland, HiLIFE, University of Helsinki, Sandrine Zahn, Université de Strasbourg, CNRS, Institut Pluridisciplinaire Hubert Curien, UMR 7178, Vincent A. Viblanc, Université de Strasbourg, CNRS, Institut Pluridisciplinaire Hubert Curien, UMR 7178, Katja Anttila, University of Turku, Suvi Ruuskanen, University of Jyväskylä ninacossinsevrin@gmail.com In altricial birds, the number of siblings within a brood can affect offspring competition for resources and rearing conditions, with potential consequences on offspring phenotype and developmental trajectories. Brood size is indeed known to impact offspring physiological and behavioral traits (e.g., begging rates, body mass gain, post-fledging survival). Mitochondria are the powerhouse of cells, which set the efficiency at which organisms convert food into cellular energy (ATP), but also the rate of production of pro-ageing compounds. Mitochondrial aerobic metabolism is expected to play a fundamental role in explaining individual heterogeneity in growth trajectories and survival. To date, little information is available on mitochondrial responses to early-life rearing conditions in the wild.

While some studies have investigated the impact of brood size on whole organism metabolic rate, no study so far has investigated the impact of brood size and early rearing conditions on cellular energetics. Here, we conducted an experimental brood size manipulation using wild great tits (Parus major) to investigate the impact of rearing conditions on offspring mitochondrial aerobic metabolism (measured in blood cells), subsequent growth trajectories and survival. We performed cross-fostering between nests allowing to unravel the contribution of genetic vs. early-stage environmental determinants on mitochondrial aerobic metabolism. We expected nestlings mitochondrial aerobic metabolism to differ according to the brood size in which they were raised. We predicted mitochondrial aerobic metabolism either to increase in larger broods (promoting begging and fast growth to outcompete siblings), or alternatively, to decrease due to metabolic exhaustion under intense sibling competition for resources.

A182 THE COMPLEX MODE OF ACTION OF THE LAMPRICIDE NICLOSAMIDE IN ISOLATED LIVER MITOCHONDRIA Wednesday 6th July 2022

A181 DO EARLY-LIFE ENVIRONMENTAL CHALLENGES IMPACT MITOCHONDRIAL AEROBIC METABOLISM AND SUBSEQUENT GROWTH? A BROOD SIZE MANIPULATION IN WILD GREAT TITS Wednesday 6th July 2022

17:35pm-17:50pm

15:35pm-15:50pm

Oana Birceanu, University of Western Ontario, Brittney G. Borowiec, Wilfrid Laurier University, Michael P. Wilkie, Wilfrid Laurier University, Jonathan M. Wilson, Wilfrid Laurier University, Allison McDonald, Wilfrid Laurier University obircean@uwo.ca Niclosamide (Nic) and TFM (3-trifluoromethyl-4-nitrophenol) are used to control invasive sea lamprey populations in the Laurentian Great Lakes. While TFM is selective to sea lamprey, Nic is more toxic in lamprey and other species. Nic is co-applied (1%) with TFM, reducing TFM requirements without comprising selectivity. It is established that TFM uncouples mitochondrial oxidative phosphorylation in fish, but the mode of action of Nic in fishes remains unclear. Using isolated mitochondria from rainbow trout and upstream migrant sea lamprey livers, we tested the hypothesis that Nic uncouples oxidative phosphorylation when applied alone and in TFM:Nic mixtures. At low

SCIENCE ACROSS BOUNDARIES ABSTRACTS 85

(&lt;1 uM) Nic concentrations, ADP-independent respiration was higher than controls and TFM alone, suggesting that Nic is a potent uncoupler in both species. At levels &gt;1 uM Nic, respiration rates collapsed in lamprey, but not in trout, suggesting that Nic has a different mode of action in the two species. In mixtures, the interaction between the lampricides was complex: in trout, lower doses of the mixture were less toxic than Nic alone, while in lamprey, the mixture was more toxic to the mitochondria than either lampricide alone. Taken together, our data show that Nic (i) uncouples oxidative phosphorylation, (ii) interacts differently with the trout and lamprey mitochondria and (iii) in TFM mixtures, it may increase specificity for the lamprey. Information on the mode of action of Nic and TFM:Nic mixtures will help identify the cellular targets of the lampricides, to better understand their interaction and prevent non-target effects.

A183 THE SOPHISTICATED ELECTRON TRANSPORT SYSTEM OF THE LONGESTLIVED ANIMAL Wednesday 6th July 2022

18:05pm-18:20pm

Pierre Blier, Université du Québec à Rimouski, Enrique Rodriguez, University College London, Hélène Lemieux, University of Alberta, Tory M. Hagen, Linus Pauling Institute pierre_blier@uqar.ca In previous studies on Arctica islandica, a bivalve that can reach more than 500 years of age, we observed that mitochondria from this mollusk have particularly robust membranes that resist to peroxidation. We also observed a particularly lower rate of mitochondrial hydrogen peroxide efflux, when compared to shorter-lived bivalves. To delineate the structural and functional causes likely related to this lower efflux, we investigated the organization of super-complexes and documented the strength of control of respiration by the different complexes (complexes I, II, III and IV). Compared to short-lived species, A islandica have stronger electron flux control at the level of complex IV, relative to complexes I and II, as well as a higher level of organization of supercompexes.

A184 THE ROLE OF MITONUCLEAR INTERACTIONS IN THERMAL AND DIETARY ADAPTATION Wednesday 6th July 2022

15:20pm-15:35pm

Stefano Bettinazzi, University College London, Florencia Camus, University College London, Damian K. Dowling, Monash University, Nick Lane, University College London s.bettinazzi@ucl.ac.uk Mitochondria play a key role in energy metabolism through cellular respiration. Despite their importance, they are uniquely exposed to perturbation because their functions depend on the correct interaction between two distinct genomes, the mitochondrial and the nuclear DNA. Even mild incompatibilities between the two genomes could impact mitochondrial functions with downstream repercussions on individual fitness. Climate change predictions estimate an increase in

ANNUAL CONFERENCE MONTPELLIER 2022

temperature and its variability, changes in food web structures, but also in the distribution of populations. Events that may generate mitonuclear mismatches (e.g. hybridization between separate populations) are therefore expected to increase in frequency following the shifts in thermal niches. In addition, temperature and dietary regimes are well-known metabolic stressors whose variation can potentially exacerbate mitonuclear incompatibilities. The aim of this research was to test how far mitonuclear interactions contribute to thermal and dietary adaptation or breakdown in changing environments. I employed experimental lines of the fruitfly Drosophila melanogaster, characterized by mitonuclear match or mismatch, to investigate the combined impact of mitonuclear genotype, temperature, and diet modulation over a wide array of phenotypic traits, including mitochondrial functions, reactive oxygen species metabolism and life-history trade-offs. Results suggest that mitonuclear interactions might impact organismal fitness in an unpredictable way, potentially influencing local adaptation in a mutating world.

A185 FLIGHT MUSCLE MITOCHONDRIA ARE SEASONALLY PLASTIC IN A MIGRATORY SONGBIRD Wednesday 6th July 2022

12:00pm-12:15pm

Soren Coulson, University of Western Ontario, James F. Staples, University of Western Ontario, Christopher G. Guglielmo, University of Western Ontario scoulso8@uwo.ca Birds metabolically remodel their flight muscle prior to migration to meet the high energetic demands of migratory flight. The degree of plasticity mediated by changes in mitochondrial function is poorly understood but could be explained by two non-mutually exclusive hypotheses: variation in mitochondrial quantity or individual mitochondrial function. For each hypothesis, we predicted higher mitochondrial abundance and predict higher substrate oxidative capacity and reduced reactive oxygen species formation during migration, respectively. We evaluated both hypotheses using yellowrumped warblers (Setophaga coronata) captured during their autumn migration at Long Point, Ontario, Canada. Half of the birds were sampled in the migratory phenotype and the remaining birds were transferred to a short day photoperiod (9L:15D) and sampled in a non-migratory phenotype. We measured mitochondrial abundance via citrate synthase maximal activity in the pectoralis major flight muscle. We investigated mitochondrial function via high-resolution fluororespirometry on isolated pectoralis mitochondria. We measured O2 consumption and H2O2 formation rates from oxidation of lipid and carbohydrate substrates. We also measured oxygen consumption specific to electron transport system protein complexes using complex-specific substrates and inhibitors. Citrate synthase activity and mitochondrial respiration for each substrate and complexes II, III and IV were higher in the migratory phenotype, yet H2O2 formation rates were similar between phenotypes. These data suggest that pectoralis mitochondrial abundance and oxidative capacity are elevated during migration without increasing reactive oxygen species formation. Our findings support both hypotheses and indicate that mitochondrial function mediates seasonal metabolic plasticity in the pectoralis flight muscle of migratory songbirds.

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A188 CAN GROWTH CONDITIONS PREDICT ADULTHOOD BLOOD MITOCHONDRIAL FUNCTION AND SURVIVAL? Thursday 7th July 2022

11:00am-11:30am

Pablo Salmon, University of Glasgow & University of the Basque Country pablo.salmon@glasgow.ac.uk There is a wealth of evidence for the impact that early-life conditions, e.g., differences in growth rate, have on individuals’ later-life phenotype and performance. Mitochondria are believed to be a key player in this, as they not only fuel the cellular processes but are also involved in health and age-related disorders. Birds have surprisingly slow ageing rates and long lifespans for their body size and physiology. Recent work with avian models has highlighted the utility of determining mitochondrial function in their nucleated red blood cells (RBCs), which enables longitudinal sampling of mitochondria within individuals as they age. Here, we employ this new perspective to test, using zebra finches (Taeniopygia guttata), whether modifying an individual’s postnatal growth trajectory, using an ecologically-relevant scenario, results in consistent changes in adulthood mitochondrial functioning and if these relate to individual’s survival. Our results demonstrate that within individual age-related changes in mitochondrial function can be detected using RCBs in birds and they are evident by middle age.

However, despite that some of the mitochondrial traits show individual consistency, we found no link between adult RBCs mitochondrial function and the pace of early growth or mid-term survival. Further research across the life course will help to interpret the implications of the observed changes for individual performance and its sensitivity to environmental changes.

A189 MITOCHONDRIAL ACCLIMATION CAPACITIES: A PROXIMATE DETERMINANT OF METABOLIC CAPACITY AND STRESS TOLERANCE IN FISH? Wednesday 6th July 2022

14:50pm-15:20pm

ANNUAL CONFERENCE MONTPELLIER 2022

function and may help to protect cardiac bioenergetic function during or after periods of warming or O2 limitation in fishes. Furthermore, we found an acclimatory adjustment of mitochondrial sensitivity to inhibition by NO suggesting NO as a putative proximate determinant of mitochondrial acclimation and plasticity. Overall, our data show that mitochondrial acclimation capacities can provide key insights into how fish will respond to changing environments.

A190 THE VERSATILITY OF MITOCHONDRIAL SUBSTRATE OXIDATION IN INSECTS: A KEYSTONE FOR TEMPERATURE ADAPTATION? Wednesday 6th July 2022

09:00am-09:30am

Nicolas Pichaud, Université de Moncton nicolas.pichaud@umoncton.ca Insect species represent more than 70% of all animal species and are also known to have the highest metabolic rates and the most rapidly contracting muscles in nature. They have also colonized just about every habitat on earth and are thus confronted to a large range of temperature changes. We hypothesized that the capacity of insects’ mitochondria to oxidize different metabolic fuels is paramount for thermal adaptation in insects. By measuring oxygen consumption in permeabilized flight muscles of three different species (Apis mellifera, Drosophila melanogaster and Leptinotarsa decemlineata) from 6 to 45° C, we detected important and species-specific mitochondrial flexibility for substrate oxidation to sustain high oxygen consumption levels at high temperatures. Specifically, mitochondrial respiration sustained by complex I substrates sharply declined at high temperatures in A. mellifera and D. melanogaster, but this was compensated with important increases of succinate and/or glycerol-3-phosphate (G3P) oxidation. We then monitored for 12 months North American colonies of honeybees enduring extremely low and high temperatures, to assess the metabolism of honeybees transitioning from a summer to a winter phenotype. Our results show that complex I-induced respiration during winter is drastically reduced compared to summer, but that overall, mitochondrial respiration is increased during winter owing to succinate and G3P being prominent substrates used to keep the hive warm. Overall, our results suggests previously unknown adaptive mechanisms of mitochondria to temperature, and shed light on potential thermoregulating strategies used by insects' thorax muscles.

Lucie Gerber, University of Oslo lucie.gerber@ibv.uio.no With climate change, temperature and oxygen level in many aquatic environments may reach levels that can have direct negative effects on fish performance. There is an urgent need to understand the effects of prolonged and short-term warming and hypoxia on the physiology of fishes as the ability and strategies to cope with these stressors can vary considerably between species. Mitochondrial function is emerging as key determinants of fish metabolic capacity and stress tolerance due to the central role of cardiac energy metabolism and performance in fishes’ thermal and hypoxia tolerance. In addition, the signaling molecule nitric oxide (NO) is a potent a regulator of cardiac and mitochondrial function. Therefore, we explored cardiac mitochondria plasticity and acclimation capacities to acute heat or hypoxia stress and prolonged warm- or hypoxia- acclimation and the sensitivity of mitochondrial respiration to NO in two temperate species, the Atlantic salmon and sablefish. We found that warmand hypoxia-acclimation have beneficial effects on mitochondrial

A191 PLASTICITY AND ADAPTATION IN MITOCHONDRIAL FUNCTION IN KILLIFIS Thursday 7th July 2022

09:00am-09:30am

Patricia Schulte, University of British Columbia pschulte@zoology.ubc.ca Atlantic killifish are found in estuarine habitats along the Atlantic coast of North America. In these habitats, fish are exposed to thermal variation at multiple scales - at timescales from days to seasons, and across latitudes, such that the northern subspecies is locally adapted to cold temperatures, and the southern subspecies to warm temperatures. The northern and southern subspecies differ substantially

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in mitochondrial properties, with mitochondria from northern fish having greater respiratory capacity, which likely helps to support their greater whole-organism aerobic metabolic rates. However, this pattern is only observed in mitochondria from the liver, and not in mitochondria from the heart or the brain, emphasizing the importance of examining mitochondrial properties across tissues. We also find differences in mitochondrial oxygen affinity between species (assayed in liver mitochondria), with mitochondria from southern fish having greater oxygen affinity, consistent with their superior whole organism hypoxia tolerance. In addition to the putatively adaptive variation, both subspecies demonstrate substantial plasticity in mitochondrial properties. Acclimation to high temperature results in a strong suppression of mitochondrial capacity in both subspecies, mediated upstream of cytochrome c oxidase, which may help to compensate for the effects of acute exposure to high temperature on reaction rates.

In contrast, acclimation to low temperatures causes relatively modest increases in mitochondrial capacity, but in the northern subspecies only, it also causes substantial increases in mitochondrial density. These data demonstrate the many ways that mitochondrial properties are shaped by both plasticity and adaptation in this small fish.

A192 THE ENVIRONMENT WITHIN: SELECTIVE EFFECTS OF MITONUCLEAR INTERACTIONS thursday 7th July 2022

14:50pm-15:20pm

Ronald S. Burton, UCSD, Timothy M. Healy, Scripps Institution of Oceanography rburton@ucsd.edu Restricted gene flow has resulted in extensive population differentiation and adaptation to local environments in the tide pool copepod Tigriopus californicus. This differentiation has also set the stage for extensive coadaptation between nuclear and mitochondrial genomes, a form of intrinsic adaptation common to all eukaryotes. The extent of coadaptation is revealed in studies of interpopulation hybrids. There is significant variation in fitness among hybrids attributable to interindividual variation in genomic composition. Using development time as a proxy for fitness, we previously found that the mtDNA haplotype had a profound effect on the fitness of alleles across the nuclear genome of F2 hybrids. These effects were apparently mediated by mitochondrial performance and correlated with the degree of match or mismatch between mtDNA and nuclear alleles derived from the same parental population. Here we attempt to extend this work in two ways: 1) using RNA-seq on developing F2 larvae to examine relationships between gene expression and larval developmental rates, and 2) using 14+ generations of interpopulation crossing to breakdown linkage disequilibrium to better localize genomic regions involved in mitonuclear coadaption. RNA-seq results suggest the several nuclear-encoded subunits of electron transport system complexes (especially Complex 1) are upregulated in fast developers, and genes involved in ROS metabolism are also differentially expressed.

Selection for developmental rate in advanced generation hybrids was largely ineffective, producing no consistent change in mitochondrial performance or developmental rate; still allelic frequencies on parts of chromosomes 2 and 3 responded to selection, genomic regions previously identified in the F2 studies.

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A402 THE DETERMINATOR: HOW DOES RESPIRATORY COMPLEX I CONTROL METABOLIC FLUX, FERTILITY AND LONGEVITY? Wednesday 6th July 2022

17:05pm-17:35pm

Nick Lane, University College London, nick.lane@ucl.ac.uk Mitochondria are not merely the powerhouses of cells, responsible for ATP synthesis, but are also the engines of biosynthesis, as the Krebs cycle provides the precursors for amino-acid, sugar, fatty-acid and nucleotide synthesis, shaping all aspects of growth and development.

Flux through the Krebs cycle is contingent on NADH oxida(on, which in turn depends on respiratory function, particularly at complex I. This depends on two genomes, mitochondrial and nuclear, which have radically different modes and tempi of evolution. Even trivial incompatibilities between these genomes can have large effects on fitness, especially when subjected to metabolic or redox stress. Complex I is especially prone to dysfunction as it is the largest complex, with the most mitochondrially encoded subunits, and is a major source of physiological reactive oxygen species. Our work using the Drosophila mitonuclear model shows that beOer complex I function in third-instar larvae and young adults corresponds to faster development, greater fer(lity, higher survival, longer lifespan and better physical performance.

By fixing an isogenic nuclear background and varying mtDNA in D. melanogaster, we can dissect the mitochondrial contribution to each phenotype using tissue-specific fluorespirometry and metabolomics.

Yet the molecular basis for these unexpected differences remains unclear. Our results suggest that complex I function is not shaped directly by mitonuclear coevolution, nor by adaptive selection on mitochondrial DNA alone, but may depend on epistatic effects linked with macromolecular organization, perhaps cristae membrane structure and supercomplex assembly, which we will explore in future work.

POSTER SESSION C15 CHRONIC ZINC EXPOSURE LEADS TO ADAPTIVE CHANGES OF MITOCHONDRIAL FORM AND FUNCTION IN VASCULAR ENDOTHELIAL AND SMOOTH MUSCLE CELLS Wednesday 6th July 2022

POSTER SESSION

Olivia Bagshaw, Brock University, Fereshteh Moradi, Brock University, Christopher Moffatt, Brock University, Hillary Hettwer, Brock University, Ping Liang, Brock University, Jeremy Goldman, Michigan Technological University, Jaroslaw W. Drelich, Michigan Technological University, Jeffrey Stuart, Brock University oliviabagshaw@gmail.com

SCIENCE ACROSS BOUNDARIES ABSTRACTS 88

Zinc is an environmental toxin that can accumulate in the mitochondrial matrix and inhibit bioenergetic functions. However, most studies of the effects of Zn2+ have been performed in isolated mitochondria or enzyme systems and not in intact cells. Further, while environmental exposure to Zn2+ will in many cases be chronic, most studies have focused on acute effects. Here we have evaluated the effects of acute (1 hour) and chronic (one-week continuous) Zn2+ exposure in primary rat aortic smooth muscle and endothelial cells, which are previously documented to demonstrate zinc sensitivity both in vitro and in vivo.

As several studies have shown mitochondrial respiratory complex inhibition in the low micromolar range, we chose two treatment conditions: 5 µM or 50 µM ZnSO4. Following treatment, we performed Seahorse metabolic flux assays and quantitative fluorescence imaging of mitochondrial networks. Our results indicate virtually no evidence of acute zinc effects on oxygen consumption rates, glycolytic activity, or mitochondrial network morphology. However, chronic treatment increased basal and maximal oxygen consumption and enhanced mitochondrial network fusion in smooth muscle cells, while increasing network fragmentation in endothelial cells. We conducted a transcriptomic analysis of both cell types following one week Zn2+ treatment. Our results indicate that expression of genes associated with mitochondrial function including oxidative phosphorylation and mitochondrial fusion/fission are differentially affected in the two cell types. These results indicate that, while acute Zn2+ exposure has limited effect on intact cells, chronic exposure results in adaptive changes of mitochondrial form and function in a cell-type specific manner.

C18 THE ALTERNATIVE GENE MTALTND4: UNCOVERING THE MITOCHONDRIA’S HIDDEN FUNCTIONS Wednesday 6th July 2022

POSTER SESSION

Thierry Choquette, Université de Montréal, Sophie Breton, Université de Montréal, Laura Kienzle, Université de Montréal, Hajar Hosseini Khorami, Université de Montréal, Stefano Bettinazzi, Université de Montréal, Annie Angers, Université de Montréal thierry.choquette@umontreal.ca Mitochondria are most known for their role in energy production, but they are also implicated in many other cellular functions (apoptosis, ROS production, cell proliferation, aging). In humans, the mitochondrial DNA was believed to encode only 37 genes involved in energy production and mitochondrial translation. However, recent studies have shown that within these genes could hide several small alternative genes (genes with translation initiation or termination sequences distinct from the reference gene sequences in which they are found) coding for micropeptides with a broad spectrum of functions that can be newly added to the large list of functions in which mitochondria are involved.

Following the discovery of the mitochondrial alternative gene mtaltnd4, we try to elucidate the functions of the gene and its peptide (MTALTND4) by studying: (1) the expression pattern of the peptide in different human tissues and blood plasma, (2) the involvement of the gene in the major mitochondrial functions by exposing cells to various treatments, (3) the interaction partners of MTALTND4 by mass spectrometry and (4) the impact of the peptide on cell transcriptome.

We have found that mtaltnd4 may potentially produce a signaling protein in response to stress that would regulate certain cell metabolic processes and there is surely more to discover.

ANNUAL CONFERENCE MONTPELLIER 2022

A162 TEMPERATURE, PH AND SEASONAL EFFECTS ON MITOCHONDRIAL RESPIRATION IN HIBERNATING RODENTS Wednesday 6th July 2022

POSTER SESSION

Anne Kim, University of British Columbia, William K. Milsom, University of British Columbia, Jeffrey G. Richards, University of British Columbia annekim@zoology.ubc.ca CO2 retention (due to a mismatch between ventilation and metabolic rate suppression) and resulting changes in intracellular pH have been suggested as a mechanism for the initiation of metabolic rate suppression in hibernation. Mammalian hibernation is typically associated with a drastic reduction in body temperatures to 1-2 °C above ambient winter temperatures, which is well documented as a passive mechanism for sustained metabolic rate suppression in hibernators. To quantify the interactive effects of temperature, pH and hibernation state on mitochondrial respiration, we isolated mitochondria from the liver of three rodent species. Most notably, succinate fueled state 3 respiration measured at 37 °C was not pH-dependent in the non-hibernating Sprague-Dawley rat (Rattus norvegicus), but was pH dependent in 13-lined ground squirrels (Ictidomys tridecemlineatus; obligate hibernator) and Golden-Syrian hamsters (Mesocricetus auratus; facultative hibernator), where respiration increased as pH was lowered, presumably due to direct effects on the proton motive force. This pH effect on state 3 respiration rate was observed in liver isolated from both torpid and interbout euthermic 13-lined ground squirrels, indicating hibernation state does not alter the relationship between mitochondrial respiration rate and pH in this species. The increase in state 3 respiration with reduced pH at 37 °C does not support the hypothesis that an initial acidosis resulting from CO2 retention serves as a mechanism for metabolic suppression during entrance into hibernation. This research was funded by the Natural Sciences and Engineering Research Council of Canada (NSERC).

A167 MITONUCLEAR INTERACTIONS IMPACT RESPONSES TO METABOLIC AND REDOX STRESS AT DIFFERENT LIFE STAGES IN DROSOPHILA MELANOGASTER Wednesday 6th July 2022

SCIENCE ACROSS BOUNDARIES ABSTRACTS 89

gene expression in Drosophila larvae, and adults of both sexes. Flies fed either a high protein diet, the glutathione precursor N-acetyl cysteine (NAC), or the NADH precursor nicotinamide riboside (NR) and had sex, life-stage, and genotype-specific responses to these stressors. Metabolomic results point to changes in TCA cycle flux, while respirometry analysis shows changes in substrate use and complex I function. Our results support the notion that subtle mitonuclear mismatches can lead to diverging responses to mild physiological stress, undermining fitness in some cases, but surprisingly improving outcomes in other mismatched fly lines.

A171 MITOCHONDRIAL FUEL SELECTION IN BIRDS AND MAMMALS: A QUESTION OF MUSCULAR TEMPERATURE Wednesday 6th July 2022

POSTER SESSION

Jessica Barbe, University of Lyon, LEHNA, Damien Roussel, University of Lyon, LEHNA, Yann Voituron, University of Lyon, LEHNA jessica.barbe@univ-lyon1.fr Birds and mammals are endotherms which maintain a high and constant body temperature. At rest, the average body temperature of birds is ~41°C and of mammals ~37°C. However, during a high-intensity exercise (flying/running), muscle temperature can reach 44°C and 42°C respectively. At the mitochondrial level the fuel selection differs between the two clades. While mammals display a general dependence on carbohydrate, birds can use both carbohydrates and lipids oxidation to respond to energy demands. Many studies have highlighted this last point but without considering the muscular temperature at different metabolic intensities as a combined factor with the preferential use of available substrate for ATP synthesis. Herein, we compared isolated mitochondria from skeletal muscle of pigeons and rats of similar body mass and measured the oxidation rates at 3 assay temperatures (37°C, 40°C, 43°C). We used 2 mitochondrial substrates: a combination based on carbohydrate (pyruvate + malate) and based on lipid (palmitoyl-Lcarnitine + malate). We found that isolated rat mitochondria exhibited higher oxygen consumption with carbohydrate-based energy substrates compared to metabolism with lipid-based substrates, a difference that was exacerbated at high temperature. The ability of avian mitochondria to oxidise different substrates in an equivalent way, even at high temperatures, would trigger a more flexible response to challenging environments and the high energy requirements of flight.

POSTER SESSION

Enrique Rodriguez, University College London, Sahutchai Inwongwan, University College London, Finley Grover Thomas, University College London, Florencia Camus, University College London, Nick Lane, University College London enrique.rodriguez@ucl.ac.uk Mitochondrial function depends on direct interactions between respiratory proteins encoded by genes in two genomes, mitochondrial and nuclear, which evolve in very different ways. Serious incompatibilities between these genomes can have severe effects on development, fitness and viability. The effect of subtle mitonuclear mismatches has received less attention, especially when subject to mild physiological stress. We investigate how various stressors affect phenotypic traits, mitochondrial function, metabolic pathways and

A175 SIRTUIN ACTIVITY INCREASES IN RESPONSE TO COLD ACCLIMATION IN THREESPINE STICKLEBACK Wednesday 6th July 2022

POSTER SESSION

Louise Cominassi, Institute of Arctic Biology, University of Fairbanks Alaska, Patrick Marbacher, Institute of Arctic Biology, University of Fairbanks Alaska, Sage Robine, Institute of Arctic Biology, University of Fairbanks Alaska, Kristin M. O’Brien, Institute of Arctic Biology, University of Fairbanks Alaska lmcominassi@alaska.edu

ANNUAL CONFERENCE MONTPELLIER 2022

In many fish species, including the threespine stickleback (Gasterosteus aculeatus), mitochondrial density and the activity of metabolic enzymes increase in response to cold acclimation to maintain the production of ATP. While these temperature-induced alterations in metabolism have been well described for many fish species, the molecular pathway mediating them remains largely unknown. Sirtuins, a family of NAD+dependent deacetylases function as metabolic sensors, increasing in activity as the ratio of NAD+-to-NADH increases during energy deficits. In mammals, sirtuins stimulate all of the hallmark metabolic shifts observed in fishes in response to cold temperature. To test the hypothesis that sirtuins stimulate metabolic remodeling in response to temperature in fishes, threespine stickleback were acclimated to 5, 12 and 20°C for 13 weeks and liver, glycolytic and oxidative skeletal muscles were harvested. NAD(H) levels were quantified using a colorometric assay kit (Sigma) and sirtuin activity was measured at 20°C using the SIRT-GloTM assay kit (Promega). Protein levels of SIRT3, one of the seven isoforms of sirtuins localized to the mitochondrion, were quantified with Western blotting. Sirtuin activity was significantly higher in liver and oxidative and glycolytic skeletal muscles of stickleback at 5°C compared with animals at 20°C but NAD+ levels were higher only in liver at 5°C. Overall, these results suggest that sirtuins may stimulate metabolic remodeling in response to cold temperature in stickleback to preserve metabolic homeostasis. This work was funded by a grant from the National Science Foundation (IOS 1756191).

A179 MISMATCH OF MITOCHONDRIAL AND NUCLEAR GENOMES LEADS TO IMPAIRED FITNESS Wednesday 6th July 2022

POSTER SESSION

Marion Bonneau, University College London, Florencia Camus, University College London, Kevin Fowler, University College London, Max Reuter, University College London marion.bonneau@ucl.ac.uk Mitochondria are small organelles located inside the cells and enclosing their own genome, as does the nucleus. They are essential for life and overall crucial for many biological processes. However, their principal role is the production of energy for which interaction between mitochondrial genome (mtDNA) and nuclear genome (nuDNA) is indispensable.

Previous studies showed that mismatch of mtDNA and nuDNA from different species lead to impaired mitochondrial function and altered fitness in hybrids. Nevertheless, the effects of inter-species mismatch have not yet been studied. Here we will look at the consequences of different mtDNA and nuDNA combination on various phenotypic traits.

Using a large diverse panel of Drosophila melanogaster with both coevolved and disrupted combinations of mtDNA and nuDNA, we will assess mito-nuclear incompatibilities by observing changes in various fitness traits such as fertility and development time, among others.

If mito-nuclear co-adaptation is disrupted, we should observe deleterious effects due to the mismatch. Additionally, as mitochondria are always passed on from the female, the effects of mito-nuclear mismatch should be more important in males.

These results will help us understand better mitochondria and nuclear co-evolution and the importance of the communication between those two genomes. Additionally, it will shed some light on the role played by mitochondrial genome in specific fitness traits.

SCIENCE ACROSS BOUNDARIES ABSTRACTS 90

A186 MITOCHONDRIAL DENSITY VARIES ACROSS POPULATIONS AND LIFE STAGES IN EUROPEAN PIED FLYCATCHERS Thursday 7th July 2022

POSTER SESSION

Tiia Kärkkäinen, University of Turku, Toni Laaksonen, University of Turku, Malcolm Burgess, University of Exeter, Alejandro Cantarero, Madrid Museum of Natural History, Jesús Martínez-Padilla, Museo Nacional de Ciencias Naturales, Jaime Potti, Doñana Biological Station, Juan Moreno, Museo Nacional de Ciencias Naturales, Robert L. Thomson, University of Cape Town tmakar@utu.fi Functional mitochondria are essential for eukaryotic life as they transduce nearly all the energy that is needed to fuel cellular processes underlying whole-animal activities. Thus, mitochondrial traits are suggested to underlie between-individual differences in performance capacity and quality. Indeed, decreased maintenance of mitochondrial DNA copy number (mtDNAcn) and expression lowers mitochondrial function. Conversely, increased mitochondrial abundance is associated with increased aerobic capacity, and therefore endurance during exercise. Long-distance migration is an extreme example of aerobic physical effort. While migratory species can have genetically adapted mitochondria compared to non-migratory species, no study has examined if mitochondrial traits can explain migratory performance within species. We measured relative mtDNA copy number (a proxy for mitochondrial density) from six different populations in the pied flycatcher (Ficedula hypoleuca) across Europe. Pied flycatcher is a long-distance migrant that breeds in Eurasia from Spain to northern Scandinavia, while all the populations winter in much more spatially restricted area in Sub-Saharan Africa, resulting in marked differences in the migration distance and duration. Contrary to our expectations, we did not find straightforward link between migration distance and mtDNAcn. Nestling mtDNAcn was repeatable during growth and seemed linked to habitat characteristics, but not to parental mtDNAcn. Mitochondrial density is known to be plastic trait so possibly the current adult measures reflect more the energetic demands during sampling than past demands during migration. However, this study is, to the best of our knowledge, the first to show large-scale within-species differences in a mitochondrial trait.

ANNUAL CONFERENCE MONTPELLIER 2022

SCIENCE ACROSS BOUNDARIES ABSTRACTS 91

A15 - CARRY-OVER EFFECTS OF GLOBAL CHANGE STRESSORS ACROSS METAMORPHOSIS: MECHANISMS AND CONSEQUENCES ORGANISED BY: NEDIM TÜZÜN (LEIBNIZ-INSTITUTE OF FRESHWATER ECOLOGY AND INLAND FISHERIES), JULIE VERHEYEN (KU LEUVEN), VIENNA DELNAT (KU LEUVEN), GERMÁN ORIZAOLA (UNIVERSIDAD DE OVIEDO), MIRCO BUNDSCHUH (UNIVERSITY OF KOBLENZ-LANDAU) A80 HOW DOES TEMPERATURE AFFECT THE ENERGY COSTS OF ONTOGENETIC CHANGE? Tuesday 5th July 2022

14:00pm-14:15pm

Dustin Marshall, Monash University

Tuesday 5th July 2022

09:00am-09:30am

Kirsty MacLeod, Bangor University

dustin.marshall@monash.edu We recently showed that costs of development depend on the relative temperature dependence of two rates: metabolic and development.

The temperature that minimises the costs of development balances these two rates. Here I extend this theory to plants and bacteria and extend it across the life history of ectothermic metazoans. I provide evidence that the costs of ontogenetic progression from one stage to the next depend strongly on temperature and that deviations from an optimal temperature incur surprisingly high costs.

A83 METAMORPHOSIS AND THE IMPACT OF CONTAMINANTS ON ECOLOGICAL SUBSIDIES Tuesday 5th July 2022

A84 THE CARRYOVER EFFECTS OF STRESS BETWEEN GENERATIONS: ECOLOGICAL CONSEQUENCES AND POTENTIAL MECHANISMS

k.macleod@bangor.ac.uk Exposure to environmental stressors during development can influence offspring traits in other life stages. A common environmental stressor is predation risk. I show using meta-analysis that show that exposure to predators during development influences offspring phenotype.

Experimental work using lizards suggests that glucocorticoid hormones are a likely candidate for these effects. For example, glucocorticoids affect offspring behaviour during the juvenile period in fence lizards, and these effects are context-dependent (i.e. they vary based on the offspring's own predation risk environment). Further meta-analysis also indicates widespread influence of maternal glucocorticoids on offspring phenotype, and that this is facilitated by viviparity. The consequences of reproductive mode for carryover effects of stressors in the environment could be profound - and reptiles provide an excellent system in which to study them.

10:30am-11:00am

Jeff Wesner, University of South Dakota jeff.wesner@usd.edu Many multicellular organisms in streams undergo metamorphosis during their transition from freshwater to terrestrial life-stages. During metamorphosis, chemical concentrations can change drastically in the body tissues, making it difficult to use aquatic contaminant data to predict risk to terrestrial consumers. This talk will summarize research that attempts to resolve this difficulty using stage-structured approaches to ecotoxicology.

A85 CARRY-OVER EFFECTS OF ENVIRONMENTAL STRESS ON BUTTERFLY PERFORMANCE Tuesday 5th July 2022

10:00am-10:30am

Marjo Saastamoinen, University of Helsinki marjo.saastamoinen@helsinki.fi It is well-known that the environment experienced early in life often affects trait expression later on in individual’s life, with impacts evident even across generations. Such ‘carry-over effects’ and their fitness

ANNUAL CONFERENCE MONTPELLIER 2022

outcomes can be either positive (adaptive) or negative, and highly stress- or environment-dependent. I am using butterflies as a model system to address the impact of carry over effects, as butterflies have distinct life stages and are highly responsive to environmental variation due to often being strictly adapted to specific resources and climatic micro-habitats during their development. I will provide an overview of results from a set of experiments in which we have assessed the impact of carry over effects in response to different types of ecologically relevant stressors, namely malnutrition and thermal condition, experienced during development. The focus will be on developmental carry over effects on adult performance traits, such as lifespan, fecundity and dispersal propensity but I will also discuss some results related to trans-generation effects. The experiments have been carried out by comparing individuals from different families within a larger metapopulation or by comparing individuals from populations across a larger scale environmental gradient, shedding some light also on heritable variation in carry-over effects.

A86 EARLY-LIFE DISRUPTION OF GUT MICROBIOTA AFFECTS RESISTANCE TO PARASITES Tuesday 5th July 2022

09:30am-10:00am

Sarah Knutie, University of Connecticut saknutie@gmail.com Changes in the early-life microbiota of hosts might affect infectious disease risk throughout life, if such disruptions during formative times alter immune system development. For this talk, I present empirical evidence that an early-life disruption of gut microbiota has immediate and long-term consequences on parasite resistance across taxa, including Cuban tree frogs and passerine birds. In these studies, we experimentally manipulated the gut microbiota of hosts, during the immune developmental period, with mild antibiotics then quantified their ability to resist parasitic nematodes (frogs) or nest flies (birds). An early-life microbiota disruption had varying effects on host resistance to parasitism. A microbiota disruption in tapoles led to a decrease in parasite resistance later in life, whereas a disruption in nestling birds lead to either an increase or decrease in resistance to nest flies, depending on the host species. These results support the idea that preventing early-life disruption of host-associated microbiota might confer protection against diseases, but this idea depends on the host taxa.

SCIENCE ACROSS BOUNDARIES ABSTRACTS 92

ANNUAL CONFERENCE MONTPELLIER 2022

SCIENCE ACROSS BOUNDARIES ABSTRACTS 93

A16 - ADAPTATION OR MALADAPTION OF COASTAL POPULATIONS TO ANTHROPOGENIC AND ENVIRONMENTAL STRESSORS ORGANISED BY: EMILIE FARCY (UNIVERSITÉ DE MONTPELLIER), JEHAN-HERVÉ LIGNOT (UNIVERSITÉ DE MONTPELLIER) A42 CONSERVING THREATENED COASTAL WILDLIFE DURING RAPID ENVIRONMENTAL CHANGE: USING BIOLOGICAL RESPONSES TO INFORM MANAGEMENT STRATEGIES OF GIANT CLAMS Wednesday 6th July 2022

15:35pm-15:50pm

Sue-Ann Watson, James Cook University & Queensland Museum, Mei Lin Neo, National University of Singapore sueann.watson@jcu.edu.au Giant clams are threatened by overexploitation for human consumption, their valuable shells and the aquarium trade. Consequently, these iconic megafauna are extinct in some former areas of their range and included in the IUCN Red List of Threatened Species and CITES list.

Now, giant clams are also threatened by rapid environmental change from both a suite of local- to regional-scale stressors, such poor water quality and pollution, and global change stressors, including ocean heating and acidification. The interplay between local- to regionalscale and global-scale drivers is likely to cause an array of lethal and sub-lethal effects, potentially limiting giant clam depth distribution on coral reefs and decreasing suitable habitat area within natural ranges. International efforts urgently need to reduce CO2 emissions to avoid lethal and sub-lethal effects on giant clams. Meanwhile, knowledge of ecological and physiological responses to local–regional and global stressors could play a critical role in the conservation of these species through rapid environmental change. Further work on how biological responses translate into habitat requirements as global change progresses, selective breeding for resilience, the capacity for rapid adaptive responses of the giant clam holobiont, and valuing tourism potential may help improve the prospects of these charismatic megafauna over coming decades.

A45 GENE EXPRESSION PLASTICITY, GENETIC VARIATION AND FATTY ACID REMODELLING IN DIVERGENT POPULATIONS OF A TROPICAL BIVALVE SPECIES UNDER DIFFERENT THERMAL REGIMES Wednesday 6th July 2022

15:05pm-15:20pm

Celine Reisser, UMR MARBEC, Université de Montpellier, CNRS, IFREMER, IRD, celine.reisser@ifremer.fr Ocean warming challenges marine organisms' resilience, especially for species experiencing temperatures close to their upper thermal limits.

A potential increase in thermal tolerance might significantly reduce the risk of population decline, which is intrinsically linked to variability in local habitat temperatures. Our goal was to assess the plastic and genetic potential of response to elevated temperatures in a tropical bivalve model, Pinctada margaritifera. We benefit from two ecotypes for which local environmental conditions are characterized by either large diurnal variations in the tide pools (Marquesas archipelago) or low mean temperature with stable to moderate seasonal variations (Gambier archipelago). We explored the physiological basis of individual responses to elevated temperature, genetic divergence as well as plasticity and acclimation by combining lipidomic and transcriptomic approaches. We show that P. margaritifera has certain capacities to adjust to long-term elevated temperatures that was thus far largely underestimated. Genetic variation across populations overlaps with gene expression and involves the mitochondrial respiration machinery, a central physiological process that contributes to species thermal sensitivity and their distribution ranges. Our results present evidence for acclimation potential in P. margaritifera and urge for longer term studies to assess populations resilience in the face of climate change.

ANNUAL CONFERENCE MONTPELLIER 2022

A49 PHYSIOLOGICAL AND MOLECULAR RESPONSES OF P. CLARKII TO DIFFERENT LEVELS OF POLLUTANTS AND SALINITY EXPOSURE: AN INTERPOPULATION STUDY Wednesday 6th July 2022

12:00pm-12:15pm

Diana Martinez-Alarcon, UMR MARBEC-IRD, Université de Montpellier, CNRS, IFREMER, Jehan-Hervé Lignot, UMR MARBEC-IRD, Université de Montpellier, CNRS, IFREMER, Marie-Catherin Raffalli, UMR MARBEC-IRD, Université de Montpellier, CNRS, IFREMER, Leandre Bertin, UMR MARBECIRD, Université de Montpellier, CNRS, IFREMER

SCIENCE ACROSS BOUNDARIES ABSTRACTS 94

Astrangia poculata – and three genera of Symbiodiniaceae – Breviolum, Cladocopium, and Durusdinium – to explore whether differences exist between coral and algal orthologs in stability and function at high temperatures. In addition, we examine whether differences in thermal sensitivity exist within GAPDHs of Symbiodiniaceae taxa that have been suggested to possess different levels of thermal tolerance. We use recombinant GAPDH to examine both thermal stability (melting temperature measured via differential scanning fluorimetry) and functional measures of thermal sensitivity (Michaelis constant Km, activation energy Ea) in each ortholog. Our data, complemented by molecular dynamics simulations, indicate that GAPDHs in coral are less sensitive to high temperature perturbation than are algal orthologs, both in kinetics and stability. These results suggest that in some coral-algal symbioses, certain enzymes of the dinoflagellate are more sensitive to heat stress than the host, which may contribute to derangement of the symbiosis and resultant bleaching.

diana.martinez-alarcon@cnrs.fr Evolution as a contemporary process that can affect changes from one generation to the next has only recently been considered in toxicology.

While rapid evolution has recently been linked with the increase of invasive capacity of Invasive Alien Species (IAS), it is still not taken into consideration for Invasive Species Predictive Schemes and risk assessments.

A53 INFLUENCES OF ANTHROPOGENIC STRESS ON THE SOCIALITY OF THREESPINED STICKLEBACK (GASTEROSTEUS ACULEATUS)

The Louisiana crayfish, Procambarus clarkii, has a strong adaptive capacity to a variety of aquatic environments, including highly contaminated water bodies, and different salinities. Here, we studied three invasive populations of P. clarkii that inhabit water bodies at different salinities and pollution levels in the South of France. Our results showed that physiological and molecular responses are populationspecific when they are exposed to pollutants and salinity shock.

Our results suggest that in P. clarkii, the capacity to inhabit polluted environments and the capacity to inhabit water bodies with different salinity levels are not related. While the capacity to face pollutants seems to share a common ancestor in these three populations, the capacity of dealing with salinity change seems to be a more recently acquired trial.

Wednesday 6th July 2022

A52 DIFFERENTIAL SENSITIVITY TO HIGH TEMPERATURE IN GLYCERALDEHYDE-3-PHOSPHATE DEHYDROGENASES OF CORAL AND ALGAL SYMBIONTS Wednesday 6th July 2022

15:20pm-15:35pm

Peter Fields, Franklin & Marshall College peter.fields@fandm.edu Acute environmental stresses including high temperature can lead to the breakdown of the mutualism between reef-building corals and their symbiotic algal partners, ultimately leading to bleaching.

However, variation in the thermal tolerance of different coral-algal symbioses has been described repeatedly, suggesting differences in sensitivity to heat among the partners. Since high temperature perturbs the structure and function of macromolecules, these differences in whole-organism temperature sensitivity may occur in part because of differences in the thermal stability of such molecules, including proteins. Here, we examine temperature sensitivity of the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in three coral species – Acropora millepora, Orbicella faveolata, and

09:45am-10:00am

Sienna Overduin, University of Alberta, Tamzin Blewett, University of Alberta, Shaun Killen, University of Glasgow, Lucy Cotgrove, University of Glasgow, Kelly Rozanitis, University of Alberta, Daniel Alessi, University of Alberta soverdui@ualberta.ca Social context influences all aspects of life, including how organisms interact with their surroundings, perceive stressors, and respond to toxicants in their environment. With the condition of aquatic environments declining worldwide, furthering our understanding of the factors that affect the success of species will be essential for their survivability. As such, we examined how copper (Cu) contamination affects behaviour and physiology of three-spined stickleback (Gasterosteus aculeatus) as a function of their social environment.

We hypothesized that exposing sticklebacks to Cu, while experiencing the stress of isolation, will lead to greater uptake of Cu and subsequent behavioural responses, as opposed to exposing sticklebacks to Cu in a group setting. Wild-caught fish were exposed to environmentally relevant Cu concentrations of 50µg/L and 150µg/L for 96 hours then assessed for activity level, social cohesion, and foraging. Furthermore, tissues (gill, liver, and intestine) were collected to measure organspecific bioaccumulation of ions and enzyme activity (Na+/K+/ATPase, H+-ATPase). The interplay between toxicology and social behaviour is not well understood, and as such is not considered in risk assessment standard practice. This potentially leaves a significant gap in our understanding of organismal response to toxicants. Observing response to copper after isolation and group exposures may highlight the need to account for the social environment to truly represent the vulnerability of populations.

A55 ANTARCTIC LIMPET CELL PHYSIOLOGY SCOPE AFTER COPPER EXPOSITION: A PROTEOMIC APPROACH

ANNUAL CONFERENCE MONTPELLIER 2022

Wednesday 6th July 2022

10:00am-10:15am

Claudio Adriano Piechnik, Universität Innsbruck, Lars Tomanek, California Polytechnic State University, Lucélia Donatti, Federal University of Parana claudio.piechnik@uibk.ac.at Sources of metals in the Antarctic marine environment can vary due to glacial melt. The limpet Nacella conccina, a well-distributed specie at Antarctic coastal zone, is able to deal with some different copper concentrations. During the experiments limpets were exposed to 0.12 µgL-1 and 0.25 µgL-1 of copper at 12, 24, 48 h (N=6/metal/ concentration/time, temperature 0°C and salinity 34 ppt). Gills were analysed using proteomics techniques. We detected 78 significantly altered proteins (two-way ANOVA, p&lt;0.02) on 2D electrophoresis gels. Among these 47 were identified using tandem mass spectrometry.

Antioxidant proteins including Mn-superoxide dismutase and ferritin were identified. This is an indication of the increased production of ROS. The chaperones involved in the maturation of proteins present in the endoplasmic reticulum showed variations in function of a possible change in the cellular redox state. Modifications in the acid-base balance of gill cells can be linked to changes in carbonic anhydrase after exposure to copper. The dynamics of proteins such as arginine kinase, glycolytic triose phosphate isomerase, as well as pyruvate dehydrogenase, can be linked to a higher rate of ATP renewal. We hypothesised that substituting protein-binding metals by copper causes an increase in ROS and acid-base effects in the gills, leading to protein maturation inhibition in the endoplasmic reticulum, an increment in ATP buffering by arginine kinase and glycolytic proteins, and changes in Cdc42 abundance impacting the cytoskeletal filaments.

These observations help to shed light on the interrelationships between metabolism, energy balance and short time copper stress tolerance in Antarctic limpets.

A56 LIVING AT THE FRONTIER – SALINITY AND TEMPERATURE DURING LARVAL DEVELOPMENT DETERMINE THE POTENTIAL FOR INVASION OF THE BALTIC SEA Wednesday 6th July 2022

11:45am-12:00pm

SCIENCE ACROSS BOUNDARIES ABSTRACTS 95

from the Baltic Sea. No evidence of elevated tolerance towards low salinity were found in the larvae from the Baltic Sea. In addition, larvae from the population located at the range limit (Neustadt) show very low survival. We did not find evidence of adaptation to low salinity by any of the local populations of H. takanoi we studied. Thus, in order to the population to persist, larvae must either migrate to waters of increased salinity, and then return to the habitat of origin; or such populations are sustained by source-sink dynamics.

A57 BIOENERGETIC ASPECTS OF POLLUTANT TOXICITY AND THEIR ROLE IN DETERMINING THE TOLERANCE LIMITS TO MULTIPLE STRESSORS IN AQUATIC ORGANISMS Wednesday 6th July 2022

11:00am-11:30am

Inna Sokolova, University of Rostock, inna.sokolova@uni-rostock.de Energy metabolism (encompassing energy assimilation, conversion and utilization) plays a central role in all life processes and serves as a link between the organismal physiology, behavior, and ecology.

Metabolic rates define the physiological and life-history performance of an organism and have direct implications for Darwinian fitness.

Anthropogenic and natural stressors affect energy balance because the stress-induced disruption of homeostasis must be corrected to ensure the organism's survival. Pollutants can negatively affect different aspects of energy metabolism of an organism interfering with energy assimilation and conversion or increasing energy costs for basal maintenance. This can diminish the energy fluxes available for other fitness functions and negatively affect the organism’s growth, reproduction and ability to deal with additional stressors or diseases.

In this talk, I will discuss the role of bioenergetics in toxicity of legacy and emerging pollutants (including trace metals, nanoparticles and pharmaceuticals) and the pollutant interactions with other abiotic stressors such as temperature, salinity or oxygen deficiency.

I will address the mechanisms underlying the pollutant-induced bioenergetics disturbances and discuss the use of bioenergetics-based approaches in linking the molecular and cellular stress responses to the whole-organism fitness in coastal environments exposed to multiple stressors.

Gabriela Torres, Alfred-Wegener-Institut gabrielatorres3625@gmail.com We study the potential of a recent invader, the Asian brush-clawed crab (Hemigrapsus takanoi), to expand its distribution range further into the Baltic Sea. H. takanoi has been documented in the southwestern Baltic Sea since 2014. The ability to persist and further expand into the Baltic Sea will depend on their potential to sustain all stages of their complex life cycle, including pelagic larvae, under the Baltic Sea’s conditions. Range limits may be established by the tolerance to low salinity, which in addition may be affected by temperature. A key question is whether local populations at the distribution limit (within the Baltic) are adapting to low salinities and hence promote further expansion. We quantified the combined effects of salinity (10-32 PSU) and temperature (15-24°C) on four populations of H. takanoi (two from the Baltic and two from the North Sea). Our results show substantial differences in larval performance between the populations from the Baltic and North Sea. Larvae from the North Sea populations show higher survival and faster development compared with those

A217 EXPLORING GENOMIC DIVERSITY WITHIN THE BLUE MUSSEL SPECIES-COMPLEX Wednesday 6th July 2022

09:30am-09:45am

Jennifer C. Nascimento-Schulze, University of Exeter, Carolina Peñaloza, The Roslin Institute and Royal School of Veterinary Studies, University of Edinburgh, Josephine R. Paris, University of Exeter, Tim P. Bean, The Roslin Institute and Royal School of Veterinary Studies, University of Edinburgh, James P. Whiting, University of Exeter, Ross D. Houston, The Roslin Institute and Royal School of Veterinary Studies, University of Edinburgh, Bonnie Fraser, University of Exeter, Robert P. Ellis, University of Exeter

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jn378@exeter.ac.uk Blue-mussels from the M. edulis species-complex (M. edulis x M. trossulus x M. galloprovincialis) are an abundant element of the benthos community, found in the high latitude habitats of both hemispheres of the globe. Aside their ecological value, these foundation species are relevant to the aquaculture industry, with over 182 thousand tonnes produced globally each year. These taxa withstand a wide range of environmental conditions and the 3 species easily hybridise in regions where their distribution overlaps. Significant effort has been made to investigate the consequences of environmental stress on the physiology of these species. However, our understanding on the genomic mechanisms underlying hybridisation and local adaptation remains limited. To refine our understanding of such processes in this species complex, we sequenced 24 blue mussel populations distributed globally using a whole-genome low coverage approach. A total of 50k SNPs were used to develop a medium-density SNP-array, a tool that will allow the rapid and consistent genotyping of individuals.

To guarantee that putative SNPs associated with environmental stress were included in the array, we selected mussel populations thriving across a gradient of environmental conditions in terms of temperature, salinity and CO2. The rapid high-throughput screening of SNPs facilitates the investigation of genomic structure among populations and can contribute to our understanding on ongoing local adaptation and hybridisation in these taxa. Besides, genome wide association studies, combining omics with physiology, will allow the characterisation of genotypes resilient to environmental stress, relevant in light of climate change.

A403 MECHANISMS OF PARALLEL ADAPTATION IN A WIDESPREAD COPEPOD Wednesday 6th July 2022

14:35pm-15:05pm

Carol Eunmi Lee, University of Wisconsin carollee@wisc.edu The ability of populations to expand their geographic ranges, whether as invaders or climate migrants, presents among the most serious global problems today. However, fundamental mechanisms that enable certain populations to rapidly adapt to novel habitats remain poorly understood. In recent years, populations of the copepod Eurytemora affinis species complex have invaded freshwater habitats multiple times independently from saline sources. These copepods are dominant grazers in aquatic habitats throughout the Northern Hemisphere and support major fisheries. Intriguingly, evolutionary changes during these salinity transitions often involved the same loci, with selection often acting on the same SNPs (alleles), in wild populations and laboratory selection lines. In our laboratory natural selection experiment, the same SNPs were favored across replicate selection lines far beyond expectations. In both wild populations and laboratory selection lines, ion transporter genes appeared as the dominant functional category under selection. Using extensive simulations, we found that this degree of parallelism was consistent with synergistic epistasis among alleles responding in concert across replicate selection lines for this polygenic trait (salinity tolerance).

The effect of synergistic epistasis appeared greater than selection from balanced polymorphisms in promoting parallel evolution.

Our results were consistent with mechanisms of ion uptake from dilute habitats, requiring the coordinated action of cooperating ion transporter proteins. Most notably, our results suggest that a very specific set of ion transporter alleles might be necessary for freshwater adaptation to occur in this system, pointing to a canalized evolutionary

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pathway. Thus, we find strong support for a novel and potentially widespread mechanism, namely positive epistasis, in promoting this parallel and canalized response. This research is funded by NSF-OCE, NSF-DEB, and ANR (Macron’s Make Our Planet Great Again award).

A404 TOWARD A UNIFIED APPROACH TO UNDERSTANDING (MAL)ADAPTATION Wednesday 6th July 2022

09:00am-09:30pm

Steven P. Brady, Southern Connecticut State University bradys4@southernct.edu Evolutionary studies often search for population divergence, increasingly at microgeographic spatial scales and across contemporary time scales, reflecting the extent and pace of natural selection. The expectation tends to be that local populations should adapt to environmental variation, including variation associated with humanmodified environments. A long history of theoretical and empirical studies supports this expectation, and indeed natural selection should diverge populations as it drives them toward local adaptive optima.

Yet, perhaps more often than we are eager to admit, we fail to find evidence for local adaptation, and when this happens, we struggle to describe the mechanisms that can generate these patterns. For instance, what do we make of data that fail to clearly demonstrate local adaptation, such as when presumptively divergent populations are found to be equivalently adapted to contrasting environments?

Or, how do we interpret the persistence of locally maladaptive trait variation? Or, how do we reconcile adaptive population demographic trajectories with maladaptive trait variation? Here, we discuss a framework of (mal)adaptation that emphasizes the importance of considering both absolute and relative fitness when interpreting local population divergence. We then use this framework to interpret outcomes from amphibian populations that show evidence of both adaptive and maladaptive divergence in response to road adjacency and runoff pollution.

POSTER SESSION A43 POTENTIAL LOCAL ADAPTATION TO INTERTIDAL LIFE OF A TROPICAL SUBTIDAL LAGOON SPECIES, PINCTADA MARGARITIFERA VAR. CUMINGII Wednesday 6th July 2022

POSTER SESSION

Antoine Gradel, Marine Biodiversity, Exploitation and Conservation (MARBEC), Alexandre Cormier, SEBIMER, Jérémy Le Luyer, UMR EIO, Chin Long Ky, UMR IHPE, Serge Planes, USR CRIOBE, Céline Reisser, UMR MARBEC antoine.gradel@ifremer.fr The Tahitian black lipped pearl oyster Pinctada margaritifera is a tropical stenothermal species with a thermal optimum of 28.7 °C, close to its tolerance limits, like many tropical species. With global

ANNUAL CONFERENCE MONTPELLIER 2022

change, an increasing number of pearl oysters populations have to face temperatures above their thermal limits for an extended period of time, reaching up to 121 days a year in the Tuamotu. This induces mortality episodes which impact both natural and exploited populations. This situation is not only problematic from a biodiversity standpoint, with the risk to see this sessile reef building organism disappear from Polynesian lagoons, it is also problematic for the pearl industry (second economic resource of French Polynesia), relying entirely on P. margaritifera’s exploitation. Surprisingly, healthy individuals have been recently observed in the Marquesas archipelago in tide pools reaching 34°C, which represents an atypical environment for the species. This could demonstrate a capacity for acclimation, or a process of adaptation to thermally challenging conditions. In this context, our study analysed genome-wide Single Nucleotide Polymorphism (SNP) in order to genetically describe how the Marquesas populations fit with the other Polynesian populations, and detect putative candidate genes linked to a possible thermal adaptation of the Marquesas populations. Our results show that the Marquesas populations are genetically differentiated from the rest of French Polynesia. Additionally, candidate SNPs impacting genes involved in energetic metabolism and apoptosis control pathways were identified.

However, this study needs further investigations, with additional sampling, and laboratory experimentations (gene expression, common garden experiment).

A44 GENOMIC ANALYSIS OF HYPOXIA INDUCIBLE FACTOR ALPHA REVEALS MISSING OHNOLOGS AND EVIDENCE OF WIDESPREAD POSITIVE SELECTION IN RAY-FINNED FISHES Thursday 7th July 2022

POSTER SESSION

Bernard Rees, University of New Orleans, Ian K. Townley, Saint George’s School, Courtney Babin, University of New Orleans, Taylor Murphy, University of New Orleans, Christopher Summa, University of New Orleans

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A47 POLLUTANTS AFFECTING THE ANTIBIOTIC RESISTANCE OF BACTERIA ASSOCIATED WITH THE OYSTER CRASSOSTREA GIGAS Wednesday 6th July 2022

POSTER SESSION

Coralie Broquard, Alfred Wegener Institute - Helmholtz Centre for Polar and Marine Research, Coastal Ecology, K. Mathias Wegner, Alfred Wegener Institute - Helmholtz Centre for Polar and Marine Research, Coastal Ecology, Jil Sonka, Alfred Wegener Institute - Helmholtz Centre for Polar and Marine Research, Coastal Ecology, Eike Petersen, Alfred Wegener Institute - Helmholtz Centre for Polar and Marine Research, Coastal Ecology coralie.broquard@awi.de The massive use of antibiotics in human and veterinary medicine has led to the emergence of resistant bacteria/pathogens in the environment.

This also applies to aquatic and marine ecosystems, where organisms can enrich these medicinal substances and resistant strains, opening up a direct route to humans by seafood consumption. In addition, other substances such as heavy metals and pesticides originating mainly from the use of agrochemicals on farms can also be enriched, and impact the evolution of bacterial resistance to antibiotics and their effects on aquatic organisms. To answer the question if aquatic pollutants can amplify antibiotic resistance in marine organisms, we carried out experiments in controlled environments where oysters (juveniles and adults) are exposed to various heavy metals (copper, cadmium) and pesticides (glyphosate, S-metolachlor, tebuconazole) regularly found in European coastal areas. After exposure to different concentrations of pollutants, targeted culture approaches with ampicillin, tetracycline, and chloramphenicol helped to identify and quantify resistant bacteria.

Complementary omics approaches will then be used to characterize the underlying antibiotic-resistant genes. Together these molecular and experimental results will allow us to scale up future experiments to the European level jointly conducted in three coastal sites; Germany, France, and Spain.

brees@uno.edu Two rounds of genome duplication (GD) in the ancestor of vertebrates, followed by additional GD during the evolution of ray-finned fishes (Actinopterygii), expanded certain gene families, including those encoding the hypoxia inducible transcription factor (HIF). The present study analysed Actinopterygian genomes for duplicates of HIFα, the subunit that confers oxygen-dependent gene regulation. In contrast to tetrapod vertebrates that retain three HIFα genes from the ancestral vertebrate GD, four HIFα forms were found in the genomes of primitive Actinopterygians (spotted gar and Asian arowana). All four forms have been retained in zebrafish and related species (Otocephala) and salmonids and their sister taxa (northern pike) but one of them (HIF4α) was lost during the evolution of more derived fishes (Neoteleostei).

In addition, the current analyses confirm that Otocephala retain duplicates of HIF1α and HIF2α from the teleost-specific GD, provide new evidence of salmonid-specific duplicates of HIF1α, HIF2α, and HIF3α, and reveal a broad distribution of a truncated form of HIF2α in salmonids and Neoteleostei. This study delivers a comprehensive view of HIFα evolution in the ray-finned fishes, highlights the need for a consistent nomenclature, and suggests avenues for future research on this critical transcription factor.

A48 PHYSIOLOGICAL, MORPHOLOGICAL, AND MOLECULAR CHARACTERIZATION OF TWO POPULATIONS OF P. CLARKII POPULATIONS IN THE SOUTH OF FRANCE Thursday 7th July 2022

POSTER SESSION

Diana Martinez-Alarcon, UMR MARBEC-IRD, Université de Montpellier, CNRS, IFREMER, Jehan-Hervé Lignot, UMR MARBEC-IRD, Université de Montpellier, CNRS, IFREMER, Marie-Catherin Raffalli, UMR MARBEC-IRD, Université de Montpellier, CNRS, IFREMER, Leandre Bertin, UMR MARBECIRD, Université de Montpellier, CNRS, IFREMER diana.martinez-alarcon@cnrs.fr Geographic variation of the environment impacts a broad range of physiological and biochemical processes and can be a major selective force leading to local population adaptation. In this context, rapid evolution might have an ecological relevance for the distribution of species and be key in the success of biological invasions. The crayfish Procambarus clarkii is an invertebrate Invasive Alien Species distributed

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around five continents. Although it is considered a freshwater species, it has been established in places with brackish water in the south of France. Intending to understand more about the specific mechanisms that allow this species to inhabit places with different salinity levels, we compare two populations; one from fresh water and the other from brackish water. The results obtained from morphogeometry analysis, and the physiological and molecular comparison of midgut gland and gills showed differences between both populations. These results may suggest that this species rapidly evolved from a common ancestor or that they may have arrived in France from more than one introduction, as frequently suggested.

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A58 LARVAL PERFORMANCE OF THE EXOTIC HEMIGRAPSUS SANGUINEUS UNDER INCREASED TEMPERATURE AND FOOD LIMITATION Thursday 7th July 2022

POSTER SESSION

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A17 - SKELETON IN THE SKIN: STUDYING STRUCTURE FROM ALL VIEWPOINTS

Noé Espinosa, School of Ocean Sciences, Bangor University noespinosarey@gmail.com

A54 EFFECTS OF FLUCTUATING OXYGEN AND TEMPERATURE REGIME ON BIOENERGETICS AND OXIDATIVE STRESS OF THE PACIFIC OYSTER CRASSOSTREA GIGAS Thursday 7th July 2022

POSTER SESSION

Torben Bruhns, University of Rostock, Inna M. Sokolova, University of Rostock, Stefan Timm, University of Rostock torben.bruhns@uni-rostock.de Sessile benthic species are submitted to fluctuating oxygen and temperature conditions that can negatively affect their energy and redox balance. Single effects of temperature and oxygen fluctuations have been extensively studied, but their combined effects are not yet well understood. We studied the bioenergetics and oxidative stress markers in the Pacific oyster Crassostrea gigas exposed for 10 days to daily immersion-emersion cycles under the control (15°C) (H), elevated (30°C) (HW), and fluctuating (15°C in water and 30°C in air) (HF) temperature. Oysters maintained under normoxia and 15°C were used as controls. Mortality increased in the oysters exposed to hypoxia and elevated temperature indicating acute thermal stress. Oysters coexposed to fluctuating oxygen and temperature showed a decrease in the mitochondrial aerobic capacity but no onset of anaerobiosis shown by the lack of succinate accumulation. Glycogen content decreased in the digestive gland, whereas protein content increased in the gill of the HF group indicating higher protein deposition combined with higher energy demand during reoxygenation. In contrast, the HW group showed decreased protein levels reflecting heat-induced suppression of protein synthesis. Lipid peroxidation levels were elevated in the gills of the oysters from HW (but not H or HF group) indicating that antioxidant systems of oysters can cope with hypoxia-induced oxidative stress under the normal or fluctuating temperature but not during constant warming. Thus, long-term warming combined with intermittent hypoxia can lead to breakdown of physiological functions and higher summer mortality like already observed in the German Wadden Sea.

For marine species with complex life cycles, a critical question concerns the response of larval stages to warming. In species with feeding larvae, warming and food limitation may result in negative (additive or synergetic) effects on growth and survival. We experimentally evaluated the combined effects of temperature and food limitation on larval performance of the invasive crab Hemigrapsus sanguineus (local population of Helgoland, North Sea, German Bight). We then compared the performance of H. sanguineus with the native competitor (shore crab Carcinus maenas). Within the studied temperature range (15-24 °C) and under the conditions of food limitation (access to food for 6 hours a day), the primary driver of survival was temperature (low temperatures decreased survival especially at the more advanced stages). Food limitation decreased survival and growth at all temperatures but larvae metamorphosed to megalopa at all food limited conditions.

The response of H. sanguineus differed from that of C. maenas where effects low temperatures have little impact on performance but high temperatures enhance the negative effects of food limitation. Hence, these two coexisting species appear to have different larval responses to warming and food limitation, with warming leading to a higher performance of the invasive relative to the native species.

ORGANISED BY: CATHERINE J.A. WILLIAMS (AARHUS UNIVERSITY), MATTHEW K. VICKARYOUS (UNIVERSITY OF GUELPH), ANTHONY HERREL (CNRS) A28 CALVARIAL OSTEODERMS AND THEIR POTENTIAL ROLE IN LIZARD FEEDING BIOMECHANICS Wednesday 6th July 2022

15:20pm-15:35pm

Arsalan Marghoub, University College London, Loïc Kéver, Muséum National d’Histoire Naturelle, Catherine J.A. Williams, Aarhus University, Arkhat Abzhanov, Imperial College London, Matthew K. Vickaryous, University of Guelph, Anthony Herrel, Muséum National d’Histoire Naturelle, Susan E. Evans, University College London, Mehran Moazen, University College London arsalan.biomech@gmail.com Osteoderms (ODs) are calcified hard tissues that develop directly within the dermis of many lizards. They can be found all over the body, or only on some parts of the body (like the head, where intimate connections with the bones of the skull are common). OD’s main role has been commonly considered to be mainly protective, however there are some evidences that they can also have other functions. We investigated the potential role of calvarial ODs in the biomechanics of feeding. Two lizard species were selected: one that has ODs all over its head (Tiliqua scincoides), and one that has ODs only over its temporal region (Timon lepidus). Several experiments were performed to quantify the level of principal strains on one of the temporal ODs while measuring bite force. At the same time, finite element models of both lizards were developed based on micro-CT images. After being validated against the experimental measurements, finite element models were used to further investigate several hypothetical scenarios regarding the function of the ODs, such as having no ODs. Our results show that ODs can have a significant role in reducing the level of strain across the skull during feeding. Perhaps the possession of cranial ODs can enhance the biting performance of some lizards.

A29 KEEPING CARTILAGE COVERED: QUANTIFYING GROWTH RULES IN STINGRAY TESSELLATED CARTILAGE Wednesday 6th July 2022

12:00pm-12:15pm

Binru Yang, Max Planck Institute of Colloids and Interfaces, Jana Ciecierska-Holmes, Max Planck Institute of Colloids and Interfaces, Jan Wölfer, Humboldt-Universität zu Berlin, David Knötel, Zuse Institute Berlin, Peter Fratzl, Max Planck Institute of Colloids and Interfaces, Daniel Baum, Zuse Institute Berlin, Mason Dean, City University of Hong Kong sueann.watson@jcu.edu.au Sharks and rays have cartilaginous skeletons covered by a continuous layer of abutting mineralized tiles (tesserae). Since these skeletons never stop growing, the presence of tesserae creates a challenging growth constraint: how can a continuous tiled covering be dynamically maintained while the volume of the underlying cartilage increases?

To answer this, we examined the development of a stingray skeletal element (hyomandibula) in microCT datasets, to quantify structural aspects of tesserae over 100% animal size increase. As animals age, the hyomandibula grows roughly isometrically and, although new tesserae are added, most skeletal growth is accomplished by proportional growth of individual tesserae. Curiously, this trend was not followed in juveniles, where disproportionately large tesserae suggest fusions of smaller tesserae. Tesserae are typically brick-like in cross-section (3-4x wider than they are thick), but several skeletal regions exhibited distinct trends: multilayered, thin tesserae at the cranial articulation; irregular, patchy tesserae where muscles attach; and columnar tesserae forming stout ridges. Across ontogeny, tesserae ranged from 4to 8-sided shapes, but were predominantly hexagonal (i.e. with 6 neighbours), especially in flat regions (zero mean curvature), whereas either individual very large or multiple small tesserae were employed to tile curved surfaces. These results provide quantitative insights into how nature can craft complex shapes from tiled architectures and into the dynamic interplays governing growth in tessellated cartilage, where topological requirements (e.g. filling of gaps generated by growth) are balanced by both geometrical and mechanical constraints (e.g. neighbouring tesserae, muscular forces).

ANNUAL CONFERENCE MONTPELLIER 2022

A30 TESSELLATED MATERIAL SYSTEMS: A CATALOGUE TO EXPLORE THE MULTIFUNCTIONALITY AND BIODIVERSITY OF A UNIVERSAL MOTIF Wednesday 6th July 2022

15:35pm-15:50pm

Jana Ciecierska-Holmes, Max Planck Institute of Colloids and Interfaces and The Cluster of Excellence: Matters of Activity, Nikolai Rosenthal, Max Planck Institute of Colloids and Interfaces and The Cluster of Excellence: Matters of Activity, Jan Wölfer, Humboldt-Universität zu Berlin, Felix Rasehorn, The Cluster of Excellence: Matters of Activity, Binru Yang, Max Planck Institute of Colloids and Interfaces and The Cluster of Excellence: Matters of Activity, Mai-Lee Van Le, The Cluster of Excellence: Matters of Activity, Lennart Eigen, Humboldt-Universität zu Berlin, John A. Nyakatura, The Cluster of Excellence: Matters of Activity, Mason Dean, City University of Hong Kong janaach@hotmail.co.uk Humans are drawn to patterns and hierarchies in nature, mimicking them particularly in decoration and architecture. Natural patterns, however, are never purely aesthetic and, since evolution works towards optimising a variety of factors simultaneously, natural structural systems are intrinsically multi-functional. In this study, we examine and classify biological tessellations or ‘tilings’: rather than starting from a specific anatomical feature or function, we focus on this unexpectedly ubiquitous natural structural motif and show its prevalence and function across the Tree of Life. Drawing on more than 100 examples, from viruses to vertebrates and over 8 orders of magnitude in size scale, we construct a hierarchical system of classification for this diverse, but largely unexamined trope in biological patterning. We detail our novel classification scheme, which captures tessellation morphology through a set of seven variables, detailing the material, form and function of tiled natural architectures. Examining the relationships of variables in a Multiple Correspondences Analysis, we observe broad structural correlations across and between taxonomic groups (e.g. materials common to particular taxonomic groups, tiling features that tend to co-occur), but also capture links between anatomical characteristics and particular functions (e.g. tiling morphologies associated with structural support or mobility). Our resulting collection of natural tessellations and its companion website are multidisciplinary meeting points, offering new windows for exploring selective pressures and trade-offs that shape anatomical evolution in nature, for interpreting man-made tessellations in history, and for guiding novel approaches in design and architecture.

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A32 BIOMECHANICAL BEHAVIOUR OF LIZARD OSTEODERMS AND SKIN UNDER EXTERNAL LOADING Wednesday 6th July 2022

15:20pm-15:35pm

Loïc Kéver, Muséum National d’Histoire Naturelle, Olivier Damien, CONACyT Autonomous University of Baja California Sur, Mexico. Arsalan Marghoub, University College London, Mehran Moazen, University College London, Susan Evans, University College London, Matthew K. Vickaryous, University of Guelph, Arkhat Abzhanov, Imperial College London, Anthony Herrel, Muséum National d’Histoire Naturelle and Ghent University loickever@gmail.com Dermal bony plates also known as osteoderms are present in several distantly related vertebrate taxa and they are particularly common and diverse among extant lizards. Lizard osteoderms have classically been considered to be protective elements against predator attacks.

However, empirical data supporting this hypothesis are scant and one of the basic questions pertaining to their diversity has never been addressed: are there interspecific differences in the deformation of lizard osteoderms under external loading? We sampled formalin fixed specimens from eleven species of lizards with osteoderms of different morphologies, instrumented one of the temporal osteoderms with a rectangular rosette strain gauge and loaded different areas of their head to better understand the mechanical responses of osteoderms to loading. Our goals were to 1) test whether loadings applied in different locations of the head (including on the instrumented osteoderm) generated strains in the instrumented osteoderm, 2) explore whether species differed in the relative stiffness of their osteoderm and skin and 3) provide insights into the morphological features and patterns of organization associated with variation in stiffness. We show that loading neighboring osteoderms can generate large strains in the instrumented osteoderm. Moreover, despite a large overlap between some species, the strains recorded showed interspecific differences in magnitude. Smaller strains were recorded in species with relatively thick osteoderms including Heloderma suspectum, H. horridum and Tiliqua rugosa.

A35 SCALED UP DEFENSES: PATTERNS AND DRIVERS OF DERMAL ARMOR IN LIZARDS Wednesday 6th July 2022

14:35pm-15:05pm

Edward Stanley, Florida Museum of Natural History elstanley@ufl.edu Ossified dermal armor is found across the vertebrate tree of life.

Despite bony plates being present in some of the earliest vertebrate ancestors (with dermal armor preceding jaws and even ossified skeletons in the evolution of the group), the ossified armor seen in modern actinopteryiigian fish, frogs, lizards, mammals, crocodiles and turtles appear to be apomorphic, having independently evolved in at least 25 lineages. Squamates—whose very name is derived from their scaly armor— have a particularly complex pattern of armor evolution, with members of 12 extant families possessing some form of osteoderms. These structures strengthen the integument, provide additional ornamentation in the form of spines or keels, and may play a

ANNUAL CONFERENCE MONTPELLIER 2022

role in calcium sequestration and thermoregulation. This study employs comparative phylogenetic analyses of micro-computed tomography (μCT) datasets to quantify and investigate the diversity of dermal armor across Squamata, with broad sampling in the families that are known to possess osteoderms. Our analysis reveals seven independent origins of osteoderms within the order, with three clades—Cordylidae, Anguidae and egerniine skinks—displaying increased rate-shifts in the distribution and extent of their armor. To better understand the mechanisms generating this variation, we sequenced the transcriptome of mammalian osteoderms and identified several pathways known to be involved in the growth of endochondral bone. Ongoing transcriptomic analysis of osteoderm development and selection analysis within the three rate-shifted squamates lineages hints at a universal mechanism for the repeated re-evolution of dermal armor in amniotes.

A36 SKELETON IN THE SKIN? TEETH IN THE SKIN! Wednesday 6th July 2022

11:00am-11:30am

Mélanie Debiais-Thibaud, Université de Montpellier, Roland Zimm, Institut de Génomique Fonctionnelle de Lyon, Fidji Berio, Université de Montpellier & Institut de Génomique Fonctionnelle de Lyon, Nicolas Goudemand, Institut de Génomique Fonctionnelle de Lyon, Nicolas Leurs, Université de Montpellier melanie.debiais-thibaud@umontpellier.fr Elasmobranch fishes (sharks and rays) display a skin covered in hypermineralized scales that resemble teeth. These structures are continuously regenerated over the individual’s lifetime, they display a range of morphological variations within one individual, but also between species. Scales and skin are under a wide set of selective pressures, including general resistance to parasites, female protection against male biting during mating, or hydrodynamism in pelagic species.

The development and regeneration of such structures raises several issues that can be addressed by developmental biologists, such as: How is the organisation of these arrays of scales regulated? How can the diversity in shape be generated within one individual? How are other physiological systems (e.g., the sensory system) organised over these locally mineralized surfaces? Here I will discuss the contribution of recent studies on the lesser spotted catshark Scyliorhinus canicula to highlight several developmental aspects related to these issues, integrating morphological descriptions, development modelling and transcriptomic data.

A37 TALES OF TILED TISSUE TRADEOFFS: BIOLOGICAL TESSELLATIONS AS ARCHITECTURAL BALANCE ACTS OF GROWTH AND MECHANICS Wednesday 6th July 2022

09:45am-10:15am

Mason Dean, City University of Hong Kong mndean@cityu.edu.hk Biological armours, unlike architectural skins, face a curious structural paradox, in that they must continue to provide protection and support even as the structure they cover grows. (This is akin to the challenge

SCIENCE ACROSS BOUNDARIES ABSTRACTS 101

of keeping fast-growing toddlers clothed.) Tessellated armours have evolved multiple times in animals as solutions for this problem, the gaps between tiles creating zones for activity (e.g. movement, growth), albeit perhaps at the expense of overall armour integrity. Our extended workgroup uses biological tessellations as model systems to explore form-function relationships and constraints in tissues, factors regulating mineralisation and growth, and material properties of biological composites. I discuss these functional morphological concepts in the context of biological tilings, drawing on examples from diverse systems and size scales, to offer perspectives on growthmechanics trade-offs (both inside and outside the body), while reflecting on the value of cross-disciplinary bridges to invigorate the study of biological tissues.

A38 HISTORY AND PALAEOHISTOLOGY OF FOSSILIZED OSTEODERMS IN EXTINCT TETRAPODS FROM THE MESOZOIC Wednesday 6th July 2022

09:00am-09:30am

Torsten M. Scheyer, University of Zurich tscheyer@pim.uzh.ch Osteoderms appear widespread across clades and evolved independently and repeatedly over the vertebrate tree of life. Despite fulfilling diverse functions, their evolutionary and developmental origins are often not well understood in extinct taxa. Although anatomical and histological description of osteoderms has a long-standing tradition that sparked in the late 19th century, and their value for taxonomy and systematics was noted early on, it is mostly the last two decades, which have brought forth a renewed interest into their biology and specifically the physiological role integumentary hard tissues play, and the classical analytical methods have been expanded by novel ways of virtual imaging techniques and advanced computational tools.

Interestingly, it was often the fossilised osteoderms and not those of the extant representatives in prominent osteoderm-bearing or ‘armoured’ clades that were studied first in detail. Furthermore, some fossil forms such as the Triassic terrestrial reptile Eusaurosphargis, the marine hupehsuchians (close relatives of the fish-shaped ichthyosaurs), saurosphargids and placodont sauropterygians, as well as various archosauromorph groups (e.g., aetosaurs, rauisuchians) and early stem-turtles provide anatomical and histological data that often lack modern analogues. At the same time, it is exactly this lack that shows the need of examining and better understanding extant taxa, which will then open up novel lines of comparative research. Here, an updated overview of the osteoderms of the aforementioned groups is presented including brief discussions on their palaeoecological and functional implications.

ANNUAL CONFERENCE MONTPELLIER 2022

A350 HISTOLOGICAL HETEROGENEITY: DEVELOPMENT AND TISSUE-LEVEL DIVERSITY OF LIZARD OSTEODERMS Wednesday 6th July 2022

09:30am-09:45am

Gabriella Willan, Ontario Veterinary College, University of Guelph, Catherine J.A. Williams, Ontario Veterinary College, University of Guelph and Aarhus University, Shreya Rai, Imperial College London, Arkhat Abzhanov, Imperial College London, Loïc Kéver, Muséum National d’Histoire Naturelle, Anthony Herrel, Muséum National d’Histoire Naturelle and Ghent University, Arsalan Marghoub, University College London, Mehran Moazen, University College London, Susan Evans, University College London, Alex Kirby, University College London, Matthew K. Vickaryous, Ontario Veterinary College, University of Guelph gburdett@uoguelph.ca Osteoderms are bone-rich elements that form within the dermis of various vertebrates including many species of lizard. Among lizards, osteoderms demonstrate variability in size, shape, and body-wide distribution but a detailed comparative assessment of osteoderm microstructure is lacking. Here, we characterize the histological diversity of osteoderms from representative members of the lizard groups Gekkota (geckos), Anguimorpha (anguids, Shinisaurus, helodermatids, varanids), and Scincomorpha (scincids, cordylids, gerrhosaurids). In virtually all lizards, osteoderms are composed primarily of bone, albeit with a heterogenous and often laminated fibrillary organization. Histologically, most osteoderms are dominated by lamellar, woven-fibred and/or Sharpey-fibred bone, although details of the organization and relative contribution of each bone matrix differs between genera. In addition, we found that multiple genera from each major group also develop a highly mineralized, collagen and cell-poor capping tissue – a feature previously restricted to only a handful of species. Singularly, the osteoderm-like elements from the gekkotan Geckolepis entirely lack bone and instead are composed of a plate of collagen topped with mineralized capping tissue. Initial studies of osteoderm development in the lacertid Timon show that specific markers for osteoblast differentiation (Osterix and β-catenin) can be successfully detected surrounding the growing osteoderm, opening possibilities of dissecting whether developmental strategies vary in sync with histological appearance, under drivers such as phylogeny, ecology and function.

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(trabeculae), and pavement-like dentitions. Our data on the strategies for skeletal strengthening against durophagy, however, are largely limited to the myliobatiform stingrays, although a hard prey diet has evolved multiple times in batoid fishes (rays, skates, guitarfishes).

Here we perform a quantitative analysis of microCT data to describe jaw strengthening mechanisms in Rhina ancylostoma (Bowmouth Guitarfish) and Rhynchobatus australiae (White spotted Wedgefish), durophagous members of the Rhinopristiformes, the sister taxon to the Myliobatiformes. Both species possess trabeculae, more numerous and densely packed in Rhina, albeit simpler structurally than those seen in stingrays like Aetobatus and Rhinoptera. Volumetric quantification of the teeth and jaw tesserae show that both Rhina and Rhynchobatus exhibit impressively thickened jaw cortices, often comprising >10 tesseral layers, most pronounced in regions where dentition is thickest, particularly in Rhynchobatus. Age series of both species illustrate that tesserae increase in size during growth, with enlarged and irregular tesserae associated with the oral surface of the jaw in larger (older) individuals of Rhina and Rhynchobatus, perhaps a feature of aging.

Unlike the flattened teeth of durophagous myliobatiform stingrays, both rhinipristiform species have pebble-like dentitions, with rounded, interlocking teeth arranged in connate ‘meta-teeth’ (bulbous structures, formed from multiple teeth). This is particularly striking in Rhina, where the upper/lower occlusal surfaces are mirrored undulations, fitting together like a rounded woodworking finger-joint. Trabeculae were previously thought to have arisen twice independently in the Batoidea; our results demonstrate they are present in all major batoid groups except the phylogenetically basal Rajiformes. Comparisons with several other durophagous and non-durophagous species also illustrate that skeletal reinforcement architectures are modular in batoids: trabeculae can be variously oriented and play great roles in some species (e.g.

Rhina, Aetobatus), whereas cortical thickening is more significant in others (e.g. Rhynchobatus), while both features can be lacking (e.g.

Raja, Urobatis). We discuss the interactions and implications of these character states, framing a classification scheme for exploring the evolution of cartilage structure in the cartilaginous fishes.

A352 UNDERSTANDING THE EXTRAORDINARY DIVERSITY OF DERMAL DENTICLES IN SHARKS Wednesday 6th July 2022

11:30am-11:45am

Molly Gabler-Smith, Harvard University, mollygablersmith@gmail.com

A351 BRICKS, TRUSSES AND SUPERSTRUCTURES: STRATEGIES FOR SKELETAL REINFORCEMENT IN BATOID FISHES (RAYS AND SKATES) Wednesday 6th July 2022

11:45am-12:00pm

Júlia Chaumel, Independent chaumel.julia@gmail.com The crushing of hard prey (durophagy) is a mechanically demanding feeding mode. The cartilage jaws of durophagous stingrays, for example, are diversely reinforced relative to non-durophagous relatives, possessing multiple layers of the mineralized blocks that form the jaw’s external cortex (tesserae), reinforcing struts within the jaw itself

Elasmobranch fishes are covered in thousands of dermal denticles – tooth-like structures consisting of enameloid and dentine with a central pulp cavity. Previous research has documented the wide range of morphological diversity across shark species, specifically differences in dermal denticle shape and size. Additionally, there have been many proposed functions of dermal denticles, including abrasion reduction, protection against parasites, drag reduction and increased lift during swimming. The field of biomimicry has historically been interested in shark skin; specifically, how surfaces covered in denticlelike structures increase performance of material ranging from airplane wings to swimsuits. However, there is still much to understand about how these morphological differences in denticles affect function. The recent application of new techniques such as surface profilometry and micro-CT scanning, combined with histology, have advanced our understanding of how surface characteristics (e.g., ridge spacing and height) and development of specific denticle morphologies differ across and within shark species. The central goal of this presentation is to showcase the extraordinary diversity of dermal denticles in sharks

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and to postulate how denticle morphology affects function using a multitude of techniques. This talk will focus on four key areas: (1) morphological variation across species, (2) ontogenetic variation in deep-sea sharks, (3) development of dermal denticles, (4) comparison between natural and man-made biomimetic denticles. Each of these four key areas will probe the importance of denticle morphology in elucidating the various functions of dermal denticles in sharks.

POSTER SESSION

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A34 TESSELLATED OSTEODERM CARAPACES IN EXTANT ARMADILLOS Thursday 7th July 2022

POSTER SESSION

Mai-Lee Van Le, Humboldt University Berlin, John A. Nyakatura, Humboldt University Berlin, Daniel Baum, Zuse Institute Berlin, Lennart Eigen, Humboldt University Berlin, Mason Dean, City University of Hong Kong maileevanle@gmail.com

A31 CARAPACE GROWTH OF THE LONGHORN COWFISH LACTORIA CORNUTA: A TESSELLATED ARMOUR THROUGH ONTOGENY Wednesday 6th July 2022

POSTER SESSION

Lennart Eigen, Humboldt-Universität zu Berlin, John A. Nyakatura, Humboldt-Universität zu Berlin, Daniel Baum, Zuse Institute Berlin, Mason Dean, City University of Hong Kong and Max-Planck Institute of Colloids and Interfaces, Daniel Werner, Max-Planck Institute of Colloids and Interfaces, Jan Wölfer, Humboldt-Universität zu Berlin lennart.eigen@hu-berlin.de The structural integrity of biological armours derives in part from their geometric architectures. Armours often involve tessellations of self-similar structural elements, tiled together to form a shell-like surface. The boxfish carapace, for example, is comprised of polygonal mineralized dermal plates, called scutes, which are arranged in a complex geometric pattern. Unlike artificial armours, the exoskeleton grows along with the fish. Therefore, the relationship between the tessellation and the overall structure of the armour is critical to maintain protection throughout growth. Using high-resolution microCT data and segmentation algorithms, we quantify architectural aspects for each of the hundreds of scutes that build the armour, across an ontogenetic series of the longhorn cowfish Lactoria cornuta (from 1.7 cm to 13.6 cm body length), to investigate the maintenance of the tessellated structure throughout growth. We show that instead of adding scutes to enlarge the carapace surface, scute number remains constant, and carapace growth is achieved by scutes increasing in absolute volume, thickness, and especially width. Scutes also become relatively thinner and in areas of more complex topology (e.g. around fin insertions, mouth, anus) smaller scutes with more variable curvature are found.

Besides providing insights into developmental constraints of this species related to carapace growth, our findings might also provide perspectives into natural strategies for construction of mutable tiled architectures.

Tessellated material systems, meaning self-similar subunits arranged to form surface structures, are found throughout various unrelated taxa as well as over a broad range of sizes. An especially interesting system constitutes the armadillo carapace, a rare example of mammal armor involving hard mineralized elements, so called osteoderms embedded in soft connecting tissue. Previous work focused on the structural integrity and histology of individual osteoderms. However, the larger scale organization of armadillo tilings has never been subjected to a larger scale comparative analysis, although the mechanics (e.g. overall fracture resistance) of a tessellation is linked to the geometrical arrangement of its subunits. In this study we digitally examined osteoderm carapaces from micro-CT scans of twelve armadillo species, representing all major lineages within the armadillo phylogeny, in order to quantitatively compare and describe osteoderm shape as well as arrangement and distribution within the entire carapace. Results show that five- and six-sided osteoderms are tied to positive Gaussian curvature similar to the patches on a soccer ball, where a comparable combination of pentagons and hexagons is used. Furthermore, osteoderm number per surface area of entire carapaces reflects a deep split in armadillo phylogeny, separating the two major groups Dasypodidae and Chlamyphoridae. Additionally, Chlamyphorinae display an outstanding carapace architecture that consists of bands comprising exclusively rectangular osteoderms, potentially related to functional adaptations to a specialized nocturnal and fossorial lifestyle that requires increased mobility compared to other armadillo species, while possibly also leading to a decrease in protective performance of the carapace. Our study reveals a hitherto understudied diversity of carapace structure and function in armadillos, a deeper understanding of which will yield further insight into the evolutionary history of the taxon.

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A18 - SURVIVING OXYGEN DEPRIVATION: THE ROLE OF MITOCHONDRIA AND THE MAINTENANCE OF METABOLIC FUNCTION ORGANISED BY: TODD GILLIS (UNIVERSITY OF GUELPH), ANGELA FAGO (AARHUS UNIVERSITY) C28 IMPORTANCE OF MAINTAINING PHYSIOXIA IN CELL CULTURE Friday 8th July 2022

09:30am-10:00am

Jeff Stuart, Brock University jstuart@brocku.ca Understanding molecular mechanisms underlying physiology benefits from studies of isolated and/or cultured cells. However, virtually all experiments in cell culture are done in the absence of O2 regulation, resulting in incubator headspace O2 levels of 18-19%. In vivo, O2 levels in heart, skeletal muscle, brain, liver, and indeed most of the mammalian body, are typically 2-6%. The supra-physiological O2 levels in cell culture drive increased cellular reactive oxygen species (ROS) production, affecting many aspects of cell physiology. We have shown that supra-physiological O2 targets mitochondria, with important effects on bioenergetic function and network dynamics. Cellular responses to hormones like 17β-estradiol are significantly different in 18%, versus 5%, O2. Our RNAseq investigations show widespread effects of 18%, versus 5% O2 on diverse molecular processes ranging from DNA repair and cell cycle to energy metabolism to the viral response. Since supra-physiological O2 affects both transcriptional and translational processes, there are additional effects on relative protein abundance that are evident in proteomic analyses. The effects of supra-physiological O2 we have characterized are generally cell linespecific, making them difficult to predict. Given these myriad cellular effects of O2, it is important to reference hypoxia experiments in cell culture to physiological normoxia (e.g. 2-6%), but the vast majority of CO2 incubators used by cell culturists are not capable of regulating O2.

We have developed a low-cost (&lt;1000 CAD) cell culture incubator capable of regulating O2, CO2, and temperature in their appropriate physiological ranges. Improved control over O2 levels will improve data quality in hypoxia experiments.

if H2O2 exposure induces PTMs responsible for regulating oxidative phosphorylation during hibernation.

C354 THE EFFECTS OF CYCLIC HYPOXIA ON FISH GROWTH, METABOLISM, AND MITOCHONDRIAL RESPIRATION: A MERE FORMALITY FOR ARCTIC CHARR? Friday 8th July 2022

15:20pm-15:35pm

Loïck Ducros, Université de Moncton, Annie Sarah Lavoie-Rochon, Université de Moncton, Mohamed Touaibia, Université de Moncton, Nicolas Pichaud, Université de Moncton, Simon G. Lamarre, Université de Moncton eld7566@umoncton.ca

A353 A FLUCTUATING INTERNAL ENVIRONMENT: DYNAMICS OF MITOCHONDRIAL ROS PRODUCTION AND RESPIRATION IN THE HIBERNATING 13-LINED GROUND SQUIRREL, ICTIDOMYS TRIDECEMLINEATUS Friday 8th July 2022

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11:30am-12:00pm

Brynne Duffy, Western University, James F. Staples, Western University bduffy5@uwo.ca Hibernation is a dynamic physiological process in which animals cycle between torpor (characterized by low body temperature and suppressed metabolism for ~12 days) and spontaneous arousals to interbout euthermia (IBE) characterized by high body temperatures and metabolism. We have demonstrated that reversible suppression of mitochondrial metabolism corresponds with the changes in wholeanimal metabolism. We recently found that the 13-lined ground squirrel (TLGS) experiences fluctuating oxygen availability between torpor and IBE as arterial oxygen saturation increases from as low as 28% oxygen saturation during early arousal to 95% oxygen saturation during IBE. We hypothesize that changes in mitochondrial metabolism help reduce reactive oxygen species (ROS) production in a variable internal environment as TLGS cycle between torpor and IBE. Using highresolution respirometry and concurrent Amplex UltraRed fluorimetry, we determined that isolated liver mitochondria produce two-fold less ROS during torpor and IBE than in summer. Previous work in our lab shows that electron transport system complex II is phosphorylated during IBE and dephosphorylated during torpor. We hypothesize that low levels of ROS during hibernation affect PTMs of mitochondrial proteins by increasing the activity of Fgr Kinase, which phosphorylates complex II. Incubation in a ten mM H2O2 solution increased torpid oxidative phosphorylation rates by 50% to levels similar to IBE mitochondria. This increase was prevented when PP2, an Fgr kinase inhibitor, was added to the incubation. Together this suggests that phosphorylation is a mechanism of metabolic control in TLGS, which is indirectly manipulated by ROS concentrations. Next, we will compare the phosphorylation states of mitochondrial proteins to determine

The intensification of anthropic activities is currently exacerbating eutrophication in aquatic environments, leading to an increase in algae populations. As a result of photosynthesis and respiration, the concentration of dissolved oxygen increases during the day and drops drastically at night, creating a daily cycle of alternating normoxic and hypoxic conditions. Lack of oxygen and then reoxygenation can have serious repercussions on mitochondrial metabolism in fish.

Hypoxia restrains aerobic metabolism and can induce a mismatch between ATP demand and supply. Then, tissue reperfusion could be responsible for an oxidative burst in mitochondria. To cope with these oxygen fluctuations, fish must adjust their phenotype. Although hypoxia is a major issue for ecosystems and fisheries worldwide, our knowledge remains limited regarding the impact of cyclic hypoxia. Our objective was to characterise the effects of cyclic hypoxia on growth, mitochondrial respiration, and metabolism in fish. We monitored the growth of Arctic charr (Salvelinus alpinus) exposed to up to thirty days of cyclic hypoxia and measured mitochondrial respiration, metabolic rate, energy reserves and relative hepatic metabolite concentrations all along this treatment. Contrary to our initial hypothesis, Arctic charr appeared to acclimate well to cyclic hypoxia. The first days of cyclic hypoxia caused a mitochondrial perturbation and induced a profound metabolome reorganisation in liver. However, the metabolic rate remained unaffected, and fish successfully maintained their growth and energetic reserves after one month of cyclic hypoxia. These results raise many questions about the ability of fish to cope with their changing environment.

A355 RESPONSES OF THE PROTEOME AND PHOSPHOPROTEOME TO ANOXIA AND REOXYGENATION IN CRUCIAN CARP (CARASSIUS CARASSIUS) Friday 8th July 2022

10:00am-10:30am

Göran Erik Nilsson, University of Oslo, Anette Johansen, University of Oslo, Jan Haug Anonsen, University of Oslo, Bernd Thiede, University of Oslo, Sjannie Lefevre, University of Oslo g.e.nilsson@ibv.uio.no

SCIENCE ACROSS BOUNDARIES ABSTRACTS 105

The crucian carp has the rare ability to survive days to months of anoxia, depending on temperature. Transcriptome analyses show that this is accompanied by widespread changes in gene expression.

However, the importance of changes on the mRNA level can of course be questioned because it is the proteins that ultimately matter. We have therefore, in addition to global analyses of transcription and translation (ribosomal footprint profiling), measured the levels of proteins and phosphopeptides in tissues of crucian carp exposed to one week of anoxia and subsequent reoxygenation at 8°C. A general conclusion is that the transcriptome is a good indicator for the direction of change but that rather few proteins show a detectable change in their concentration during one week of anoxia and subsequent reoxygenation (e.g. 66 out of 3304 proteins in brain), which probably reflects that protein synthesis is slow and occur on top of a background of existing protein pools. Moreover, most proteins may have structural or housekeeping functions that are not altered during anoxia, and making major changes in protein concentrations would be energetically expensive, and energy use needs to be suppressed in anoxia. Phosphorylation of proteins, on the other hand, is an instant response, but also here relatively few changes were seen. In brain 109 out of 4316 phosphopeptides were regulated, while in liver 395 out of 1293 were regulated. The changes found in the proteome and phosphoproteome are likely to point at important adaptive mechanisms, which include mitochondrial adjustments, AMPK signalling and glucose metabolism.

C358 EFFECTS OF ANOXIA AND REOXYGENATION ON PACIFIC HAGFISH (EPTATRETUS STOUTII) MITOCHONDRIAL RESPIRATION Friday 8th July 2022

15:05pm-15:20pm

Michael Yusishen, University of Guelph, Todd Gillis, University of Guelph, Georgina Cox, Washington State University yusishenm@gmail.com Pacific hagfish (Eptatretus stoutii) can survive up to 36 hours of anoxia exposure through a combination of low basal metabolism, hypometabolism during anoxia, and extensive glycogen stores. An understudied aspect of the anoxia/reoxygenation response in hagfish is how the mitochondria respond. Under anoxic conditions, the electron transport system (ETS) can become unbalanced, with significant consequences upon reoxygenation. As a burst of reactive oxygen species (ROS) produced by the mitochondria can cause widespread oxidative damage, triggering apoptotic cell death. Our goal was to investigate the ability of E. stoutii mitochondria to survive anoxia using a novel protocol measuring mitochondrial respiration in permeabilized cardiac muscle. The development of this protocol revealed that hagfish mitochondria had a comparatively low rate of oxygen consumption averaging 39.8 pmol/sec/mg DW. Confounding characteristics were a low sensitivity to oligomycin and high endogenous ATPase activity.

Mitochondria were exposed to either one or three hours of anoxia in State II or State III respiration. The oxygenation consumption in State II was reduced by 30.1% and 45.5% after one and three hours of anoxia respectively. In State III respiration the reduction was 24.5% after one hour and 32.0% after three hours. We are currently repeating these studies using rainbow trout (Oncorhynchus mykiss), a hypoxia intolerant species. Metabolic responses to anoxia were also examined. Six hours of anoxia did not significantly change concentrations of succinate or lactate in the heart, white muscle, or liver. These results present a promising start in the research of hagfish mitochondrial physiology.

ANNUAL CONFERENCE MONTPELLIER 2022

C359 PROTEOMES AND JUVENILES: A SYNTHESIS OF IDEAS ON THE ONTOGENY OF HYPOXIA TOLERANCE Friday 8th July 2022

14:20pm-14:50pm

Sarah Alderman, University of Guelph alderman@uoguelph.ca Surviving in low oxygen environments requires complex and integrated physiological responses, many of which center on economizing energy budgets. At the cellular level, significant reductions in protein synthesis and even translational arrest (in anoxia) can save as much as 90% of routine ATP demand. This suggests strategic investment in the protein complement of essential tissues, like the heart, that must maintain some level of function for the animal to survive through and recover from a hypoxic bout. The use of quantitative proteomics in animal models of hypoxia tolerance has unveiled new ideas about how the cardiac proteome is influenced by hypoxia exposure, as well as the ontogenic constraints on this aspect of cardiac plasticity. For example, developmental hypoxia exposure of American alligators (Alligator mississippiensis) induces persistent shifts in the cardiac proteome that, paradoxically, reflect an increased capacity for translation, proteolysis, and metabolic capacity. Concomitant with these changes was an equitable down-regulation of seemingly random cardiac proteins, which may offset the cellular energy budget. In Western painted turtles (Chrysemys picta bellii), the cold acclimation required to prepare tissues for chronic anoxia during winter dormancy induced general down-regulation of electron transport system proteins in adult but not hatchling turtles. Interestingly, both studies revealed ‘age’ as a key explanatory variable in the cardiac proteome. This suggests a robust developmental program in the ectotherm heart that is resilient even to potent environmental stressors like oxygen and temperature, and warrants further investigations into the developmental thresholds of hypoxia tolerance.

C360 LOW IN VIVO PRODUCTION OF REACTIVE OXYGEN SPECIES AFTER ANOXIA AND REOXYGENATION PREVENTS OXIDATIVE DAMAGE IN THE TURTLE HEART Friday 8th July 2022

11:00am-11:30am

Amanda Bundgård, University of Cologne, Ilan Ruhr, University of Manchester , Anja Gruszczyk, University of Cambridge, Hiran Prag, University of Cambridge, Andrew M. James, University of Cambridge, Michael P. Murphy, University of Cambridge, Gina Galli, University of Manchester, Angela Fago, Aarhus University ammagabu@bio.au.dk Reactive oxygen species (ROS) are by-products of oxidative metabolism, and while low levels contribute to cell signalling, high levels can be toxic. In mammals, ischaemia-reperfusion leads to production of toxic levels of ROS, which cause oxidative tissue damage. In contrast, anoxia-tolerant species, such as the freshwater turtle, do not sustain oxidative tissue damage after anoxia and reoxygenation. How anoxia-

SCIENCE ACROSS BOUNDARIES ABSTRACTS 106

tolerant animals are able to prevent ROS dysregulation and oxidative damage with anoxia is unclear. We investigated ROS production and antioxidant capacity in the turtle heart upon anoxia-reoxygenation.

Using the in vivo mass-spectrometric H2O2-probe MitoB, we found that there is no excessive production of ROS in the turtle heart after whole animal anoxia-reoxygenation. We hypothesized that this was due to the fact that turtles avoid large accumulation of succinate in the heart and preserve energy levels. This would prevent reverse electron transfer and extensive ROS production from complex I after anoxia. However, addition of exogenous succinate and manipulation of membrane potential with oligomycin did not induce excessive ROS production in turtle heart strips in vitro. This suggests that other factors, such as S-nitrosation of complex I, supercomplex stability or high antioxidant capacity may also be involved in preventing ROS after anoxia in the turtle heart. Together, this study shows that turtles are able to avoid toxic levels of ROS in the heart and oxidative tissue damage after anoxia and reoxygenation.

A361 MITOCHONDRIAL MECHANISMS OF TOLERANCE TO FLUCTUATING OXYGEN CONDITIONS: WHAT CAN WE LEARN FROM INTERTIDAL ANIMALS? Friday 8th July 2022

09:00am-09:30am

Inna Sokolova, University of Rostock inna.sokolova@uni-rostock.de Mitochondria play a central role in ATP provisioning, redox and Ca2+ homeostasis and stress signaling of aerobic organisms. Animal mitochondria are extremely sensitive to fluctuating oxygen (O2) levels such as occur during tissue ischemia and/or environmental hypoxia. In hypoxia-sensitive organisms, hypoxia and especially post-hypoxic reoxygenation cause mitochondrial injury due to the elevated production of reactive oxygen species, Ca2+ overload and damage to the metabolic machinery; yet many hypoxia-tolerant species (including intertidal invertebrates) endure frequent hypoxiareoxygenation cycles without apparent ill effects. The mechanisms of such exceptional mitochondrial robustness are not yet fully understood.

I will discuss the mitochondrial responses to intermittent hypoxia in marine intertidal mollusks emphasizing the potentially adaptive functional and proteomic changes of the mitochondria and integration of the mitochondrial responses with cellular protection and stress response pathways (including antioxidant defense, autophagy and apoptosis) that might contribute to high tolerance to fluctuating O2 levels and support recovery in these organisms. I will also discuss the current knowledge gaps with an outlook to future studies needed to shed light on mitochondrial adaptations and evolution of metabolism in the environments with highly variable oxygen levels such as the intertidal zone.

ANNUAL CONFERENCE MONTPELLIER 2022

A362 EXPRESSION OF PHDS IN THE BRAIN OF CRUCIAN CARP: INSIGHTS INTO REGULATION OF THE HIFRESPONSE IN ANOXIA AND REOXYGENATION Friday 8th July 2022

12:00pm-12:15pm

Lucie Gerber, University of Oslo lucie.gerber@ibv.uio.no The hypoxia-inducible factor (HIF) is considered key in the transcriptional response to low oxygen. Yet, activation of HIF under anoxic conditions in the anoxia-tolerant crucian carp (Carassius carassius) remains unclear. Mounting a general HIF response would be counterproductive in a species such as the crucian carp that experience only a short hypoxic window in the onset of anoxia (i.e. due to high O2 affinities). We therefore hypothesized that expression of prolyl hydroxylase domains, PHDs (the enzymes responsible for hydroxylation of HIF-α and targeting it for degradation) are upregulated to circumvent an energy-costly activation of HIF and in preparation for re-oxygenation. The three isoforms PHD1, PHD2 and PHD3 are coded for by multiple paralogs of the genes egln2, egln1 and egln3, respectively. We quantified mRNA and protein expression using qPCR and western blotting, respectively, in brain of crucian carps exposed to 5 days normoxia or anoxia, and 5 days anoxia followed by 3 or 24 hours re-oxygenation. The mRNA expression of most egln paralogs were upregulated in anoxia; up to 15-fold for egln3 paralogs. The protein expression of all PHD isoforms were also increased 24hrs after re-oxygenation. Furthermore, immuno-reactivity of PHDs were observed in axons of the brain, using immunohistochemistry. Overall, our results confirm that upregulation of egln/PHDs is part of the anoxia and re-oxygenation response of crucian carp, likely to 1) prevent HIFresponse in anoxia, 2) precondition for the re-oxygenation period and 3) protect and/or repair/recover from tissue damage that occurs in crucian carp brain both during and after anoxia.

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POSTER SESSION A356 EPIGENETIC MECHANISMS DURING ANOXIA AND RE-OXYGENATION IN CRUCIAN CARP BRAIN Thursday 7th July 2022

POSTER SESSION

Magdalena Winklhofer, University of Oslo, Sjannie Lefevre Nilsson, University of Oslo magdalena.winklhofer@ibv.uio.no Crucian carp (Carassius carassius) overwinter in ice-covered lakes and can survive hypoxia and anoxia for several months, depending on the temperature. The physiological adaptations allowing this survival are well understood at the whole-organism level, but we know less about the molecular machinery coordinating the various elements of adaptation to anoxia and re-oxygenation, and the possible role of epigenetic mechanisms. Posttranslational modifications such as methylation, on either the histone tail or the globular domain, or both, can cause chromatin remodeling. Consequently, gene expression can be activated, altered or repressed solely depending on the epigenetic environment. Previous experiments analyzing whole brain transcriptome (RNAseq) data have shown that a large proportion of the transcriptome is regulated differentially in response to anoxia, and we suspect that at least some of these changes in gene transcription during anoxia are regulated by epigenetic mechanisms. By whole genome DNA sequencing before and after bisulfite conversion, we want to determine if DNA methylation loci are altered. Furthermore, the resulting data from methylation sequencing can be correlated with RNAseq data to investigate which specific genes are under epigenetic regulation. The obtained data will help to uncover the role of epigenetic mechanisms involved in response to anoxia and further guide us towards uncovering potentially novel molecular players in anoxia tolerance.

ANNUAL CONFERENCE MONTPELLIER 2022

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A19 - NOT JUST DOWN THE HATCH: FOOD PROCESSING, TRANSPORT AND ASSIMILATION IN JAWED VERTEBRATES

ANNUAL CONFERENCE MONTPELLIER 2022

A5 WHAT SALAMANDERS MIGHT TEACH US ABOUT THE FOOD PROCESSING BEHAVIOUR OF EARLY TETRAPODS? Tuesday 5th July 2022

10:30am-11:00am

Daniel Schwarz, State Museum of Natural History Stuttgart, Egon Heiss, Friedrich Schiller University Jena, Nicolai Konow, University of Massachusetts daniel.schwarz@smns-bw.de

ORGANISED BY: NICOLAI KONOW (UNIVERSITY OF MASSACHUSETTS) CALLUM F. ROSS (UNIVERSITY OF CHICAGO) A3 HEAD POSTURE AND GAPE IMPACT HYOID POSTURE IN MAMMALS Tuesday 5th July 2022

16:45pm-17:15pm

Peishu Li, University of Chicago, Nicholas J. Gidmark, Knox College, Zhe-Xi Luo, University of Chicago, Callum F. Ross, University of Chicago peishuli0830@gmail.com Resting hyoid position in mammals varies across phylogeny and ontogeny. Previous studies postulated that evolutionary shifts in hyoid position result from changes in hyoid and cranial morphology, yet this hypothesis has been difficult to test because both head posture and gape angle impact hyoid position within individuals. Thus, it is important to evaluate hyoid position in the kinematic context of jaw gape and head position change. Here we examine the effect of head posture and gape angle on hyoid position in six anesthetized Didelphis virginiana. CT scans were taken across three head flexion angles and three gape angles resulting in nine scans per animal. We used Autodesk Maya to quantify hyoid position across each head and gape angle combination. From full head extension to full flexion, hyoid shifts rostrally and superiorly relative to cranium at given gape with minimal mediolateral movement. Geniohyoid is estimated to shorten by 22.0-25.5% and the stylohyoid lengthen by 25.0-30.7%. Increasing gape moves the hyoid caudally at given head posture, with minimal impact on muscle length. Effects of head posture on hyoid position are more pronounced at large gapes than small gapes. Head flexion may be important for modulating the length and orientation of suprahyoid muscles critical for hyoid movement during chewing and swallowing, and controlling the travel distance of boluses required to clear the airway. Our findings establish a framework for comparing interspecific variation in hyoid position, and highlight the need to monitor head posture during comparative studies of hyolingual kinematics using non-human animal models.

A4 TEMPERATURE-DEPENDENT TOXICITY AND MACRONUTRIENT SELECTION IN FOLIVOROUS MARSUPIALS Wednesday 6th July 2022

11:45am-12:15pm

Phillipa Beale, Australian National University, Karen J. Marsh, Australian National University, William J. Foley, Australian National University, Ben D. Moore, Western Sydney University, Patrice K. Connors, Colorado Mesa Universitym, M. Denise Dearing, University of Utah, Andrew Krockenberger, James Cook University phillipa.beale@gmail.com The nutritional decisions of herbivores are inextricably tied to the thermal environment they experience. This pertains not just to the total energy eaten, but also to the macronutrients from which they choose to get that energy, and to the plant secondary metabolites (PSMs) that complicate the decision. The relationship between thermal physiology and nutritional ecology runs deeper than simply adjusting food intake to meet changes in metabolic rate. I will present results on how temperature-dependent toxicity applies to marsupial folivores ingesting diets high in plant secondary metabolites. Ambient temperature may also influence the mixing of macronutrients to minimise heat generation, and when a plant toxin is included in the diet, these feeding decisions can be further complicated. The addition of a plant secondary metabolite removed the effect of temperature on macronutrient balancing, so it may be that ingesting enough protein to deal with the cost of plant secondary metabolite ingestion overrides the desire to minimise the obligatory thermogenesis of a higher protein diet in warm conditions. Field data collected on koalas fitted with radio collars with microphones will be considered to observe this phenoma in a wild setting. Intake patterns of koalas were indeed influenced by temperature and plant secondary metabolite concentrations of available trees resulting in altered daily and per meal food intake.

Temperature can have considerable impact on nutrition, and warming ambient temperatures due to climate change are likely to result in a new challenges for marsupial folivores and other herbivores, particularly those ingesting PSM rich diets.

Ancestrally, aquatic food processing in gnathostomes involves the action of a diversity of tooth-clad bones intraorally and on the mandibular, hyoid, and branchial arch skeletons to mechanically reduce food (i.e., “fish-like” processing). Like many extant fish, early gnathostomes likely used a skeletal and relatively inflexible hyobranchial system or “tongue” during processing to create water currents that move and orient food intraorally. However, during tetrapod evolution, the “fish-like” mechanism was replaced by an “amniote-like” mechanism where food is processed between the mandibular lower and upper jaws, accompanied by a general skeletal reduction and a large fleshy tongue that directly contacts and reorients food between chews. The switch in food processing mechanism likely relates to the transition of early tetrapods between the different physical properties of water and air. A functional analogue of this would be extant amphibians such as salamanders, which transition from an aquatic to a terrestrial lifestyle during development. Unsurprisingly, salamander food processing mechanisms undergo developmental shifts associated with the switch from aquatic to terrestrial life. Pre-metamorphic salamanders are aquatic and chew “fish-like”, whereas metamorphic, more terrestrial salamanders use tongue-palate rasping. Similarities between this peculiar form of intraoral food processing and amniote chewing include the tongue acting directly in transporting and orienting food intraorally. Hence, tongue-palate rasping might represent a processing mode intermediate between “fish-like” and “amniote-like” chewing where the jaws do not assist in processing. Accordingly, paleontological evidence could be used to determine if early tetrapods may have used tongue-palate interactions before evolving “amniote-like” chewing.

A6 COMPARING NEURAL AND STRUCTURAL DRIVERS OF IN VIVO BITE FORCE PRODUCTION Tuesday 5th July 2022

14:30pm-15:00pm

Myra Laird, University of Southern California, Jose Iriarte-Diaz, University of the South, Craig D. Byron, Mercer University, Michael C. Granatosky, New York Institute of Technology, Andrea B. Taylor, Touro University, Callum F. Ross, University of Chicago myra.laird@usc.edu Jaw movements and bite forces are dependent on neural factors, such as muscle activation, and structural factors, such as jaw muscle architecture. Both factors are thought to reflect functional demands of the muscle during feeding. However, it is unknown how dynamic jaw-muscle architecture relates to muscle activation, and how food material properties impact this relationship. Here we investigated variation in dynamic muscle architecture and muscle activation across the functionally heterogeneous temporalis muscle in relation to food

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properties. We recorded fascicle-level architecture dynamics in the superficial anterior, middle, and posterior temporalis of three adult tufted capuchins (Sapajus apella) using biplanar video radiography and the X-Ray Reconstruction of Moving Morphology (XROMM) workflow. Architecture dynamics data were paired with fine wire electromyography data from across the temporalis collected in four adult tufted capuchins. Timing differences in dynamic muscle architecture and muscle activation were compared within the gape cycle. We found that gape accounted for the majority of architectural changes across the temporalis, but the anterior region underwent greater variation in most architecture variables compared to the posterior. We also found that in tufted capuchins, fascicle rotation varied with gape to reduce the architectural gearing ratio during bite force production. However, the timing of dynamic architectural changes did not vary between muscle regions, in contrast to peak muscle activation, which varied anteroposteriorly. These results suggest that muscle force production capacity in the temporalis is strongly influenced by jaw gape, whereas patterns of muscle activation work within that framework to contribute to jaw movements.

A7 COMPARATIVE MORPHOLOGY OF RORQUAL WHALE BALEEN Tuesday 5th July 2022

09:30am-09:45am

Shirel Kahane-Rapport, California State University, Fullerton, Megan L. Vandenberg, University of Washington, Karly E. Cohen, Friday Harbor Laboratories, University of Washington, Robert Rubin, Santa Rosa Junior College, Jeremy A. Goldbogen, Hopkins Marine Station, Stanford University, Adam P. Summers, Friday Harbor Laboratories, University of Washington, E.W. Misty Paig-Tran, California State University, Fullerton skahane-rapport@fullerton.edu Rorqual whales are lunge filter-feeders that use baleen plates to process millions of liters of prey-laden water. Baleen is a keratinous oral tissue that hangs down from the roof of the mouth in bi-laterally symmetrical racks, with larger keratin plates positioned labially and smaller plates positioned lingually. The edges of the baleen plate fray into hairs, or fringes, that interlock, creating a dense mat. This mat allows the enormous amount of water engulfed to flow out of the oropharyngeal cavity and retains the prey captured. To define the morphological parameters that dictate water flow and prey capture, we used a multimodal approach to visualize and describe the hierarchical anatomy of baleen across five species of rorqual whales that span an order of magnitude in body length. We hypothesized that baleen morphology would vary by species and prey preference. We used computed tomography (CT) and scanning electron microscopy (SEM) to quantify and understand how variability in baleen morphology may affect filtration. CT showed cylindrical keratin hairs embedded in the baleen plates growing out of the gum tissue. SEM revealed that the keratin plates are worn away at the ventral side, peeling away the exterior layers and exposing the bristles. Although many morphological features of rorquals scale with body size, hair diameter does not. The differences in filter depth, hair diameter, and hair density that we found across the species may not be a proxy for prey size, but instead may reflect changes in resistance throughout the filter that affect fluid flow.

ANNUAL CONFERENCE MONTPELLIER 2022

A8 TEETH AND THE GASTROINTESTINAL TRACT IN MAMMALS: WHEN 1 + 1 = 3 Wednesday 6th July 2022

09:00am-09:30am

Marcus Clauss, University of Zurich, Julia Fritz, Napfcheck, Jürgen Hummel, University of Göttingen mclauss@vetclinics.uzh.ch Both the teeth and the digestive tract show adaptations that are commonly interpreted in the context of trophic guilds – faunivory, herbivory, and omnivory. Teeth prepare the food for the digestive tract, and dental evolution focuses on increasing durability and functionality of teeth; in particular, size reduction of plant particles is an important preparation for microbial fermentative digestion. In narratives of digestive adaptations, microbes are typically considered service providers especially for herbivorous animals, facilitating digestion. The fact that the majority of herbivorous (and possibly omnivorous) mammals display adaptations to maximize the use of microbes themselves as prey, in terms of harvesting the microbes multiplying in their guts, is less emphasized, and is not reflected in the trophic label ‘herbivory’. Adaptations to maximize the harvest of the microbiome are widespread, and given the expansion of the nutritive niche – as compared to animals that cannot use this prey source – this appears self-evident. Harvesting of microbes occurs either in the form of coprophagy after a separation from indigestible material in the hindgut, by the ‘colonic separation mechanism’, or from a forestomach by a ‘washing mechanism’ that selectively removes fine material, including microbes, to the lower digestive tract. The evolution of this washing mechanism as part of the microbe farming niche opened the opportunity for the evolution of another mechanism that links teeth and guts in an innovative way – the sorting (and cleaning) of not-yet-sufficiently-size-reduced ingesta that is then re-submitted to repeated mastication (rumination), leading to unprecedented chewing and digestive efficiency.

A39 THE CONTRIBUTION OF PERIODONTAL AFFERENT FEEDBACK TO CONTROL OF JAW MOVEMENTS DURING CHEWING IN OPOSSUMS Tuesday 5th July 2022

14:00pm-14:30pm

Kelsey Stilson, Brown University, Zhe-Xi Luo, The University of Chicago, Callum F. Ross, The University of Chicago kelsey_stilson@brown.edu Mammal teeth are subjected to periodic, high bite forces during mastication. Bite force orientation and magnitude are transduced into neural signals via tension and compression of the periodontal ligaments.

This neurofeedback is used to elicit and modulate oral reflex arcs, muscle activity and jaw kinematics during chewing cycles. However, the precise contribution of these afferents to chewing kinematics has not been examined. The hemimandibles of Didelphis virginiana (the Virginian opossum) are joined at the midline by an unfused, fairly mobile symphysis. We hypothesized that periodontal feedback in this system might primarily impact kinematics of the ipsilateral hemimandible. To address this question, we used biplanar videoradiography and the X-Ray Reconstruction of Moving Morphology pipeline to measure bilateral

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hemimandibular kinematics in five D. virginiana individuals before and after transection of the left inferior alveolar nerve. Results show that transection impacted jaw rotation about, and translation along, all three rotational axes during the occlusal phases of the gape cycle.

The rotational dimension with the most change was roll about the AP axis, associated with significant effects on mediolateral translation at the m1 talonid basin. Importantly, this demonstrates that a one-sided nerve transection changes the kinematics of both hemimandibles, and bilateral periodontal afferent feedback is necessary for efficient mastication. Whether the changes in muscle activity are ipsilateral, contralateral, or bilateral to the one-sided transection can be tested further by electromyography.

A40 INTRAORAL WATERFLOWS IN FEEDING CARP AND TILAPIA Tuesday 5th July 2022

10:00am-10:30am

Sam Van Wassenbergh, University of Antwerp, Pauline Provini, Centre for Research and Interdisciplinarity sam.vanwassenbergh@uantwerpen.be Despite many decades of research on how fish capture food by generating suction, it remains unclear how food is transported to the oesophagus. Especially relatively small food items are expected to follow the trajectory of the engulfed water, which, in theory, should flow towards and in between the branchial arches. These food items should then end up sieved by the gill rakers. So then how can food be intercepted, for example by the pharyngeal jaws, near the entrance of the oesophagus? What type of water flows are used to deposit food centrally at the back of the pharynx? Using our stereoscopic highspeed x-ray video system (3D2YMOX) in conjunction with a newly developed protocol of constructing small, neutrally buoyant tracers of water flow with X-rays, we managed to visualise intra-oral water flows in tilapia and carp. Tilapia showed a strong jet in the centre of the mouth cavity, often enabling a direct deposit of the food at the pharyngeal jaw region. At the sides of the mouth cavity, flow tends to recirculate, similar to the vena contracta effect behind a narrow nozzle (the mouth aperture in this case). Such flow pattern also appeared in earlier numerical simulations, but was (apparently wrongly) assumed to be an artefact of modelling inaccuracies. This flow pattern could contribute to improving suction feeding performance and efficiency.

The central jet pattern was less pronounced in carps, which could be related to their predominantly bottom-detritus feeding habit relying specifically on branchial sieving and tasting before ingestion.

A41 VERTEBRATE TOOTH-GRIT-FOOD INTERACTIONS Wednesday 6th July 2022

10:00am-10:30am

Ellen Schulz-Kornas, University of Leipzig ellen.schulz-kornas@medizin.uni-leipzig.de Despite copious measuring of highly variable tooth wear patterns in numerous vertebrates, the etiology of dental wear caused by interactions between tooth and food material (incl. dust and grit) is still a matter of intense interdisciplinary debates. During the last decade, central questions regarding the relation between forage properties

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and the effect of abrasives on dental wear has been tested by new sets of in-vivo as well as in-vitro feeding experiments in mammals, birds and reptiles. In addition, data from recent field observations in primates provide new evidence that variation in feeding behaviors is another key player that is influenced by food geometric and material properties. Yet, these studies include usually highly precise but invasive animal experiments, access to the habitat and in the best-case longterm observations. Here, a comprehensive overview is given based on new insights from these studies and a set of testable tooth wear approximations is compiled. In order to provide a new and less invasive investigation option that combines the outcome of these studies, a new tool to simulate tooth wear during the masticatory process is introduced starting with selected model cases in equids. Simulation outcomes allowed the formulation of biomechanical explanations for the transition of the unworn (primary) occlusal surface into the functional, lateroventrally angulated (secondary) occlusal surface.

The simulations are highly generalizable for many vertebrate groups, including possible morphological changes, simulating chewing as well as dental treatment options in a time reduced way.

A202 HIERARCHICAL DESIGN OF BASKING SHARK GILL RAKERS AND THEIR POTENTIAL FOR HIGH-VOLUME SUSPENSION FILTERS Tuesday 5th July 2022

09:45am-10:00am

Mike Schindler, City University of Hong Kong, Hong Kong, Chuang Liu, Hohai University, Venkata A. Surapaneni, City University of Hong Kong, Luciano Caruggi de Faria, University College London, Aurora Li, University College London, Martha Paskin, Zuse Institute Berlin, Frederik Mollen, Elasmobranch, Research Belgium, Shahrouz Amini, Max Planck Institute of Colloids & Interfaces, Mason Dean, City University of Hong Kong, Sean Hanna, University College London mm.schindler@posteo.net Basking sharks, like baleen whales, are planktivores, filtering thousands of litres per hour, indicating possession of a highly efficient filter. The combination of splayed pharyngeal arches and attached comb-like gill raker arrays surely provide this filter efficiency, but the actual mechanisms are unknown due to logistical challenges of studying these immense fish, and decisive data on raker anatomy are still lacking. We characterized basking shark filter anatomy at multiple size scales, from clinical CTs of shark heads down to high-resolution micro-CTs of rakers, combining diverse material techniques (e.g. SEM, spectroscopy, nanoindentation), linking raker morphology and materials with filtering biomechanics.

Although the evenly spaced, thread-like rakers in the pharynx appear similar to keratinous baleen, we show they are modified tooth-like denticles of apatite-reinforced collagen, with a hypermineralized outer enameloid acting jointly with a softer, dentin-like inner layer to allow simultaneous flexibility and wear resistance. Stability and performance of the raker array are supported by several features of individual raker threads — e.g. drag-reducing hydrofoil cross sections, elongated sigmoid morphologies and subtle surface microstructures — which promote canting of adjacent rakers relative to flow. Surprisingly, digital models of raker morphology from our tomographic data indicate raker surface texturing can generate local suspension vortices that may enable indirect filtration. We will verify this with physical models informed by in vivo field observations of head, raker and water motion to understand specific links between anatomy, kinematics and filtering ecology, contributing to conservation of this threatened species and providing bioinspiration for dynamic, high-volume suspension filters.

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A203 INTEGRATION ACROSS ANATOMY AND PHYSIOLOGY IS THE BASIS FOR UNDERSTANDING FEEDING BEHAVIOUR IN VERTEBRATES Wednesday 6th July 2022

14:35pm-15:05pm

Rebecca German, Northeast Ohio Medical University (NEOMED), Christopher J. Mayerl, Northeast Ohio Medical University (NEOMED) rgerman@neomed.edu Vertebrate feeding is a complex process with multiple aspects of integration, including among anatomical systems and physiologic levels. Success in feeding, both in enhanced performance and avoidance of failure, is a mission-critical function for all animals.

Hiiemae and Crompton (1985) argued for this integration as the basis of understanding vertebrate feeding in general, and mammalian feeding in specific. The return to this perspective within the comparative biology/ biomechanics/ evolution community is reflected in the enthusiasm for this symposium .

Feeding—from ingestion through mechanical and chemical processing to transport and the ultimate swallow into the mid-GI system—is a continuous process through what was embryologically and evolutionarily a simple tube. Irrespective of anatomical and evolutionary elaboration, this basic tube is the foundation of the function and survival of the organism. Focusing on specific system functions (prey capture or mastication) provides insight into how natural selection may act on regional anatomy. Yet, consideration of the entire gastrointestinal tract and its outgrowths is necessary to understand how natural selection operates on the feeding performance of the organism as a whole.

Neurophysiologic integration produces the function or behaviour of feeding. Performance in feeding is ultimately a feedback loop, taking sensory input from soft tissues and bones and converting that information into muscular activation in the central nervous system (CNS), including the brain stem and the cerebral cortex. Focusing on individual parts or specific levels of this elaborate system has provided an essential detail of how the system works. Integration among these individual functional components as well as consideration of downstream gastrointestinal structure and function may yield further insights into fundamental constraints and key evolutionary pressures on this essential system. Mammalian feeding is an exemplar of how both anatomical and physiologic integration have provided both the basis for the variation in mammalian evolution as well as the limits on what is possible.

Hiiemae KM, Crompton AW. Mastication, food transport and swallowing. In: Hildebrand M, Bramble D, Liem K, Wake D, editors.

Functional Vertebrate Morphology. Cambridge: Harvard University Press; 1985. pp. 262–90.

ANNUAL CONFERENCE MONTPELLIER 2022

A204 DIMENSIONALLY COMPLEX CHEWING KINEMATICS OCCUR ACROSS VERTEBRATES Tuesday 5th July 2022

09:00am-09:30am

Nicolai Konow, University of Massachusetts Lowell, Meghan Spence, University of Massachusetts Lowell, Daniel Schwarz, Friedrich Schiller University Nicolai_Konow@uml.edu Complex jaw kinematics during chewing are often interpreted as a derived amniote trait, or even a trait unique to mammals. Contrary to these views, this review compiles data from diverse gnathostome jaw systems, including recent biplanar videofluoroscopy analyzes to support the relegation of the origin of rhythmic and cyclic chewing with dimensionally complex jaw kinematics to the base of the gnathostome phylogeny. These data come from taxa often claimed not to chew but instead swallow food whole or relatively unprocessed, including elasmobranch stingrays, teleostean pacus, sirenid salamanders, and anseriform birds. The new examples of dimensionally complex chewing include not only dorsoventral (arcuate) jaw rotations, but also rostrocaudal (propalinal) and transverse jaw movements, which are jaw movements considered diagnostic of mammalian mastication.

Like in mammals, propalinal and transverse jaw movements across these groups are facilitated by complex suspensorial and jaw joint anatomies and driven by architecturally diverse jaw adductor muscles. Dimensionally complex chewing kinematics are not limited to mandibular motion but are also seen in hyoid (tongue) kinematics from suction feeding to chewing in terrestrial newts and ambystomatid salamanders, suggesting that the origin of 3D food handling predates mammals. Future studies should include comparative sensorimotor analyses of basal, dimensionally complex chewing systems to determine how metabolic efficiency is maintained and dental wear is minimized to extend individual life-spans across these diverse vertebrate groups.

A205 NO BONES ABOUT IT: SOFT TISSUE DYNAMICS DURING MAMMALIAN MASTICATION Wednesday 6th July 2022

15:05pm-15:35pm

Rachel Olson, University of Akron , Susan W. Herring, University of Washington, Stephane J. Montuelle, Ohio University Heritage College of Osteopathic Medicine, Christopher J. Vinyard, Ohio University Heritage College of Osteopathic Medicine, Susan H. Williams, Ohio University Heritage College of Osteopathic Medicine rolson@uakron.edu Mandibular kinetics and associated occlusal relations have been a significant focus of physiological studies of mammalian mastication.

However, soft tissue deformations of the masticatory apparatus are essential to mastication. Whereas the jaw muscles, ligaments and temporomandibular joint (TMJ) articular disc are vital for jaw movements, perioral muscles and the tongue are key to bolus management and transport. We synthesize deformations of these soft tissue structures as the jaw moves during chewing and propose future avenues of research investigating soft tissue dynamics during mastication. Jaw muscles shorten 5-10% and cheek muscles over 15%

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during mastication, and their bulging creates pressure on adjacent bones and ligaments. Muscle contraction moves and loads the TMJ, causing the disc and capsule to elongate anteroposteriorly during jaw closing. During jaw opening, muscles lengthen, stretching aponeuroses 4-5%. Chewing side, food hardness, regional and individual differences all modify these effects. The most important soft tissue for mammalian mastication is, however, the tongue, and it undergoes the largest deformations. There are differences in how various species use the tongue during mastication, but all species examined exhibit regional complexity in the amplitude and timing relative to jaw movements.

In pigs, for example, the anterior tongue lengthens as the jaw closes, reaching maximum length around minimum gape, then quickly shortens as jaw opening begins. Posterior regions lengthen during jaw closing and opening but shorten much later during opening. Synthesizing these functional roles emphasizes the significance of soft tissue mechanics in masticatory performance.

A206 FOOD PROCESSING AND TRANSPORT: INTERACTION BETWEEN FOOD PROPERTIES AND TROPHIC STRUCTURES Wednesday 6th July 2022

09:30am-10:00am

Vincent Bels, Institute of Systematics, Evolution and Biodiversity vincent.bels@mnhn.fr Food processing and transport is a complex mechanism acting on the food before swallowing. In such processes, the tongue plays a key role at various stages. Numerous studies showed the lingual morphological characteristics (e.g., surface) suggested being associated with the food intrabuccal transport. In contrast, only a few numbers of studies demonstrate how the hyo-lingual apparatus acts in these feeding phases. Here we survey the diversity of mechanisms suggested being involved in these feeding phases in relationship with the properties of the food and the morphological traits of the pharyngeal cavity and the hyo-lingual apparatus. These mechanisms have been largely discussed on the basis of kinematics and functional studies in various species exploiting highly variable (e.g., liquid and solid) food resources. The coordinated jaw, tongue, and head movements permitting to transport the food after a complex process of transformation or manipulation has been determined in highly different vertebrates as amphibians, reptiles (including birds), and mammals. Here we propose an empirical comparison of the food transport mechanism across tetrapods to show the invariant behavioral and functional traits shared in food transport in the vertebrates and highlight specialized responses to suggest some hypotheses on the evolutionary pathways of these feeding phases to gain the nutriments, the water and the energy in crossing environmental data (food properties) and historical (phylogenetic) characters.

ANNUAL CONFERENCE MONTPELLIER 2022

A207 IN AND OUT OF THE GASTROINTESTINAL TRACT OF TROUT: SELECTIVE TRANSPORT OF HIGH LUMINAL AMMONIA INTO THE VENOUS DRAINAGE Wednesday 6th July 2022

16:05pm-16:20pm

Ellen Hyewon Jung, University of British Columbia, Colin J. Brauner, University of British Columbia, Chris M. Wood, University of British Columbia

SCIENCE ACROSS BOUNDARIES ABSTRACTS 113

Here, we report the first direct measurements of the energetic cost of mastication in humans. We demonstrate that chewing food substitutes can induce a 10-15% increase in energetic expenditure when compared to basal metabolic rates. The level of energy expended is related to the mechanics of the substrate being chewed, driven by the bite force required during masticatory events. Our results indicate that the real-world cost of chewing in humans may constitute an important consideration when interpreting diet from the human fossil record.

The results provide a foundation for the development of further studies illustrating how dietary mechanical metrics contribute to masticatory energetics and indicate that we may need to reframe our understanding of the evolution of derived craniodental morphologies in the human family tree.

jung@zoology.ubc.ca Ammonia is produced via protein catabolism of ingested food in the gastrointestinal tract (GIT), resulting in total ammonia (Tamm) levels in the chyme up to 50-fold higher than blood ammonia levels. Chyme ammonia also far exceeds the water ammonia levels considered toxic for fish. Thus, the high luminal ammonia concentration must impose a challenge if ammonia is transported across the gastrointestinal epithelium into the bloostream, but relatively little is known about this possibility. To address this, we monitored Tamm of blood supplying and leaving the GIT in freshwater rainbow trout (Oncorhynchus mykiss) over 48 h following feeding. We also investigated possible NH3 transport across GIT epithelia by measuring Rhesus glycoprotein mRNA expression levels (as possible NH3 transporters) and ammonia flux rates in in vitro in response to experimentally varied PNH3 gradients. We found that the subintestinal venous blood Tamm levels near the posterior intestine remain undisturbed after a meal and differ markedly from those in the lumen. Although Rhesus glycoproteins appear to be present selectively in different regions, PNH3 may not be a significant driver for ammonia transport into the bloodstream. However, high rates of ammonia absorption occurred in the stomach in vitro and Tamm in the hepatic portal vein, which collects blood from the whole GIT, increased following feeding. Overall, we found that in addition to the intestine, the stomach is involved in ammonia assimilation and that each GIT region may have distinct roles in ammonia metabolism and transport (NSERC Discovery).

A208 THE ENERGETIC COST OF CHEWING IN HUMANS Wednesday 6th July 2022

12:15pm-12:30pm

Adam van Casteren, University of Manchester, Jonathan R. Codd, University of Manchester, Kornelius Kupczik, University of Chile, Guy Plasqui, Maastricht University Medical Centre, William I. Sellers, University of Manchester, Amanda G. Henry, Leiden University adam.vancasteren@gmail.com The amount of energy needed to chew food and how feeding energetics may have effected food selection in human ancestors has important connotations for the evolution of the human masticatory system.

Much of our knowledge about the evolution of human physiology and behaviour, in relation to diet, comes from the interpretation of hominin fossil masticatory systems. When interpreting diet from fossils remains, the influence of feeding energetics has often been overlooked or even assumed to have a negligible impact on human behaviour or the evolution of the feeding apparatus. However, feeding energetics has previously never been quantified using respirometry.

A209 TOWARDS AN INTEGRATED UNDERSTANDING OF NUTRITIONAL PHENOTYPES Wednesday 6th July 2022

11:00am-11:45am

David Raubenheimer, Charles Perkins Centre, University of Sydney david.raubenheimer@sydney.edu.au Nutrition is a complex process of matching multiple and changing nutrient needs to variable and uncertain nutrient supply. Many behavioural and physiological mechanisms evolved to meet this challenge have been identified. However, little is known about how nutritional behaviour and physiology interact to produce an integrated, adapted nutritional phenotype, and how these integrated phenotypes vary with evolutionary and ecological circumstances. In this talk I present a series of studies that have used a framework from nutritional ecology, called nutritional geometry, to examine these issues. Examples span highly controlled laboratory studies of insect to observational studies of primates in the wild. I end by showing how this approach has been used to develop a new understanding of the human obesity epidemic

A210 JAW–TONGUE COORDINATION DURING CHEWING IN PIGS Wednesday 6th July 2022

15:35pm-16:05pm

Stephane Montuelle, Ohio University, Rachel Olson, University of Akron, Geoffrey Gerstner, University of Michigan, Susan Williams, Ohio University montuell@ohio.edu Jaw movements during mammalian chewing drive occlusion and food breakdown. As important as jaw movements are for chewing, soft tissues within the oral cavity are essential for handling the food bolus throughout the chewing sequence. For instance, tongue movements and deformations (1) position the food between the tooth rows, (2) help mix the bolus with saliva to initiate digestion and improve swallowability, and (3) transport the bolus to the oropharynx to initiate the swallow. Tongue movements and deformations must be coordinated with jaw movements to ensure chewing performance and efficiency as well as to avoid self-injury, and previous research shows that disruption of the sensory input from the tongue alters jaw movements during chewing in pigs. Even though jaw and tongue

ANNUAL CONFERENCE MONTPELLIER 2022

movements during mammalian chewing are investigated extensively, their coordination pattern(s) have received less attention. We present three different approaches to quantify the correlation between jaw movements (opening and closing, mediolateral deviation) and tongue movements (positional changes such as protraction-retraction) and deformation (length and width changes) during chewing in pigs. At the sequence level, cross-correlations are used to calculate the lag in time between tongue and jaw kinematics. Cross-correlation analyses can also be carried out at the cycle level, albeit with less statistical power. Finally, functional data analysis standardizes and resamples the data to test for jaw-tongue correlation at each time point, essentially testing bivariate correlation continuously throughout the chewing cycle. We discuss the benefits and limitations of each methodology to emphasize the impact of combining analytical tools.

A298 FOOD HARDNESS, ACTIVATION LEVEL, AND FIBER ARCHITECTURE INFLUENCE IN VIVO OPERATING LENGTH-RANGES OF RAT JAW MUSCLES Tuesday 5th July 2022

15:15pm-15:30pm

Devin Jenness, University of Massachusetts Lowell, Nicolai Konow, University of Massachusetts Lowell Devin_Jenness@student.uml.edu Jaw muscles operate at lengths that are gape-dependent and determine critical feeding parameters, including bite force. The force-length (FL) relationship dictates that force peaks at optimal length (LO) and declines at longer and shorter lengths. Twitch-contraction studies suggest that optimal bite force is generated at lengths below LO, favoring stability but limiting occlusal force. However, subsequent studies have demonstrated that LO shifts to longer muscle lengths as activation increases, prompting our hypothesis that jaw muscles might operate at the FL plateau, or at longer, unstable lengths during high-force behaviors like incisor biting. We used a carefully sizecontrolled food assay to measure the influence of food hardness on rat jaw adductor muscle operation. We measured the operating lengths of zygomaticomandibularis (ZM) and superficial masseter (SM) for each food type in vivo, and then determined force-length-activation properties for the same muscles in situ under tetanic stimulation.

During incisor biting on hard food, peak operating lengths reached the descending FL limb for both ZM (11% ± 2% LO) and SM (4.5 ± 0.5% LO). These findings support our hypothesis and align with limb muscle data as unipennate fiber architecture allows SM to operate at fiber lengths closer to LO, whereas parallel fiber architecture drives ZM to long, unstable lengths. Our data provide new insight into the mechanical function of jaw muscles with potential implications for interventions targeting temporomandibular joint disorders.

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A320 THE EFFECT OF GAPE ANGLE ON BITE FORCES IN LEAF-CUTTER ANTS Wednesday 6th July 2022

15:00pm-15:15pm

Frederik Püffel, Imperial College London, Richard Johnston, Swansea University, David Labonte, Imperial College London fp4418@ic.ac.uk For many animals, the magnitude of bite force limits the range of accessible food; it determines which shells can be cracked, which seeds can be masticated, or which leaves can be cut. Bite force magnitude depends on muscle volume, fibre length and pennation angle, muscle stress and the mechanical advantage of the mandibular lever system.

Most of these parameters change dynamically with the mandibular gape angle. To quantify the effect of gape angle on bite forces, the morphological force determinants were extracted from tomography scans of Atta cephalotes soldiers across the gape angle range. Variation in gape was achieved by clamping rods of different diameters between the mandibles prior to scanning. Bite forces were measured across the mandible opening range using a custom-built force setup. Bite forces were maximum at the smallest gape angles, reaching 2000 times of the body weight, and decreased continuously to a minimum about a factor of three smaller for the largest gape angle. The strong decrease in bite force is caused by the combined effects of a decreasing effective inlever, and the stress-strain properties of the muscle. Changes in pennation angles countered these effects, but only weakly. The relation between fibre length, pennation angle, inlever and mandible opening can be predicted from first principles, enabling us to extract the stressstrain relationship of the mandible closer muscle. The stark decrease in bite force with opening angle suggests that leaf-cutter ants may cut smaller bites from tougher leaves – a hypothesis that will be tested in future experiments.

A330 NOT JUST HINGES: ANT MANDIBLES HAVE MORE THAN ONE DEGREE OF FREEDOM Tuesday 5th July 2022

16:30pm-16:45pm

Victor Kang, Imperial College London, Frederik Püffel, Imperial College London, David Labonte, Imperial College London k.kang@imperial.ac.uk Ant mandibles are multi-functional tools used for foraging, defence, and brood care. Despite this functional diversity, mandible kinematics of ants (and indeed of all winged insects) is thought to be restricted to a single rotational degree of freedom (DoF). However, quantitative evidence in support of this hypothesis is absent. Here, we report a detailed analysis of mandible kinematics in leaf-cutter ants (Atta vollenweideri). We built a multi-camera recording station to capture small-scale motion in 3D, and developed a novel rigid body mechanics analysis to determine rotational axes as well as minimal joint DoFs. We verified these new methods with 3D-printed model joints, then quantified mandible kinematics in restrained ants moving their mandibles across their opening range. We identified two different kinematic regimes: when mandibles move from large to small opening angles, their motion can indeed be described by a single DoF. When the

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two mandibles are close to each other, however, the kinematics is more complex, and involves more than one DoF. Indeed, each mandible can be either on the top or the bottom when the mandibles are crossed.

Since this ‘criss-crossing’ is also observed in foraging ants when cutting challenging substrates such as thick leaf veins, there appears to be a biological relevance for this type of movement. Our study shows that even seemingly simple hinge joints are complex, and offers a novel quantitative framework for investigating insect joints.

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A420 WHY WAS THE FORCE STRONG IN THAT ONE? INVESTIGATING THE RELATIONSHIP BETWEEN CRANIAL MORPHOLOGY AND BITE FORCE IN TAPIRS (PERISSODACTYLA: TAPIRIDAE) Tuesday 5th July 2022

A401 3D HYOLINGUAL KINEMATICS REVEAL NEW INSIGHTS INTO BIOMECHANICAL AND NEURAL CONTROL OF CHEWING AND SWALLOWING IN PRIMATES Tuesday 5th July 2022

16:00pm-16:30pm

Callum F. Ross, The University of Chicago rossc@uchicago.edu Recent application of biplanar videoradiography and the XROMM workflow to the study of hyolingual kinematics in primates provides new insight into tongue movements during chewing and swallowing.

During chewing in macaques, during fast open and fast close the molar region of the tongue rolls to the chewing side simultaneously with sagittal flexion. Twisting and flexion reach their maxima early in the fast close phase of chewing cycles, positioning the food bolus between the approaching teeth prior to the power stroke. Nerve block of tactile sensation from trigeminal innervated oral structures decreased feeding performance, and the fast open phase of the gape cycle became significantly longer, relative to the other phases. The tongue made similar shapes in both the control and nerve block conditions, but the pattern of tongue-jaw coordination became significantly more variable after the block. Disruption of oral somatosensation impacts feeding performance by introducing variability into the typically tight pattern of tongue-jaw coordination. During swallowing, tongue base retraction (TBR) drives the food bolus across the oropharynx towards the esophagus but the mechanics of TBR are poorly understood. XROMM of macaque monkeys falsifies both the hypothesis that extrinsic tongue muscle shortening pulls the tongue base posteriorly, and the muscular hydrostat hypothesis that intrinsic muscle shortening displaces the tongue base posteriorly. Our data suggest a novel hydraulic mechanism of TBR in which shortening and rotation of suprahyoid muscles compresses the tongue between the hard palate, hyoid and mouth floor, squeezing the midline tongue base and food bolus into the oropharynx.

15:30pm-15:45pm

Jamie MacLaren, Universiteit Antwerpen, Lisa Van Linden, Universiteit Antwerpen, Kim Stoops, Universiteit Antwerpen, Larissa Dumbá, Universidade Federal de Minas Gerais, Mario Cozzuol, Universidade Federal de Minas Gerais j.maclaren@uliege.be Bite force is frequently associated with specific morphological features (e.g. sagittal crests), particularly in mammals. Among megaherbivores, a pronounced sagittal crest morphology developed in several species of tapir (Perissodactyla: Tapiridae) in the Plio-Pleistocene (c.2-3Mya); the presence of such a crest has been suggested to be negatively correlated with skull strength and hard-object feeding. This study aimed to elucidate the relationship between bite force and sagittal crest morphology across a wide range of modern and extinct tapirs, aiming to establish whether these features were correlated across a broad phylogenetic scope. Our prediction was that bite forces would be negatively correlated with sagittal crest height, irrespective of phylogenetic relatedness. We examined a sample of 71 specimens representing 15 tapirs species (five extant, 10 extinct) using the dry-skull method (validated via dissection), with additional linear measurements of cranial features and an informal phylogenetic reconstruction. Our results demonstrate that sagittal crest height is poorly correlated with cranial bite force in tapirs, suggesting an alternative driver and function for pronounced sagittal crests in this group. Tapirs exhibit variation in estimated bite-force and sagittal crest height across their phylogeny and between biological realms, with high-crested species occurring almost exclusively in the Neotropics.

Bite forces in tapirs seem to peak in the Pleistocene, independent of body size, suggesting potential dietary shifts as a result of climatic changes during this epoch. In particular, the divergent biomechanical capabilities of different contemporaneous tapirids may allowed multiple species to occupy overlapping territories and reduce interspecific competition.

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A21 - ILLUMINATING HOT TOPICS IN EXPERIMENTAL BIOLOGY: A META-ANALYTIC APPROACH TO UNDERSTANDING BIOLOGICAL PHENOMENON ORGANISED BY: ESSIE RODGERS (UNIVERSITY OF CANTERBURY), NICHOLAS WU (WESTERN SYDNEY UNIVERSITY), DANIEL W.A. NOBLE (THE AUSTRALIAN NATIONAL UNIVERSITY) A118 THE EFFECTS OF SIMULATED OCEAN ACIDIFICATION ON THE BEHAVIOUR AND PHYSIOLOGY OF THE ECONOMICALLY IMPORTANT DUNGENESS CRAB, METACARCINUS MAGISTER Thursday 7th July 2022

17:20pm-17:35pm

Cosima Porteus, University of Toronto Scarborough, Andrea Durant, University of Miami, Elissa Khodikian, University of Toronto Scarborough cosima.porteus@utoronto.ca Although there is much controversy regarding the effects of ocean acidification on the behaviour of marine fish, marine invertebrates have been much less studied. Dungeness crabs, Metacarcinus magister, are found on the West coast of North American and their commercial and recreational fishery is one of the most valuable fishery in the Pacific region, with annual revenues of $220 million.

Dungeness crabs live in the deep-sea and enter intertidal areas in order to find food. Previous studies have found that they routinely encounter pCO2 concentrations of up to 1300 µatm in their coastal habitat and that these levels of ocean acidification can affect larval development and mechanoreceptors. We exposed adult Dungeness crabs to control (600 µatm) and high pCO2 (1300 µatm) for 10 days and assessed their behaviour and physiology using electrophysiology, gene expression, immunohistochemistry and transmission electron microscopy of their olfactory organs, the antennules. Dungeness crabs exposed to high pCO2 had a 25% lower rate of antennular flicking rate in response to all concentrations of cadaverine, a food cue, than crabs exposed to control pCO2. No differences in antennular flicking were found in response to ammonium chloride, a deterant, however there was a large increase in the expression of Rh proteins that function as ammonia transporters in their antennules indicating a potential compensatory mechanism. We propose that a more holistic approach to the overall question of the effects of ocean acidification needs to be taken at multiple levels of biological organization and using environmentally relevant odorants and concentrations.

A119 INVESTIGATING THE GILLOXYGEN LIMITATION HYPOTHESIS IN FISHES: INTRASPECIFIC SCALING RELATIONSHIPS OF METABOLIC RATE AND GILL SURFACE AREA Thursday 7th July 2022

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A120 REPRODUCTIVE METABOLISM SCALING ACROSS ECTOTHERMS Thursday 7th July 2022

09:30am-09:45am

Samuel Ginther, Monash University, Hayley Cameron, Monash University, Craig R. White, Monash University, Dustin Marshall, Monash University samuel.ginther@monash.edu Life history theory typically considers the costs of reproduction in terms of energy content to released offspring (often measured as clutch mass at birth), yet direct reproductive costs are actually accrued by the mother during the offspring production and provisioning phase.

While female body size is well recognised as a strong predictor of clutch mass, remarkably, there is no consensus on how the total energetic costs of reproduction should relate to adult size, nor whether the type of offspring produced (egg or live-young) can modify these relationships. We compiled estimates of body size and metabolism (i.e., reproductive costs) across gravid and non-gravid females, as well as species-specific estimates of clutch mass, for ~80 ectotherm species spanning ~10 orders of magnitude in body size, from rotifer to python.

Reproductive cost scaling was hypoallometric – larger species had less reproductive costs relative to their body size than smaller species.

Furthermore, species that produced heavier clutches also had relatively less costs than species that produced lighter clutches. Surprisingly, these patterns were congruent across reproductive modes implying that metabolic demands of viviparous and oviparous offspring may change dramatically once released from the mother.

14:50pm-15:05pm

Hanna Scheuffele, Deakin University, Timothy Darren Clark, Deakin University, Fredrik Jutfelt, Norwegian University of Science and Technology (NTNU) h.scheuffele@gmail.com Many ectotherms have shown a reduction in maximum body size in the past decades in parallel with climate warming. The gill-oxygen limitation (GOL) hypothesis is a prominent concept regarding the physiological mechanisms underlying the observed trends, implicating oxygen uptake limitations in driving the decline in fish body size with warming. Investigations of GOL have largely been theoretical and therefore the hypothesis’ merit has been questioned. We performed a literature review of the allometry of gill surface area (GSA) and metabolic rate. Furthermore, we reared barramundi under optimal, warm and cold conditions and measured metabolic rate and GSA at various time points. In our analyses, we introduced a new parameter, the ratio S, which provides a measure of GSA in relation to the metabolic requirements for maintenance (SSMR) and maximum activity (SAMR).

Contrasting with the GOL hypothesis, we show that scaling exponents for S are consistently close to zero, with only a few exceptions where S either increased or decreased. We further demonstrate that S only decreases with body size when fish are acclimated to coolerthan-optimal temperatures, and not, as predicted by GOL, when temperatures rise. This suggests that GSA is sufficient to meet fish oxygen requirements even when temperatures increase, and that growth is not universally restricted by oxygen supply limitations at the gills. We identify the need to investigate alternative hypotheses to help explain the observed declines in maximum fish body sizes with climate warming, to facilitate accurate forecasts of fish populations and fisheries in the face of climate change.

A121 HEATWAVES IN THE INTERTIDAL: HOW MICROHABITAT, THERMAL UNPREDICTABILITY, AND FOOD AVAILABILITY SHAPE PHYSIOLOGICAL PERFORMANCE IN MUSSELS Thursday 7th July 2022

17:35pm-17:50pm

Sarah Nancollas, University of California, Davis, Anne E. Todgham, University of California, Davis

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found that microhabitat was the strongest driving factor for shaping physiological performance in Mytilus californianus. Food availability played a larger role in shaping performance in tidally exposed mussels, and the influence of thermal predictability depended on heatwave day. Our results suggest that the predicted increases in heatwave events and thermal unpredictability from climate change will not have a uniform effect in different microhabitats, which could have severe consequences for intertidal community and composition.

A122 FIELD METABOLIC RATES OF WILD MARINE FISHES: REVIEWING OLD QUESTIONS WITH NEW DATA Thursday 7th July 2022

09:45am-10:00am

Clive Trueman, University of Southampton, Sarah Alewijnse, University of Southampton, Natalie Cooper, Natural History Museum, Joseph Jones, University of Southampton trueman@soton.ac.uk Time integrated Field Metabolic Rate (FMR) is arguably the most ecologically relevant measure of the energetics of wild animals, but the relative complexity of determining FMR routinely means that we have relatively few large datasets describing variation in energy use in free-living wild animals, particularly for aquatic ectotherms where double labelled water methods cannot be used.

Emerging proxies based on stable isotope systematics associated with respiration allow retrospective estimation of time integrated field metabolic rate, experienced temperature and growth in any free living marine teleost fish. We have estimated FMR in over 1000 individual fish, across nearly 100 species. Here we draw on our data compilation to explore predictions for two contentious topics in fish ecophysiology: (1) Metabolic cold adaptation: We show that polar species have higher FMR than temperate but not tropical species at equivalent body sizes and temperatures, and that, within species, populations at the cold edge of the range express higher FMR but lower growth rates than populations at the warm edge of the species range.

(2) Gill oxygen limitation theory: FMR data covering 4 orders of magnitude body size within single species show no strong evidence for reduction in metabolic capacity at large body sizes as predicted by the GOLT.

snancollas@ucdavis.edu A central prediction of recent climate change models is that there will be an increase in thermal unpredictability and heatwave events.

Sessile intertidal organisms experience a high degree of thermal unpredictability due to combined effects of solar radiation and tidal movement. How thermal unpredictability operates in microhabitats with different media, such as tidepool (aquatic) or tidally exposed (aerial) environments is poorly understood, especially when coupled with other important determinants of performance, such as food availability. Understanding how these factors interact to influence performance is essential towards understanding the effects of climate change on intertidal communities. We examined how acclimation to different levels of thermal predictability (no, predictable, unpredictable) with high and low food availability shape performance during a threeday heatwave in Mytilus californianus in two microhabitat treatments: tidepool and tidally exposed. During the heatwave, mussels were warmed to 35°C each daytime low tide in their respective medium (water or air). Tissues samples were taken for biochemical analyses the day before, each day during, and the day after the heatwave. We

A123 USING META-ANALYSES TO UNDERSTAND PHENOTYPIC RESPONSES TO URBANIZATION IN ANIMALS Thursday 7th July 2022

15:20pm-15:35pm

Bree Putman, California State University, San Bernardino breanna.putman@csusb.edu Human migration into urban areas has increased urbanization worldwide.

As natural areas become urbanized, animals are forced to migrate, adapt, or perish in response to drastic habitat changes. Studies have documented how animals respond to the changes in biotic and abiotic factors associated with urbanization. Mostly, these studies document changes in phenotypic traits—morphology, physiology, and/or behaviors.

With so many studies now available, meta-analyses offer insights into

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whether general trends in phenotypic responses among animals occur with urbanization. My lab has used phylogenetic meta-analyses to understand whether certain animal groups exhibit consistent phenotypic responses to urbanization, and to determine if the phenotypes of animals are consistently different across cities within studies. We have found that lizards—an animal group which has many urban-dwelling species—generally respond to urbanization through changes in body size. Urban lizards are larger than their non-urban counterparts. However, among all animal groups, the effects of urbanization depend on how many cities are included in a study, and the geographic distance between those cities. Phenotypic differences between urban populations of the same species increase as the more cities are investigated and as the farther away cities are from each other. Thus, separate urban populations of the same species can diverge phenotypically. Overall, it remains difficult to generalize the effects of urbanization on animal phenotypes with the current state of the literature. As more research emerges, meta-analyses will help us recognize if and how animals respond to human-induced habitat changes.

A124 WHAT META-ANALYSES AND COMPARATIVE ANALYSES CAN, AND CAN’T, TELL US ABOUT BIOLOGICAL PHENOMENA Thursday 7th July 2022

09:00am-09:30am

Craig R. White, Monash University craig.white@monash.edu

by rapid range shifts, is unclear because few modern, global extinctions are unequivocally caused by CRS. We use meta-analysis to attempt a quantitative cross-scale evaluation of the role of CRS as extinction triggers. We do this by comparing individual responses to CRS in laboratory experiments and the range shift responses to global warming over recent decades, to extinction selectivity at ancient hyperthermal events and across the sum of metazoan evolutionary history, the Phanerozoic aeon. Clades and traits with strong negative responses to experimental CRS are most likely to go extinct at hyperthermal events, their genera also having the shortest geological durations.

Among CRS, the synergistic combination of seawater warming and hypoxia has the most severe impact on marine organism performance.

Response details suggest chiefly metabolic constraints in setting organism performance responses to CRS, which appear to scale up to extinction probabilities of past (and potentially future?) hyperthermal events. Ecological experiments are the only way to test underlying physiological mechanisms. Meanwhile, the fossil record documents myriad extinctions, often with strong selectivity patterns, that amount to mass proportions under hyperthermal conditions. Uniting the strengths of the two approaches may enrich our abilities to predict the future.

A126 FARMING FITTER FISH THROUGH FORCED EXERCISE: A META-ANALYSIS Thursday 7th July 2022

10:00am-10:30am

A125 A DANGEROUS SYNERGY OF WARMING AND HYPOXIA: THE PAST AND PRESENT FOR THE FUTURE 11:30am-12:00pm

The physiological benefits of exercise can be profound. Across the animal kingdom, exercise has been shown to improve locomotor performance and growth, increase brain plasticity and cognition, enhance resistance to disease, and even heighten tolerance to various environmental stressors. In aquaculture particularly, forced exercise is seen as tool to promote the productivity and welfare of fish. Yet, physiological changes following periods of exercise training can be small and context dependent. Experimental evidence has failed to reach a consensus on the mechanisms driving the physiological benefits of forced exercise in fish, particularly because the use of varying of species, life stages, and training regimes can muddy interpretations and because of the limited statistical power that any one individual study holds. We shed light on the physiological benefits of forced exercise in fish by compiling data from published literature. We focus on common physiological traits, such as metabolism, swimming performance, and growth, that are beneficial to wild and captive fishes.

Using meta-analytical tools, we capture between-study heterogeneity that allows for stronger predictions on the physiological benefits of exercise training for aquaculture. Exercise training remains an exciting management prospect for the culture of ‘fitter’ fish that is strengthened by this new holistic understanding.

Carl Reddin, Museum für Naturkunde - Leibniz Institute for Evolution and Biodiversity Science (MfN), creddin01@qub.ac.uk Anthropogenic increases in atmospheric CO2 levels are raising seawater temperatures, lowering seawater oxygen concentrations and pH (‘climate-related stressors’, CRS), among other changes. Under such change, some marine groups, such as stony corals, may have less ability to tolerate stress than others, potentially leading to population loss and thereby extinction. However, whether these vulnerabilities directly scale up to extinction risk, or tend to be somehow compensated e.g.

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Essie Rodgers, University of Canterbury, Craig R. White, Monash University Daniel W.A. Noble, The Australian National University

A127 USING META-ANALYSIS TO RESOLVE UNCERTAINTY AROUND THE OXYGEN- AND CAPACITY-LIMITED THERMAL TOLERANCE (OCLTT) HYPOTHESIS Thursday 7th July 2022

11:00am-11:30am

SCIENCE ACROSS BOUNDARIES ABSTRACTS 119

juveniles? Do early thermal environments have persistent influence on heat tolerance? What is the current state of knowledge and what are pressing future directions in the field?

essie.rodgers@canterbury.ac.nz The oxygen- and capacity-limited thermal tolerance (OCLTT) hypothesis is the most prominent, albeit contentious, hypothesis aiming to explain the mechanisms setting thermal tolerance limits in ectotherms. At its core, the OCLTT hypothesizes that ectotherms lose performance at both low and high temperature thresholds due to metabolic oxygen demands exceeding supply capacities. Currently there is no consensus within the ecophysiology community regarding the universality of the OCLTT hypothesis, but there is a demand for an unbiased, systematic assessment of the existing literature. Therefore, we conducted a systematic review and several meta-analyses of studies testing core OCLTT predictions. Given the diverse range of experimental approaches used to test OCLTT predictions, we conducted quantitative syntheses for each relevant area. Additionally, to provide increased clarity on perceptions of the OCLTT hypothesis we surveyed the ecophysiology community involved in OCLTT research. The aim of this survey was to shed light on which variables are considered most relevant when testing OCLTT predictions, which experimental designs are considered valid tests of OCLTT predictions, and where further clarification around OCLTT predictions and assumptions are necessary. By combining quantitative tools to evaluate the OCLLT with a summary of the views and needs of the ecophysiology community, we aim to propel this area of research forward in positive manner.

Daniel Gomez Isaza, Harry Butler Institute, Murdoch University, Essie Rodgers, University of Canterbury daniel.gomezisaza@uqconnect.edu.au

Among-species comparisons have been a mainstay of comparative, ecological, and evolutionary physiology for many decades. The ongoing collation of trait databases coupled with the widespread adoption of phylogenetic comparative methods has created fertile ground for the demonstration of new patterns, and for the re-examination of well-known patterns. However, the increases in data richness and analytical sophistication have not changed the fundamental limitations of correlational approaches. Here I explore these limitations, focussing on the important differences between congruence, correlation, and causation. I then use multivariate phylogenetic mixed models to demonstrate the limited extent to which among-species patterns can be used to infer the within-species processes that generate them.

Thursday 7th July 2022

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A129 DEVELOPMENTAL PLASTICITY IN THERMAL TOLERANCE: ONTOGENETIC VARIATION, PERSISTENCE, AND FUTURE DIRECTIONS Thursday 7th July 2022

14:20pm-14:50pm

Patrice Pottier, The University of New South Wales, Sydney, Samantha M. Burke, The University of New South Wales, Sydney, Rose Y. Zhang, The Australian National University, Canberra, Lisa E. Schwanz, The University of New South Wales, Sydney, Daniel W.A. Noble, The Australian National University, Canberra, Szymon M. Drobniak, The University of New South Wales, Sydney, Shinichi Nakagawa, The University of New South Wales, Sydney p.pottier@unsw.edu.au Ectothermic animals represent most of the animal diversity on the planet and yet, are the most challenged by rising temperatures. As such, understanding the factors affecting thermal tolerance is crucial for predicting the impact climate change will have on ectotherms. However, the role developmental plasticity plays in allowing populations to cope with thermal extremes is poorly understood. Neglecting how early environmental experiences shape thermal tolerance (i.e., developmental plasticity) may be an important oversight given that early life experiences have major and often persistent effects on phenotypes. To quantify the acute and persistent influence of early thermal environments on thermal tolerance, we systematically reviewed 6000 studies and meta-analysed data from 150 studies. In this talk, I will address the following questions: How much do early thermal environments impact heat tolerance, and is that enough to compensate for rising temperatures? Are embryos more plastic than

A131 HOW TEMPERATURE VARIATION DRIVES LATITUDINAL DIFFERENCES IN ECTOTHERM SENSITIVITY TO HEAT EXTREMES Thursday 7th July 2022

16:50pm-17:20pm

Alex R. Gunderson, Tulane University, Julie Rej, Tulane University agunderson@tulane.edu Climate change is increasing the frequency of heat extremes, and therefore the overheating risk of wildlife. Latitudinal patterns of overheating risk are expected, and many analyses have concluded that tropical organisms are at greater risk because they live in environments closer to their thermal limits (i.e., have lower warming tolerance).

Overheating risk should be dictated by interactions between mean habitat temperature, habitat temperature variation, organismal heat tolerance limits, and tolerance plasticity. How these factors collectively dictate overheating risk and responses to warming requires greater scrutiny, however. To address this issue, we combined data on physiological heat tolerance, heat tolerance plasticity, and temporally fine-scaled operative thermal environments for terrestrial ectotherm populations across a 120° latitudinal range. Consistent with previous research, we find that tropical organisms have lower warming tolerance than temperate organisms based on mean thermal conditions. However, temperate taxa currently have greater overheating risk than tropical taxa and will experience greater increases in overheating risk with warming because of differences in thermal variation between the regions. These results show that characterizing thermal variation and incorporating it into predictions of global change responses is critical, as doing so can alter predictions about global patterns of vulnerability to global change.

A132 WHAT PREDICTS PACE-OF-LIFE? DISTINGUISHING AMONG MULTIPLE HYPOTHESES IN TERRESTRIAL ECTOTHERMS Thursday 7th July 2022

15:05pm-15:20pm

Fonti Kar, Evolution and Ecology Research Center, University of New South Wales, Shinichi Nakagawa, University of New South Wales, Daniel W.A. Noble, Australian National University fonti.kar@gmail.com Life history strategies are incredibly diverse across taxa, yet traits covary predictably along a fast-slow continuum such that species exhibit a distinct pace-of-life. Theory puts acquisition-allocation trade-offs at the core of life history evolution; however, reproductive investment in species with different reproductive modes can modify acquisitionallocation trade-offs which ultimately alters their life history. While metabolic rate has been touted as a key explanation for pace-of-life

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across diverse taxa some consider trade-offs between current and future reproduction as being more influential. Other evidence points to environmental variation playing an overarching role. No comparative study has attempted to disentangle these competing explanations.

Here, we integrate physiological, reproductive and ecological data across more than 500 terrestrial ectotherms (snakes, lizards and the tuatara) where viviparity has arisen independently over 100 times throughout their evolutionary history. Applying a single multivariate phylogenetic framework, we test how metabolic rate, the environment and reproductive investment contribute in explaining the (co)variation in age at maturity and life span. We also determine if the importance of these factors vary according to reproductive mode (oviparous and viviparous taxa). Overall, while metabolic rate had a negative impact on age at maturity and lifespan, there was high heterogeneity among taxa in its relative role. Age at maturity and lifespan were strongly influenced by the environment, possibly through its effect on mediating activity patterns. Relative reproductive investment was also moderately important in predicting variation in age at maturity but not lifespan, particularly in oviparous species. Our results exemplify the complex nature of life history evolution. We highlight environmental drivers and its effect on patterns of growth, resource availability and mortality as likely sources of life history variation.

A405 ARE THERE DIFFERENCES IN PLASTICITY BETWEEN POPULATIONS WITHIN SPECIES? Thursday 7th July 2022

12:00pm-12:15pm

Clayton Stocker, The University of Sydney, Frank Seebacher, The University of Sydney, Daniel W.A. Noble, Australian National University clayton.stocker@sydney.edu.au Phenotypic plasticity can increase resilience of animals to environmental change, and can therefore be important in naturally variable environments and under anthropogenic climate change. Phenotypic plasticity presents at three time scales, within-individual acclimation, developmental plasticity, and transgenerational effects. These different forms of plasticity can adjust phenotypes to at least partially buffer the organism from potentially harmful environmental conditions.

Plasticity can thereby be important for population persistence and species survival. Conservation is commonly applied in a species-specific ecological context. However, it may be that populations within species have different capacities for plasticity, which may render the species as a whole more resilient to change via the portfolio effect. We tested this hypothesis by implementing novel meta-analytic approaches to quantify plastic capacities across populations of ectothermic species.

We determined whether moderators including ecosystem (aquatic and terrestrial), plastic mechanisms (acclimation, developmental and transgenerational) and environmental variables (temperature and salinity) impact variability in plasticity between populations.

The outcome of this study are important for conservation and in an evolutionary context to understand the complexity of transient responses to environmental change within species.

A421 META-ANALYSES: A FUNCTIONAL TOOL FOR ANSWERING BROADSCALE QUESTIONS IN PHYSIOLOGY IN THE ANTHROPOCENE

SCIENCE ACROSS BOUNDARIES ABSTRACTS 120

Thursday 7th July 2022

15:35pm-15:50pm

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A22 - OPEN BIOMECHANICS

Amanda Kelley, University of Alaska Fairbanks alkelley@alaska.edu Abstract: Despite its origins in ecology, the use of the meta-analysis has gain traction in the last few decades, particularly when it comes to answering broadscale questions about the impacts of human activities across levels of biological organization. Here, I will review the utility of a meta-analytical approach by highlighting several studies that found significant impacts of anthropogenic forces such as ocean acidification on metabolic processes as well as physiological mechanisms utilized by non-indigenous species to increase performance relative to native species across multiple functional categories.

ORGANISED BY: NICOLAI KONOW (UNIVERSITY OF MASSACHUSETTS) P51 THE FRACTURE TOUGHNESS OF LEAVES Friday 8th July 2022

10:00am-10:15am

compressive behaviour, and inbuilt residual stress. Imaging techniques (microscopy and microCT scanning) contributed to our understanding of how both structural and material properties determine performance.

This work advances our understanding of how plants have developed superior defect tolerance and may assist in the development future engineering structures and materials.

David Taylor, Trinity College Dublin

POSTER SESSION A130 FINDING THE MISSING PIECES OF AN ECOLOGICAL PUZZLE TO ASSESS THE CLIMATE VULNERABILITY OF AMPHIBIANS Thursday 7th July 2022

POSTER SESSION

Patrice Pottier, The University of New South Wales, Sydney, Szymon M. Drobniak, The University of New South Wales, Sydney, Shinichi Nakagawa, The University of New South Wales, Sydney p.pottier@unsw.edu.au Rising temperatures pose a significant threat to the survival of ectothermic animals. Thermal physiological traits, including upper thermal limits, are proven useful traits to assess the vulnerability of ectotherms to changing temperatures. For instance, one may use upper thermal limits to estimate current and future thermal safety margins (i.e., the proximity of upper thermal limits to experienced temperatures), use this trait in coercion with other physiological traits in species distribution models, or investigate the plasticity, heritability and evolvability of these traits for buffering the impacts of changing temperatures. While datasets on thermal tolerance limits have been previously compiled, they often report single estimates for a given species, do not present measures of data dispersion, and are biased towards certain parts of the globe. In this project, we systematically searched the literature in seven languages and produced a dataset of over 3000 heat tolerance estimates for 616 amphibian species. I will first present how the dataset we compiled can be used to address various questions in ecophysiology, and its limitations. Indeed, despite its scope, this dataset also suffered from geographical biases and captured less than 10% of described amphibian species. Here, I will demonstrate how we can fill the missing parts of this puzzle using powerful imputation procedures and estimate the heat tolerance of most described amphibian species. I will then demonstrate how we used this comprehensive database to estimate the vulnerability of the worlds’ amphibians to current and projected temperatures.

dtaylor@tcd.ie Toughness is a mechanical property of great importance in engineering materials and natural materials alike. However it is one which is poorly understood and difficult to measure. The toughness of leaves is important in relation to damage caused by mechanical factors such as wind, and also to herbivory by insects and mammals. As such it is an important factor in understanding an ecosystem. The literature reveals several different approaches to the measurement of toughness in leaves, each with its advantages and disadvantages. In this work, experiments were conducted to measure fracture toughness and tensile strength in leaves from monocot and dicot species, allowing their defect tolerance (notch sensitivity) to be determined. The results show that precise values of toughness can be obtained in this way using standard fracture mechanics methods, illustrating important effects such as strain rate (viscoelasticity), anisotropy and the effect of veins.

P54 INVESTIGATING DEFECT TOLERANCE AND FAILURE MECHANISMS OF THREE PLANT STEMS WITH DIFFERENT CROSS-SECTIONAL TISSUE PATTERNS Friday 8th July 2022

10:15am-10:30am

Timothy Hone, Trinity College Dublin, David Taylor, Trinity College Dublin, Max Mylo, University of Freiburg , Olga Speck, University of Freiburg timohone@live.com Plant stems have evolved to resist mechanical forces and to survive events which cause damage. This study investigates their ability to resist the impacts of external damage on their mechanical integrity.

This resistance is defined in engineering by a property known as defect tolerance. We developed a new approach for quantifying defect tolerance as a structural attribute, based on relative changes to various mechanical properties. Stems from three species (fuchsia, elder and ash) were tested in three point bending: results were compared with those from two idealised engineering materials obtained from finite element analysis. Testing revealed that the defect tolerance of plant stems is remarkably good, in many cases exceeding the expected maximum behaviour derived from the ideal materials. This was attributed to a number of factors: material anisotropy; differences between tensile and

A301 MODULATION OF FLAPPING KINEMATICS AT DIFFERENT FLIGHT SPEED IN A TINY PARASITOID WASP (ERETMOCERUS MUNDUS) Tuesday 5th July 2022

14:15pm-14:30pm

Amir Sarig, Tel Aviv University, Gal Ribak, Tel Aviv University, Fritz-Olaf Lehmann, University of Rostock amirsarig@mail.tau.ac.il To cope with the physical constraints in flight at low Reynolds number, miniature insects have unique wing flapping kinematics. Besides the use of clap-and-fling, miniature animals rely on lift- and drag-based propulsion at different phases of the stroke cycle. Little is known about the alterations of this flapping kinematics during maneuvering flight.

We here studied wing kinematics of the miniature parasitic wasp Eretmocerus mundus flying freely at different flight speeds. We filmed the insect with three high-speed video cameras and reconstructed wing motion with high resolution. We found that wing tip trajectory is crescent-shaped with the upstroke following a more posterior trajectory than the downstroke. As flight speed increases the trajectory lengthens by the wings reaching a more posterior angular position. The wing incidence angle at the fling increased at faster flight speeds, resulting in lower angles of attack at the beginning of the downstroke, and the relative duration of the clap became longer while the relative duration of the upstroke became shorter. Relative to air, the backward motion of the wings interacted with the forward motion of the body and the wingtip trajectory became almost vertical at the faster flight speeds, utilizing lift for forward thrust and wing drag for weight support. The efficiency of drag-based propulsion decreases with flight speed and the observed modulation in flapping kinematics represents a shift to lift-based thrust at faster flight speed. Our data show how subtle alterations in wing kinematics control thrust production in flying insects below one millimeter body length.

A302 HOW DO NOCTURNAL MOSQUITOES ESCAPE FROM BEING SWATTED? Tuesday 5th July 2022

09:00am-09:15am

ANNUAL CONFERENCE MONTPELLIER 2022

Antoine Cribellier, Wageningen University antoine.cribellier@wur.nl To avoid being swatted or eaten, flying insects have to rely on their ability to evade looming objects. This is particularly true of bloodfeeding insects like mosquitoes that often need to evade defensive actions of their blood-hosts. To maximize their chance of escape, mosquitoes can use two distinct strategies: continuously exhibit an unpredictable flight path or maximize their escape manoeuvrability.

We studied how these two strategies affects the escape performance of day-active and night-active mosquitoes (Aedes aegypti and Anopheles coluzzii, respectively). We used a multi-camera highspeed videography system to track how freely flying mosquitoes escape from an automatically-triggered mechanical swatter, in four light conditions ranging from pitch darkness to overcast daylight.

Results show that both species exhibit enhanced escape performance in their natural blood-feeding light condition (daylight for Aedes and dark for Anopheles). To achieve this, they show strikingly different behaviours. The enhanced escape performance of Anopheles at night is explained by their baseline unpredictable flight behaviour, whereas the increased escape performance of Aedes in overcast daylight is due to their enhanced escape manoeuvrability. This shows that both day and night active mosquitoes modify their flight behaviour in response to light intensity such that their escape performance is maximum in their natural blood-feeding light conditions, when these defensive actions by their blood-hosts occur most. Because Aedes and Anopheles mosquitoes are vectors of deadly human diseases such as malaria, dengue and the yellow fewer, this knowledge can be used to optimize vector control methods for these specific species.

A304 TESTING THE RELATIONSHIP BETWEEN MUSCLE DEFORMATION AND VERTEBRAL CURVATURE DURING FEEDING IN RAINBOW TROUT (ONCORHYNCHUS MYKISS) Friday 8th July 2022

09:45am-10:00am

Ariel Camp, University of Liverpool, Yordano Jimenez, Tufts University ariel.camp@liverpool.ac.uk Muscle shortening underpins most skeletal motion, and ultimately animal performance. Shortening is usually assumed to be homogenous within a muscle. However, in swimming fish, the whole body deforms like a bending beam: as the vertebral column flexes laterally, muscle shortening increases along a medio-lateral gradient. Recently it has been shown that fish also bend their bodies dorsally during feeding, resulting in dorsoventral shortening gradients in some regions. This suggests these dorsal motions also follow beam-like bending, where the curvature of the vertebral column predicts the linear, dorsoventral shortening gradient in the muscle. We tested this hypothesis by measuring vertebral curvature and dorsal body (epaxial) muscle shortening during feeding motions in rainbow trout (Oncorhynchus mykiss). We used XROMM to measure dorsal and lateral curvature across the anterior vertebral column and used fluoromicrometry to measure shortening between markers throughout the epaxial muscles. Vertebral curvature and muscle marker position were used to predict muscle strain following beam theory. Predicted strains were compared to the measured strains from fluoromicrometry. Trout flexed the anterior vertebrae dorsally and laterally during feeding

SCIENCE ACROSS BOUNDARIES ABSTRACTS 122

strikes. When curvature and marker position in both planes were included, the model’s predicted strain matched the measured strain well across most vertebral regions. Our model confirms dorsal flexion during feeding in trout can be modelled with beam theory, even when accompanied by lateral flexion. We find evidence of linear dorsoventral and mediolateral shortening gradients in the epaxial muscles, although it remains to be determined if these reflect shortening of the fibres within these muscles.

A305 EGG ECLOSURE – THE ESCAPE OF PHASMID HATCHLINGS Friday 8th July 2022

09:30am-09:45am

Brian Saltin, Independent, Susanna Labisch, Hochschule Bremen – City University of Applied Sciences, Jan-Henning Dirks, Hochschule Bremen – City University of Applied Sciences brian.saltin@gmx.de In Phasmids, there are multiple steep demands on the egg, which needs to provide a durable outer protective layer while still allowing for the hatchling to open it from inside. Many Phasmid embryos have – by insect standards – long developmental times (e. g. 80-90 days in C. morosus). During this time, the eggs need to provide sufficient protection against stressors, be they biotic or abiotic. Previous studies have shown a complex ultrastructure of Phasmid eggshells. They consist of several distinct layers – some of which feature calcium crystals – presumably “reinforcing” the structure. However, the hatchlings lack a documented structure for egg opening, convergent to an egg tooth as observed in birds, or – among other characters – defining for cyclorrapha flies. Therefore, the question remains how hatching is facilitated. Despite a longstanding taxonomic interest in Phasmid eggs, investigations of their functional aspects have been scarce. Our research sheds light on the principles and demands of the fascinating biological hatching process with biomechanical investigations. Phasmids can circumvent some of the more demanding aspects of this process by using a distinct opening hatch (operculum) to leave the egg. Thus, the forces required to open the hatch from inside are relatively low compared to breaking the shell. At the same time, the operculum must not be a structural weak spot for predators. In our present study of biomechanical properties in the model species C. morosus, we investigated the eggshell’s “resistance” and the mechanical interaction of operculum, shell, and animal, which allows the realisation of these apparently contradicting properties. To address this question, a variety of techniques, including 3D microCT data of the operculum’s zipper-like ultrastructure and fracture tests, were employed. Effects of egg-age and environmental humidity conditions are also considered.

ANNUAL CONFERENCE MONTPELLIER 2022

Scott Dixon, University of Leeds, Jordan Balaban, University of Leeds, Simon M. Walker, University of Leeds bssrdi@leeds.ac.uk Visual feedback acts as an important control mechanism during insect flight, enabling a spatiotemporal analysis of the environment that contributes towards in-flight control. For this to be possible during high-speed traversal, insects must possess sufficient temporal acuity, often measured by their critical flicker-fusion frequency, the maximum frequency of stimulation that the eye can discern as discontinuous. Using simple flickering light, several species have had this value determined electrophysiologically. However, psychophysical experiments in vertebrates imply that animals cannot discern the flicker of complex stimuli to the same extent, and this may be dependent on several stimulus characteristics. In this study, we therefore set out to determine the flicker-fusion frequency of two common laboratory insects, Calliphora vicina and Drosophila melanogaster, using behavioural assessment. Flies were presented with a variety of optic flow stimuli mimicking yaw, roll and pitch perturbations that triggered their well-studied optomotor response.

Stimuli were composed of several frames and projected at a range of refresh rates, based on the prediction that only projection frequencies above the species’ flicker-fusion threshold would be perceived by flies as continuous motion and therefore elicit a stereotypical behavioural response. By extracting wingtip kinematics from recordings of flying insects, we found no changes in behaviour until projection frequencies increased to 60-70 Hz, far below the previously reported critical flickerfusion frequencies of both species (240 Hz for C. vicina, 200 Hz for D. melanogaster). We further tested how the flicker-fusion threshold was affected by the spatial and temporal frequency of the stimuli and their brightness levels.

A314 SPECIFIC FOLDING OF THE INTERSEGMENTAL MEMBRANE IN THE FEMORAL-TIBIAL JOINT OF LOCUSTA MIGRATORIA Tuesday 5th July 2022

17:00pm-17:15pm

Arsalan Marghoub, University College London, Loïc Kéver, Muséum National d’Histoire Naturelle, Catherine J.A. Williams, Aarhus University, Arkhat Abzhanov, Imperial College London, Matthew K. Vickaryous, University of Guelph, Anthony Herrel, Muséum National d’Histoire Naturelle, Susan E. Evans, University College London, Mehran Moazen, University College London arsalan.biomech@gmail.com

A311 USING THE OPTOMOTOR RESPONSE TO DETERMINE THE CRITICAL FLICKER FUSION FREQUENCY OF TWO COMMON LABORATORY INSECTS: CALLIPHORA VICINA AND DROSOPHILA MELANOGASTER Tuesday 5th July 2022

09:45am-10:00am

The exoskeleton of arthropods is an extremely successful concept for the functional combination of protection and mobility for hundreds of millions of years. The intersegmental membranes connecting sclerotized exoskeletal elements must combine both protection and a high mechanical load capacity, as the exoskeletal segments move relative to each other during various forms of locomotion. These cuticular membranes are compressed or stretched, presumably forming cuticular folds. So far the detailed mechanisms of cuticular folding are not yet fully understood. For example, it is not clear whether the membranes form regular (specific) or irregular (unspecific) folds and which role the cuticle microstructure plays in determining the folding pattern. It’s also not clear if and how the degrees of freedom of the

SCIENCE ACROSS BOUNDARIES ABSTRACTS 123

movement are a result of the folds. To answer these questions, we studied the femoral-tibial joints of Locusts (Locusta migratoria) using destruction free microCT. We analyzed the joints at different flexion angles and characterized the cuticular folds in terms of their geometry and shape at different joint positions. Our first results show that very characteristic folds occurred within the examined joint of several individuals. We will discuss the role of sclerotized microstructures in the membrane in determining the shape of these folds and the degrees of freedom of the respective joints.

A316 WHOLE BONE DISTRIBUTION OF TRABECULAR COMPACTNESS AND ANISOTROPY REVEALS HOW LONG BONES SUSTAIN IMPORTANT FORCES IN RHINOCEROSES Tuesday 5th July 2022

16:45pm-17:00pm

Cyril Etienne, CNRS; Muséum National d’Histoire Naturelle, Axel de Jésus, UMR 7179 Mécanismes Adaptatifs et Evolution, CNRS/MNHN, Baptiste Collin, UMR 7179 Mécanismes Adaptatifs et Evolution, CNRS/MNHN, Alexandra Houssaye, UMR 7179 Mécanismes Adaptatifs et Evolution, CNRS/MNHN cyril.etienne@cri-paris.org Bone trabeculae are known to remodel during the life of vertebrates, aligning themselves in accordance with the forces going through the bones. Heavy animals present very high forces passing through their limb bones during locomotion, through body weight and the necessarily important muscle pull associated. It is expected that their cortical and trabecular structures will adapt to those constraints, but a quantified description of how trabecular architecture varies in the limb bones of heavy animals is not available. Here we use a new approach to quantitatively and precisely describe the distribution of anisotropy and compactness of cancellous bone in the six limb long bones of all living species of rhinoceroses, the heaviest animals capable of galloping. We show that trabecular compactness and anisotropy are correlated in our sample. Highly anisotropic and compact trabeculae are concentrated along articulations and muscle insertion areas, and dissipate the forces into the more resistant cortical bone. The radius, ulna and tibia present a simple, vertical anisotropy pattern associated with body weight support (or triceps pull for the ulna), whereas the humerus and femur present a more complex trabecular pattern, linked with attachment areas for powerful muscles that generate anisotropic trabeculae in various directions. Few variations were observed between species, highlighting that rhinos share a common strategy for bone resistance allowing galloping while weighing up to three tons. Further studies on their more cursorial relatives and on fossil rhinos, some of which reached 20 tons, could yield interesting complementary results for untangling the adaptations to heavy weight and cursoriality in perissodactyls.

A319 ADDED-MASS AND WAGNEREFFECT-BASED FORCES IN HIGHFREQUENCY FLAPPING INSECT WINGS Tuesday 5th July 2022

14:00pm-14:15pm

ANNUAL CONFERENCE MONTPELLIER 2022

Florian T. Muijres, Wageningen University, Wouter G. van Veen, Wageningen University, Bas W. van Oudheusden, Delft University of Technology, Johan L. van Leeuwen, Wageningen University florian.muijres@wur.nl To produce the aerodynamic forces required for flight, two-winged insects (Diptera) move their wings back and forth at high wingbeat frequencies. Because the angular accelerations of this oscillating wing system scales quadratically with the wing-beat frequency, accelerationbased forces as a result of wing stroke-accelerations are expected to be particularly high for these flying insects. These accelerationbased forces consist of added-mass forces and Wagner-effect-based forces. Added-mass forces are resulting from the acceleration of fluid around the wing, and the Wagner-effect describes the delay in bound circulation build-up in accelerating wings. Here, we used computational fluid dynamics (CFD) simulations to systematically study how both added-mass forces and the Wagner-effect affect aerodynamic force production and airflow dynamics in accelerating insect wings. Based on the simulation results, we developed an aerodynamic model that captures the stroke-acceleration forces based on the wing-beat kinematics and wing morphology. This shows that current added-mass models fail to accurately predict added-mass forces on insect wings, primarily because these semi-empirical models ignore the Wagnereffect. Our novel Wagner-effect model is based on the interaction between stroke-rate and stroke-acceleration, and accurately predicts the delay in Leading-Edge Vortex build-up in accelerating wings as well as the delay in Leading-Edge Vortex reduction in decelerating wings. Finally, we applied our newly-developed aerodynamic model in a quasi-steady approach to the wingbeats of a fruit fly and malaria mosquito. This shows that particularly for high-frequency flapping flyers such as the mosquito, acceleration-based forces contribute substantially to aerodynamic lift and drag production.

A321 3D KINEMATICS OF BIPEDAL WALKING IN THE OLIVE BABOON, PAPIO ANUBIS: EVOLUTIONARY IMPLICATIONS Tuesday 5th July 2022

14:30pm-14:45pm

François Druelle, CNRS, Pablo Molina-Vila, Station de Primatologie du CNRS (UAR 846), Gilles Berillon, UMR 7194 (Histoire Naturelle de l’Homme Préhistorique), CNRS-MNHNUPVD francois.druelle@mnhn.fr Humans are efficient bipedal walker and runner. Extant non-human primates (NHP) are not habitual bipeds, yet, they occasionally walk bipedally. According to 2D kinematics, they use a typical “bent-hip, bent-knee” posture coupled with a forward-leaning trunk, a limited stride length, a high stride frequency, and knees that remain flexed during the stance phase. No structural specialization is required for them to occasionally walk bipedally and compared to humans, extant NHPs do not exhibit any adaptations for bipedalism. Hence, it is suggested that the origin of a more habitual form of bipedal locomotion emerged from the common pattern observed in NHPs. However, one wonders whether the general lens through which the bipedal gait in NHPs has been described is discriminating enough to identify subtle differences that might exist between species. We conducted a study on the bipedal walking of olive baboons, at the Primatology Station of the CNRS (UAR 846). We provide detailed information on the 3D kinematics of bipedal walking. Our results

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show that the common pattern of the joint and segment angles can be easily described in the sagittal plan, but specificities related to the baboon model can be described in the frontal plan, such as the adduction of the thigh at touch-down. We compare these results with the 3D kinematics available for chimpanzees, capuchins, macaques and gibbons and identify subtle differences between species. Fundings: IRN-GDRI0870 & HoBiS-ANR-18-CE27-0010-01

A323 GAZE STRATEGY AND AERIAL PURSUIT IN HARRIS’ HAWKS TRACKED USING PRECISION PPK GNSS-INERTIAL BIOLOGGING Tuesday 5th July 2022

09:30am-09:45am

James Shelton, University of Oxford, Graham K. Taylor, University of Oxford james.shelton@zoo.ox.ac.uk Pursuit behaviours in diurnal raptors involve visually-guided targettracking and interception. Here we investigate the gaze strategy and guidance behaviour of N=5 Harris’ hawks (Parabuteo unicinctus). The birds were fitted with a custom-built high-accuracy PPK GNSS/GPS biologger with head-mounted inertial sensor, providing validated horizontal positional accuracy better than 20mm. Over 100 pursuit flight trials were conducted using a radio-controlled car as a target, also fitted with a PPK GNSS/GPS logger. Simulations of the birds’ guidance were fitted using a forward Euler method, and were used to assess the effect of the measured wind on the guidance dynamics. Analysis of the head inertial data reveals the bird’s gaze strategy during flight.

This algorithmic approach to animal behaviour has implications for target-tracking and interception in autonomous robots, and the PPK GNSS-Inertial biologger that we developed to enable it has broad application for precision tracking in many other areas of biology.

A326 MECHANISMS FOR AEROSTRUCTURAL FLOW CONTROL DURING AVIAN WING MORPHING Tuesday 5th July 2022

10:15am-10:30am

Jasmin Wong, University of British Columbia, Vaibhav Joshi, Birla Institute of Technology & Science, Rajeev K. Jaiman, University of British Columbia, Douglas L. Altshuler, University of British Columbia

ANNUAL CONFERENCE MONTPELLIER 2022

increase in stiffness via feather-feather interaction. We next applied computational fluid-structural interaction methods to quantify the effect of increasing or decreasing wing stiffness in the context of wing shape. These data revealed that the trends in wing stiffness due to wing folding can enhance lift production. Specifically, folding prevented destructive interference by the aerostructural deformations on flow vortices during high speed gliding flight. In conclusion, this study proposes that the natural coupling in the avian wing structural system between passive flight feathers and active musculoskeletal actuators allows for aerostructural flow control for enhanced flight performance over a variety of flight speeds.

A331 POTENTIAL INTRA-CANAL MOVEMENTS OF SPINAL CORD SOFT TISSUE IN AVIANS Tuesday 5th July 2022

17:30pm-17:45pm

Viktoriia Kamska, Max Planck Institute for Intelligent Systems, Alexander Badri-Sprowitz, Max Planck Institute for Intelligent Systems, An Mo, Max Planck Institute for Intelligent Systems, Monica A. Daley, University of California, Irvine kamska@is.mpg.de Birds exhibit outstanding legged locomotion robustness, and several explanations have been suggested. Here we focus on the hypothesis that the limited nerve conduction velocity is compensated by intraspinal mechanoreceptors that help reduce perception delay. Previous research documents spinal canal morphologies unique to birds; the potentially mechanosensitive lumbosacral organ (LSO). We hypothesized that LSO soft structures could oscillate inside the lumbosacral canal in previous work. Spinal cord movement would be caused by body oscillations during legged locomotion. The hammock-like LSO ligament network and the glycogen body could become entrained by external accelerations. Mechanoreceptive accessory lobes would pick up fluid flow surrounding the LSO soft structure and rapidly transmit sensor information to contralateral spinal cord hemispheres. While mammalian CNS mobility has been shown, no studies test LSO soft tissue mobility in avians. Identification of spinal cord tissue movement during birdlegged locomotion is non-trivial. Instead, we digitally dissected the LSO region of avian cadavers in various orientations and found that LSO soft tissues exhibit minor position changes. Our adaptation of the iodine staining protocol allowed us to observe previously undocumented details of the denticulate ligament network. We further conducted experiments with a biophysical LSO model parallel to our digital dissection. In our presentation, we will show results from our digital dissection, the biophysical model, new morphological details of the ligament network, and we will explain our modified staining procedure.

jasmin.wong@bristol.ac.uk Wing morphing during flight expands the performance envelope of flying animals and likely facilitates their ability to adapt to a broad range of habitats and atmospheric conditions. In birds, wing morphing is achieved by coupling a series of flexible and passive individual feathers to active musculoskeletal components. Although the aerodynamic effects of wing shape are relatively well characterised, the changes to the mechanical properties due to the structural rearrangement of feathers and the effects these changes have on flight performance are unknown. We first used dynamic mechanical testing at the base of in situ feathers of pigeons (Columba livia) to characterise the local mechanical properties. Wing folding decreased feather-anchoring tissue stiffness, an effect overcome in the proximal wing by an

A332 EFFECT OF MECHANICAL STRESS ON INSECT EXO- AND ENDOCUTICLE Tuesday 5th July 2022

17:15pm-17:30pm

Karen Stamm, Hochschule Bremen – City University of Applied Sciences, Jan-Henning Dirks, BiomimeticsInnovation-Centre, Hochschule Bremen – City University of Applied Sciences

SCIENCE ACROSS BOUNDARIES ABSTRACTS 125

karen.stamm@hs-bremen.de A typical feature of many biological materials is the ability to react to experienced mechanical stress, as described in the “mechanostat” model by H.M. Frost. In this study we investigated so far unknown possible reactions to stress of one of the evolutionary most successful forms of skeletons: the insect exoskeleton. Locusts (Locusta migratoria) were raised under controlled conditions at increased mechanical load using a custom build centrifuge. Although the increase of mechanical stress notably decreased the survival rate, locusts surprisingly survived for several weeks at up to 8g. Biomechanical properties such as strength and stiffness of locust hindleg tibia were characterised using standardized mechanical tests. Further analysis using X-ray microtomography and a novel, simple staining method examine possible responses of the exoskeletons two main layers, exocuticle (outer layer) and endocuticle (inner layer). For the first time, our results show that insect exoskeleton cuticle material (e.g. Youngs modulus, bending strength) and structural properties (thickness of exo-, and endocuticle) were significantly influenced by the experienced mechanical stress. These findings not only allow us to better understand the biomechanical role of exo- and endocuticle within an insect exoskeleton however also help us to discuss the evolutionary context and validity of the “mechanostat” model for the largest and most successful group of animal species.

A333 OBSTACLE NEGOTIATION IN THE VERTICAL PLANE Tuesday 5th July 2022

10:30am-10:45am

Marco KleinHeerenbrink, University of Oxford, Graham K. Taylor, University of Oxford Marco.KleinHeerenbrink@zoo.ox.ac.uk When flying in near ground environments, birds encounter obstacles that force deviations from their flight paths. This raises the question of how they achieve the necessary guidance and control to perform these manoeuvres safely. In a flight arena equipped with a motion capture system, we challenged four Harris' hawks to negotiate a horizontal bar along their flight path between two perches (14 m apart). The unobstructed trajectory of the birds consists of a powered dive followed by glide up to the landing perch. The horizontal bar was positioned halfway between the perches, and was actuated to go through a vertical composite sinusoidal motion. While the minimum height of the bar was such that the typical unobstructed trajectory would not lead to a collision, the perceived risk of collision caused approximately half of the 880 flights to divert over the bar.

The likelihood of diverting was primarily affected by the height of the bar and variation in individual preference. In cases where they would pass over the bar, three individuals directed their flight paths towards the bar shortly after take-off. This tracking mechanism, which arises as a risk averse behaviour, guides the birds nearer to the obstacle and thus increases the risk of collision. Obstacles acting as attractors would explain how many birds collide with overhead lines, despite the marginal probability for a random trajectory to encounter them.

ANNUAL CONFERENCE MONTPELLIER 2022

A335 THE COLLECTIVE MECHANICS AND CONTROL OF LOCOMOTION IN SEA STARS Tuesday 5th July 2022

16:15pm-16:30pm

Matt McHenry, University of California, Irvine, Theodora Po, University of California, Irvine, Olaf Ellers, Bowdoin College, Amy Johnson, Bowdoin College, Sina Heydari, University of Southern California, Eva Kanso, University of Southern California mchenrylab@gmail.com

Supporting our hypothesis, we found skin was stiffer when tested in the hoop direction compared to the longitudinal direction (across species and sexes). Our study provides evidence of sexual variation in shark skin mechanical behavior and further supports the exotendon hypothesis of shark skin.

A339 CAPTURING WING LOADS: BIOMECHANICS OF STRAIN SENSING CAMPANIFORM SENSILLA ON THE DRAGONFLY WING BASE Tuesday 5th July 2022

Sea stars move with crawling and bouncing gaits that are generated by the action of hundreds of tube feet. Bouncing at high speed is characterized by the feet moving in synchrony, which is unlike the asynchronous and slow crawling motion. It is unclear what forces are generated by individual tube feet and how those forces coordinate to generate distinct gaits. We have therefore investigated the mechanics of locomotion in sea stars at the levels of individual feet and the whole body through a combination of experimentation and mathematical modeling. These efforts have included a definition for the mechanical advantage and gearing of helically wound hydrostatic skeletons, as well as the development of an optical under-water force plate. Our results suggest that tube feet primarily serve to push against the substratum and that the gait transition is generated by the collective dynamics of tube feet that are mechanically coupled to a common body. Therefore, the transition to synchronous bouncing may be generated purely through mechanics, without a need for a change in nervous control.

A337 SEXUAL DIMORPHISMS IN THE MECHANICAL PROPERTIES OF SHARK SKIN Friday 8th July 2022

SCIENCE ACROSS BOUNDARIES ABSTRACTS 126

09:00am-09:15am

Madeleine E. Hagood, Florida Atlantic University, Marianne E. Porter, Florida Atlantic University, Joseph R.S. Alexander, Florida Atlantic University mhagood2018@fau.edu Shark skin is a composite of mineralized dermal denticles embedded in an internal collagen fiber network. Shark skin is sexually dimorphic; females have skin that is thicker, denticle density and degree of overlap is greater, and denticle morphology differs from males. Shark skin behaves with mechanical anisotropy, showing greater extensibility when tested along the longitudinal axis and increased stiffness along the hoop axis. As a result, shark skin has been hypothesized to function as an exotendon. The goal of this study was to quantify mechanical properties (tensile strain at maximum load (%), strength (MPa), stiffness (MPa), and toughness (MPa)) of shark skin between sexes and testing directions (longitudinal and hoop). We hypothesized that female sharks would have greater skin mechanical properties due to observed skin morphological and denticle density differences between sexes. We also hypothesized that skin tested in the hoop direction would be stiffer than skin tested longitudinally. We tested skin from two juvenile male and two juvenile female sharks from three species (bonnethead, Sphyrna tiburo; bull, Carcharhinus leucas; silky, Carcharhinus falciformis) in tension with 250N load cell on an Instron E1000 at a 2 mm/s strain rate. Refuting our hypothesis, we found that male shark skin was stiffer and stronger than female skin.

09:15am-09:30am

Myriam Uhrhan, Imperial College London, Igor Siwanowicz, HHMI Janelia Research Campus, Huai-Ti Lin, Imperial College London myriam.uhrhan18@imperial.ac.uk Insect wings are highly compliant and deform passively during flight. In addition to this high aeroelasticity (elastic deformation due to inertia and aerodynamic loads), insect wings can only be driven at the wing base. In the soft-robotics term, insect wings are an underactuated soft system with a complex control challenge. Interestingly, insect wings are often covered by hundreds of mechanosensors, which could provide the relevant information about wing aeroelastic state.

Specifically, clusters of strain sensing campaniform sensilla (CS) are found near the wing base. At the dragonfly wing base, CS are arranged in five fields, each showing a directional bias via its elliptical shape.

Previous investigations suggested that shape, size, and the number of sensors in each field collectively contribute to the sensory performance.

However, little is known about the mechanical performance of CS fields under realistic conditions (i.e. as on the complex structure of the insect wing base). In order to explore and manipulate the system, we built a high-fidelity three-dimensional model of the dragonfly wing base from high resolution confocal imaging data. This model allows us to analyse the biomechanics of CS fields via finite element analysis (FEA), with simulated loading conditions and variations in the CS arrangements.

These results will transform our understanding of how these strain sensors enable the nervous system to monitor an aeroelastic wing.

A341 INFLUENCE OF THE AVIAN UPPER VOCAL TRACT ON SOUND MODULATION Friday 8th July 2022

09:15am-09:30am

Pauline Provini, CRI, Morgane Fournier, CRI, Alireza Kazemi, CRI pauline.provini@cri-paris.org The vocal repertoire of birds is incredibly diverse. They vocalize using a specific organ, the syrinx, producing a primary vibration at the origin of a primary sound. This sound propagates through the suprasyringeal system, composed of the trachea, the larynx, and the oral cavity. The large volume of this suprasyringeal system, compared to mammals of similar size, suggests that it plays a role in the modulation of the sound initially emitted. To investigate this, we filmed 21 species of dead birds and manipulated them under biplanar X-ray. Markers were implanted in tissues (e.g., on the trachea contour, glottis, beak) to calculate the passive deformations and volume changes of the vocal tract during a range of movements of the neck/head system. Our results show that

ANNUAL CONFERENCE MONTPELLIER 2022

neck extension and beak closing are associated with an elongation of the trachea of up to 20% of its initial length. We tested the effect of such elongation on sound modulation using computational simulations.

Our work shows that the complexity of bird vocalizations is not only related to the syrinx, but also to the entire upper vocal system. This work provides new elements to better understand complex communication, one of the amazing characteristics we share with birds.

A345 JOLTED FIRST, THEN PULL: WORK CIRCUMSTANCES OF LEG MUSCLES IN RUNNING Tuesday 5th July 2022

16:30pm-16:45pm

SCIENCE ACROSS BOUNDARIES ABSTRACTS 127

flight arena. Concurrently, we tracked the insects with high-speed cameras to extract their flight trajectory, from which we calculated the mechanical power invested in flying for each flight bout. We found that the chemical (metabolic) energy input converted to mechanical flight energy output at a mean efficiency of 10.4 ± 5.2 %, with a trend of increased efficiency in larger conspecifics (efficiency scaled with body mass to the power of 1.4). The transition during summer from a diet of pollen to that of fruits may affect the energy budget available for foraging. Starved P. cuprea, feeding on apples ad libitum, increased their body mass by an average of 6% in two hours. According to our calculations such a meal can power a 630-meter flight (assuming a carbohydrate assimilation efficiency of 90%). The high cost of aerial locomotion is inherent to the foraging behaviour of rose chafers, explaining their short flight bouts followed by prolonged feeding activity. The ability to measure both flight and its energetic cost is crucial for obtaining realistic estimates for the cost of locomotion.

Michael Günther, Universität Stuttgart s7gumi@uni-jena.de In running, any leg is exposed to impacts right after touch down; the leg bones are rapidly decelerated first. In the wake of the impact, shock waves also travel through the muscles. Due to soft tissues being jolted like that as a response to an impact, such tissue compartments are evocatively labelled as “wobbling masses” in the literature to draw attention to their delayed and distributed oscillatory dynamics. Not a lot is known about how nature has designed its well-nigh monopolistic actuator “muscle” to deal with such an unavoidable superposition of oscillations to a muscle's core function: contracting to generate force, and absorb energy or do work. Based on reductionist model calculations, I will show in this talk that one design strategy seems to be that the absorption and generation of energy during a leg's ground contact are time-separated. In the first part of the stance duration, the required eccentric contractions of leg extensors, which definitely dissipate energy, are superposed by likewise dissipative wobbling mass oscillations. However, the memory of these oscillations is predicted to be wiped out when leg extensors do work during late stance to compensate for preceding energy dissipation. The model is used to compare the allometries of the stance duration and the cycle period of a wobbling (muscle) mass (0.5% body mass), from the smallest to the largest animals. It seems that the biomechanical leg-muscle design, including the limitation of maximum running speed, guarantees the leg extensors enough time to do 'undisturbed' work at late stance.

A348 THE METABOLIC COST OF FLIGHT AND AEROBIC EFFICIENCY IN THE ROSE CHAFER, PROTAETIA CUPREA (CETONIINAE) Tuesday 5th July 2022

A412 AIR RETAINING SURFACE STRUCTURE OF SALVINIA MOLESTA – PHYSICS, APPLICATIONS AND CHALLENGES Friday 8th July 2022

11:00am-11:30am

Albert Baars, Biomimetics-Innovation-Centre, Christoph Wilms, Hochschule Bremen – City University of Applied Sciences ,Daniel Matz, Hochschule Bremen – City University of Applied Sciences , Antonia B. Kesel, Hochschule Bremen – City University of Applied Sciences albert.baars@hs-bremen.de On the upper surface of its leafs salvinia molesta has pillar shaped structures which are hydrophilic at the tip and hydrophobic at the shaft.

When submerged under water, air is retained between the surface structure. Beside the storage of oxygen this feature enables a variety of further applications. The air layer could serve as barrier to prevent the settlement of biological organisms (antifouling) and reduce wall shear stress if water flows along the surface. These phenomena are from higher interest in case of ships or liquid transport in pipes. If an air retaining structure could be realised on such surfaces, a reduction of frictional drag, fuel consumption and CO2 production could follow.

A requirement for this is the understanding of the physics and the influence of fundamental parameters such as structure geometry, size, contact angle of the structure material, pressure, or air saturation of the liquid. In this work the effect of different parameters is presented and discussed using numerical simulation, analytical approaches and experiments.

10:00am-10:15am

Tomer Urca, Tel-Aviv University, Gal Ribak, Tel-Aviv University, Eran Levin, Tel-Aviv University tomerurca@gmail.com Rose chafer beetles (Protetia cuprea) are pollinators as well as agricultural pests, flying between flowers and trees while foraging for pollen and fruits. Calculating the energy they expend on flying during foraging activity faces the challenge of measuring the metabolic rate (MR) of free-flying insects in an open space. We overcame this challenge by using the bolus injection of 13C Na-bicarbonate technique to measure their metabolic energy expenditure while flying in a large

A422 LEGS AS LINKAGES: THINKING OF ISOMETRIC MUSCLES AND TENDONS AS BICYCLE SPOKES Friday 8th July 2022

11:30am-11:45am

Jim Usherwood, The Royal Veterinary College jusherwood@rvc.ac.uk Muscles perform a number of roles, acting as motor, brakes and shock absorbers. Tendons also perform several roles, acting as transmission

ANNUAL CONFERENCE MONTPELLIER 2022

and/or elastic springs. But a distinct and perhaps largely overlooked role of isometric muscles and tendons is as functional tension bicycle spokes, becoming loaded in turn through simple geometry, and enabling horizontal translation during vertical weight support without high mechanical power demand. Here, quadrupedal mammal leg structure and function is considered in the context of enabling low mechanical demand at the level of the limb by maintain forces perpendicular to velocity, at the same time as providing low power supply by keeping muscles isometric when loaded, or unloaded when changing in length. These principles provide a simple account for the general structure of the scapula, serratus ventralis and triceps brachii of the forelimb, and the biceps femoris (curiously crossing across the femur), vastus, rectus femoris and tensor fasciae latae of the hindlimb.

Different muscles experience tension at different stages in stance, each resulting in linkages where the links are isometric, and the limb supports predominantly vertical forces during horizontal translation.

POSTER SESSION AP3 DISENTANGLING THE INFLUENCE OF GEOMETRY AND MATERIAL PROPERTIES ON THE ‘SPRINGBOARD’ TRAPPING MECHANISM IN CARNIVOROUS NEPENTHES GRACILIS PITCHER PLANTS Wednesday 6th July 2022

POSTER SESSION

Anne-Kristin Lenz, University of Bristol, Ulrike Bauer, University of Bristol

SCIENCE ACROSS BOUNDARIES ABSTRACTS 128

A306 VARIABLE SCALING OF LIMB SEGMENT PROPORTIONS IN BIPEDS: DOES ALLOMETRY DRIVE DIVERGENC Thursday 7th July 2022

POSTER SESSION

Ike Brown, University of Nevada, Las Vegas, David V. Lee, University of Nevada, Las Vegas browni5@unlv.nevada.edu Bipeds provide a unique study system to address hindlimb allometry both across and within archosaurs and mammals — having size ranges spanning five orders of magnitude yet overlapping near 1 kg body mass for most major clades. Previous work on non-avian and avian theropods shows that hindlimb proportions cluster within 1/9th of available morphospace, centered around a 60:40 tibia:femur isoline. Here we expand on previous work by including bipedal hopping mammals and examining potential drivers of divergence. We investigate 1) within group scaling, 2) phylogenetic signal, and 3) differences between hopping and striding bipeds.

Our avian analysis includes 374 species, spanning 74 families and 17 orders. Our mammalian analysis is restricted to habitual bipedal hoppers and includes 47 species distributed across 5 families and 2 orders. Prior to phylogenetic correction, significant hindlimb positive allometry is seen in Anseriformes, Gruiformes, and Palaeognathae, while significant allometry of some individual segments is found in nearly all avian clades. For mammals, significant positive allometry is seen in Macropodiformes but not Rodentia. After phylogenetic correction using PGLS, significant positive allometry persists in the metatarsal segment of Galliformes, Gruiformes, Palaeognathae, and Diprotodontia. (Macropodiformes exhibited positive allometry of the hindlimb, tibia, and metatarsals after PGLS.) Examining segment proportions revealed negative allometry of the femur with respect to total hindlimb length in these same groups. Hence, whether striding or hopping — avian or mammalian, significant positive allometry of the distal segment is a hallmark of both birds and mammals.

anne-kristin.lenz@bristol.ac.uk Carnivorous Nepenthes pitcher plants normally use motionless pitfall traps with slippery walls to catch their prey. Nepenthes gracilis uniquely exploits rain drop impacts on the roof-like pitcher lid to flick insects into the pitcher. This mechanism relies on three independent adaptations of the lid: a horizontal orientation, an attachment-reducing wax crystal coating of the lower lid surface, and high stiffness of the lid itself combined with an elastic ‘hinge’ that facilitates a torsion spring-like impact response. Previously, it has been postulated that this elastic element is located in the ‘neck’ region between pitcher and lid. We superimposed three serial micro-computerised tomography (µ-CT) scans with different lid positions to show an asymmetric deformation reaching far into the pitcher body. Downward lid displacement deformed two distinct areas in the neck and the pitcher body, while upward displacement stretched the entire dorsal spine of the pitcher uniformly. Cross-sectional slices and densities from the µ-CT scans showed that areas of maximal deformation coincide with local minima of the second moment of inertia, while stiffer areas are geometrically and structurally reinforced. Load-displacement trials revealed strongly asymmetric spring properties, with 83% larger downward than upward lid displacement under equal loading. Our results point to a key role of pitcher geometry for effective ‘springboard’ trapping in N. gracilis.

A307 THE ENERGETICS OF FREEAND TETHERED FLIGHTS ACROSS A SPEED RANGE IN THE BUMBLEBEE, BOMBUS TERRESTRIS Wednesday 6th July 2022

POSTER SESSION

Graham N. Askew, University of Leeds, Emily Senior, University of Leeds, Peter Tickle, University of Leeds bs18e2js@leeds.ac.uk Animal flight physiology, including energetics, is often studied using flights performed in a wind tunnel. Many insects are incapable of free-flight in the confined spaces of a wind tunnel, and their flight performance has often been investigated in tethered flights. Tethered insects may not generate sufficient lift to support their body weight and their wing kinematics may differ from free-flight. Whether metabolic rate is affected by tethering, across a speed range is unknown. In this study we quantified flight metabolic rate as the rate of carbon dioxide production (VCO2) in the bumblebee worker, Bombus terrestris, in a closed-circuit wind tunnel during both tethered and free flight across a flight speed range (0 – 4.14m s-1). VCO2 varied in shallow

ANNUAL CONFERENCE MONTPELLIER 2022

U-shaped curve with airspeed during both free (N=9, P&lt;0.05) and tethered (N=8, P&lt;0.05) flights. This is contrary to previous assessment of free-fight energetics in insects where metabolic rate (also in bumblebees) was independent of flight speed (Ellington et al., 1990: Nature 347, 472-473). Tethered VCO2 as significantly lower (by 30:50% P&lt;0.05) across the entire speed range, but there was no significant different in the relationship between VCO2 and airspeed (P=0.0893). Our data demonstrate that tethered flight can serve as a proxy for free flight energetics. Interestingly, the minimal metabolic costs of transport (J kg-1 m-1) in both tethered and free-flight coincided with field observations of preferred speed, indicating that bumblebees are attuned to fly at speeds (3.52 m s-1) where locomotion is most economical.

A308 THE EFFECT OF GRADIENT ON HINDLIMB MUSCLE FUNCTION IN GALLUS GALLUS DOMESTICUS Thursday 7th July 2022

POSTER SESSION

John Marrin, University of Leeds, Graham N. Askew, University of Leeds, Simon M. Walker, University of Leeds bsjmcm@leeds.ac.uk During locomotion skeletal muscles generate the force to drive locomotion; in addition, they may also generate mechanical work and absorb energy. The mechanical function of an individual muscle may change depending on the locomotory task. Changing the gradient that an animal is moving over changes the mechanical demands on the skeletal muscles as work must be done on the body centre of mass (BCoM) during incline locomotion, whereas energy must be absorbed during decline locomotion. The aim of the study was to investigate the mechanical function of two muscles in the hindlimb of chickens during incline and decline locomotion: the iliotibialis lateralis pars preacetabular (ILPR) and the iliotibialis lateralis pars postacetabular (ILPO) which are integral to knee and hip extension and flexion. The length change of the muscle fascicles and their activity patterns were determined using sonomicrometry and electromyography, respectively.

Simultaneously, the movements of the limb were determined using high-speed videography. The mechanical function of the muscles can be inferred from the anatomy of the muscles, the movements of the joints and the length change and activity patterns of the muscles. However, to quantify the mechanical function of muscles, the force generated must also be known. Ongoing work is focussed on determining the pattern of force generation to investigate how the mechanical function of the muscle varies over the course of the stride and in relation to gradient.

A309 ASSESSING THE USE OF INFRARED THERMOGRAPHY AS A TOOL FOR ESTIMATING THE METABOLIC POWER REQUIREMENTS OF AVIAN FLIGHT Wednesday 6th July 2022

POSTER SESSION

Madeleine Inglis, University of Leeds, Graham N. Askew, University of Leeds, Charles M. Bishop, Bangor University

SCIENCE ACROSS BOUNDARIES ABSTRACTS 129

bsmri@leeds.ac.uk Much of the metabolic energy expenditure is used during avian flight by the locomotory muscles, which control wing shape and generate power. The relatively low efficiency of these muscles means that much of the energy used is dissipated as heat. Therefore, the total heat dissipated during flight can give an indirect estimate of the bird’s metabolic energy expenditure. This study used infrared thermography to quantify the variation in the mean surface temperature of different body regions and used heat transfer modelling to determine heat dissipation in pigeons (Columba livia) flying at different speeds in a wind tunnel. As hypothesised, the total heat dissipated followed a U-shaped relationship with flight speed. Such a relationship has also been observed with measurements of metabolic rate using respirometry, and is expected given the high mechanical power demands of flight at relatively slow and fast speeds. The metabolic power requirements of pigeons recorded using respirometry exceeded the values obtained using infrared thermography. The most important regions for dissipating heat were the ventral brachial region of the wings, feet, breast, and head at all speeds. Non-uniform surface temperatures imply that birds use specific, poorly feathered, regions of the body to dissipate heat. Increasing surface blood flow to these regions during exercise may aid regulation of body temperature and prevent hyperthermia. This study indicates that infrared thermography can provide an index of metabolic energy expenditure, however, further research is required before the approach can be used to quantify metabolic rate.

A310 HIGH-PRECISION INSECT WING AND BODY KINEMATICS ACQUISITION USING A NEW AND FLEXIBLE FREE-FLIGHT ARENA Thursday 7th July 2022

POSTER SESSION

Rachel Han Soc Tran, University of Leeds, Simon M. Walker, University of Leeds bsrhst@leeds.ac.uk During flight, insects can make subtle changes to their wing kinematics that in turn have large effects on their aerodynamic forces. To understand and model the above, therefore requires measurements of natural flight with appropriate spatiotemporal resolution and duration. These factors are determined by wingbeat frequency, size, and behaviour, which are limited by trade-offs within the operating equipment. Here, we describe a new and flexible arena setup that uses ten high-speed cameras to record insects flying freely in an optically clear chamber that can scale from the smallest to some of the largest insects. Pulsed far-red LEDs are focused and aligned with the highspeed cameras to provide bright, uniform backgrounds that eliminate motion blur and are beyond the insects’ visible spectrum. Separate, stereo cameras function as triggers, using real-time image analysis when subjects enter the recording volume. These triggers can control additional stimuli, such as a white light, to induce flight manoeuvres at specific times. The resultant footage is coupled with a comprehensive voxel-carving software package to automatically calculate wing and body kinematics. This includes wing deformations in the form of wing torsion, which is important for accurate aerodynamic modelling. To date, we have documented free-flight in several species, including Calliphora vicina and Drosophila melanogaster at 6,400 fps, and Anopheles gambiae at 12,000 fps. This setup will generate a large database of high-precision insect free-flight kinematics to better our

ANNUAL CONFERENCE MONTPELLIER 2022

understanding of this diverse class and be used to feed into studies of insect flight control and aerodynamics.

A313 THE EFFECT OF MUSCLE FIBRE TYPE ON HIGH-FREQUENCY BEAK MOVEMENT: A FORWARD DYNAMIC MODELLING APPROACH Wednesday 6th July 2022

POSTER SESSION

Cas Jorissen, University of Antwerp, Sam Van Wassenbergh, University of Antwerp cas.jorissen@uantwerpen.be Musculoskeletal lever systems are typically regulated by antagonistic muscle pairs. Some of these systems are involved in mechanically varying task. For example, bird beaks exert high static forces while biting and move the beak up-and-down at high velocities during food handling and vocalisation. As increased bite force evolves, the closer muscle force will become multiple times stronger than the opener muscle force. This has a direct effect on high frequency movement performance, as fully activating the closer muscles will impede beak opening while the closer muscles are relaxing. Muscle fibre type composition could influence the frequency further as slower fibres have considerably longer relaxation times. To investigate how muscle activation patterns should be regulated to achieve maximal beak frequency, we constructed a simple forward dynamic model of two antagonistic muscles pairs, both with fast-twitch and slow-twitch muscles, which rotate a lever back and forth in MATLAB Simulink.

Morphological model parameters are based on measures from a songbird (Padda oryzivora) and muscle contractile properties were taken from the literature. The model shows that fibre type, especially those from the most forceful (closer) muscle group, has a strong effect.

To achieve maximal frequencies, models using only slow muscle fibre types should twitch larger parts of their closer muscle (13.4% vs. 4.6%) and will inevitably achieve lower beak-tip frequencies (13.45 vs. 27.95 Hz) than models with fast muscle fibre types. We will discuss how an orderly recruitment of motor units in muscles consisting of mixtures of fibre types affects the performance.

A315 COMPARATIVE ANATOMY OF A MECHANICALLY COUPLED MUSCLE SYSTEM IN THE AVIAN WING Wednesday 6th July 2022

POSTER SESSION

Francesca Ciocca, University of British Columbia, Vikram B. Baliga, University of British Columbia, Douglas L. Altshuler, University of British Columbia, Robert E. Shadwick, University of British Columbia

SCIENCE ACROSS BOUNDARIES ABSTRACTS 130

Metacarpi Radialis (EMR), instead of to bone. This mechanicallycoupled muscle system spans the elbow and wrist, and can move both joints simultaneously. Thus, TPB-EMR connectivity may be functionally important for coordinating elbow and wrist motion.

Using morphological data from over 100 species, we find that TPBEMR anatomy is highly variable but can be broadly categorized. To determine if the evolution of body mass, wing shape and/or flight behaviour associates with specific coupling anatomy, we map TPBEMR diversity across the avian phylogeny. We reveal that the TPB-EMR system varies primarily in terms of muscle and tendon length as well as TPB tendon complexity. Morphological characteristics were not strongly associated with body mass, wing shape, or flight behaviour, contrary to the expectation that muscle-tendon configurations would be constrained by the biomechanical and ecological demands of flight.

However, TPB-EMR morphology was more constrained in certain flight behaviour groups than others. Collectively, these results suggest that the functional role of TPB-EMR coupling can be fulfilled by diverse anatomical arrangements, but that some forms of flight may place greater selective pressures on this system.

A317 MUSCLE POWER PRODUCTION DURING INTERMITTENT SWIMMING IN BLUEGILL Wednesday 6th July 2022

POSTER SESSION

David Coughlin, Widener University, Kristin Santarcangelo, Widener University, Emma Wilcock, Widener University, Daniel Tum Suden, Widener University djcoughlin@widener.edu Locomotion is essential for the survival and fitness of animals. Fishes have evolved a variety of mechanisms to minimize cost of transport.

For instance, bluegill sunfish have recently been shown to employ intermittent swimming in nature and in laboratory conditions. We focused on understanding the functional properties of the powerproducing muscles that generate propulsive forces in bluegill to understand the implications of intermittent activity. We used in vivo aerobic muscle activity parameters (e.g. oscillation frequency, muscle strain, timing of activation) in muscle physiology experiments to examine muscle power output during intermittent vs. steady swimming in these fish. Intermittent propulsion involves swimming at relatively slow speeds with short propulsive bursts alternating with gliding episodes. The propulsive bursts are at higher oscillation frequencies than would be predicted for a given average swimming speed. The work-loop muscle physiology experiments demonstrated that intermittent activity allows muscle to produce sufficient power for swimming compared to imposed steady swimming conditions.

Further, the intermittent muscle activity in vitro reduces fatigue relative to continuous activity. This work lends support to the fixedgear hypothesis that suggests that there are preferred oscillation frequencies that optimize efficiency in muscle use and minimize cost of transport.

ciocca@zoology.ubc.ca Birds have unparalleled ability to adjust wing shape, and therefore stability, during flight. Variation in elbow and wrist angles underlies much of this capacity. Though the muscular control of flapping is well understood, the musculoskeletal dynamics of elbow and wrist flexion and extension are largely unknown. In many avian taxa, two of the intrinsic wing muscles have a peculiar arrangement: the Tensor Propatagialis Brevis (TPB) inserts directly on to the Extensor

A318 PREACTIVATION IMPROVES THE ROBUSTNESS TO STEP DOWN PERTURBATIONS IN SIMULATED HUMAN WALKING

ANNUAL CONFERENCE MONTPELLIER 2022

Thursday 7th July 2022

POSTER SESSION

Elsa Bunz, Institute for Modelling and Simulation of Biomechanical Systems, University of Stuttgart, Syn Schmitt, Institute for Modelling and Simulation of Biomechanical Systems, University of Stuttgart elsa.bunz@imsb.uni-stuttgart.de Stability of human walking is critical to prevent falls. This work studies the influence of preactivation, i.e. the activation of muscles prior to touchdown at the end of the swing phase. Preactivation is observed in humans not only during walking, but also in running and during drop jumps. Experimental studies agree, that a higher co-contraction caused by preactivation leads to higher joint stiffness, which prepares the forthcoming impact. However, experimental studies cannot selectively turn-off preactivation, therefore we study preactivation within a neuromusculoskeletal model. We show that preactivation of only one muscle significantly improves the robustness of our model when subjected to unexpected step down perturbations and large steps of up to -0.12m can be rejected. Thereby, the preactivation leads to muscular activations which closely resemble human data. The effect of the preactivation is two-fold. It improves the landing of the swing foot and furthermore produces a gait with longer steps. Especially during the step encounter larger push-off forces can be generated and a large step of the contralateral foot helps to stabilize the model.

Selectively turning off the preactivation shows that the ipsi- as well as the contralateral step before the step encounter have to be preactivated in order to improve the robustness. Our results show, that humans might use preactivation not only to prepare for ground contact but also to act fast upon upcoming unexpected perturbations.

A325 DIFFERENTIATION OF SINGLE LIMB MECHANICS DURING ASYMMETRICAL RUNNING LOCOMOTION IN THE MONGOLIAN GERBIL MERIONES UNGUICULATUS Wednesday 6th July 2022

POSTER SESSION

Jan Wölfer, Humboldt-Universität zu Berlin, Emanuel Andrada, Friedrich-Schiller-Universität Jena, Manuela Schmidt, Friedrich-Schiller-Universität Jena jan.woelfer@hu-berlin.de During terrestrial running locomotion, mammals frequently exploit asymmetrical gaits from gallop to bound. These gaits are characterised by a rather synchronised support phase of either fore- or hind limbs.

Limbs of a girdle touch down simultaneously or in sequence after a short time lag (then, the first limb is called trailing, the second leading). A potential functional differentiation of trailing and leading limbs has been investigated in studies of medium-sized mammals but information especially on mouse-sized mammals is still sparse. We analysed the running behaviour of the Mongolian Gerbil Meriones unguiculatus to further our understanding of the differentiation of single limb mechanics during asymmetrical gaits. We recorded highspeed x-ray videos with synchronized support reaction forces (SRFs) of strides with running speeds ranging from 0.5-1.1 m/s. The four individuals most frequently used half-bounds (i.e., forelimbs are less synchronised than hind limbs) during short bursts of locomotion, suggesting a stronger functional separation between forelimbs. Our preliminary results show that, when accounting for running speed, the

SCIENCE ACROSS BOUNDARIES ABSTRACTS 131

peak vertical SRF was larger in the leading than in the trailing forelimb, indicating higher stiffness in the leading limb. Previous analyses on asymmetrical gaits interpret this as an adaptation to increase locomotor robustness on uneven ground. Our results contrast with findings in, e.g., dogs and squirrels, suggesting that the functional differentiation might depend on factors such as body size or body proportion, etc.

However, our trends were accompanied by a significant variability, cautioning against the clear-cut assignment of specific functional roles.

A327 MULTILEVEL EXPLORATION OF KINEMATIC AND DYNAMIC ADJUSTMENTS OF GECKOS (HEMIDACTYLUS FRENATUS) CLIMBING VERTICALLY UP AND DOWN Wednesday 6th July 2022

POSTER SESSION

Johanna Schultz, University of the Sunshine Coast, Christofer J. Clemente, University of the Sunshine Coast, David Labonte, Imperial College London johanna.schultz@research.usc.edu.au Geckos are skilled climbers, and can even scale smooth surfaces, due to powerful adhesive structures on their feet. Gecko adhesive toepads are activated when pulled towards the body, but readily detach when pushed away from it. This direction-dependence allows rapid control of attachment but presents a problem when climbing head-down.

To study the kinematic and dynamic alterations with direction, we extracted kinematics and 3D-ground-reaction-forces for six individuals of geckos (Hemidactylus frenatus), climbing head-up or head-down on a vertical racetrack.

Based on previous work, we expect the adhesive role of the feet to swap when climbing head-down. We proposed three hypotheses for mechanisms likely to be employed: (1) Hind limbs are rotated backwards, aligning the activation direction of the adhesives with the direction of the gravitational force – (2) diagonally opposed foot angles sum up to 180 ° generating inward forces of opposite orientation – and (3) toes are spread further apart with individual digits pulling.

We found that hind feet were rotated further backwards for head-down climbing, increasing the relative adhesive force. While the sum was 173°, the direction of the force vectors did not oppose each other, and adhesive forces did not increase with greater diagonal angles. Finally, against expectations the toe spreading in hind feet decreased for headdown climbing, but not increasing relative adhesive forces significantly.

By setting kinematic adjustments in context with forces produced we determined which kinematics are good predictors for generating adhesion, representing a valuable insight into climbing locomotion and application of bio-inspired gaits to legged robotics.

A328 LEGS, LINKAGES AND LOLLIPOP STICKS: A KS3 TO UNDERGRADUATE PRACTICAL CLASS Thursday 7th July 2022

POSTER SESSION

Jim Usherwood, The Royal Veterinary College

ANNUAL CONFERENCE MONTPELLIER 2022

jusherwood@rvc.ac.uk Muscles perform a number of roles, acting as motor, brakes and shock absorbers. Tendons also perform several roles, acting as transmission and/or elastic springs. But a distinct and perhaps largely overlooked role of isometric muscles and tendons is as functional tension bicycle spokes, becoming loaded in turn through simple geometry, and enabling horizontal translation during vertical weight support without high mechanical power demand. Several aspects of animal leg form and function can be considered as linkages that facilitate this economical weight support. Here, a practical class is described that demonstrates mammalian fore and hindlimb structure and function as simple linkages.

It is simply adapted to range from KS3 as an introduction to 4-bar and 6-bar linkages, to undergraduate anatomy level, demonstrating the origin, insertion and functions of various muscles throughout stance. The demonstrated principles include how passive linkages can 1) support the body with predominantly vertical forces (requiring varying moments about hips and shoulders), during 2) horizontal motion of the body during stance (resulting in an economical ‘sliding’ action), with 3) links that are isometric when under load (and so not performing mechanical power), and 4) change between linkages and loaded muscles through changes in geometry.

A336 THE HYDRODYNAMIC FUNCTION OF KEELS IN BOXFISH Thursday 7th July 2022

POSTER SESSION

Merel Van Gorp, University of Antwerp, Sam Van Wassenbergh, University of Antwerp, Jana Goyens, University of Antwerp merelvangorp2@gmail.com Boxfish (Ostraciidae) have peculiar body shapes, with conspicuous keels formed by their bony carapaces. Previous studies have proposed various hydrodynamic roles for these keels, including reducing drag during swimming, contributing to passive stabilisation of the swimming course, or providing resistance against roll rotations. We tested these hypotheses using computational fluid dynamics simulations of five species of Ostraciidae with a range of carapace shapes. The hydrodynamic performance of the original carapace surface models, obtained from laser scanning of museum specimens, was compared with models where the keels had been digitally reduced. The original carapaces showed no reduced drag or increased passive stability against pitch and yaw compared to the reduced-keel carapaces. However, consistently for all studied species, a strong increase in roll drag and roll added mass was observed for the original carapaces compared to the reduced-keel carapaces, despite the relatively small differences in keel height. In particular, the damping of roll movement by resistive drag torques increased considerably by the presence of keels. Our results suggest that the shape of the boxfish carapace is important in enabling the observed roll-free forward swimming of boxfish and may facilitate the control of manoeuvres.

A338 MORPHOLOGY OF KESTRELS’ HANGING FLIGHT IN A WIND TUNNEL OF VARYING TURBULENCE INTENSITIES Thursday 7th July 2022

POSTER SESSION

SCIENCE ACROSS BOUNDARIES ABSTRACTS 132

George Yi, University of Bristol, Mario Martinez GrovesRaines, University of Bristol, Matthew Penn, RMIT, Abdulghani Mohamed, RMIT, Shane Windsor, University of Bristol, Simon Watkins, RMIT mw21041@bristol.ac.uk

A343 AUDITORY SENSORY RANGE OF MALE MOSQUITOES FOR THE DETECTION OF FEMALE FLIGHT SOUND Wednesday 6th July 2022

Birds are especially agile fliers in challenging environments: far more so than human-made fixed-wing micro aerial vehicles (MAVs) of a similar scale. Research into bird flight kinematics of steadily flying birds in a quasi-fixed-wing mode, rather than a flapping mode, will provide novel insights into bird flight maneuverability and innovative bio-inspired solutions for steadier MAVs. Two nankeen kestrels (Falco cenchroides) were trained to perform highly steady hanging flight (non-flapping windhovers) in a wind tunnel configured to varying turbulence intensities. The control kinematics used to steady their flights were captured with motion capture technology. Preliminary statistical analyses show that mean wing and tail morphologies correlate most strongly with body yaw. In significantly yawed flight, the upstream wing is significantly more active than the downstream wing. Wing sweep, twist and tail roll correlate most strongly with body yaw, whereas wing dihedral correlates most with turbulence intensity. These morphological trends provide valuable insights into the configurations of very steady bird flight in challenging environments.

A340 HOW DIGIT DIVARICATION ANGLE CHANGES AT TOUCHDOWN AND MIDSTANCE AS GUINEAFOWL TRAVERSE SOLID AND DEFORMABLE SUBSTRATES Thursday 7th July 2022

ANNUAL CONFERENCE MONTPELLIER 2022

POSTER SESSION

Clara A.A.L. Fraschini, Liverpool John Moores University, Stephen Gatesy, Brown University, Peter Falkingham, Liverpool John Moores University fraschiniclara@gmail.com When terrestrially locomoting, birds tend to swing the foot with the toes together, and then spread the toes prior to touch down, creating a larger surface area over which to spread the bird’s weight. However, on deformable substrates, particularly on very soft substrates like saturated mud, the ground does not fully, nor immediately bear the weight of the animal. Instead, the foot (and therefore bird) will sink some distance before finding support. We used X-ray Reconstruction of Moving Morphology to measure the digit divarication angle, or the spread of the toes, throughout the swing and stance phase of a Guineafowl walking over a solid surface, firm mud, and soft mud (11 trials). Maximum digit spread was slightly larger (82°) on soft mud compared with solid (71°) and firm mud (68°). However, our data show that at touchdown, digit divarication angle is more variable on soft substrates than firm ones. This indicates that in some cases, when the substrate is softest, the toes are still spreading as the foot sinks into the mud. We also found that digit divarication angle was much greater at mid stance when traversing soft mud than firm mud.

Our data provide an interesting touch-stone for interpreting motions from deep dinosaur tracks, which may only present the surficial footsediment interaction.

POSTER SESSION

Richard Bomphrey, Royal Veterinary College, Toshiyuki Nakata, Chiba University, Patrício Simões, University of Sussex, Simon M. Walker, University of Leeds, Ian J. Russell, University of Brighton rbomphrey@rvc.ac.uk Male mosquitoes detect and localise conspecific females by their flight tones using the Johnston's organs (JO), which detect antennal deflection under the influence of local particle motion. Acoustic behaviours of mosquitoes and their JO physiology have been investigated extensively within the frequency domain, yet the auditory sensory range and the behaviour of males at the initiation of phonotactic flights are not well known. In this study, we predict a maximum spatial sensory envelope for flying Culex quinquefasciatus by integrating the physiological tuning response of the male JO with female aeroacoustic signatures derived from numerical simulations. Our sensory envelope predictions were tested with a behavioural assay of free-flying male mosquitoes responding to a female-like artificial pure tone. The minimum detectable particle velocity observed during flight tests was in good agreement with our theoretical prediction formed by the peak JO sensitivity measured in previous studies. The iso-surface describing the minimal detectable particle velocity represents the quantitative auditory sensory range of approaching males and is directional with respect to the female attitude. Our results illuminate the intricacy of the mating behaviour dynamics and point to the importance of observing the attitude of flying mosquitoes to understand fully the sensory ecology of conspecific communication.

SCIENCE ACROSS BOUNDARIES ABSTRACTS 133

fibre length, and muscle attachment area. After scanning the heads of the specimens and segmenting their mandibular apparatus, we used manual and automated approaches to measure the above mentioned values, to assess the comparability of the various PCSA methods and proxies, as well as the reliability of the automatization process. In addition, using the different PCSA estimates and muscle stress values from the literature, we model bite forces, which we compare to in vivo measurements from the same individuals.

A349 DO HUMANS OPTIMISE THE ENERGETIC COST OF STEPPING OVER AN ASYMMETRIC OBSTACLE? Wednesday 6th July 2022

Yansangni Luo, University of Bristol, Jeremy Burn, University of Bristol, Ute Leonards, University of Bristol yl16485@bristol.ac.uk Rising temperatures pose a significa

AP3 DISENTANGLING THE INFLUENCE OF GEOMETRY AND MATERIAL PROPERTIES ON THE ‘SPRINGBOARD’ TRAPPING MECHANISM IN CARNIVOROUS NEPENTHES GRACILIS PITCHER PLANTS Wednesday 6th July 2022

A346 MODELLING BITE FORCE IN INSECTS: COMPARISON OF DIFFERENT PCSA APPROACHES WITH IN VIVO MEASUREMENTS Wednesday 6th July 2022

POSTER SESSION

Samuel Ginot, Universität Bonn, Alexander Blanke, Universität Bonn sginot@evolution.uni-bonn.de Animal bite force is an ecologically relevant performance trait, crucial for individual fitness through its impact on food ingestion and intraspecific agonistic interactions. Despite its popularity in vertebrates, bite force has only recently begun to be measured across the huge diversity of insects. Bite force studies generally use either in vivo measurements or forces modelled based on muscle physiological cross-sectional area (PCSA), and very rarely compare both. PCSA can be measured in a variety of ways, in particular in insects, which have never been thoroughly compared. Here we compare several digitally computed estimates of PCSA (and its components muscle volume and fiber length) in the major mandibular adductor muscle of Schistocerca gregaria, together with an experimental baseline estimate. This experimental estimate relies on dissecting out the muscles, weighing them, dissolving fiber bundles in acid and measuring fibre length. The digital estimates are based on CT scans of the heads, in which it is possible to measure muscle volume,

POSTER SESSION

POSTER SESSION

Anne-Kristin Lenz, University of Bristol, Ulrike Bauer, University of Bristol anne-kristin.lenz@bristol.ac.uk Studies of humans and other animals stepping over obstacles have shown that step length during the approach is regulated to position the ultimate footfall close to the obstacle before crossing. Amongst the various potential explanations for this behaviour is the possibility that it is an adaptation to minimise energetic cost by reducing the length of crossing steps. If a flat rectangular obstacle were placed with its long side perpendicular to the walking direction the energetic cost of stepping over the obstacle would be independent of whether the left or right foot were placed immediately before the obstacle. If however the obstacle were placed at an oblique angle to the approach, the minimum possible cost of stepping over the obstacle would depend on whether the right or left foot were placed immediately before it. We hypothesised that in such an experiment, human participants would preferentially place the foot which facilitated minimum energetic cost immediately before the obstacle. Eight participants walked over a rectangular obstacle at 11 different angles in the range of +/- 60 degrees to the perpendicular. For angles with an absolute value of 40 degrees and above, there was a strong preference for placing the foot which facilitated the least cost crossing steps. Additionally, we observed behaviour consistent with minimising the combined cost of both the approach and the crossing steps. These results imply the use of a more complicated scheme for anticipatory control of obstacle crossing than has previously been described.

ANNUAL CONFERENCE MONTPELLIER 2022

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A23 - OPEN ANIMAL

activity, the neural response to visual stimuli, and CTmax. Our results suggest that the mechanism limiting the upper thermal tolerance in zebrafish larvae is reduced oxygen availability in the brain tissue causing impaired brain function.

ORGANISED BY: JACK THOMSON (THE UNIVERSITY OF LIVERPOOL) AC1 MCOX2 IN THE DUI BIVALVE SCROBICULARIA PLANA ENCODES THE LONGEST KNOWN MITOCHONDRIAL PROTEIN IN METAZOANS Tuesday 5th July 2022

16:00pm-16:15pm

Mélanie Tassé, Université de Montréal, Sophie Breton, Université de Montréal, Thierry Choquette, Université de Montréal, Annie Angers, Université de Montréal, Eric Pante, Institut Universitaire Européen de la Mer (IUEM) melanie.tasse.1@umontreal.ca Modifications in the cytochrome c oxidase 2 gene of male-transmitted genome (Mcox2) have been found in some bivalve species that exhibit a unique mode of mitochondrial transmission named doubly uniparental inheritance (DUI). In DUI, paternal mitochondria (and their male mtDNA) as well as maternal mitochondria (and their corresponding female mtDNA) are transmitted to male offspring. Scrobicularia plana, a bivalve exhibiting this inheritance model possess an important inframe insertion of ~ 4,8 kb in its Mcox2 gene that is translated into a polypeptide of 1892 amino acids (~ 220 kDa), the largest metazoan COX2 protein known to date. The insertion is conserved amongst individuals from different populations and, according to analysis of synonymous and non-synonymous substitution rates, evolves under purifying selection which would suggest maintenance of functionality in MCOX2. MCOX2 protein might act as a tag at the surface of male mitochondria to facilitate their sex-specific fate in bivalve embryos.

The long-transcribed insertion could also explain low OXPHOS rates that were found in M mitochondria of DUI bivalves thus affecting male mitochondrial metabolism.

AC97 KEEPING COOL WITH UV FILTER EXPOSURE: INVESTIGATING POTENTIAL MULTIGENERATIONAL PLASTICITY OF FRESHWATER INVERTEBRATES TO UV FILTERS Thrsday 7th July 2022

09:30am-09:45am

Aaron Boyd, University of Alberta, Jessica Choi, University of Alberta, Grace Ren, University of Alberta, Zuo Tong How, University of Alberta, Mohamed Gamal El-Din, University of Alberta, Keith B. Tierney, University of Alberta, Tamzin A. Blewett, University of Alberta boyd2@ualberta.ca Organic ultraviolet filters (UVFs) such as avobenzone, octocrylene and oxybenzone are widely used in common sunscreens and other personal care products to protect against harmful ultraviolet radiation. Their use

in sunscreens leads to widespread environmental contamination due to the leaching of these chemicals during recreational activities, posing a threat to both many aquatic systems. Current research indicates that marine invertebrates such as corals are particularly sensitive to UVF contamination; however, research in freshwater species is lacking. This study sought to model the long-term effects of chronic UVF exposure to the freshwater invertebrate, Daphnia magna to determine adaptation potential over four subsequent, continuously exposed generations.

Initial generations of Daphnia suffered physiological impairment through both a 30% decreased reproductive output and a 10-fold greater proportion of non-viable offspring. In addition, 50% mortality was observed in the first two generations of oxybenzone exposures; however surviving daphnids proved capable of adapting to long-term UVF exposure, ultimately returning to a similar physiological state as observed in control treatments. Minimal differences were observed between adult daphnids that survived through to the end of the F0 generation and those that did not, indicating that the eventual recovery of Daphnia populations to the control physiological state is a result of adaptation, rather than the weakest individuals being removed from the population via natural selection. This data suggests that Daphnia are capable of adapting to sublethal levels of UVFs, indicating that perhaps current estimates of toxicity through short-term exposures are an overestimation of long-term toxicity in an environmental setting.

A145 BRAIN FAILURE DURING WARMING IS CAUSED BY OXYGEN LIMITATION IN LARVAL ZEBRAFISH Wednesday 6th July 2022

ANNUAL CONFERENCE MONTPELLIER 2022

15:05pm-15:20pm

Anna Andreassen, Norwegian University of Science and Technology, Petter Hall, Norwegian University of Science and Technology, Pouya Khatibzadeh, Norwegian University of Science and Technology, Fredrik Jutfelt, Norwegian University of Science and Technology, Florence Kermen, Norwegian University of Science and Technology anna.h.andreassen@ntnu.no Understanding the physiological mechanisms that limit animal thermal tolerance is crucial in predicting how animals will respond to increasingly severe heatwaves. It has been hypothesised that the upper thermal tolerance in fish is limited by the thermal tolerance of the brain and that it is ultimately caused by a spreading depolarization in the brain. In this study, we developed methods for measuring the upper thermal limit (CTmax) in larval zebrafish (Danio rerio) with simultaneous recordings of brain activity using GCaMP6s calcium imaging in both free-swimming and agar-embedded fish. We discovered that during warming, CTmax precedes, and is therefore not caused by, a seizurelike brain depolarization. Instead, the CTmax coincides with a decline in spontaneous neural activity and a loss of neural response to visual stimuli. By manipulating water oxygen levels, we found that oxygen availability during heating affects both locomotor-related neural

A155 OXYGEN AVAILABILITY PLAYS A NEGLIGIBLE ROLE IN THE REPRODUCTIVE DEVELOPMENT AND GROWTH OF THE TEMPERATE FISH GALAXIAS MACULATUS Wednesday 6th July 2022

14:50pm-15:05pm

Michael Skeeles, Deakin University, Timothy Clark, Deakin University, Hanna Scheuffele, Deakin University michaelskeeles@gmail.com The decline in the maximum size of fishes with increasing temperature (temperature-size rule) is a concerning and widespread observation in the face of climate warming. Despite the potential for far-reaching ramifications, the physiological mechanisms driving the temperaturesize rule remain hotly debated. The prominent hypotheses attempting to explain the drivers of the temperature-size rule place emphasis on oxygen as the limiting factor, yet these remain largely untested.

Here, we reared fish (Galaxias maculatus) over the majority of their lifecycle in cold (15oC) and warm (20oC) environments, under normal (normoxia) or supplementary (hyperoxia) oxygen supply. We routinely assessed aerobic performance and monitored maturation rates and growth trajectories. At both temperatures, the aerobic scope of fish in the hyperoxia treatments was maintained 58-73% higher than fish in normoxia treatments throughout 11 months. As expected, fish in the warm treatments grew quicker and reached sexual maturation earlier than their cool-reared counterparts. However, despite enhancements in aerobic scope and additional oxygen availability at the gills, we found no effect of the oxygen treatment on the size at maturation or maximum body size of the fish. These findings suggest that oxygen-limitation is not a proximate factor driving the temperature-size rule in fish.

A212 ELEVATED TEMPERATURES DAMPEN INNATE IMMUNE RESPONSES OF DEVELOPING LAKE STURGEON (ACIPENSER FULVESCENS) WHEN CHALLENGED WITH BACTERIAL LIPOPOLYSACCHARIDES Tuesday 5th July 2022

17:15pm-17:30pm

William S. Bugg, University of Manitoba, Gwangseok Yoon, University of Manitoba, Alexandra Schoen, University of Manitoba, Alyssa Weinrauch, University of Manitoba, Ken Jeffries, University of Manitoba, Gary Anderson, University of Manitoba buggw@myumanitoba.ca Chronic temperature stress may leave freshwater fishes vulnerable to opportunistic pathogens, particularly during early life stages. Lake

SCIENCE ACROSS BOUNDARIES ABSTRACTS 135

sturgeon, Acipenser fulvescens, populations within the northern expanse of their range in Manitoba, Canada, may be susceptible to high temperature thermal stress. We acclimated developing lake sturgeon for 21 days to two ecologically relevant temperatures (16 and 20oC) . Both acclimation treatments were exposed to 0, 30, and 60 µg.ml-1 bacterial lipopolysaccharides (endotoxins), as an immune stimulus, for 48 hr, with samples taken 4 and 48 hr during trial exposures and following a 7-day recovery period. We then measured whole body transcriptional (mRNA) and physiological (lysozyme activity, cortisol, glucose) responses involved in the innate immune, general stress, and fatty acid responses following acute exposure to bacterial endotoxins. Data detailing the responses involved in the above physiological processes revealed that while overall expression levels were higher at 20oC under control conditions, during bacterial stimulus 16oC reared lake sturgeon produced a more robust response with higher induced expression of the above responses than their 20oC acclimated counterparts. Additional whole-animal performance metrics (critical thermal maximum and metabolic rate) demonstrated acclimation-specific responses indicating compromised metabolic capacity following the initiation of immune related responses. Our study showed that acclimation to 20oC during early development impaired the activation of molecular pathways involved in the immune, stress, and fatty acid responses of lake sturgeon, highlighting the effects of chronic thermal stress on transcriptional activation and recruitment of downstream biological processes in this critically threatened and endangered species.

A213 THE EFFECTS OF DOMESTICATION ON RAINBOW TROUT PERFORMANCE AND FITNESS Wednesday 6th July 2022

18:05pm-18:20pm

Madison Earhart, The University of British Columbia, Clark McMaster, The University of British Columbia, Jarrett Blair, The University of British Columbia, Tessa S. Blanchard, The University of British Columbia, Nicholas Strowbridge, The University of British Columbia, William S. Bugg, University of Manitoba, Rashpal Dhillon, The University of British Columbia, Robert Devlin, Fisheries and Oceans Canada, Patricia M. Schulte, The University of British Columbia earhart@zoology.ubc.ca Rainbow trout, Oncorhynchus mykiss, are an economically and recreationally important species worldwide that is both farmed for human consumption and hatchery-reared and released for conservation and recreational purposes. Both intentional and unintentional selection during captive rearing has resulted in a “captive” phenotype that is generally thought to have lower fitness in natural environments when compared to wild fish. However, the genetic mechanisms underlying fish domestication, or the “captive” phenotype, are largely unknown, and identifying genes associated with different domesticated phenotypes is crucial to understanding how the introduction of these genes could affect wild fish populations. In this study we investigated the genetic basis of hatchery domestication and how domesticated alleles affect various phenotypes and fitness by creating F2 crosses from F1 (domestic x wild) parents and releasing the resulting F2 alevin into semi-natural ponds. Six months after stocking, fish were recaptured, phenotyped, and sampled for subsequent SNP-Chip genotyping to assess the genetic basis of trait variation and survival via a genome-wide association study (GWAS). There was substantial variation among the surviving fish from the semi-natural ponds in multiple phenotypes including hypoxia tolerance, body size, morphometrics and colour, and these

ANNUAL CONFERENCE MONTPELLIER 2022

traits had significant associations with genetic variants (P&lt;0.001), suggesting a genetic basis for this variation in traits. The relationship of these traits to the presence of “domesticated” alleles will be discussed.

A214 BEHAVIORAL VARIATION ACROSS THE DAYS AND LIVES OF HONEY BEES Thursday 7th July 2022

16:50pm-17:05pm

Jacob Davidson, Max Planck Institute of Animal Behavior, Michael L. Smith, Auburn University, Benjamin Wild, Freie Universität Berlin, David M. Dormagen, Freie Universität Berlin, Tim Landgraf, Freie Universität Berlin, Iain D. Couzin, Max Planck Institute of Animal Behavior jdavidson@ab.mpg.de Social insect colonies are highly decentralized systems where individual workers undertake different roles to fulfill colony needs. In honey bee colonies, workers generally take on different tasks as they age (from brood care, to nest work, to foraging), in a process that is driven by physiological development as well as social interactions and and colony conditions. While these general trends are well-established, our understanding of how individuals distribute tasks during a day, and how individuals differ in their lifetime behavioral trajectories, is limited. Here, we use automated tracking to obtain long-term data on 4,100+ bees tracked at 3Hz, day and night, across an entire summer, and define an analysis framework that uses behavioral metrics to compare behavior at different timescales. Considering single days, we describe how bees differ in space use, detection, and movement. Although differences exist between young and old bees, we see considerable variation in the behavior exibited by similarly aged bees. Analyzing the behaviors exhibited across their entire lives, we show that individuals differ in the age they transition from activity inside the nest to taking trips outside. In addition, we find consistent inter-individual differences in the movement characteristics of individual bees across their entire lives.

For example, bees differ in their movement speed and how extensively they range within the nest, with faster bees tending to visit multiple nest areas when both young and old. Bees also differed in how quickly they transition through behavioral space to ultimately become foragers, with fast-transitioning bees living the shortest lives. Our analysis framework provides a quantitative approach to define the behavioral repertoires of individuals, and the results demonstrate the extent of individual behavioral variation within a colony from single days to entire lifetimes.

SCIENCE ACROSS BOUNDARIES ABSTRACTS 136

the last decade. Most studies have used stable pCO2 treatments based on average projections for the open ocean. However, pCO2 levels vary spatially and temporally in marine environments, and recent studies indicate this variation can have effects on how marine organisms respond to projected future pCO2 levels. However, there is a lack of knowledge examining the metabolic and swimming traits of coral reef fishes in these ecologically relevant fluctuating conditions.

Thus, the first study compared the metabolic effects of acute (8hr) constant elevated pCO2 treatment with increasing and decreasing elevated pCO2 treatments on two species of damselfishes both while they were swimming and resting. The second study examined the metabolic and swimming effects of a prolonged (9-11d) exposure to fluctuating and constant elevated pCO2 on four different species of fishes from different families, both during the day and at night. There were species-specific differences in the responses to fluctuating and constant pCO2 exposure. The first study showed that one damselfish was generally positively affected by fluctuating pCO2; whereas, the other was seemingly unaffected. The second study showed that three species were generally positively affected by elevated pCO2 treatments, specifically the fluctuating treatment, when compared to ambient exposures. Whereas, the fourth species was generally negatively affected by elevated pCO2 treatments. These results encourage the use of fluctuating treatments in future OA studies, and help more accurately inform how coral reef fishes will be affected in the future.

A220 EFFECTS OF METFORMIN ON FISH PHYSIOLOGY: FROM LAB TO FIELD Thursday 7th July 2022

09:45am-10:00am

Oana Birceanu, University of Western Ontario, Erin Ussery, Environment and Climate Change Canada, Rachel Snelgrove, McMaster University, Jessica Qiu, McMaster University, Shemar Williams, McMaster University, Joanna Wilson, McMaster University, Karen Kidd, McMaster University, Kristin Nielsen, Marine Science Institute, College of Natural Sciences, University of Texas at Austin, Vince Palace, International Institute for Sustainable Development Experimental Lakes Area, Nicholas Blandford, University of Manitoba, Charis Lai, University of Western Ontario, Mark McMaster, Environment and Climate Change Canada, Joanne Parrott, Environment and Climate Change Canada, Jessie Cunningham, Environment and Climate Change Canada, Abby Wynia, Environment and Climate Change Canada, Thomas Clark, Environment and Climate Change Canada obircean@uwo.ca

A218 CONSTANT AND FLUCTUATING ELEVATED PCO2 AFFECT THE METABOLIC AND SWIMMING PERFORMANCE OF CORAL REEF FISHES Tuesday 5th July 2022

11:15am-11:30am

Kelly Hannan, University of California, Davis, Philip L. Munday, James Cook University, Jodie L. Rummer, James Cook University kdhannan@ucdavis.edu Laboratory experiments examining the effects of elevated ocean acidification on marine organisms have increased dramatically over

The impacts of pharmaceuticals on aquatic organisms, along with their mode of action, is an emerging issue in aquatic toxicology.

One of the most prevalent contaminants is the type-2 diabetic drug, metformin, which is released in freshwaters via wastewater effluent.

Levels of metformin in surface waters range from 0.4-30 µg/L. Lab and field studies have attempted to reconcile the impacts of this highly used pharmaceutical on fish health. Here, we present work done in the laboratory and in the field, to better understand how metformin impacts fish physiology and gut microbiome content. In the laboratory, adult zebrafish were exposed to 0, 4 and 40 µg/L metformin for 30 days and the gut content was collected and analyzed. While metformin had minimal impacts on microbiome diversity, clear differences between male and female responses were noted. In the field, wild adult fathead minnows were exposed to 0, 4 and 40 µg/L metformin for eight weeks, and tissues were collected to measure energy reserves and liver metabolic capacity. Metformin impacted carcass lipid content,

ANNUAL CONFERENCE MONTPELLIER 2022

while the effects on the liver metabolic capacity and fish condition were transient. Taken together, our work proposes to explore the sex-specific impacts of this pharmaceutical in fish population, with a focus on energy allocation, particularly during conditions of stress, to better understand how fish allocate energy to meet the demands of the body, following chronic metformin exposure.

A222 FOOD QUALITY INFLUENCES CATERPILLAR SILK PRODUCTION BEHAVIOUR Thursday 7th July 2022

11:15am-11:30am

Simon Chen, University of Cambridge, Tadzio Tavares de Wand, Independent, Walter Federle, University of Cambridge sc836@cam.ac.uk

documented using multiple cameras tracking reflective markers fixed to their wings, tails and bodies. Initial results have demonstrated the feasibility of the facility and techniques and have shown insights into the coupling between wing body and tail kinematics. An unexpected finding is that both birds favoured yawed flight (~30 degrees to the mean wind direction) which is potentially due to localising targets in their visual fovea.

A225 THE FLYING BEHAVIOURS OF BEES IN RESPONSE TO TYPICAL AERIAL DISTURBANCES Tuesday 5th July 2022

09:00am-09:15am

Timothy Jakobi, RMIT, Simon Watkins, RMIT, Alex Fisher, RMIT, Sridhar Ravi, UNSW tjakobi@163.com

Caterpillars of some Lepidoptera species can use silk carpets to attach to slippery host plant leaves which would otherwise be inaccessible.

Silk production may represent a major resource expenditure for caterpillars, especially considering that they are mostly herbivorous and therefore consume a low-protein diet. After finding that substrate quality influences silk production behaviour in the model species Bicyclus anynana, we further hypothesised that protein availability should influence how readily B. anynana caterpillars produce silk. We carried out feeding experiments with control and artificially proteinenriched host plant leaves and our initial results show more extensive silk production behaviour in caterpillars fed with a higher-protein diet.

Additional observations suggest that caterpillars may regain some protein used in silk production by eating previously-laid silk carpets.

A224 STUDYING KESTRELS SOARING IN A WIND TUNNEL: THE FACILITY, TECHNIQUES AND INITIAL RESULTS Tuesday 5th July 2022

SCIENCE ACROSS BOUNDARIES ABSTRACTS 137

09:15am-09:30am

Simon Watkins, RMIT, Matthew Penn, RMIT, George Yi, University of Bristol, Mario Martinez Groves-Raines, University of Bristol, Shane Windsor, University of Bristol, Abdulghani Mohamed, RMIT simon.watkins@rmit.edu.au Kestrels exhibit steady flight in gusty conditions, including maintaining a headlock whilst soaring in strong winds; known as “windhovering”.

Trying to understand what gives them this remarkable ability, and perhaps how this could be utilised in the growing area of drone flight is not feasible outdoors as it would require simultaneous measurements of the impinging atmospheric wind and wing, body and tail kinematics.

We describe a novel wind-tunnel facility which enables such studies; whereby an updraft provides the environment to continuously soar, and upstream turbulence grids can generate a range of smooth and turbulent flows. To provide discrete gusts we have also developed a dedicated gust generator where prior calibration gives us timeaccurate knowledge of a range of gust profiles. In a range of smooth and turbulent conditions the kinematics of two Nankeen Kestrels were

Bumblebees exhibit remarkable abilities to operate in complex environments, where disturbances such as wind gusts and clutter demand agility and honed control operations. Bumblebees normally carry heavy loads while maintaining precision control for gleaning pollen and nectar from small moving platforms in the outdoor environment. In this work, experiments with bees were separated into two parts – one aimed at testing the behaviours of bees flying through gusts, and the other aimed at testing the behaviour of bees responding to an obstacle appearing before their flight path. In the gust experiments, we examined the 3D kinematics of the bee body and wings throughout the flights to compare differences between the response trajectories when flying through gusts of different directions.

Bees had significantly greater disturbance and recovery periods in the downward gust compared to the upward gust. Bees also showed unique wing kinematics when flying through each gust direction which produced interesting resultant body manoeuvres in recovery. In the braking response experiments, we investigated the main behaviours that characterised the response to a gate obstacle appearing at various distances in front of the bees. The resultant 3D trajectories showed linked attitude manoeuvres that were dependent on the direction of the lateral component of the initial heading angle. The resultant roll and yaw changes correlated strongly with longitudinal deceleration and appeared to play an important role in braking. The mass of individual bees was also measured after each flight and initial momentum was the main factor influencing resultant braking response duration.

A226 INVESTIGATING THE RELATIONSHIP BETWEEN ACUTE WARMING AND METABOLIC RATE IN WILD GILTHEAD BREAM (SPARUS AURATA) Wednesday 6th July 2022

11:30am-11:45am

Davide Thambithurai, IFREMER, UMR MARBEC, David J. McKenzie, CNRS, Theo Navarro, University of Science and Technology, Montpellier, Jérôme Bourjea, IFREMER, UMR MARBEC thamby.davide@gmail.com Over the past decades, the maximum body size of many ectotherms has decreased as climate has warmed, this trend has been particularly

ANNUAL CONFERENCE MONTPELLIER 2022

strong in fishes. The gill-oxygen limitation (GOL) hypothesis is perhaps among the best-known paradigms to explain this decline in size.

It proposes that, as fishes grow, there is a decoupling between gill respiratory surface area and body volume, with gill surface increasing at a slower rate than body volume. The result of this is that, once a specific size threshold is attained, all available oxygen supplied by the gills is used in meeting basal metabolic demands, and fish cannot longer invest energy in other activities. This mechanism is exacerbated by a warming climate, as metabolic rate is higher in warmer conditions. Much of the work that has gone into understanding the relationship between a decrease in maximum size and temperature has been theoretical, empirical evidence is needed. We investigated evidence to uphold GOL hypothesis assumptions in wild gilthead bream (Sparus aurata). We did this by challenging fish ranging in size (mean ± sd = 327 ± 188 g) to undertake intense aerobic swimming – 80% of theoretical aerobic capacity - whilst simultaneously increasing temperature (CTSmax).

Results showed that the metabolic cost of swimming increased steadily with temperature up to a point of fatigue, this was consistent across all fish tested. In general, larger fish had lower CTSmax, suggesting that when faced with acute warming smaller fish are better able to meet their metabolic demands. Interestingly, although we saw some consistent global trends, there were some clear outliers and we suggest possible reasons for this. Overall, these data demonstrate that as waters warm, larger individuals of some fish species may struggle to meet their metabolic demands. However, further empirical evidence is needed to understand the physiological basis of this phenomenon.

SCIENCE ACROSS BOUNDARIES ABSTRACTS 138

over time, whereas total protein and albumin levels (both reflective of liver function) declined over the season. Renal biomarkers also experienced a progressive change, with potassium, uric acid, and phosphorous increasing with date, while calcium levels decreased.

These results suggest that the cumulative breeding effort exerts a detectable physiological toll on little auks at the organ level, with reduced renal and hepatic function, and increased muscle damage being experienced as the reproductive season progresses. Furthermore, blood chemistry does not seem to be a reliable proxy of the sublethal effects of Hg contamination in this Arctic seabird.

A229 EXTRACELLULAR CARBONIC ANHYDRASE ACTIVITY UNDERLYING A CARBON CONCENTRATION MECHANISM IN METAZOAN CALCIFYING CELLS Wednesday 6th July 2022

09:15am-09:30am

Ann-Sophie Matt, Institute of Physiology, ChristianAlbrechts-Universität zu Kiel, Marian Y. Hu, Institute of Physiology, Christian-Albrechts-Universität zu Kiel William Chang, Institute of Physiology, Christian-AlbrechtsUniversität zu Kiel a.matt@physiologie.uni-kiel.de

A228 BLOOD CHEMISTRY SUGGESTS A NEGATIVE IMPACT OF CUMULATIVE BREEDING EFFORT ON THE PHYSIOLOGICAL STATUS OF AN ARCTIC SEABIRD, THE LITTLE AUK Thursday 7th July 2022

10:00am-10:15am

Miguel Hernández González, University of Glasgow, Jérôme Fort, Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS - La Rochelle Université, David Grémillet, Centre d’Etudes Biologiques de Chizé (CEBC), UMR 7372 CNRS - La Rochelle Université, Alice Carravieri, Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS - La Rochelle Université, Paco Bustamante, Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS La Rochelle Université 2393938H@student.gla.ac.uk Mercury (Hg) is a naturally occurring toxic metal of environmental concern. Sublethal effects of Hg contamination on Arctic wildlife have been previously investigated by using different proxies of physiological condition such as the Scaled Mass Index (SMI). A more comprehensive assessment of an individual’s physiological status can be obtained through the study of molecular biomarkers provided by blood chemistry (VetScan) analysers. This study aims to evaluate the effects of mercury (Hg) contamination on the physiological status of little auks (Alle alle) from East Greenland. Blood was sampled from 141 breeding birds to quantify Hg concentrations and blood chemistry (2018-2021). A negative association was found between Hg and body condition index; but out of the 10 blood parameters investigated (related to muscular, hepatic, and renal function), only uric acid was negatively associated to Hg. In addition, there was a strong effect of sampling date with most parameters evolving in a predictable way along the breeding season. Parameters associated with muscle damage (aspartate aminotransferase and creatine kinase) increased

Many calcifying organisms utilize metabolic CO2 to generate CaCO3 minerals to harden their shells and skeletons. Carbonic anhydrases are evolutionary ancient enzymes that were proposed to play a key role in the calcification process with the underlying mechanisms being little understood.

Here we used the calcifying primary mesenchyme cells of the sea urchin larva to study the role of cytosolic (iCAs) and extracellular carbonic anhydrases (eCAs) in the cellular carbon concentration mechanism (CCM). Molecular and phylogenetic analyses identified iCAs and eCAs in PMCs and highlight the prominent expression of a GPIanchored membrane-bound CA (Cara7). Intracellular pH recordings in combination with CO2 pulse experiments were used to measure iCA activity. iCA activity measurements together with pharmacological approaches demonstrated an opposing contribution of iCAs vs. eCAs on the CCM. H+-selective electrodes were used to measure eCA catalyzed CO2 hydration rates at the cell surface. Knock-down of Cara7 reduced extracellular CO2 hydration rates accompanied by impaired formation of specific skeletal segments. Finally, pHi measurements in combination with the ammonia pulse method demonstrated reduced HCO3- uptake during inhibition and knock-down of Cara7.

This work revealed the function of carbonic anhydrases in the cellular CCM of a marine calcifying animal. Extracellular hydration of metabolic CO2 by Cara7 coupled to HCO3- uptake mechanisms is critical to mitigate the loss of carbon and to reduce the cellular proton load during the mineralization process. The findings of this work provide insights into a fundamental biological process that is capable of utilizing CO2 to generate a universal construction material.

ANNUAL CONFERENCE MONTPELLIER 2022

A230 ACID-BASE REGULATORY RESPONSE TO HCL-MEDIATED ACIDIFICATION IN THE MARINE OSMOCONFORMER, METACARCINUS MAGISTER Thursday 7th July 2022

15:05pm-15:20pm

Garett Allen, University of Manitoba, Jonathan M. Wilson, Wilfrid Laurier University, Dirk Weihrauch, University of Manitoba Alleng3@myumanitoba.ca Interest in the acid-base regulatory strategies of aquatic species has rapidly expanded due to concerns relating to climate change and ocean acidification. Although the acid-base regulatory capacity of several brachyuran species has been studied, mechanistic details are biased towards euryhaline, osmoregulating species such as Carcinus maenas. Osmoregulating species possess specialized gills with relatively ion-tight paracellular pathways capable of dramatically transforming their ion-transport machinery to hyperosmoregulate in dilute media while osmoconforming in seawater. Conversely, the gills of marine osmoconformers are incapable of actively absorbing Na+/ Cl- in dilute media and possess ion-leaky paracellular junctions that presumably facilitate the equilibration of some environmental and extracellular factors. Due to the interconnectedness of transporters used for transbranchial osmoregulation and acid-base balance, marine osmoconformers may not be accurately described by the hypothetical transport models of euryhaline crabs. The Dungeness crab, Metacarcinus magister, is a typical marine osmoconformer that is tolerant to several acid-base stressors such as high environmental ammonia and hypercapnia. In the presented study, perfused gills revealed that branchial acid-base regulatory mechanisms of M. magister were largely dependent on carbonic anhydrase, the Na+/K+-ATPase, and an intact microtubule network. Acidified seawater (HCl-mediated, pH 7.10) caused an influx of protons into the hemolymph space and inversion of CO2 and HCO3- flux rates in perfused gills whose transport was dependent on carbonic anhydrase, the Na+/K+-ATPase, an intact microtubule network, and the V-type H+-ATPase. Whole animal studies revealed that the slight respiratory acidosis experienced by these crabs is not corrected by accumulation of HCO3- but potentially through urinary acid-excretion.

A232 LOCOMOTOR JOINT MOMENTS IN MONITOR LIZARDS (VARANIDAE) AND THE SCALING OF LOCOMOTION IN SPRAWLING TETRAPODS Tuesday 5th July 2022

10:00am-10:15am

Robert Cieri, The University of British Columbia, Taylor J.M. Dick, The University of Queensland, Peter J. Bishop, Harvard University, Christofer J. Clemente, University of the Sunshine Coast bob.cieri@gmail.com Geometric scaling predicts a major constraint for legged, terrestrial locomotion. Locomotor support requirements at dynamically equivalent speeds scale isometrically with body mass (α M1), while force generation capacity should scale α M2/3 as it depends on tissue cross-sectional

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area. Mammals compensate with more upright postures at larger sizes, but it remains unknown how sprawling tetrapods deal with this constraint. Varanid lizards are an ideal group to address this question because they cover an enormous body size range while maintaining similar posture and body proportions. This study reports the scaling of joint moments from the hindlimb and forelimb from varanid species ranging from 7-37,000 g. Joint moments were calculated via inverse kinematics and inverse dynamics in OpenSim using a Varanus varius model scaled to the size of each species. Peak joint moments scale between M1-1.4 in both limbs. Joint moments associated with stance phase (e.g. hip adduction, knee flexion, and ankle plantarflexion) generally scale higher (~ α M1.35-1.45) than those associated with swing phase (e.g. knee extension, ankle dorsiflexion) (~ α M1.1-1.35 in the hindlimb. Muscle parameters (fascicle length, muscle mass, physiological cross-sectional area, and fibre cross-sectional area) were also found to scale with positive allometry in varanids, suggesting that varanid lizards respond to predicted biomechanical demands of increased body size with both anatomical and kinematic adjustments.

These results provide insight into the scaling of sprawling locomotion generally, and biomechanics of extinct, sprawling megafauna.

A233 BRANCHIAL PLASMA-ACCESSIBLE CARBONIC ANHYDRASE IS AN EMBRYONIC TRAIT IN TELEOSTS THAT IS LOST WITH THE ONSET OF THE ROOT EFFECT Wednesday 6th July 2022

15:50pm-16:05pm

Charlotte Nelson, The University of British Columbia, Angelina M. Dichiera, The University of British Columbia, Colin J. Brauner, The University of British Columbia cnelson@zoology.ubc.ca Teleosts are unique in their collection of respiratory characteristics; traits which are thought to have played an important role in the evolution of this taxa. In adults of a model teleost, the rainbow trout, the respiratory system is comprised of a strong Root effect (reduced O2 affinity and carrying capacity under acidic conditions), red blood cell (RBC) intracellular pH (pHi) protection, and a lack of plasma-accessible carbonic anhydrase (paCA) in the gill. While most vertebrates possess paCA in the respiratory epithelium, it appears to be absent in teleosts to safeguard O2 uptake at the gills during a generalised blood acidosis.

The presence of paCA in the gill would short circuit the mechanism of RBC pHi protection causing reduced RBC pH and compromised O2 loading. Previous work has shown that pre-hatch rainbow trout express embryonic hemoglobins which lack a Root effect entirely. Here we tested the hypothesis that branchial paCA is an embryonic trait that is constrained in adults due to the onset of the Root effect with the transition to adult hemoglobins. We show that pre-hatch fish expressed CA4 (the major paCA isoform) in the gills, that this expression was lost with the transition to adult hemoglobin isoforms, and that embryonic RBCs do not utilise the adult mechanism of RBC pHi protection. We conclude that branchial paCA represents an embryonic trait and suggest this trait may be an ancestral condition, in trout and possible teleosts in general, which is lost due to the selective advantage conferred by Root effect hemoglobins.

ANNUAL CONFERENCE MONTPELLIER 2022

A237 PATHS TOWARDS GREATER CONSENSUS BUILDING IN EXPERIMENTAL BIOLOGY Wednesday 6th July 2022

11:00am-11:15am

Dominique Roche, Université de Neuchâtel dom.g.roche@gmail.com In a recent editorial, the Editors-in-Chief of Journal of Experimental Biology argued that consensus building, data sharing, and better integration across disciplines are needed to address the urgent scientific challenges posed by climate change. In this talk, I will expand on the importance of cross-disciplinary integration and transparency to improve consensus building and advance climate change research in experimental biology. We investigated reproducible research practices in experimental biology through a review of open data and analysis code associated with empirical studies on three debated paradigms and for unrelated studies published in leading journals in comparative physiology and behavioural ecology over the last 10 years. Nineteen per cent of studies on the three paradigms had open data, and 3.2% had open code. Similarly, 12.1% of studies in the journals we examined had open data, and 3.1% had open code. Previous research indicates that only 50% of shared datasets are complete and re-usable, suggesting that fewer than 10% of studies in experimental biology have usable open data. Encouragingly, our results indicate that reproducible research practices are increasing over time, with data sharing rates in some journals reaching 75% in recent years. Rigorous empirical research in experimental biology is key to understanding the mechanisms by which climate change affects organisms, and ultimately promotes evidence-based conservation policy and practice. I will argue that a greater adoption of open science practices, with a particular focus on FAIR (Findable, Accessible, Interoperable, Re-usable) data and code, represents a much-needed paradigm shift towards improved transparency, cross-disciplinary integration, and consensus building to maximize the contributions of experimental biologists in addressing the impacts of environmental change on living organisms.

A239 ATLANTIC SALMON MATURATION: CONTRIBUTIONS FROM LARGE-EFFECT LOCUS AND ENVIRONMENTAL FACTORS IN INFLUENCING MATURATION AGE IN TWO POPULATIONS IN A COMMON GARDEN SETTING Tuesday 5th July 2022

16:30pm-16:45pm

Eirik Åsheim, University of Helsinki, Paul V. Debes, Hólar University, Andrew House, Helsinki Institute of Life Science (HiLIFE) and Institute of Biotechnology, University of Helsinki, Petri Niemelä, University of Helsinki, Jukka Siren, Helsinki Institute of Life Science (HiLIFE) and Institute of Biotechnology, University of Helsinki, Jaakko Erkinaro, Natural Resources Institute Finland (Luke), Craig Primmer, Helsinki Institute of Life Science (HiLIFE) and Institute of Biotechnology, University of Helsinki eirik.asheim@helsinki.fi The Atlantic salmon (Salmo salar) is a unique species with regards to studies on life history, as it not only shows significant variation in

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age at maturity but also because a large proportion of the variation in this trait has been associated with a single genetic locus, vgll3. While this association is now well known, less is known about this gene’s mechanistic pathway and how it interacts with other environmental or genetic factors. To follow up on vgll3 as a large-effect locus for age at maturity in Atlantic salmon, we present a long-term common garden experiment aimed at studying the sources of variation for this trait, covering different vgll3 genotypes across two environmental temperature regimes, two feed treatments, and two populations-oforigin. We show that the effect of vgll3 genotype on maturation timing in male Atlantic salmon is consistent across the temperature treatments and populations. Additionally, we show a population-dependent effect of temperature, with the northern population having a smaller difference in maturation rates between the two temperature regimes.

Finally, we discuss the relative contribution of these environmental and genetic factors to Atlantic salmon maturation timing.

A240 TESTING HEAT DISSIPATION LIMIT THEORY IN A CAPTIVE AVIAN MODEL Wednesday 6th July 2022

17:50pm-18:05pm

Elisavet Zagkle, Institute of Environmental Sciences, Jagiellonian University, Edyta Teresa Sadowska, Institute of Environmental Sciences, Jagiellonian University, Ulf Bauchinger, Institute of Environmental Sciences, Jagiellonian University elisavet.zagkle@doctoral.uj.edu.pl Reproduction is energetically demanding and may entail sustained workload; however, such sustained activity can be limited by the individual’s capacity to dissipate the excess of body heat during hard work, as proposed by the heat dissipation limit (HDL) theory.

Manipulation of heat dissipation via feather-clipping in free-living birds supports HDL theory, although HDL testing under laboratory-controlled conditions has yet to be implemented. Therefore, we implemented a two-factorial experimental design to test HDL theory by exposing captive zebra finches (Taeniopygia guttata) to cold and warm ambient temperatures (14 and 25 °C), and by manipulation of the insulating layer of feathers around the brood patch in females (clipped and unclipped).

We increased the energetic costs of foraging through a feeding system that required hovering to access food under ad libitum conditions. We quantified reproductive performance of both parents at the beginning of reproduction, maternal reproductive performance during nestlingrearing period, and output in terms of offspring quantity and quality.

We found lower egg-laying success, smaller clutch size and lower egg mass at the warm temperature compared to the cold, indicating thermal limitations already at the beginning of reproduction. Females with enhanced possibility to dissipate heat revealed with higher body mass and raised larger in tarsus and heavier offspring than unclipped females in the warm. Our research corroborates HDL theory, particularly at warm temperatures, indicating that parental thermal constrains may influence reproductive output. Under the global change scenario, high temperatures may induce constrains affecting current or future reproduction, and consequently fitness.

ANNUAL CONFERENCE MONTPELLIER 2022

A243 EPIGENETIC AND POSTTRANSCRIPTIONAL REPRESSION SUPPORTS METABOLIC SUPPRESSION IN CHRONICALLY HYPOXIC GOLDFISH Wednesday 6th July 2022

12:15pm-12:30pm

Elie Farhat, University of Oslo, Giancarlo G.M. Talarico, University of Ottawa, Mélissa Grégoire, University of Ottawa, Jean-Michel Weber, University of Ottawa, Jan A. Mennigen, University of Ottawa Farhat.elie.90@gmail.com Goldfish enter a hypometabolic state to survive chronic hypoxia.

We recently described tissue-specific contributions of remodeling membrane lipid composition and mitochondrial function to metabolic suppression across different goldfish tissues. However, the molecular and especially epigenetic foundations of hypoxia tolerance in goldfish under metabolic suppression are currently not well understood.

Therefore, we sought to test the hypotheses that goldfish support metabolic suppression by (i) activating molecular cellular hypoxia sensing pathways and (ii) suppress transcription and post-transcription via induction of epigenetic markers when exposed to 1-week and 4-week hypoxia. Here we show that components of the molecular hypoxia-sensing machinery are robustly activated across tissues irrespective of hypoxia duration. Induction of gene expression of enzymes involved in global DNA methylation turnover and in miRNA biogenesis components suggest a role of epigenetic transcriptional and posttranscriptional silencing in the hypoxia-acclimated brain. However, key mechanistic target of rapamycin (m-TOR)-dependent translational machinery involved in protein synthesis does not exhibit reduction in activity, thus suggesting no contribution of these pathways to lowering cellular energy expenditure. Finally, molecular evidence supports previously reported chronic hypoxia-dependent changes in membrane cholesterol, lipid metabolism and mitochondrial abundance via changes in transcripts involved in cholesterol biosynthesis, β-oxidation as well as mitochondrial fusion. Overall, this is the first study to show that chronic hypoxia robustly activates hypoxia-sensing, induces repressive transcription/posttranscriptional marks in the brain and epigenetically supports a role for membrane remodeling in promoting metabolic suppression.

A244 AN IN VIVO ELECTROPHYSIOLOGICAL APPROACH TO STUDY ACID EXCRETION IN ADULT FISH GILLS Thursday 7th July 2022

14:20pm-14:35pm

Shang-Wu Shih, National Taiwan University frank4xx36@gmail.com Molecular and physiological analyses in ionoregulatory organs (e.g. adult gills and embryonic skin) are essential for studying fish ion regulation. Most of the recent progress in fish ion regulation have been studied from the skin of fish embryos but not from the gills of adult fish. One of possible reasons is the lack of direct methods for in vivo functional assays in adult gills. Here, the present study aims to apply the scanning ion-selective electrode technique (SIET) in adult

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gills and investigate branchial acid-excreting functions in vivo. We removed the opercula from zebrafish and then performed long-term acid acclimation experiments. The results showed that the expression of acid excretion-related genes and the number of H+-ATPase-rich ionocytes were increased in the gills under acidic situations. By using SIET, we proved that the H+ and NH4+ excretion capacities were indeed enhanced in the gills acclimated to acidic water. Besides, both H+-ATPase and Na+/H+ exchanger (NHE) inhibitors decreased branchial H+ excretion capacity, suggesting that H+ is excreted through H+-ATPase and NHE in zebrafish gills. These results suggested that SIET is competent for in vivo detection in fish gills. The SIET applied in the gills would be a new breakthrough to approach fish ion regulation physiology.

A245 PERFORMANCE TRADE-OFFS IN THE WORLD’S LARGEST SEMELPAROUS MAMMAL, THE AUSTRALIAN NORTHERN QUOLL (DASYURUS HALLUCATUS) Tuesday 5th July 2022

14:30pm-14:45pm

Gabriella Sparkes, The University of Queensland, Robbie Stuart Wilson, The University of Queensland, Vincent Careau, University of Ottawa, Nicholas Smith, The University of Queensland, Jaime Heiniger, The University of Queensland, Ami Fadhillah Amir Abdul Nasir, The University of Queensland,, Skye Cameron, Australian Wildlife Conservancy g.sparkes@uqconnect.edu.au Male northern quolls (Dasyurus hallucatus) die after a single synchronous breeding season, while females live and breed for 2-3 years. This provides a unique life history strategy in which to explore sex differences in performance trade-offs. Here, we assessed whether sprinting and biting performance trade-off for male or female northern quolls before, during, or after breeding (2012-2014). The activities that define survival and reproductive success for all animals depend on movement. However, movement is a complex trait, affected by multiple underlying factors, and organisms must balance the competing demands of these factors whenever they move. The morphology that increases bite force in northern quolls (i.e., increased head size)—which can improve fighting ability—should constrain sprinting performance by adding mass to the body. Trade-offs between fighting and escape performance might therefore be sex-specific or manifest only during particular times, such as during breeding. We studied northern quolls in the wild, and found that bite force and sprint speed do not tradeoff functionally — bigger, heavier quolls with greater bite forces are not slower sprinters. We also found that males sprint slower in the post-breeding season. Because we have high recapture rates, we also assessed the repeatability of performance traits across several temporal scales. Performance was highly repeatable within seasons, but less repeatable across seasons, likely associated with the costs of the species’ extreme breeding. These findings suggest that ecologically relevant tasks important for survival and reproduction—fighting capacity and locomotor performance—may evolve independently in male and female northern quolls.

ANNUAL CONFERENCE MONTPELLIER 2022

A246 REGENERATION OF GILL FILAMENTS IN LABORATORY-REARED ATLANTIC SALMON (SALMO SALAR) Tuesday 5th July 2022

17:30pm-17:45pm

Ensiyeh Ghanizadeh-Kazerouni, The University of British Columbia, Phillip R. Morrison, The University of British Columbia, Simon R.M. Jones, Fisheries and Oceans Canada, Colin J. Brauner, The University of British Columbia ghanizad@zoology.ubc.ca Fish gills’ direct contact with the aquatic environment exposes them to a diverse range of infectious and non-infectious stressors which can cause physical damage and tissue loss contributing to “complex gill disease” (CGD), an emerging threat in finfish aquaculture. The pathology induced by CGD can compromise respiratory gas exchange and osmoregulation. Regeneration of damaged gill tissue has been reported for some species, however it is not known for Atlantic salmon, which is an economically important aquaculture species.

Here, we investigated changes in the morphology of gill filaments and lamellae following resection in a laboratory population of Atlantic salmon held in freshwater. Two levels of resection severity were investigated: 30% or 50% of filament length from the most distal part of 16 filaments from the first branchial arch. Filament length was then measured in the same 8-12 individuals at 1, 2, 4, 8, and 12 weeks post-resection (wpr). Additional fish were terminally sampled at these times for determining branchial cell population changes using immunohistochemistry. Filament regeneration was evident at all time points, but was most notable from 4- to 12- wpr. At 12 wpr, 10-15% of the resected filament length was regenerated. However, resection severity did not have a significant effect on regeneration rate.

Regeneration rate was significantly different among individuals, but was not correlated with initial body size, condition factor, or overall growth rate. Our results demonstrate significant gill regeneration in Atlantic salmon following resection which has important implications for recovery from CGD in aquaculture.

A254 ASSESSING THE IMPACT OF UNUSUAL CARBONATE CHEMISTRY IN RECIRCULATING AQUACULTURE SYSTEMS ON LUMPFISH PHYSIOLOGY AND GROWTH Thursday 7th July 2022

14:50pm-15:05pm

Jennifer Finlay, University of Exeter, Rod Wilson, University of Exeter, Rob Ellis, University of Exeter jf536@exeter.ac.u Lumpfish (Cyclopterus lumpus) are a relatively new aquaculture species that are being intensively farmed within recirculating aquaculture systems (RAS) prior to deployment in salmon sea pens. Lumpfish are used as biocontrol against sea lice, a parasite that causes substantial losses. Lumpfish are under-researched, so it is not yet clear how intensive farming affects lumpfish growth. During their life in RAS, lumpfish are exposed to a number of carbonate chemistry changes which are never experienced by lumpfish naturally and likely affect their acid-base regulation. Whilst in RAS, CO2 from respiration unavoidably builds to levels which has been shown to detrimentally impact growth

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in other species. Because CO2 acidifies water, an alkaline buffer is added to at least partially return pH back to a 'normal' range, but carbonate alkalinity (HCO3- + CO32-) is then also elevated. Lumpfish are exposed to further carbonate chemistry changes during 1-3 days transportation to salmon farms (rising CO2) and then, without acclimation, after being deployed into salmon sea pens (suddenly reduced CO2). To assess how growth is affected by changes in carbonate chemistry, lumpfish were exposed to either control CO2 and alkalinity or elevated CO2 and alkalinity (as measured at the U.K.’s largest lumpfish farm) for 8 weeks.

All lumpfish were then exposed to incrementally increasing CO2 over several days to mimic transport conditions, before being exposed to control CO2 and alkalinity to mimic deployment conditions. Growth was measured throughout the experiment, and physiological changes were also tracked during blood sampling when changes in carbonate chemistry occurred.

A255 IS INDIVIDUAL THERMAL AND HYPOXIA TOLERANCE RELATED TO STANDARD METABOLIC RATE IN SEA BASS (DICENTRARCHUS LABRAX)?

Wednesday 6th July 2022

14:35pm-14:50pm

Julie Nati, Memorial University of Newfoundland, Felipe R. Blasco, Federal University of São Carlos, Charles Rodde, UMR MARBEC, Université de Montpellier, CNRS, IFREMER, IRD Montpellier, David J. McKenzie, UMR MARBEC, Université de Montpellier, CNRS, IFREMER, IRD Montpellier julienati3@gmail.com With global climatic changes, it is important to determine the physiological tolerance of fish populations. This will give us a clearer picture of population robustness and resilience to environmental challenges. We measured whether individual standard metabolic rate (SMR) was related to thermal tolerance (CTswim) and hypoxia tolerance (Scrit) in three genetically distinct sea bass populations (Eastern, Western Mediterranean and Atlantic; EM, WM, AT) reared for several months at two temperatures (18 and 24°C), n = 10 in each case. We measured SMR by intermittent flow respirometry over 36h and then Scrit by closed respirometry. CTswim was measured in swim tunnels, warming fish 1 °C every 30 min while they swam at a speed of 2.5 body lengths s-1, and noting the temperature at which they fatigued (CTswim). Both SMR and Scrit were higher at 24 than at 18 °C but CTswim did not differ. There were no differences among populations for Scrit. However, CTswim of WM was higher (32.4 ±0.43°C) than AT (30.7 ± 0.39°C), with EM intermediate (31.2 ± 0.43°C). When all individuals were considered together there was wide variation in SMR, Scrit and CTswim, but SMR was only related to Scrit at 24°C, with a significant positive relationship. Thus, tolerance of warming and hypoxia do not appear to depend systematically upon individual oxygen demand, any relationship may be contingent on acclimation temperature. The fact that Scrit and CTswim were not correlated would seem to indicate that, despite expectations, they do not share a common mechanism defining tolerance.

ANNUAL CONFERENCE MONTPELLIER 2022

A256 EFFECTS OF BODY MASS AND OXYGEN ENVIRONMENT ON MAMMALIAN BLOOD OXYGEN AFFINITY Wednesday 6th July 2022

15:35pm-15:50pm

Kelly E. Ross, University of Liverpool, Michael Berenbrink, University of Liverpool, David Atkinson, University of Liverpool kellyr@liverpool.ac.uk Species differences in vertebrate blood oxygen (O2) affinity have long been invoked as contributing to adjusting rates of O2 supply in response to differences in metabolic rate or environmental O2 availability.

Mammalian blood O2-affinity is thought to scale positively with body mass, with lower blood O2-affinities in smaller mammals facilitating the demands of their higher mass-specific metabolic rates. Although a textbook example in animal physiology, the original study proposing these relationships has been criticised for standardising O2-affinity measurements to a constant blood partial pressure of CO2, rather than at a physiological pH. The original data included high-altitude descendant and burrowing species, although the effect of different environmental O2 backgrounds was not explored. Here we combine previous and new data for a comprehensive, phylogeny-aware analysis of the topic. We show that across 127 species, pH-standardised blood O2-affinity in mammals does not significantly scale with body mass.

At lower taxonomic levels we find some clades with significantly positive as well as clades with significantly negative body-mass scaling of O2-affinity. When grouped according to environmental O2 availability, high-altitude dwellers, burrowers, and breath-hold divers together showed a significantly higher blood O2-affinity than remaining mammals. Using body mass in addition to O2 availability as a second predictor did not significantly improve predictions of O2-affinity. We conclude that there is no pervasive, positive body-mass scaling of blood O2-affinity across all mammals and that other factors such as clade-specific allometric differences and environmental O2 availability play larger roles in determining mammalian blood O2-affinity than previously recognised.

A257 GENETIC DIFFERENTIATION IN PESTICIDE RESISTANCE BETWEEN URBAN AND RURAL POPULATIONS OF A NONTARGET FRESHWATER KEYSTONE INTERACTOR, DAPHNIA MAGNA Thursday 7th July 2022

09:15am-09:30am

Kristien Brans, KU Leuven, Rafaela Almeida, KU Leuven, Maxime Fajgenblat, KU Leuven kristien.brans@kuleuven.be There is growing evidence that urbanization drives adaptive evolution in response to thermal gradients. One such example is documented in the water flea Daphnia magna. However, organisms residing in urban lentic ecosystems are increasingly exposed to chemical pollutants such as pesticides through run-off and aerial transportation. The extent to which urbanization drives evolution of pesticide resistance in aquatic organisms and whether this is impacted by warming and thermal adaptation remains limitedly studied. We performed a common garden rearing experiment using multiple clonal lineages (from 5 replicated urban and rural populations), in which we implemented an acute

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toxicity test exposing neonates (<24h) to either a solvent control or the organophosphate pesticide chlorpyrifos, and at two temperatures (20°C vs. 24°C) to test for temperature-associated differences in urbanization-driven evolved pesticide resistance. We identified a strong overall effect of pesticide exposure on Daphnia survival probability (−72.8 percentage points). However, urban Daphnia genotypes showed higher survival probabilities compared to rural ones in the presence of chlorpyrifos (+29.7 percentage points). Our experiment did not reveal strong temperature x pesticide or temperature x pesticide x urbanization background effects on survival probability. The here observed evolution of resistance to an organophosphate pesticide is a first indication Daphnia likely also adapts to pesticide pollution in urban areas. Increased pesticide resistance could facilitate their population persistence in urban ponds, and feed back to ecosystem functions, such as top-down control of algae.

A258 BLOOD VESSELS IN REPTILE SKIN BEFORE AND AFTER REGENERATION: VARIABILITY IN VASCULARIZATION Wednesday 6th July 2022

09:45am-10:00am

Keeley Schwann, University of Guelph, Matthew K. Vickaryous, University of Guelph kschwann@uoguelph.ca Injuries to the skin resolve with either fibrotic scar formation or are regenerated scar-free. During scar formation, the wound bed is initially characterised by a transient infill that is rich in capillaries. As the wound bed is remodelled, unsupported capillaries are degenerated and replaced with a fibrous scar. Previous reports have indicated that fully regenerated skin is a near-perfect replication of the original tissue. However, details of the regenerated vascular system remain poorly understood. Here, we quantitatively investigated blood vessels in the original and regenerated skin of the leopard gecko. We compared the original and fully regenerated skin of the body and tail using serial histology and immunostaining for the endothelial marker Von Willebrand factor. We focused on multiple vascular measurements, including blood vessel cross-sectional area, area fraction (the percentage of blood vessel area to total area), and blood vessel number. We determined that in geckos there are region-specific differences in blood vessel size and distribution. Within original and regenerated skin, the superficial dermis has significantly more blood vessels than the deep dermis. Overall, regenerated skin has significantly more blood vessels than original skin, but the blood vessels do not differ in cross-sectional area or area fraction. Comparing regions of the original skin, we found that blood vessels within the tail skin are significantly larger and more abundant than those within the skin of the body. These findings indicate that the blood vessel network of the skin is regionally variable and that there are fundamental differences in vascularity following regeneration.

ANNUAL CONFERENCE MONTPELLIER 2022

A260 CONSEQUENCES OF A PLASTIC DIET IN THE HUNGRY CATERPILLAR, THE GREATER WAXWORM (G. MELLONELLA) Thursday 7th July 2022

no difference in maximum metabolic rates. Shelter availability did not influence metabolic rates. Our results suggest that dominance rank and number of interactions lost incur higher metabolic costs for fish held in smaller group size than in larger ones, highlighting the importance of understanding the role of social dynamics on variations in physiological traits associated with energy expenditure.

11:00am-11:15am

Christophe LeMoine, Brandon University, Paola Geronimo, Brandon University, Bryan J. Cassone, Brandon University lemoinec@brandonu.ca

A263 NEST SANITATION AS AN EFFECTIVE DEFENCE AGAINST BROOD PARASITISM Thursday 7th July 2022

The larvae of the greater wax moth (Galleria mellonella) are avid plastivores, as they actively feed on a variety of plastics polymers such as low-density polyethylene (LDPE). From a biodegradative perspective, there is evidence that the waxworm’s intestinal microbiome play an important role in plastic degradation and bioassimilation, however the impact of a plastic diet on the physiology of the insect is unclear at best. In these studies, we employed an integrative approach to assess the physiological consequences of a sole diet of plastic in waxworm larvae. Through comparison with food-deprived caterpillars or larvae fed their natural honeycomb, we show that an LDPE diet is not sufficient to maintain the rapid growth of 5th instar larvae and precipitate their entry into pupation. Furthermore, LDPE fed larvae demonstrated a number of metabolite deficiencies, though surprisingly these caterpillars maintained fat body mitochondrial function and higher lipid reserves than food-deprived counterparts. In addition, an LDPE diet triggered a unique gene expression signature in both the guts and fat body further confirming that the caterpillars are directly affected by plastic metabolic pathways. Overall, this work unveils novel insights in the complex interplay between plastic biodegradation and the physiology of this emerging model plastivore.

A261 THE EFFECTS OF THE SOCIAL ENVIRONMENT ON FISH METABOLISM Wednesday 6th July 2022

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16:05pm-16:20pm

Emmanuelle Chrétien, Institut National de la Recherche Scientifique (INRS), Shaun S. Killen, University of Glasgow manuchretien@gmail.com Group living is widespread among animal species and yields both costs and benefits. Presence of conspecifics can restrict or enhance the expression of individual behaviour, and the recent social environment is thought to affect behavioural responses in later contexts, even when individuals are alone. However, little is known about how social dynamics influence the expression of individual physiological traits, including metabolic rates. There is some evidence that shoaling can reduce fish metabolic rates, but habitat conditions such as shelter availability may generate density-dependent influences on individual metabolic rates. We investigated how social dynamics influence Eurasian minnow Phoxinus phoxinus metabolic rates estimated by respirometry. Respirometry trials were conducted before and after we housed fish for three weeks in a social treatment consisting in a specific group size (n= 4 or 8) and shelter availability (presence or absence of plant shelter in the holding tank). During the social treatment, behaviour were observed to quantify interactions and assess dominance structures. There was an overall increase in standard metabolic rates after the social treatment, which was higher for fish held in groups of four compared to that of fish held in groups of eight. There was

17:35pm-17:50pm

Lisandrina Mari, Institute of Vertebrate Biology, Czech Academy of Sciences,

ANNUAL CONFERENCE MONTPELLIER 2022

environment, particularly in polar areas. This work describes the use of a microsonar tag deployed on a deep-diving marine mammal, the elephant seal (Mirounga leonina), during their at-sea foraging trips.

This tag combines active acoustics with very high-resolution movement and light sensors, allowing for the first time to describe hunting tactics used by elephant seals to capture their prey and simultaneously their prey defence mechanisms. Analysis of more than 5,800 prey capture events in nine female elephant seals enabled the identification of a hunting mode similar to stalking in big cats, allowing seals to get as close as possible to their prey before attacking. Prey consistently reacts at the last moment, by emitting bioluminescent flashes, by escaping or by combining these two defence mechanisms. We demonstrate that the characteristics and behaviour of prey are key factors in determining both predators’ hunting efficiency and prey survival. The ability of seals to approach their prey without eliciting a reaction from them maybe a key factor in the success of this far-ranging generalist predator. This study confirm the use of the microsonar tag to study very fine-scale predator-prey interactions in diving predators in the Southern Ocean.

mari@ivb.cz Egg rejection is a crucial defence strategy against brood parasitism, that requires the host to correctly recognise the foreign egg. Rejection behaviour has thus evolved in many hosts, facilitated by the visual differences between the parasitic and host eggs, and driving hosts to rely on colour and pattern cues. On the other hand, the need to recognise non-egg-shaped objects to carry out nest sanitation led birds to evolve the ability to discriminate and eject objects using mainly shape cues.

However, little is known regarding the evolutionary significance of rejection behaviour in general and the cognitive processes underlying it. Here, we investigated the response of the barn swallow (Hirundo rustica) during pre-laying and laying stages to four objects types that differed in shape (eggs vs stars) and colour/pattern (mimetic vs nonmimetic) to investigate 1) what cognitive mechanisms are involved in object discrimination and 2) whether egg rejection is a direct defence against brood parasitism, or simply a product of nest sanitation. We found that swallows ejected stars more often than eggs in both stages, indicating that both true recognition and discordancy mechanisms rely on shape cues. Since the effect of colour/pattern on ejection decisions was minor, we suggest that barn swallows have not evolved a direct defence against brood parasitism but instead, egg ejection might be a product of their well-developed nest sanitation behaviour. Nonetheless, the fact that mimetic eggs were ejected especially in the pre-laying stage shows that nest sanitation could be an effective defence against poorly timed brood parasitism.

A264 THE MICROSONAR: A TAG TO STUDY FINE-SCALE INTERACTIONS BETWEEN DIVING PREDATORS AND THEIR PREY IN THE SOUTHERN OCEAN Thursday 7th July 2022

17:20pm-17:35pm

Mathilde Chevallay, Centre d’Etudes Biologiques de Chizé, CNRS, Tiphaine Jeanniard du Dot, Centre d’Etudes Biologiques de Chizé, CNRS, Pauline Goulet, Centre d’Etudes Biologiques de Chizé, CNRS, Martin Tournier, Centre d’Etudes Biologiques de Chizé, CNRS, Mark P. Johnson, Aarhus Institute of Advanced Studies, Aarhus University, Christophe Guinet, Centre d’Etudes Biologiques de Chizé, CNRS mathilde.chevallay@cebc.cnrs.fr Predator-prey interactions play a key role in ecosystem structure and functioning, but remain very challenging to study in the marine

A265 SEASONAL METABOLITE ADJUSTMENT IN TROPICAL TILAPIA: A CONVENTIONAL INVESTIGATION VIA MACHINE LEARNING PERSPECTIVES Wednesday 6th July 2022

17:20pm-17:35pm

Min-Chen Wang, Institute of Cellular and Organismic Biology, Academica Sinica, Yung-Che Tseng, Academia Sinica, Tzu-Hao Lin, Academia Sinica, Ching-Wei Wang, Academia Sinica mcwinlab@gmail.com Temperature is one of the primary environmental factors in which ectothermic fish must behave adequately in physiological compensation during seasonal dynamic changes. Fish species have developed a ‘seasonal rhythm’ to deal with seasonal fluctuations. As the physiological compensations are an energy-limited process, determining the seasonal metabolic provision in fish could benefit to understand the machinery underlying energy requirement and physiological state in different climatic variations. However, most related studies were conducted on the cold-water fish, and limited information was reported on the tropical/subtropical species. In the study, the machine-learning algorithms were applied to investigate the seasonal variations of fatty acids, amino acids and carbohydrates abundances in serum of tropical tilapia (Oreochromis mossambicus). The result of Uniform Manifold Approximation and Projection (UMAP) analysis shows that the metabolite compositions changed each month during summer and autumn. Until the ambient temperature decreased, the metabolite compositions in serum tended to be unanimity. Besides, it is also noteworthy that male and female tilapia had different metabolite compositions in the winter and spring season. This study is expected to reveal the seasonal metabolites adjustments in tropical fish and provide a piece of feasible nutrient supply information that benefits to aquaculture improvement in the tropical/subtropical area.

SCIENCE ACROSS BOUNDARIES ABSTRACTS 145

A267 A NOVEL ROLE FOR MYOGLOBIN AS A SULPHUR STORE DURING CATASTROPHIC FEATHER MOULT IN FASTING PENGUINS Wednesday 6th July 2022

10:00am-10:15am

Michael Berenbrink, University of Liverpool michaelb@liverpool.ac.uk The annual feather moult in penguins is critically important for survival and reproduction and a recognised energetic bottleneck, because penguins cannot hunt for several weeks during this time and yet need to renew their whole plumage in what is called catastrophic feather moult.

All feathers consist of &gt;90% proteins that are exceptionally rich in the sulphur-containing amino acid cysteine, which enables crosslinked disulphide bridges that provide structural stability. Because of a low average sulphur content of non-feather proteins, an exceptionally high amount of body protein is broken down during the penguin moulting fast to provide sulphur for the complete renewal of their feather coat.

Pre-moult ‘fattening’ of penguins includes a built-up of pectoral muscle mass with high levels of oxygen-storing myoglobin that supports the prolonged breath-hold feeding dives of these animals and that is broken down during moult fast. The present study analysed recently released penguin draft whole genome sequences to test for a role for myoglobin as a protein sulphur store that is recycled during catastrophic feather moult. Results show a 2- to 3.5-fold higher sulphur content of myoglobin in penguins compared to all other vertebrate myoglobins.

Myoglobin sulphur content was negatively correlated with body mass, consistent with the observed hypo-allometric scaling of total feather mass with avian body mass. Ancestral reconstructions of maximum muscle myoglobin concentrations and myoglobin sulphur contents revealed concurrent increases by the time of the last common ancestor of extant penguins, suggesting co-option of oxygen-storing myoglobin as a sulphur store already 16-20 million years ago.

A268 COST OF TRANSPORT IS A REPEATABLE TRAIT BUT IS NOT DETERMINED BY MITOCHONDRIAL EFFICIENCY IN ZEBRAFISH (DANIO RERIO) Tuesday 5th July 2022

14:45pm-15:00pm

Miki Jahn, The University of Sydney, Frank Seebacher, The University of Sydne miki.jahn@sydney.edu.au Locomotion is essential for fitness as it facilitates predation, escape, and reproductive behaviours. The energy expended for a given distance travelled (cost of transport; COT) varies significantly between individuals of the same species. Lower COT allows animals to allocate more of their energy budget to growth and reproduction. High COT may cause animals to adjust their movements to reduce energy allocated to movement, and potentially reduce energy allocation trade-offs. Our aim was to determine whether COT is a repeatable trait within individuals, and to determine its physiological causes and ecological consequences. We found that COT is a repeatable trait in zebrafish (Danio rerio). We rejected the hypothesis that mitochondrial efficiency (P/O ratio) predicted COT. We also rejected the hypothesis

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that COT is sensitive to temperature acclimation, exercise training, or their interaction, although COT increased with increasing acute test temperature. There was a weak but significant negative correlation between COT and dispersal, measured as the number of exploration decisions made by fish, and the distance travelled against the current in an artificial stream. However, COT did not correlate with the realised speed of fish swimming against the current. The implications of these results are that COT is an inherent characteristic of an individual which reflects a fixed physiological phenotype. Consequently, different energy budgets may be associated with individual movement patterns across environments. Warming environments may increase COT and exacerbate the magnitude of difference between individuals.

A269 MOLECULAR AND FUNCTIONAL CHARACTERIZATION OF THREE AQUAPORINS IN THE GREEN CRAB, CARCINUS MAENAS: INVESTIGATION OF THEIR POTENTIAL ROLE IN OSMOREGULATIO Thursday 7th July 2022

15:20pm-15:35pm

Mikyla Nash, University of Manitoba, Alex R. QuijadaRodriguez, University of Manitoba, Garett J.P. Allen, University of Manitoba, Jonathan M. Wilson, Wilfrid Laurier University, Dirk Weihrauch, University of Manitoba mikylatnash@outlook.com Euryhaline crustaceans such as Carcinus maenas are well-known for their ability to shift between an osmoconforming and hyperosmoregulating state. Upon entering brackish water, C. maenas increase the abundance of ion-transport machinery within their posterior gills to actively absorb Na+/Cl- from the environment into their hemolymph. Although maintaining a hyperosmoregulating state requires the crabs to eliminate excess water, very few studies have investigated the topic of the osmoregulatory role of aquaporins (AQPs). In this study, it was found that seawater-acclimated C. maenas start eliminating excess water through the production of hypoosmotic urine when exposed to dilute conditions. By mining the C. maenas transcriptome, we identified 3 different types of AQPs, a classical AQP (CmAQP), an aquaglyceroporin (CmGLP), and a big-brain protein (CmBIB), all of them expressed in the antennal gland. Functional expression studies confirmed water transport characteristics for CmAQP, CmGLP, but not for CmBIB, while only CmGLP also allowed the transport for urea. An increase in the antennal gland’s mRNA expression of CmGLP upon exposure to dilute media may suggest an osmoregulatory role of this AQP isoform in the production of hypotonic urine. In addition, hemolymph urea concentration increased with exposure to dilute media, but no urea was detected in the final urine. All AQPs were also expressed in the gills of the crab. The apical/sub-apical localization of CmAQP in osmoregulating posterior gills suggests a role of this water channel in transepithelial water balance as increases in transcript levels in dilute media indicate a relief in osmotic pressure.

SCIENCE ACROSS BOUNDARIES ABSTRACTS 146

A270 DEALING WITH THE HEAT: RESPONSES AND CONSEQUENCES OF A SEVERE HEATWAVE IN A COLD-ADAPTED MAMMAL Wednesday 6th July 2022

17:05pm-17:20pm

Liv Monica Trondrud, Norwegian University of Life Sciences, Gabriel Pigeon, Université du Québec en AbitibiTémiscamingue, Leif Egil Loe, Norwegian University of Life Sciences, Elżbieta Król, Institute of Biological and Environmental Sciences, University of Aberdeen, Steve Albon, The James Hutton Institute, Erik Ropstad, Norwegian University of Life Sciences, Jouko Kumpula, Natural Resources Institute Finland, Alina L. Evans, Inland Norway University of Applied Sciences, John R. Speakman, Institute of Biology and Biotechnology, Shenzhen Institutes of Advanced Technology monica.trondrud@gmail.com Extreme temperature events (‘heat waves’) may impose thermoregulatory challenges for endotherms. Heat stress may incur both behavioural and physiological adjustments to reduce heat loads but can result in energy deficits or reduced reproductive output over time. We studied the physiological and behavioural responses of semi-domestic reindeer females (Rangifer tarandus tarandus), a cold adapted arctic ungulate, to abnormally high air temperatures (Ta) during a record-breaking heatwave in the summer of 2018 in Northern Finland. We collected activity data, heart rate (HR) and subcutaneous body temperature (Ts) from 10 females with calves (n = 6) and without calves (n = 4). Reindeer were less active during mid-day and increased activity in the afternoons on warm days (daily mean Ta &gt; 13°C) to compensate for lost foraging time. On very hot days (Ta &gt; 20°C) however, reindeer failed to compensate fully, and total time spent active was reduced by 10%. Females with calves spent ca. 65% of their day in activity, had higher resting HR (~67 bpm) than females without a calf (~59 bpm), but similar Ts (36 °C). Resting HR declined, while body temperature increased, with higher air temperatures, suggesting a reduction in food intake (via lowered HR) and increased heat load (elevated Ts). The response to Ta was similar in both reproductive groups. The 2018 summer was exceptionally hot in Northern Finland, and the average September body mass of females in this reindeer herd was 12 kg lower that year (adj. mean of 70.9 kg, n = 53), compared to both past and previous years (1990–2021, adj. mean of 83.6 kg, n = 1533). We provide a detailed insight into short-term physiological and behavioural responses of an abnormally hot summer in a rapidly changing Arctic. We show that summer heatwaves can impose a severe thermoregulatory challenge causing high internal heat loads and potentially result in reduced body condition in a cold-adapted mammal.

A271 DISTINCT PHYSIOLOGICAL RESPONSES OF THE GOLDFISH (CARASSIUS AURATUS) TO ANOXIA AT COLD COMPARED TO WARMER TEMPERATURES Wednesday 6th July 2022

17:35pm-17:50pm

ANNUAL CONFERENCE MONTPELLIER 2022

Michael Wilkie, Wilfrid Laurier University, Oana Birceanu, Western University, Brittney G. Borowiec, Wilfrid Laurier University, Matthew Trzcinski, Wilfrid Laurier University mwilkie@wlu.ca Anoxia tolerance in the goldfish, and the closely related crucian carp (Carassius carassius), relies on their capacity to meet ATP demands via anaerobic glycolysis. Their ability to withstand anoxia is greater at colder temperatures because it facilitates metabolic depression and the conservation of ATP. Less is known about how colder temperatures mitigate the physiological disturbances known to occur during anoxia and post-anoxia recovery. We tested the hypothesis that physiological disturbances observed in goldfish during and after anoxia were greater in warmer water (13°C) compared to cooler water (6°C). The goldfish were exposed to short-term anoxia (dissolved O2 &lt; 1 % saturation) for 24 h followed by a 12 h recovery in normoxia. Brain water content, an index of cerebral edema (brain swelling), increased by 20% during anoxia at 13°C, but was unchanged at 6°C. Surprisingly, lactate accumulation in the muscle was 2-fold greater in the plasma and muscle at 6°C than at 13°C after anoxia. Ethanol showed the opposite trend, increasing by 4-fold after anoxia in 13°C water, with no change at 6°C. Both the lactate and ethanol concentrations were quickly restored during post-anoxia recovery. The effects of water temperature on postanoxia oxidative damage (protein carbonyls; lipid peroxidation) and antioxidant enzyme activity (catalase; superoxide dismutase) were also examined. These findings reveal that the physiological responses of Carassius fishes to anoxia in warmer waters differ from their responses in cold water conditions, where they are more likely to experience hypoxia or anoxia under environmentally relevant conditions.

A273 CREATING A PATH WHERE THERE IS NONE: STRATEGIES FOR GUIDANCE IN CLUTTERED ENVIRONMENTS Tuesday 5th July 2022

09:45am-10:00am

SCIENCE ACROSS BOUNDARIES ABSTRACTS 147

A274 EFFECTS OF DIFFERENT OXYGEN AND PH REGIMES ON ECOLOGICAL FUNCTIONS AND BIOENERGETICS OF THE RAGWORM HEDISTE DIVERSICOLOR Thursday 7th July 2022

15:35pm-15:50pm

Natascha Ouillon, University of Rostock, Inna M. Sokolova, University of Rostock, Christian Müsse, University of Rostock, Stefan Forster, University of Rostock natascha.ouillon@uni-rostock.de Oxygen deficiency (hypoxia) and low pH (hypercapnia) are common stressors in coastal habitats that can negatively affect metabolic performance of benthic organisms due to the perturbations of energy metabolism and acid-base status. These changes can have implications for behavior and ecological functions of marine organisms. However, the physiological mechanisms and ecological consequences of the effects of hypoxia and hypercapnia on bioturbators such as the ragworms Hediste diversicolor are not understood. We exposed H. diversicolor for 21 days to four different combinations of two oxygen (100% and 20% air saturation) and two pH (normocapnia pH 7.9; hypercapnia pH 7.4) levels and measured their bioturbation and bioirrigation capacity, respiration, ammonia excretion and cellular bioenergetics. Oxygen consumption was not affected by hypoxia and/or hypercapnia, while ammonia excretion decreased in all conditions compared to the control (normoxia-normocapnia) group. Worms acclimated to normoxiahypercapnia showed a decrease in glycogen reflecting increased energy need for acid-base regulation during hypercapnia. Protein content also decreased in worms co-exposed to hypercapnia under normoxic or hypoxic conditions, but O:N ratio did not change indicating that the decrease in proteins was likely due to a decreased protein deposition rather than enhanced protein breakdown. Bioturbation was not affected, while bioirrigation capacity increased in worms acclimated to normoxia-hypercapnia and hypoxia-normocapnia. Our results indicate that despite increased energy demand for acid-base regulation in hypercapnia, ecological activities (bioturbation and bioirrigation) were not negatively affected by environmentally relevant hypoxia and hypercapnia levels in the ragworms.

Natalia Pérez-Campanero, University of Oxford, Graham K. Taylor, University of Oxford natalia.perez-campanero@zoo.ox.ac.uk Animals are frequently faced with the challenge of negotiating unfamiliar structured environments during goal-oriented behaviours.

Recent work on visually-guided flight through clutter has conceptualised this as a process of identifying and negotiating gaps that are broadly aligned with the animal’s expected or intended goal. These gaps are thereby conceived as attractors in their own right, rather than as features incidental to obstacles acting as repellers. Here we ask what information birds use to detect and fly through such gaps by tracking pigeons flying through an artificial forest of vertical poles.

We find evidence for pigeons combining brightness cues with the sizes of visual gaps available ahead to choose which clearances to fly through. Modelling the free-flight behaviour as a process of sequential gap selection allows us to decompose it into components that can be independently evaluated. We find the observed behaviour is best captured by an autoregressive model including the effect of brightness, the absolute distance between obstacles and apparent visual gaps between a bird’s position and the end of the obstacle field. This can, in turn, be combined with established models of pigeon steering to provide a more complete picture of how birds guide their flight through complex environments

A275 WITH A LITTLE HELP FROM MY FRIENDS: DIVISION OF LABOUR AND GEOMETRY OF GROUP HUNTING IN KILLER WHALES Thursday 7th July 2022

17:05pm-17:20pm

Paolo Domenici, CNR Italy, Jacob L. Johansen, University of Hawaii, Francesca Leggieri, CNR Italy, Richard Karoliussen, Norwegian Orca Survey, Eve Jourdain, Norwegian Orca Survey paolo.domenici@cnr.it Killer whales are a gregarious species known for their group tactics when hunting their prey. Although qualitative information has been gathered on their group-feeding strategies, little is known about how killer whales interact during a hunt. Using drone-based videos, here we demonstrate that killer whales show division of labour and a preferred geometrical arrangement when hunting their schooling prey in shallow waters. Typically, a hunt consists in a killer whale swimming side by side with a neighbouring whale, with their belly facing each other while

ANNUAL CONFERENCE MONTPELLIER 2022

the prey is channeled between them. As a whale (the striker) starts its horizontal tailslap (tail slap speed: 10.56±1.22 m/s) to stun the prey, the two whales position themselves at preferred angles from one other (i.e. at approximately 40 degrees between their heading). This geometrical arrangement is likely to allow the neighboring whale (the helper) to provide a barrier for the prey as they are tail-slapped from the opposite side and to position its mouth near the stunned prey as soon as the tail slap motion is over. The-geometrical pattern of this feeding behaviour is likely to have evolved as a strategy to maximize the outcome of an attack whilst benefiting both participants to the hunt.

Furthermore, killer whales were found to preferentially act as strikers or helpers suggesting that this group behaviour implies a division of labour among the individuals taking part in the hunt.

A276 HOMOLOGOUS EXPRESSION SYSTEM FOR IN VITRO CHARACTERIZATION OF THERMAL EFFECTS ON TILAPIA PEPTIDE TRANSPORTERS Thursday 7th July 2022

12:00pm-12:15pm

Avner Cnaani, The Hebrew University of Jerusalem, Pazit Con, The Hebrew University of Jerusalem, Jens Hamar, University of California, Davis, Dietmar Kültz, University of California, Davis pazpazr@gmail.com Many fishes are subjected to varying water temperatures, which projects on their physiological performances. Environmental temperatures affect fish at different levels, inducing metabolism changes, tissue remodeling and proteins differential expression. However, prior to these induced reactions, temperature also affect the organism’s biochemical processes, affecting energetic and nutritional constrains available to cells and tissues. The peptide transporter (PepT) systems are important for protein absorption in all animal species. These symporters, located at the cell apical membrane, mediate the absorption of small peptides. In fish, there are three PepT variants, all found to express in the intestinal epithelia (enterocytes). Like all tissues of ectotherms, the enterocytes are constantly exposed to changes in thermal conditions, which can affect the function of various pumps, transporters and channels mediating transmembrane movement of different substances between the enterocytes and the intestinal lumen. Tilapia is an important aquacultured fish as well as an emerging model for environmental physiology research. In order to study the functionality of PepTs under different temperatures relevant to fish physiology, we have established homologous expression system, based on the tilapia Tmb cell line. In this study, we have established three modified Tmb cell lines, each of them expressing only one of the PepT variants. The expression and functionality of the three transporters were verified using PCR and fluorescence imaging of the dipeptide β-Ala-Lys(AMCA) accumulation in the cells. The absorption of β-Ala-Lys(AMCA) was tracked under different thermal conditions, revealing a temperature-dependent function of peptide absorption, affecting nutrients absorption capabilities under different temperatures.

SCIENCE ACROSS BOUNDARIES ABSTRACTS 148

A218 THE SECRET DINING HABITS OF CRABS: INVESTIGATION INTO AMINO ACID TRANSPORT IN THE BRANCHIAL EPITHELIUM OF CRUSTACEANS Thursday 7th July 2022

16:05pm-16:20pm

Robert Griffin, University of Alberta, Tamzin A. Blewett, University of Alberta, Aaron Boyd, University of Alberta ragriffi@ualberta.ca Many aquatic species are well known as extremely successful invaders.

The green crab (Carcinus maenas) is an arthropod native to European waters; however, it is now known to be a globally invasive species.

Recently it was discovered that the green crab could transport nutrients in the form of amino acids across their gill from the surrounding environment, a feat previously thought to be impossible in arthropods.

We compared the ability for branchial amino acid transport of crustacean’s native to Canadian pacific waters to that of the invasive green crab, determining if this was a novel pathway in an extremely successful invasive species, or a shared trait among crustaceans.

Active transport of L-leucine and L-alanine was exhibited in Carcinus maenas, Metacarcinus magister, Cancer productus, and Metacarcinus magister across their gill epithelia. C. maenas exhibited the highest rate of branchial L-leucine transport at 47.3 ± 6.06 nmolg-1h-1 when compared to the native Canadian crustaceans. We also examined the influence of feeding, gill specificity, and organ accumulation of L-leucine. Feeding events displayed a heavy influence on the branchial transport rate of amino acids, increasing L-leucine transport rates by up to 10-fold in C. maenas. L-leucine displayed the highest accumulation in the gills of C. maenas at 3.09 ± 0.63 nmolg-1h-1, a significantly higher accumulation rate than the rest of the body. For the first time, the novel transport of amino acids in Canadian native arthropods is described, suggesting that branchial amino acid transport is a shared trait among arthropods, contrary to existing literature.

A283 THE UPRIGHT POSTURE HYPOTHESIS: VERTICAL DESCENTS IN SMALL ARBOREAL MAMMALS SHEDS LIGHT ON THE ORIGINS OF PRIMATE SPECIALIZATIONS Tuesday 5th July 2022

10:15am-10:30am

Séverine Toussaint, Humboldt University of Berlin, John A. Nyakatura, Institute of Biology and Comparative Zoology, Humboldt University of Berlin, Dionisios Youlatos, University of Thessaloniki severine.toussaint@hu-berlin.de Negotiating sloping branches is a crucial aspect of arboreal life as animals must efficiently ascend and descend various supports. Climbing vertical supports likely played a major role in the acquisition of unique early primate specializations, but the functional and evolutionary interpretations of their locomotor, grasping, and visual adaptations, and their dependence on the arboreal environment remain unclear.

Moreover, very little is known about descents in mammals. We investigated postural, kinematic, and grasping characteristics during ascents and descents on vertical supports in 22 small arboreal mammals, including 11 strepsirrhine and platyrrihine primates, 1

ANNUAL CONFERENCE MONTPELLIER 2022

scandentian, 3 rodents, 3 carnivorans and 4 marsupials. We linked these behaviors to key morphological parameters to help reconstruct the paleoecology of extinct euarchontoglires. Vertical descents induced specific locomotor adjustments compared to ascents, notably increasing the proportion of asymmetrical gaits in all animals surveyed. Also, while all non-primate species preferentially employed headfirst descents regardless of their morphologies and body mass, primates exhibited specific upright strategies with strepsirrhines descending rump-first and platyrrhines descending in a side posture. Surprisingly, these upright vertical descents of primates were quite efficient compared to other mammals, allowing them to maintain higher speed and grasping postural diversity. Arboreal postural adaptations are highly influenced by the evolutionary history of mammals and result from a trade-off between body mass, limb proportions, grasping abilities and head size. We propose an ecological scenario of the sequence of acquisition of early primate grasping and locomotor specializations, constituting a hitherto unrecognized prerequisite for the origin of their encephalization.

A284 CHANGES IN HAEMOGLOBIN GENE EXPRESSION DURING DEVELOPMENT OF A CORAL REEF FISH Wednesday 6th July 2022

15:20pm-15:35pm

Sjannie Lefevre, University of Oslo, Adam Downie, The University of Queensland, Jodie Rummer, James Cook University, Göran E. Nilsson, University of Oslo sjannie.lefevre@imbv.uio.no Tropical reef fishes, such as the orange clownfish and other anemonefishes share a particular life history: The larvae hatch at the reef, go through a pelagic stage, after which the larvae return to the reef for settlement and maturation into adults. The two environments – coral reef and open sea – are vastly different, and poses unique challenges to the physiology of the fish. It has been shown that several species start out by having high maximum oxygen consumptions rates as larvae, but low hypoxia tolerance, a pattern that then reverses before or during the time of settlement. It has been hypothesised that shifting from low-affinity to high-affinity haemoglobin could be responsible for this pattern, but due to the very small size of the larvae, it has been difficult to investigate. In this study we used RNA sequencing to look at transcriptomic changes during larval development of the cinnamon clownfish (Amphiprion melanopus), focusing on the haemoglobin genes, which have different paralogs of the alpha and beta subunits.

Larvae were bred and hatched in the lab, and sampled at 4, 6 and 9 days post-hatch. We found a clear shift from 4 to 9 days in the paralogs dominating the expression of both alpha and beta subunits. While investigation of the functional properties are still necessary to confirm that they switch from low- to high-affinity isoforms, specifically, the data supports the hypothesis that haemoglobin isoform switching occurs just before the larvae settle on the reef.

A285 COULD DIMETHOATE COUPLED WITH SALINITY DECREASE ALTER THE PHYSIOLOGY AND BEHAVIOUR OF A MANGROVE FIDDLER CRAB? Thursday 7th July 2022

09:00am-09:15am

SCIENCE ACROSS BOUNDARIES ABSTRACTS 149

Thibaut L’Honoré, CUFR Mayotte, Elliott Sucré, CUFR Mayotte, Jehan-Hervé Lignot, UMR MARBEC, Université de Montpellier, CNRS, IFREMER, IRD Montpellier, Laura Mégevand, CUFR Mayotte, Sophie Hermet, UMR MARBEC, Université de Montpellier, CNRS, IFREMER, IRD Montpellier , Emilie Farcy, UMR MARBEC, Université de Montpellier, CNRS, IFREMER, IRD Montpellier thibautlhonore@gmail.com Mangrove are tropical complex and fragile environments under growing pressure of climatic changes and anthropogenic wastes. Dimethoate (DMT), one of the most commonly used organophosphate pesticide, is found in high concentration in fruits and vegetable end-products in Mayotte Island (Comoros archipelago, Indian Ocean). Tubuca urvillei is a mangrove fiddler crab species living around flooded environments exposed to agricultural run-off. It is considered as an engineer species through its burrowing activity contributing to matter and energy exchanges between the different links in food webs. To characterise the toxicity of DMT on mangrove organisms, T. urvillei adults and larvae were exposed to dimethoate in either seawater (SW) or in diluted seawater (dSW). We evaluated whether DMT exposure coupled with hyposaline stress would affect T. urvillei physiology through a multi-biomarkers approach. We focused on neurotoxicity through AChE activity, osmoregulation capacities (hemolymph osmolality, NKA activity) and metabolism markers (citrate synthase and lactate dehydrogenase activities). Preliminary results tend to highlight a high sensitivity at sublethal doses regarding behaviour, physiology and survival.

A286 ROLE OF RHESUS PROTEINS IN BRANCHIAL AMMONIA AND CO2 EXCRETION IN THE GREEN SHORE CRAB CARCINUS MAENAS Thursday 7th July 2022

15:50pm-16:05pm

Alex Quijada-Rodriguez, University of Manitoba, Sandra Fehsenfeld, Université du Québec à Rimouski, Jonathan M. Wilson, Wilfrid Laurier University, Anne-Marie Marini, Université Libre de Bruxelles, Dirk Weihrauch, University of Manitoba umquijaa@myumanitoba.ca Excretion of gaseous metabolic byproducts such as CO2 and ammonia had initially been believed to occur by simple membrane diffusion.

We now know that transport of these compounds can be regulated by membrane composition and presence/abundance of transport proteins. Using heterologous expression systems and gene silencing technology vertebrate Rhesus glycoproteins are now believed to function as dual ammonia/CO2 channels. Due to a lack of heterologous protein expression studies on invertebrate Rhesus proteins, it remains unclear whether invertebrate and vertebrate Rhesus proteins function the same. This study characterized the role of the green crab (Carcinus maenas) Rhesus protein (CmRh) in ammonia and CO2 excretion.

Sequence analysis suggested high conservation of key amino acid known to promote ammonia transport in vertebrate Rhesus proteins and the presence of a CO2 binding pocket. Through radiotracer fluxes and yeast complementation assays we determined the ammonia transport capabilities of CmRh. Further, we used a novel approach to measure direct CO2 efflux in Xenopus oocytes to characterize the CO2 transport capacity of CmRh. Using mRNA transcript abundance and western blot analysis we determined that CmRh is most abundant in

ANNUAL CONFERENCE MONTPELLIER 2022

the gills which are the main site of acid-base regulation and ammonia excretion. Finally, we immunolocalized CmRh in the posterior gills of C. maenas relative to Na+/K+-ATPase, H+-ATPase and membrane bound carbonic anhydrase. Our results suggest CmRh is an apically localized dual ammonia/CO2 transporter that colocalizes with a membrane bound carbonic anhydrase where it may facilitate CO2 excretion and trapping at the apical membrane.

A287 FISHERIES-INDUCED EVOLUTIONARY CHANGES RECOVER SLOWLY BUT SURELY OVER TIME Tuesday 5th July 2022

16:15pm-16:30pm

Stephan Van Dijk, University of Jyväskylä, Daniel Sadler, University of Jyväskylä, Phillip Watts, University of Jyväskylä, Silva Uusi-Heikkilä, University of Jyväskylä vandijkz@jyu.fi Overfishing is one of the greatest threats to fish populations. Sizeselective harvesting favours faster juvenile growth, younger maturation, small adult body size and low reproductive output. These changes might be slow to recover and ultimately threaten population’s survival. To study the recovery potential of exploited experimental populations, we compared life-history traits in three differently size-selected experimental lines (large-selected, small-selected, randomly-selected) after five generations of harvesting and ten subsequent generations of recovery. We show that after a recovery period twice as long as the harvesting period, the differences in adult body size among the selection lines have eroded. While there was still a significant body size difference among the selection lines, this did not translate to differences in reproductive success. Our experimental results demonstrate that, despite that size-selective harvesting can cause contemporary evolutionary changes in exploited fish populations, these changes can be reversible if populations are allowed to recover long enough.

A288 SOLUBLE ADENYLYL CYCLASE COORDINATES INTRACELLULAR ACIDBASE REGULATION RELEVANT FOR CALCIFICATION IN THE SEA URCHIN LARVA Wednesday 6th July 2022

09:30am-09:45am

William Chang, Christian-Albrechts-Universität zu Kiel, Marian Y. Hu, Institute of Physiology, Christian-AlbrechtsUniversität zu Kiel, Angus B. Thies, Scripps Institution of Oceanography, Martin Tresguerres, Scripps Institution of Oceanography w.chang@physiologie.uni-kiel.de Calcifying cells concentrate dissolved inorganic carbon and require orchestrated mechanisms to remove protons liberated by the mineralization process. Therefore, clacification and cellular pH homeostasis are intrinsically linked. However, there is little information about the underlying mechanisms that coordinate cellular acid-base transport.

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Here we use the sea urchin larva to test the hypothesis that intracellular pH regulation relevant for biomineralization is mediated by soluble adenylyl cyclase (sAC). By using single cell transcriptome analysis, in situ hybridization, and Immunohistological staining, we demonstrated the presence of a sAC in the calcifying primary mesenchyme cells (PMCs) during the skeletogenesis process. Pharmacological assay via sAC specific inhibitor, KH7, led to reduction in calcification rates accompanied by a decrease in intracellular pH regulatory capacities, which can be rescued by the addition of cAMP. Indicating the presence of a cAMP-mediated acid-base regulatory mechanism in PMCs. We next demonstrated that sea urchin sAC, similar as its mammalian homologs, carries the splicing variants that express only the catalytic domains, and expression analysis suggests the splicing forms are differential regulated. CO2-induces seawater acidification elevated the expression level of sAC catalytic domain, implying the abundance of splicing form may participate to the regulation of sAC activity.

These results demonstrated the present of sAC in the calcifying PMCs of the sea urchin larva and its critical role in modulating intracellular acidbase homeostasis relevant for intracellular formation of CaCO3. These findings have important implications for our understanding regarding the mechanisms of acid-base regulation in calcifying systems.

A289 A NOVEL METHOD FOR ACHIEVING ACCURATE BLOOD ACIDBASE CHEMISTRY IN FISH WITHOUT CANNULATION Thursday 7th July 2022

14:35pm-14:50pm

William Davison, University of Exeter, Chris A. Cooper, International Zinc Association, Katherine A. Sloman, University of West Scotland, Rod W. Wilson, University of Exeter

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A291 THE IMPACT OF HIGH CO2 IN AQUACULTURE ON THE DIGESTIVE PHYSIOLOGY OF RAINBOW TROUT Thursday 7th July 2022

11:45am-12:00pm

William Davison, University of Exeter, Rod W. Wilson, University of Exeter w.davison2@exeter.ac.uk Globally, aquaculture development has outstripped wild capture fisheries as the main source of fish for human consumption. However, for future growth to be maximised, a holistic understanding of the relationship between the farm environment and animal biology is required. Intensive aquaculture is synonymous with elevated dissolved carbon dioxide far beyond anything most fish would regularly experience in the wild. Exposure to elevated CO2 induces significant acid-base disturbance to fish, specifically a respiratory acidosis compensated by active retention of blood bicarbonate. However, feeding induces a blood “alkaline tide” that necessitates rapid excretion of excess bicarbonate to restore blood pH. A linear decline in growth as CO2 increases has been documented in salmonids and we hypothesised that the conflicting acid-base regulatory needs associated with high environmental CO2 and feeding may be a causative factor. Utilising a combination of intermittent flow respirometry to measure specific dynamic action (SDA), whole organism fluxes, and analysis of body fluid acid-base chemistry we investigated this idea in freshwater rainbow trout after feeding on a 3 % body mass meal. Contrary to our prediction we conclude that the reduced growth observed under high CO2 may be linked to impairment of nitrogen handling during digestion, with a 10% increase in cumulative ammonia excretion observed under elevated CO2. This influence on nitrogen handling may be a key factor in the reduced growth observed in studies using aquaculture relevant levels of elevated CO2 if greater loss of nitrogen as ammonia is symptomatic of reduced protein growth in tissues.

w.davison2@exeter.ac.uk Phlebotomy of fishes has long been a vital tool in studying how fish respond to environmental stimuli. Two main methods are typically used: grab ‘n’ stab and cannulation. Grab ‘n’ stab involves rapidly removing a fish from the water, rendering it insensible, and then taking the blood sample from the vasculature. In contrast cannulation involves surgically implanting a cannula into the vasculature under anaesthesia, after sufficient recovery blood can be drawn. While both methods have their benefits, both have significant issues that prevent them being useful in various scenarios. The acute capture stress associated with grab ‘n’ stab renders blood gas and acid-base variables useless while cannulation is limited to sufficient body sizes, has certain technical requirements, and induces chronic stress that can influence typical behaviours such as feeding. Here we present a novel method involving gradual introduction of anaesthetic to a tank to render fish insensible without physical struggling and anaerobic muscle use, before transfer to a gill irrigation table to maintain adequate water flow across the gills.

This method avoided the blood chemistry disturbances associated with grab ‘n’ stab (e.g. elevated catecholamines, lactate, pCO2 and metabolic acid, low pH and pO2) and generated results directly comparable to samples taken using cannulation. Crucially this method was also successfully applied to fish too small for cannulation (e.g. 10-30 g). This method therefore opens up a key avenue in the fields of comparative physiology, aquaculture and climate change, generating data that has thus far been unable to be captured.

A292 A VISUAL SENSORY ESTIMATION SYSTEM FOR DETECTING ELECTRORETINOGRAM IN BIGFIN REEF SQUID UNDER CO2 PERTURBATION Tuesday 5th July 2022

17:00pm-17:15pm

Yung-Che Tseng, Institute of Cellular and Organismic Biology, Academia Sinica, Pou-Long Kuan, Academia Sinica yctseng@gate.sinica.edu.tw Acidified ocean system would affect marine livings was already proved. The inadequate potential difference and ions gradient may jam the neural transmitting in turn; moreover, the evoking pathological behavioral defects such as impaired visual capacity may impact the survival and fitness of several marine species. As such, the electrophysiological method, electro-retinography (ERG), is one of the most commonly used techniques to investigate the properties of the visual response to a light stimulus in aquatic animals. A simplified and low-cost ERG apparatus was assembled and used to determine the threshold of flicker electroretinogram (fERG) of bigfin reef squid under control (pH 8.1) or laboratory CO2-induced acidified conditions at the retinal level. An epoxy-insulated tungsten microelectrode was placed on the midline of the retina and enabled us to estimate the

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visual sensitivities practically in squid retina to a series of light-emitting diodes (LEDs) emitting different wavelengths. Under the control pH 8.1 conditions, the average critical flicker fusion (CFF) threshold toward a white light source in bigfin reef squid retina was found to be 47 Hz at the illumination level of 50 cd/m2, while the average CFF of CO2acclimated squid is slightly increased by about 15%. In the future, pharmacological studies could further indicate whether this effect could be caused by the CO2-involved neuronal functional irregularity.

A296 MANTA MOUTHFULS: MODELING ACCURATE MOBULA MORPHOLOGY FOR FLOW ANALYSIS Tuesday 5th July 2022

14:15pm-14:30pm

Julia Teeple, California State University julia.teeple@csu.fullerton.edu Mobula rays are large marine fishes that filter great volumes of water and zooplankton with minimal clogging using highly specialized filter structures. Previous studies on simplified manta filter structures revealed a unique solid-fluid separation mechanism, now known as ricochet separation. These studies provide a basic understanding of this novel mechanism, but used a generalized model that did not account for the intricacy and diversity of the filter structures observed in mobulas. To better understand both the biology of mobula and the fluid dynamic processes that govern ricochet separation, this study investigated how morphological variation among mobula filters changes the filtration mechanisms and filter performance. We used micro CT scans to 3D print biologically accurate filter models in four species of mobula. We visualized flow across and through the filters using digital particle image velocimetry (DPIV). We found that the differences in filter lobe morphology affected flow pressure and velocity as water moved through the filter pore. This inevitably affects the particle selectivity of the filter. This work can be used to guide engineers in creating biomimetic systems that can effectively filter particles smaller than the pore size without suffering clogging effects.

A300 CHARACTERIZATION OF INSECT CUTICLE: CHALLENGES AND INSIGHTS Wednesday 6th July 2022

09:00am-09:15am

Michael Jansen, University of Bonn, Alexander Blanke, University of Bonn, David Labonte, Imperial College London, Nikhilesh Chawla, Purdue University ajansen@evolution.uni-bonn.de The microstructural and mechanical characterization of insect cuticle is a significant obstacle for the study of functional morphology in exoskeletal structures. In particular, the impact of meso-scale composite structure (viz. laminate organization) on the mechanical performance of cuticle is poorly understood. Here we reflect on the challenges inherent to the study of cuticle mechanics, and how these may be mitigated or overcome using a suite of microscopy techniques in conjunction with high-throughput nanoindentation testing. We examine, both theoretically and empirically, the effect of fiber orientation patterns and ply structures (i.e., unidirectionally aligned fibers vs. “helicoidally”

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stacked fibers) on the nanoindentation properties of the cuticle in Polyneopteran head-capsules. We additionally report on our efforts to obtain and analyze nanoindentation data on individual plies and cuticle regions (e.g., exocuticle and endocuticle), and compare the efficacy of various optical and electron microscopy techniques for differentiating ply micro-architecture. Above all, we emphasize the need for continued methods development in this field, including (1) practical methods for automated characterization of layering patterns and gradients within the cuticle, (2) methods for mechanical characterization of individual plies, and (3) theoretical methods for the analysis and measurement of ply anisotropy. Finally, we consider the implications of our findings for future work involving finite element modeling of cuticular structures in biomechanical studies of insects.

A334 WING BIOMECHANIC COUPLINGS OF KESTRELS DURING WIND HOVERING FLIGHT Tuesday 5th July 2022

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is quite limited. Among sperm, we believe that three key factors that are likely to affect sperm metabolism; temperature, size, and density.

Here, we used empirical data from two species combined with all of the available data on sperm metabolism to estimate how sperm metabolic rate changes with temperature, size and sperm concentration both within- and among-species. Sperm from species at hotter temperatures have higher metabolic rates than sperm from species at cooler temperatures, but sperm metabolism is half as temperaturedependent than expected based on general metabolic rules. We also found evidence for countergradient covariation in sperm midpiece size, where sperm from species that experience warmer conditions have smaller midpieces, offsetting the effects of temperatures on metabolic rate, potentially buffering sperm function. Our results also support the long-hypothesized Respiratory Dilution Effect. We found that sperm exhibit density-dependent metabolism, both among- and within-species whereby sperm experience metabolic suppression at high densities within a dense ejaculate but rapidly increase metabolism at low densities following dilution. Together, our results reveal sperm metabolism is relatively robust to temperature variation and local competitive environments (density), within- and among-species.

09:30am-09:45am

Mario Martinez Groves-Raines, University of Bristol, George Yi, RMIT University, Matthew Penn, RMIT University, Simon Watkins, RMIT University, Abdulghani Mohamed, RMIT University, Shane Windsor, University of Bristol

POSTER SESSION

mario.grovesraines.2016@bristol.ac.uk Birds’ wings have a high number of potentially independent degrees of freedom of motion. This enables their wings to morph in shape to suit a range of flight conditions, but potentially increases the complexity of flight control. Here we used motion tracking data from Nankeen kestrels (Falco cenchroides) performing steady wind hovering flights in a wind tunnel to study how different degrees of freedom in wing motion changed as the birds held station. To judge the contribution of a particular degree-of-freedom to flight control, metrics such as variance, correlation and control effectiveness were considered, along with Principal Component Analysis. Wing sweep, which represents the flexion/extension movement of the wing, was the major component of almost all wing motions. This was followed by sectional twist at the root, which although showing lower actuation, would have a strong effect on aerodynamic loads. Together these results highlight the major wing motions which contribute to the wind hovering flight of kestrels and suggest degrees of freedom to concentrate on when considering the design of future agile morphing wing uncrewed air vehicles.

A376 TEMPERATURE, SIZE AND DENSITY DRIVE SPERM METABOLISM ACROSS THE TREE OF LIFE Tuesday 5th July 2022

16:45pm-17:00pm

Ashley Potter, Monash University, Craig White, Monash University, Dustin Marshall, Monash University ashley.ashpot.potter@gmail.com Sperm face the singular, formidable task of successfully fertilising eggs, but they have finite energy reserves, and a limited lifespan. The trade-off between sperm metabolism and longevity imposes strong selection to optimise energy allocation but the drivers of sperm metabolism remain poorly resolved. While our understanding of metabolism more generally has increased enormously, our understanding of sperm metabolism

A82 CUTICLE ULTRASTRUCTURE: HOW DOES A BUTTERFLY HATCH? Thursday 7th July 2022

POSTER SESSION

Nikolai Rosenthal, Max Planck Institute of Colloids and Interfaces & Cluster of Excellence Matters of Activity Image Space Material, Michaela Eder, Max Planck Institute of Colloids and Interfaces, Michael Doser, Deutsche Institute für Textil- und Faserforschung, Markus Milwich, Deutsche Institute für Textil- und Faserforschung, Sanja Sviben, Washington University School of Medicine, Yael Politi, Technische Universität Dresden, Clemens Schmitt, Max Planck Institute of Colloids and Interfaces, Emeline Raguin, Max Planck Institute of Colloids and Interfaces Nikolai.Rosenthal@mpikg.mpg.de The puparium, the pupal case that encloses lepidoptera during metamorphosis requires functionality for the organism until hatching.

It must act as a protective shell and at the right time allow the imago to break open the puparium to eclose when metamorphosis is complete. In this study we use a diverse set of techniques, from classical histological staining to FIB-SEM to identify and quantify the structural composition of the pupal cuticle. These visualization methods are complemented by nano-indentation mapping and aminoacid analysis. With these methods the existence of an ecdysial line of weakness was demonstrated in M. peleides in the meso- and prothorax.

A wax covering and an underlying layer of sclerotized tissue as well as the wedge-shaped geometry of the elow, which appears as a protrusion of the mesocuticle towards the outer layer, the exocuticle, of the pupae, provide sufficient stability during metamorphosis.

The presence of numerous pore canals in the line of weakness likely ensure early/controlled degradation of this region and the subsequent formation of a crack. The simultaneous degradation of the endo- and mesocuticle is expected to reduce the bending stiffness and strength

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of the remaining (exo)cuticle, facilitating successful hatching of the butterfly. As an ecdysial line of weakness is commonly found in many arthropod species and is of high evolutionary relevance for successful molting research into its ultrastructure can offer new insight into its biological significance and set the groundwork for future research of the line of weakness for other species as well as for technical applications.

A215 HYPERACTIVE AND SYNCHRONIZED PRE-MATING BEHAVIOR OF HONEY BEE DRONES INSIDE THE NEST Wednesday 6th July 2022

POSTER SESSION

Jacob Davidson, Max Planck Institute for Animal Behavior, jdavidson@ab.mpg.de Eusocial insects, such as colonies of ants, wasps, and bees, operate as an integrated collective with tasks allocated among individuals.

There is a long tradition of detailed work on the female workers that carry out colony tasks. Males, however, are typically ignored, because they do not perform work, and/or they simply disperse from the natal nest. In the Western honey bee, (Apis mellifera), males (drones) live in the colony throughout their lives, but prior research focuses almost exclusively on their behavior outside of the nest (mating flights), while ignoring their in-nest behavior. To understand the in-nest behavior of drones across their entire lives, we used the BeesBook tracking system to track 192 individually-marked drones at 3 fps for 25 days.

We used these trajectories to extract behavioral parameters, including how drones developed, how they moved, and where they spent their time. While drones do spend around 21 hours of their time immobile at the periphery of the nest, as expected, we also found that drones have periods of in-nest hyperactivity, in these times moving faster than even workers. This hyperactivity develops in drones after 7 days, occurs daily between 14:00 and 17:00, and is synchronized across the cohort. While active, drones move towards the nest entrance, and gaps in tag detections indicate trips outside of the nest (presumably flying to mating sites). Surprisingly, we even found this behavior on days of poor weather, when drones would not fly, suggesting that drones must inspect the daily weather themselves. While drones are typically attributed to being the lazy members of the colony, here we show that they have hyperactive bouts that surpass even worker activity. The duration, however, is short, likely to conserve energy. Drones are part of the colony’s organization, even if their role is simply to become active once daily to maximize opportunities for mating success.

A219 YOU HEARD IT EAR FIRST - THE ROLE OF THE MANDIBLE IN MYSTICETE AUDITORY RECEPTION Wednesday 6th July 2022

POSTER SESSION

Madison Wilson, California State University Fullerton, Petr Krysl, University of California San Diego, Ted W. Cranford, San Diego State University, E. Misty Paig-Tran, California State University Fullerton mnwils03@csu.fullerton.edu Modern cetaceans rely on two mechanisms to conduct sound waves into the inner ear. These two mechanisms are soft tissue pressure

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conduction and bone conduction. Of the two extant suborders, the soft tissue pathway is prevalent within the toothed whales, or odontocetes.

The bone conduction pathway is used by both suborders, but is the main pathway used by the baleen whales, or mysticetes. The soft tissue pathway operates by funneling sound to the ear through two fat bodies nestled in the mandibular fossa. Mysticetes do not have these mandibular fat bodies. The aim of this project is to understand the role of the mandible in mysticetes’ auditory reception. Finite element analysis software was used to simulate the effect of the motion of the complete skull with the mandibles attached for a fin whale, Balaenoptera physalus. That geometry was acquired by CT scanning.

The simulations were parametrized by changing the Young’s modulus of the temporomandibular joint, the modulus of the pedicles, or the suspension of the tympanic from the periotic bone, and the modulus of the bones of the skull. This was done to determine if the stiffness of the connection of the mandible to the skull impacts the output at the middle ear. Preliminary findings show that the elasticity of the temporomandibular joint does not result in any significant change in the output at the ear. The mandible may only have an integral role in odontocete auditory reception and does not appear to be consequential in mysticetes’ auditory bone conduction.

A227 RELATIONSHIPS BETWEEN TAILBEAT FREQUENCY AND SWIMMING SPEED IN FREE-SWIMMING FISHES Wednesday 6th July 2022

POSTER SESSION

Meghan Lavery, University of Glasgow, Hannah Whyte, University of Glasgow, Stefano Marras, Italian National Research Council, Paolo Domenici, CNR-IAMC, John F. Steffensen, University of Copenhagen, Shaun S. Killen, University of Glasgow 2254636l@student.gla.ac.uk Understanding the metabolic costs of locomotion is key for understanding the energy budgets of wild animals, yet can be challenging to quantify, especially for aquatic animals that may be difficult to observe or recapture. Here we quantified relationships between tail-beat frequency and swimming speed in free-swimming fishes at a large pelagic display aquarium at the Nordsøen Oceanarium, Denmark. Using stereocamera footage of free-swimming fish, we were able to determine the swimming-speed and body size of individuals from four study species: Atlantic mackerel, horse mackerel, needlefish, and the starry smooth-hound shark. While there were strong relationship between tailbeat frequency and swimming speed, the steepness of this relationship varied among species and between swimming types. Furthermore, for Atlantic mackerel, the relationship between swimming speed and tailbeat observed in free-swimming individuals differed from that measured for individuals swimming within a swim tunnel. This may be due to differences in how momentum can be used to maintain speed while freely swimming, or the energetic saving that can be gained by swimming in schools, and suggests caution be used when applying relationships between oxygen uptake and swimming speed derived from swimming tunnel respirometry to free-swimming fishes. Overall, more work examining the swimming behaviour and bioenergetics of free-swimming fishes is required to understand energy use in differing environments in the wild.

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A231 DISTINGUISHING DE NOVO PROTEIN SYNTHESIS FROM PROTEIN TURNOVER WITH RAPAMYCIN TO INHIBIT THE MTORC1 PATHWAY IN THE EUROPEAN PERCH Wednesday 6th July 2022

POSTER SESSION

Alexander Rosén, DTU – Aqua, Emil Rindom, Aarhus University, Mark Bayley, Aarhus University axdrosen@gmail.com The mTORC1 pathway is believed to play a very important role in the regulation of de-novo protein synthesis across vertebrates as well as many other organisms, although the evidence in fish is presently limited.

This pathway can be specifically inhibited by rapamycin, which stops the up-regulation of protein synthesis while allowing constitutive protein synthesis to continue. This contrasts to the classically used cycloheximide, whose mechanism is now understood to cause total protein turnover inhibition. Since it is de-novo protein synthesis that is thought to underly the post prandial increase in metabolism (systemic dynamic action or SDA) and of course growth itself, this method has the potential to promote both a better understanding of protein metabolism but also to vastly improve feed development. We tested this system in Perca flvitalis using a protocol with fasted fish that where either force-fed 3% of body mass or sham fed with saline. Using an intra-peritoneal injection of 20mg/kg Rapamycin the post prandial increase in protein synthesis was completely inhibited resulting in fish that had the same rate of protein synthesis as sham fed fish. Oral administration of Rapamycin in feed was also attempted but failed to inhibit post prandial increases in protein synthesis, suggesting that oral dosing requires elevated doses. This study indicates that Rapamycin and mTORC1 regulated protein synthesis in fish has great potential for increasing our understanding of fish growth.

A234 DOES EXERCISE TRAINING IMPROVE HEAT TOLERANCE IN CHINOOK SALMON (ONCORHYNCHUS TSHAWYTSCHA)?

Thursday 7th July 2022

POSTER SESSION

Daniel Gomez Isaza, Harry Butler Institute, Murdoch University, Essie Rodgers, University of Canterbury daniel.gomezisaza@uqconnect.edu.au The progression of climate warming will expose ectotherms to transient heatwave events and temperatures above their tolerance range at increased frequencies. It is therefore pivotal that we understand species’ physiological limits and the capacity for various controls to plastically alter these thresholds. Exercise training could have beneficial impacts on organismal heat tolerance through improvements in cardio-respiratory capacity, but this remains unexplored. Using juvenile Chinook salmon (Oncorhynchus tshawytscha), we tested the hypothesis that exercise training improves heat tolerance through enhancements in oxygen-carrying capacity. Fish were trained once daily at 60% of their maximum sustainable swim speed for 60 min.

Tolerance to acute warming was assessed following three weeks of exercise training, measured as the critical thermal maximum (CTMax).

CTMax measurements were coupled with examinations of the oxygen

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carrying capacity (haematocrit, haemoglobin concentration, relative ventricle size, and relative splenic mass) as critical components of the oxygen transport cascade in fish. Contrary to our hypothesis, we found that exercise training did not raise the CTMax of juvenile Chinook salmon with a mean CTMax increase of just 0.35°C compared to unexercised control fish. Training also failed to improve the oxygen carrying capacity of fish. Exercise training remains a novel strategy against acute warming that requires substantial fine-tuning before it can be applied to the management of commercial and wild fishes.

A236 THE PHYSIOLOGICAL RESPONSE OF WATER FLEAS TO HEAT WAVES IN COMBINATION WITH ELEVATED ENVIRONMENTAL AMMONIA Thursday 7th July 2022

POSTER SESSION

Dirk Weihrauch, University of Manitoba, Nathalie Nash, University of Manitoba, Aaron KlymaszSwartz, The University of British Columbia Dirk.weihrauch@umanitoba.ca Due to increasing anthropogenic impacts, heatwaves and prolonged exposure to elevated concentrations of ammonia (HEA) may occur in aquatic environments as a single stressor or a combination thereof potentially impacting the physiology of exposed animals. In the current study, Daphnia magna were exposed for one week to either a 5°C increase in temperature, an increase of 300 µmol l-1 total environmental ammonia, or to both of these stressors simultaneously. Exposure to elevated temperature caused a decrease in MO2, ammonia excretion rates, and mRNA downregulation of the energy consuming Na+/K+ATPase and V-type H+-ATPase, the energy distributing crustacean hyperglycemic hormone, and the excretory Rh-protein. In contrast, exposure to HEA had little effect on the energy metabolism of Daphnia, but initiated ammonia detoxification processes via urea synthesis evident by elevated urea excretion rates and mRNA upregulation of arginase. Effects observed under the combined stressors resembled largely the effects seen after acclimation to elevated temperature alone, potentially due to the animals’ capability to efficiently detoxify critical ammonia loads.

A238 SORTEE: PROMOTING OPEN, RELIABLE, AND TRANSPARENT ECOLOGY AND EVOLUTIONARY BIOLOGY Thursday 7th July 2022

POSTER SESSION

Dominique Roche, Université de Neuchâtel dom.g.roche@gmail.com Science and society benefit when scientists conduct research in a transparent, reproducible, and collaborative fashion. SORTEE (the Society for Open, Reliable, and Transparent Ecology and Evolutionary biology) was founded in December 2020 with the aim of bringing together researchers working to improve reliability and transparency through cultural and institutional changes in ecology, evolutionary biology, and related fields. In 2021, over 700 researchers became members of SORTEE and participated in the society’s first annual virtual conference. This poster will showcase SORTEE’s success and

ANNUAL CONFERENCE MONTPELLIER 2022

activities thus far, and provide conference attendees with information and resources on how to engage in open, reliable, and transparent research practices. Links will be drawn to recommendations on open science practices from a recent perspective article “Paths towards greater consensus building in experimental biology” published in the Journal of Experimental Biology’s 2022 special issue “Building New Paradigms in Comparative Physiology and Biomechanics”.

A241 DO BIRDS USE CONTRAST CUES FOR VISUAL GUIDANCE DURING FLIGHT? Wednesday 6th July 2022

POSTER SESSION

Emma Borsier, University of Oxford, Graham K. Taylor, University of Oxford emma.borsier@zoo.ox.ac.uk Many flying animals such as birds, bats and insects are able to navigate through cluttered environments and have a robust guidance strategy to avoid crashes and collisions. Some of their most impressive behaviours include flying rapidly through small gaps, dodging obstacles, and perching on moving objects. Lab studies have shown that many diurnal birds and insects use visual guidance strategies relying on optic flow to avoid obstacles when flying;a however, dense natural environments such as forests are visually cluttered which can make integrating information from optic flow a complex cognitive task. Therefore, optic flow could be used in conjunction with other cues, such as contrast between obstacles and their background. This project aims to investigate the possibility that birds use a strategy based on relative brightness to stay clear of edges when negotiating gaps, as was found in a study by Baird and Dacke in orchid bees.

Zebra finches were presented with different brightness gradients behind the aperture of a tunnel. The gap negotation strategy of the birds as they were flying through the aperture was not directly affected by alternating the contrast; however, the birds' decision of whether to fly through the tunnel, as well as the exit direction taken after flying through it, were both influenced by the different brightness gradients.

This hints at a possible pre-planning of the trajectories before the onset of flight, where birds approach obstacles after having already established their flight strategy.u

A248 MIDGUT NA+ AND PH HOMEOSTASIS IS DIFFERENTALLY REGULATED BY NA+/ H+ EXCHANGERS IN THE SEA URCHIN LARVA Thursday 7th July 2022

POSTER SESSION

Inga Petersen, Institute of Physiology, Christian-AlbrechtsUniversität zu Kiel, Marian Hu, Institute of Physiology, Christian-Albrechts-Universität zu Kiel, William Chang, Institute of Physiology, Christian-Albrechts University Kiel i.petersen@physiologie.uni-kiel.de Analogous to the situation in several lepidopteran and dipteran insects also the larval stages of some echinoderms and hemichordates (ambulacraria superphylum) evolved highly alkaline midguts up to pH 10.5. Despite its pivotal role in species´ sensitivity to changes

SCIENCE ACROSS BOUNDARIES ABSTRACTS 155

in seawater pH, the underlying epithelial transport mechanisms are largely unknown. Using ion-selective microelectrodes we found that pluteus larva of the purple sea urchin not only have highly alkaline midgut fluids (pH ~9) but also a substantial reduced sodium concentration (150 mM) compared to the surrounding sea water (450 mM). We pharmacologically investigated the role of Na+/H+ exchangers in intracellular pH (pHi) regulation and midgut proton and sodium maintenance using the NHE inhibitor 5 (n ethyl n isopropyl) amiloride (EIPA). While life cell imaging demonstrated the importance of NHEs in pHi regulation of midgut epithelia cells, basolateral EIPA application decreased midgut pH whereas luminal application, via micro-injections, increased midgut [Na+], without affecting pH. Gene expression analyses identified putative NHE candidates for midgut pH and Na+ homeostasis. Based on this information an antibody was generated against the sea urchin Slc9a2, which showed that the protein is localized in luminal membranes of the midgut. Additionally the use of specific vivo morpholino knock down of spslc9a2 provoked an increase in midgut [Na+] without affecting pH underlining the role of this transporter in midgut Na+ maintenance.

This work provides new insights of NHEs being involved in ion regulatory mechanisms, especially the maintenance of pH and [Na+] in larval midgut fluids and thereby show conserved features to insect and vertebrate digestive systems, which may contribute to the ability of sea urchin larvae to cope with changes in seawater pH.

A250 A NEW METHOD TO INDUCE POLYMORPHIC TRANSFORMATION FROM ARAGONITE TO VATERITE IN ORYZIAS OTOLITHS Thursday 7th July 2022

POSTER SESSION

Iki Murase, Tropical Biosphere Research Center, University of the Ryukyus, Takahiro Irie, Atmosphere and Ocean Research Institute, The University of Tokyo iki.murase@gmail.com Otoliths are paired calcified structures and are used for hearing and keeping balance of teleost fishes. Otoliths are mainly composed by aragonite, one of the three calcium carbonate polymorphs. However, the otolith carbonate structures often transform from aragonite to another polymorph, vaterite and the mechanism for this transformation remains unclear. To examine the transformation mechanism, we established a new method for changing otolith carbonate polymorphs.

Ten individuals of an inbred strain of Oryzias latipes were independently reared in aquaria with adding SrCl2・6H2O to tap water. The other set of individuals were reared in normal tap water as a control group.

Sagittal otoliths were removed after 114¬¬–146 days of experimental period. To distinguish between aragonite and vaterite polymorphs, strontium (Sr) and magnesium (Mg) compositions of otoliths were analysed using an electron probe micro analyser. The individuals reared in Sr-rich water had otoliths of which the margins were replaced with vaterite, while control individuals had entirely aragonite otoliths. Our results clearly show that the addition of Sr to rearing water induces polymorphic transformation from aragonite to vaterite. Considering that the polymorphic transformation from inorganic calcite to inorganic aragonite is induced by adding Mg to water, thermodynamic mechanisms possibly affect the observed transformation. Our findings have a potential to explore the impact of having vaterite otolith on fishes as well as to improve understanding of vaterite-forming mechanisms.

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A251 COMPARATIVE ANALYSIS OF MUSCULAR TOPOLOGY AND ESTIMATED FORCE GENERATION CAPACITY RELATED TO HALLUCAL GRASPING IN SMALL ARBOREAL MAMMALS Wednesday 6th July 2022

POSTER SESSION

Irene Montanez-Rivera, Comparative Zoology, Humboldt Universität zu Berlin, Séverine Toussaint, Comparative Zoology, Humboldt Universität zu Berlin, John A. Nyakatura, Comparative Zoology, Humboldt Universität zu Berlin irene.mntz@gmail.com Primates and several non-primate arboreal specialists use a hallucal grasp to securely accommodate their feet when navigating arboreal habitats. “Powerful” hallucal grasping is a category defined by primate osteological features, whereas “non-powerful” grasping is usually assigned to marsupials and other non-primate arborealists that lack osteological primate-like adaptations. This definition of grasping power does not account for foot musculature responsible for the diverse underlying movements, which include adduction and flexion to various degrees. This study aims at investigating hallucal grasping of small arboreal mammals informed by muscle topology and assessment of muscle force generating capacity. We analysed µCT-based 3D reconstructions of the hallux-related intrinsic musculature of four primates and six non-primate arboreal species proposed as modern analogues to various “stages” of early primate evolution. The results reveal species-specific muscular complexes that prioritize force generation capacity in different muscles, suggesting heterogeneous functional significance. Relative to body size, Microcebus possesses the most powerful grasp based on adduction due to well-developed adductor musculature that is likely a convergent specialization of primates and diprotodontians. Callitrichids have less developed adductor musculature, and in Callithrix jacchus the flexor component is prioritized. In general, diprotodontians have a grasping force generation capacity lower than Microcebus, but potentially higher than callitrichids.

Tupaia displays a muscular configuration and force generation capacity that prioritizes hallucal abduction over adduction. Rodents possess the least strong and least varied musculature. Our results highlight the complexity of grasping force generation capacity and reject the binary notion of “powerful” vs. “non-powerful” in primates and nonprimates, respectively.

A252 PROTANDROUS HERMAPHRODITISM WITH MALE REGRESSION: AN EXPLANATION BASED ON EVOLUTIONARILY STABLE MIXED STRATEGIES Thursday 7th July 2022

POSTER SESSION

Takahiro Irie, The University of Tokyo irie@aori.u-tokyo.ac.jp The adaptive significance of sequential hermaphroditism, typically found in tropical fish and marine invertebrates, has been successfully explained by the size-advantage principle (SAP) and notable exception has not been reported. Here we focus on a novel type of protandrous sequential hermaphroditism in an intertidal holothurian as a case

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not amenable to SAP. This species typically participates as a male in the first three spawning events, and then spawn eggs at the fourth, which is followed by the second sex change to release sperm again. By incorporating published empirical findings into evolutionary invasion analyses, we successfully specified the theoretical conditions that a population containing the reversible sex change is evolutionarily stable.

Our scheme is a natural extension of the classical Fisher's principle of sex allocation, and is also capable of consistently explaining a strongly biased operational sex ratio found in sequential hermaphrodites.

A253 CHANGES IN METABOLIC SCALING THROUGHOUT DEVELOPMENT IN SMALL MAMMALS Wednesday 6th July 2022

POSTER SESSION

Jessica Li, University of British Columbia, Ryan Sprenger, University of Wisconsin - Oshkosh, William K. Milsom, University of British Columbia jessli@zoology.ubc.ca Metabolic scaling describes the relationship between metabolic rate and body size, and can be calculated using the equation Metabolic Rate = a(Body Mass)B. Juvenile mammals have been reported to have higher exponent (B) values until they reach adult body size experience a critical switch, after which B decreases and scaling is hypometric. This study measured and compared metabolic rate and mass in 13-lined ground squirrels (Ictidomys tridecemlineatus) through a wide range of developmental stages to investigate how mass specific metabolic rate (MSVO2) change throughout parturition (change in metabolism with no change in weight), as well as how MSVO2 scale as pups gain weight though development (weight gain due to growing tissue).

Metabolic rates of 6 litters were found to increase roughly 150% upon birth. Developing I. tridecemlineatus pups then displayed a switch from hyper- to hypometric scaling at 20-26 days of age, as marked by a decrease in the exponent B value from 1.20 to 0.76 (adj R2=0.90, p p=2.70E-03; adj. R2=0.67, p=2.84E-02). The critical switch in B was found to occur before reaching adult size, thus indicating factors other than body size may be more influential for scaling during development.

A259 DE NOVO ASSEMBLY OF THE CRUCIAN CARP GENOME Wednesday 6th July 2022

POSTER SESSION

Sjannie Lefevre, University of Oslo.

Laura Valencia, University of Oslo l.m.v.pesqueira@ibv.uio.no The crucian carp (Carassius carassius) is a champion of anoxia tolerance and the physiological mechanisms are well documented. Still, there is a need for better understanding at the molecular and genetic level, and a fully sequenced, assembled and annotated genome will facilitate such studies. To obtain a high-quality genome assembly, we sequenced the crucian carp genome using methods such as chromosome conformation capture (HiC) and PacBio long-read sequencing, in addition to shortread sequencing for error correction. For annotation we are using fulllength transcripts (IsoSeq data) as well as regular RNAseq data from both normoxic, anoxic and re-oxygenated crucian carp. The genome

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of crucian carp and other cyprinids consists of 50 chromosomes that originated from several whole-genome duplication events, with the most recent occurring 14 Mya. The presence of duplicated genes offers the possibility for evolutionary changes through the mechanism of expression dominance: one paralog remains most expressed, while the other paralog is free to change without compromising the expression integrity of the biological systems required for normal function. This is hypothesized to be the genetic mechanism having allowed the crucian carp and goldfish (Carassius auratus) pyruvate dehydroxylases to obtain the decarboxylation function necessary for conversion of pyruvate to acetaldehyde; an important metabolic process in the crucian carp’s survival strategy in anoxia. We expect that paralogs of other important genes may have undergone similar changes, and aim to elucidate any differences that may have arisen between the crucian carp and the goldfish due to the long domestication history of the latter.

A266 THE EFFECT OF TEMPERATURE ON MOSQUITO AERODYNAMICS Thursday 7th July 2022

POSTER SESSION

Marcos Georgiades, Royal Veterinary College, Rachel H.S. Tran, University of Leeds, Toshiyuki Nakata, Chiba University, Masateru Maeda, Chiba University, Joerg T. Albert, University College London, Simon M. Walker, University of Leeds, Richard J. Bomphrey, Royal Veterinary College

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A277 ONE OR TWO FACTS ABOUT THE EARLY DEVELOPMENT OF ASTYANAX MEXICANUS: ONTOGENY OF THE GUT AND PHOTOTAXIS IN CAVE AND SURFACE MORPHS Wednesday 6th July 2022

POSTER SESSION

Patrícia Ferreira, Wilfrid Laurier University, Jonathan M. Wilson, Wilfrid Laurier University pferreira@wlu.ca The characid fish Astyanax mexicanus is an emerging model in fundamental and biomedical sciences. This species has the peculiarity of presenting two forms, a cave (blind) adapted morph and a surface morph. The aim of the present study is to investigate hallmarks of the development of both morphs of A. mexicanus with emphasis on the digestive tract. The development of the gastrointestinal tract is compared between morphs, where presumably adaptations to the oligotrophic cave environment could produce shifts in the onset of the molecular mechanisms of feeding. The expression of genes related to gastric function (atp4a, atp4b and pepsinogens), and to intestinal and neuro-endocrine regulation of feeding (sstr, grpr, sctr, mc4r and insra) were analysed. Moreover, the progression of phototaxis behaviour was analysed in larvae of both surface and cave morphs. Preliminary data points to a surprisingly negative phototaxis behaviour in the blind cave morphs. This study lays the groundwork for novel comparative studies using A. mexicanus as a model species.

mgeorgiades20@rvc.ac.uk The relationship between temperature and wingbeat frequency has been the focus of many studies over several decades and it has been shown repeatedly, across taxa, that warmer temperatures lead to higher flapping frequencies. This phenomenon is thought to be driven chiefly by the muscle properties of the flight motor. There are knock-on consequences for the kinematic pattern of the wing stroke that is required in order to generate aerodynamic forces sufficient to balance body weight. Specifically, we might predict that as frequency increases, the stroke amplitude or angle of attack must decrease to avoid producing excess force.

Since mosquitoes have very high baseline wingbeat frequencies for their size, they operate with low wing stroke amplitudes, resulting in unusual aerodynamic mechanisms that place a greater burden of lift generation on the supinatory and pronatory rotations during the wingbeat cycle. Temperature-modulated increases in frequency reduce the stroke amplitude still further. Here, we investigate the aerodynamics of male Anopheles gambiae mosquitoes during flights recorded over a range of temperatures spanning almost 10 degrees Celsius. The kinematics were captured in a new multicamera arena, and the flow fields were subsequently simulated by solving the incompressible Navier-Stokes equations. We present noteworthy variation in Anopheles kinematics with temperature and the mechanism of aerodynamic force production across the range of recorded kinematics.

A280 THE DYNAMIC ROLE OF RABBIT MASTICATORY APPARATUS DURING FEEDING Thursday 7th July 2022

POSTER SESSION

Roger Kissane, University of Liverpool, Karl T. Bates, University of Liverpool, Graham N. Askew, University of Leeds, Michael J. Fagan, University of Hull, Peter J. Watson, University of Hull, Linjie Wang, University of Hull r.kissane@liverpool.ac.uk The rabbit is a widely used model system in comparative and clinical sciences for understanding correlations between anatomy and function in the masticatory system. Experimental and simulation studies have hypothesised that the rabbit is able to modulate chewing mechanics to process a variety of food types with high efficiency.

Through synchronously measuring 3D jaw motions (using biplanar x-ray videography), muscle length change (using fluoromicrometry) and muscle activity (using electromyography) during feeding on foods of varying material properties and maximum bite-force in-situ experimentation we have begun to test these hypotheses. Processing tougher food types resulted in an increase in whole chew-cycle duration, and particularly in the slow-closing proportion of chewing. Additionally, working side muscles appear to be recruited more during feeding on tougher food types. Finally, the capacity to generate force varies greatly over the entire gape cycle, with rabbits working at the lower end of the gape-force relationship. Our data suggest that the masticatory system modulates power output through two mechanisms, primarily

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through changes in masticatory frequency, specifically modulating the power stroke phase of the chew cycle, while also modulating muscle recruitment. Finally, our preliminary in-situ data suggests the rabbit functions outside the optimal range of the force-gape relationship.

A282 THE OPTOREG SYSTEM: A LOWCOST, PLUG-AND-PLAY, EASY-TO-USE SOLUTION FOR REGULATING WATER OXYGEN LEVELS Thursday 7th July 2022

POSTER SESSION

Rasmus Ern, Norwegian University of Science and Technology, Fredrik Jutfelt, Norwegian University of Science and Technology rasmus@ern.dk Studying the effects of water oxygen on aquatic organisms is essential for understanding the impacts of ocean deoxygenation on aquatic ecosystems. Until now, the ability to regulate water oxygen levels in laboratory settings required either large funds for available commercial systems or the technical skills to build and program custom systems.

We have figured out how to assemble a system for regulating water oxygen levels via the analogue outputs on the FireSting O2 meter and the Pyro Workbench software. This OptoReg system uses inexpensive commercially available hardware and software to control solenoid valves for oxygen and nitrogen gases. Assembling the OptoReg system requires no engineering, programming, or other technical skills. The total cost of the hardware components for a 4-channel system is less than €250 ($275) (excluding the solenoid valves and the FireSting O2 system). The control software is free and has a graphical user interface.

With this OptoReg system, any lab with a 4-channel FireSting O2 meter can set up four independently controlled systems for regulating water oxygen levels. This paper describes how to assemble the OptoReg system and presents a scientific data set demonstrating the stability of the OptoReg system during static acclimation experiments and dynamic temperature ramp trials.

A290 THE EFFECTS OF FRESHWATER SALT AND CO2 LEVELS ON ZEBRAFISH GROWTH Thursday 7th July 2022

POSTER SESSION

Will Davison, University of Exeter, Cosima Porteus, University of Toronto, Ella Waples, University of Exeter, Madeline Calvert, University of Exeter, Gregory Paul, University of Exeter, Rod W. Wilson, University of Exeter wd222@exeter.ac.uk Water chemistry varies greatly across zebrafish research facilities (sodium and chloride alone can vary by &gt;10,000-fold), with no guidelines available on many parameters important for healthy populations. Moreover, CO2 levels are not usually measured in aquarium facilities, yet CO2 is known to affect the acid-base physiology and behaviour of many fish species, including adult zebrafish. Here we aimed to determine what effect various freshwater salt concentrations

SCIENCE ACROSS BOUNDARIES ABSTRACTS 158

and CO2 levels have on zebrafish growth and development. Zebrafish embryos were exposed to three different total salt concentrations (0.0005, 0.08, and 2.0 ppt) combined with three different CO2 levels (400, 2000, or 4000 µatm) from the first day after fertilization and fed a mixed diet of dry food and live rotifers once hatched at day 4-5.

After 18 days zebrafish exposed to 2.0 ppt salt grew 2 times longer and had a 4 times larger body mass then fish exposed to the two lower salt levels. In a separate experiment, zebrafish larvae fed only dry food displayed no growth effect of these salt/CO2 treatments. CO2 had no significant effect in either experiment. The direct impact of salt/CO2 concentration on behaviour and survival of live feed (rotifers) was also quantified to determine whether this may be a contributing indirect factor in the observed effects of salt level on zebrafish growth. Future studies will determine the effect of different salt and CO2 levels on the immune response, growth and reproduction in zebrafish during early development and adulthood.

A293 METABOLIC AND ANTIOXIDANT MACHINERY STIMULATION BY RESVERATROL IN TILAPIA LIVER UNDER COLD STRESS Wednesday 6th July 2022

POSTER SESSION

Yu-Chun Wang, Fisheries Research Institute, Min-Chen Wang, Marine Research Station, Institute of Cellular and Organism Biology, Academia Sinica, Hui-Wen Peng, Marine Research Station, Institute of Cellular and Organism Biology, Academia Sinica, Yung-Che Tseng, Marine Research Station, Institute of Cellular and Organism Biology, Academia Sinica yctseng@gate.sinica.edu.tw Exposures to low ambient temperature require ectothermic fish to adjust their metabolic machinery and mount protective responses against oxidative stress. In this study, we tested whether diets supplemented with resveratrol (RSV), a naturally occurring polyphenol known to stimulate metabolic and protective responses in various animals, would benefit tilapia (Oreochromis mossambicus) under hypothermic challenge. Feeding tilapia with an RSV-supplemented diet promoted liver expression of sirtuins and their known targets, including metabolic/ antioxidative enzymes. After exposure to 15°C cold conditions for 3 days, the oxygen-nitrogen (O: N) ratio was decreased in controldiet-fed tilapia but not in RSV-fed counterparts. Moreover, at 27°C, RSV-fed tilapia showed significantly higher prolonged swim speed than controls. These findings suggest that RSV stimulates beneficial metabolic/antioxidative adjustments in teleosts and may serve as a valuable feed supplement for tropical fish exposed to cold stress during winter.

A294 THERMAL ACCLIMATION AFFECTS FITNESS COMPONENTS DIFFERENTLY IN GASTROPODS WITH DIFFERENT REPRODUCTIVE MODES Thursday 7th July 2022

POSTER SESSION

ANNUAL CONFERENCE MONTPELLIER 2022

Ahmed Abbas, University of Plymouth, John Spicer, University of Plymouth, Robert P. Ellis, University of Exeter, Manuela Truebano, University of Plymouth ahmed.abbas@plymouth.ac.uk Evaluating the acclimation capacity of marine organisms to increased water temperatures is essential to predict populations’ responses to ocean warming. While many studies have documented the acclimation capacity of marine ectotherms, fewer consider the fitness costs associated with this capacity. The potential tradeoffs between reproductive and somatic growth and/or survival, are likely to differ between species with different reproductive modes, thus reproductive investment. Here, we investigate the effects of thermal acclimation on some fitness traits in two congener gastropod species with different reproductive modes, the oviparous Littorina littorea and the ovoviviparous Littorina saxatilis. Scope for growth (SfG), survival, and reproductive output were measured under three acclimation temperatures representing current annual average temperature, summer extremes, and projected end-of-century summer temperatures. At the highest temperature tested, L. littorea had high survival associated with a series of physiological adjustments , but experienced a reduction in SfG, and suppression of reproduction. L. saxatilis showed similar physiological adjustments, but had dramatically reduced survival and SfG, while maintaining reproductive output. We suggest that under thermal stress, energy allocation differs between the two congeners. We discuss the costs of short-term thermal acclimation, and the potential trade-offs between reproduction and survival in species with different reproductive modes.

A297 POTENTIAL MARINE BENTHIC MACRO-INVERTEBRATES’ RESPONSES TO FLOODING: IN VITRO RESPONSES TO A COMBINATION OF FRESHWATER EXPOSURE, LOW PH AND HIGH TURBIDITY ON THREE INTERTIDAL MOLLUSKS Wednesday 6th July 2022

POSTER SESSION

Marie-Valentine Loiseau, Université du Québec à Rimousk loim0005@uqar.ca Potential marine benthic macro-invertebrates’ responses to flooding: in vitro responses to a combination of freshwater exposure, low pH and high turbidity on three intertidal mollusks In estuaries, flooding of natural or anthropogenic origin cause a sharp decrease in salinity and pH as well as an increase in turbidity that can be maintained for several days. Although salinity is the main biogeographical determinant in these ecosystems where it changes along a dynamic gradient, the responses of benthic intertidal communities to intense hypoosmotic stress may differ from those caused by daily and seasonal salinity variations that are typically studied. In addition, the response of these communities to several combined stressors encountered during floods (decreased salinity and pH, increased turbidity) has rarely been studied. Here, we aim to evaluate the relative sensitivity of three benthic macroinvertebrate species (Littorina saxatilis, Limecola balthica and Mytilus spp.) to conditions mimicking spring flooding. We measured the survival rate of organisms exposed to a gradient of periodic exposure (12 treatments,

SCIENCE ACROSS BOUNDARIES ABSTRACTS 159

characterized by a period of exposure lasting 0 to 9 days interspersed with 24 hours of exposure to marine salt water, over a continuous sixweeks cycle) in acidic and turbid freshwater (pH 5.7, 60 NTU), and in untreated freshwater (pH 7.7, 0 NTU). For the three species, the mortality was higher in the treatments in the acidic and turbid water, and in the treatments with the longest period of exposure. L. saxatilis showed the highest mortality rate, followed by L. balthica. Mytilus spp. showed almost no mortality. Longer and more frequent flooding might have an impact on estuaries invertebrate communities. Our study also highlights the importance of considering combined factors that are more representative of natural conditions.

A424 NEURONAL SIGNIFIERS OF SPIKE ARREST AS A GABA RESPONSE IN THE WESTERN PAINTED TURTLE (CHRYSEMYS PICTA) Thursday 7th July 2022

POSTER SESSION

Danielle Pyne, University of Toronto Leslie Buck, University of Toronto danielle.pyne@mail.utoronto.ca Neuronal signifiers of spike arrest as a GABA response in the western painted turtle (Chrysemys picta).

The Western Painted Turtle (Chrysemys picta) is one of the most hypoxia tolerant organisms currently being studied, as it is able to withstand up to five months of anoxic conditions when overwintering. The current processes by which this organism is able to survive for so long with such extreme oxygen deprivation are still being discovered. Previous research has found that the neurons within the cortex undergo spike arrest, a process that allows for the decrease of neuronal electrical excitability, as well as channel arrest, which reduces membrane ion permeability. This works to reduce ATP demand to match the decreased ATP production. Our research looks to determine at which critical oxygen tension (Pcrit) the cortex begins to undergo spike arrest, looking at alterations of neuronal dynamics including action potentials (APs), whole-cell conductance, and membrane currents. We are also looking to determine the Pcrit at which there is a release of GABA into the synapse, as we hypothesize this to be one of the first determinants of the hypoxic response in turtles. Our research has determined Pcrit to be 35Torr (SD = +/- 2.3), at which point there is a negative shift in wholecell conductance, depolarization of the resting membrane potential, and an increase in AP half-width.

CELL BIOLOGY ABSTRACTS

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C1 - EMERGING TECHNOLOGIES IN MICROSCOPY AND CELL BIOLOGY

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C39 EXPANSION MICROSCOPY FOR STRUCTURAL CELL BIOLOGY: FROM CENTRIOLE ARCHITECTURE TO HUMAN DISEASES Friday 8th July 2022

Paul Guichard, University of Geneva

ORGANISED BY: JOE MCKENNA (UNIVERSITY OF WARWICK), JAMES BANCROFT (UNIVERSITY OF OXFORD) C4 TRACING THE DEVELOPMENT OF THE EYE USING SPATIAL TRANSCRIPTOMICS Friday 8th July 2022

09:30am-10:00am

Christian Damsgaard, Aarhus University, Tobias Sandbæk, Aarhus University, Catherine J. Williams, Aarhus University, Michael Pedersen, Aarhus University, Torben H. Jensen, Aarhus University, Magnus Stougaard, Aarhus University, Joanna M. Kalucka, Aarhus University, Jens R. Nyengaard, Aarhus University christian.damsgaard@aias.au.dk Spatial transcriptomics is a new technology for capturing and mapping whole transcriptome gene expression on histological sections close to single-cell resolution. This technique allows researchers to gain insight into organs’ molecular morphology, as well as regional changes in gene expression during disease progression, development, and evolution. We apply this technique to the light-absorbing retina within the developing mouse eye. The mouse retina lacks internal blood vessels at birth but develops these structures over the first four weeks, which changes the diffusion dynamics for O2 and nutrients and affects the metabolic phenotypes of the retinal cells. Using spatial transcriptomics, we have generated spatial molecular atlases of the retina and extracted combined information on nutrient diffusion distances and whole transcriptome gene expression. With this technique, we can now provide a new quantitative understanding of the cellular responses to changes in O2 and nutrient availabilities during organ development.

C7 2D AND 3D OPTICAL MESOSCOPY WITH THE MESOLENS Friday 8th July 2022

09:00am-09:30am

Gail McConnel, University of Strathclyde, Glasgow g.mcconnell@strath.ac.uk Since the invention of the microscope, optics have been optimized to match the performance of the human eye. However, since the advent of sensitive and advanced photodetectors the human eye is no longer a limitation, and this has opened up new and exciting possibilities for imaging instrumentation and biological applications.

We have developed an objective with a magnification of 4x and a numerical aperture of just less than 0.5 which we call the Mesolens. The

paul.guichard@unige.ch

pupil size of the lens is so great that it cannot be used with a conventional microscope frame, so we have built the imaging system around the lens. Like the original optical microscope, we have found that the Mesolens has a wide range of applications in biomedical research.

We will present an overview of the Mesolens imaging technology and we will give current examples of its use as a confocal and widefield imaging instrument, but we will mainly report new imaging modes for the Mesolens including light-sheet imaging at the mesoscale and total internal fluorescence mesoscopy, and we will show how we are using these to reveal new biological information.

C8 CRYOSIM: THE TRIALS AND TRIBULATIONS OF CORRELATIVE SUPER RESOLUTION CRYO FLUORESCENCE IMAGING Friday 8th July 2022

11:00am-11:30am

10:00am-10:30am

Ian Dobbie, Johns Hopkins University Ian.dobbie@jhu.edu We have developed a super resolution cryo-fluorescence optical microscope in order to perform correlative imaging with the cryo Soft X-ray Tomography (SXT) beamline at the Diamond Light Source. Using Structured Illumination Microscopy (SIM) the microscope generates images at almost twice the achievable conventional optical resolution in 3 dimensions. By reducing the gap between the resolution in optical fluorescence images and the X-ray tomography significantly more information can be extracted from the correlated image sets. However, there are many barriers to reliably produce high quality fluorescence images of 3D samples in cryo while preserving the sample integrity.

The sample must be kept cold, condensation must be avoided on both the sample and the optics, sample position must be highly stable and light must be collected at as high a numerical aperture as possible. We have open source control software providing a simple interface with high speed control of the wide range of hardware involved as well as a high degree of flexibility to provide a range of experimental options.

Despite these challenges we have been able to reliably produce images with sub 200 nm resolution and achieve correlative alignment at sub 100 nm. The CryoSIM and cryoSXT instruments are available for open access via peer reviewed applications.

The centriole is an evolutionary conserved organelle that coordinates fundamental biological processes including cell division, cellular signalling and cell motility. This organelle, of 500 nm long and 250 nm in diameter is composed of about 100 different proteins, some of which have been associated with human diseases. How these proteins are organized at the level of the centriole architecture and how associated mutations could be involved in pathologies is still poorly understood. I will present the latest work from my laboratory, which tackle these fundamental structural cell biology questions using cryo-tomography, cell biology and our newly developed ultrastructure expansion microscopy (U-ExM) method.

C40 MECHANOBIOLOGICAL CONTROL OF T-CELL ACTIVATION Friday 8th July 2022

11:30am-12:00pm

Marco Fritzsche, University of Oxford marco.fritzsche@kennedy.ox.ac.uk New perspective of mechanobiology is currently emerging across multiple disciplines in the biomedical sciences. In contrast to conventional believes, recent evidence indicates that cells regulate their cell mechanics not downstream of signalling events triggered by ligand–receptor binding, but that cells employ a diversity of feedback mechanisms to dynamically adjust their mechanics in response to external stimuli. Quantifying cellular forces has therefore become an contentious challenge across multiple disciplines at the interface of biophysics, cell-biology, and immunology. Mechanical forces are especially important for the activation of immune T cells. Using a suite of advanced quantitative super-resolution imaging and force probing methodologies to analyse resting and activated T cells, we demonstrate activating T cells sequentially rearrange their nanoscale mechanobiology, creating a previously unreported ramifying actin network above the immunological synapse (IS). We show evidence that the kinetics of the antigen engaging the T-cell receptor controls the nanoscale actin organisation and mechanics of the IS. Using an engineered T-cell system expressing a specific T-cell receptor and stimulated by a range of antigens, force measurements revealed that the peak force experienced by the T- cell receptor during activation was independent of the kinetics of the stimulating antigen. Conversely, quantification of the actin retrograde flow velocity at the IS revealed a striking dependence on the antigen kinetics. Taken together, these findings suggest that the dynamics of the actin cytoskeleton actively adjusted to normalise the force experienced by the T-cell receptor in an antigen specific manner. Consequently, tuning actin dynamics in response to antigen kinetics may thus be a mechanism that allows T cells to adjust the length- and time- scale of T-cell receptor signalling.

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POSTER SESSION C5 AN INEXPENSIVE INCUBATOR FOR MAMMALIAN CELL CULTURE CAPABLE OF REGULATING O2, CO2, AND TEMPERATURE Wednesday 6th July 2022

POSTER SESSION

Christopher Moffatt, Brock University, Philip Samokhin, McMaster University, Georgina L. Gardner, Brock University, Jeffrey A. Stuart, Brock University cmoffatt2@brocku.ca Emerging research has highlighted the importance of maintaining physiological oxygen conditions in cell culture. The atmospheric O2 levels typically usually used in cell culture incubators are significantly higher than those experienced by most mammalian cells in vivo. This leaves cells vulnerable to oxidative damage, senescence, transformation, and otherwise aberrant physiology. One of the barriers to widespread adoption of O2 regulation into cell culture workflows has been the expense of new equipment, as most laboratory CO2 incubators do not regulate O2. Here we describe an inexpensive, portable and userfriendly O2/CO2 incubator that can establish and maintain physiological O2, CO2, and temperature levels. We used a customizable Arduinobased apparatus to add O2 and CO2 control to a temperature regulating egg incubator. To verify our incubator’s efficacy, we tested against a commercial laboratory O2/CO2 incubator. Using Presens-Oxodish technology we demonstrated that at a setpoint value of 5% gas-phase incubator O2, pericellular O2 averaged 5.03 (SD=0.03) with a range of 4.98-5.09%. Testing revealed no difference in the morphology, proliferation, or viability of MCF7, LNCaP, or C2C12 cell lines cultured in our incubator versus a commercial version. Taken together, our incubator provides an inexpensive means of maintaining physioxia in routine mammalian cell culture. We are currently modifying this system to use media, rather than headspace gas, O2 levels as the reference point. This will ensure cells in culture are experiencing the desired O2 tension throughout an experiment. Taken together, the tools we have developed will help cell culturists maintain physioxia in their experiments.

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C6 RAPID NUTRIENT DEPLETION BY CANCER CELLS CULTURED IN THE PHYSIOLOGIC MEDIUM PLASMAX Thursday 7th July 2022

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C2 - PLANT NUCLEAR AND CHROMATIN DYNAMICS – INDEPTH

POSTER SESSION

Georgina L. Gardner, Brock University, Fereshteh Moradi, Brock University, Christopher Moffat, Brock University, Meagan Cliche, Brock University, Bianca Garlisi, Brock University, John Gratton, Brock University, Fatima Mehmood, Brock University, Jeffrey A. Stuart, Brock University gg17ww@brocku.ca Mammalian cell culture is a fundamental tool used to study living cells.

Presently, the standard protocol for performing cell culture involves the use of commercial media that contain an excess of nutrients to prevent depletion during experiments. While this reduces the likelihood of cell starvation, it creates non-physiological culture conditions that have been shown to ‘re-wire’ cellular metabolism and broadly influence cell physiology. Recently, researchers have developed physiological media like Plasmax, formulated to approximate the nutrient composition of human blood plasma. Although this represents an improvement in cell culture practice, such physiologic media may be vulnerable to nutrient depletion over the course of an experiment extending over several days. In this study we directly addressed this concern by measuring the rates of glucose and amino acid depletion from Plasmax by several cancer cell lines (PC3, LNCaP, MCF-7 and SH-SY5Y) over 48 hours. In all cell lines, depletion of glucose from Plasmax was rapid such that, by 48h, cells were hypoglycemic (less than 2mM glucose).

Most amino acids were similarly rapidly depleted to sub-physiological levels by 48h. In contrast, glucose and most amino acids remained within the physiological range at 24h. Using RNA sequencing, we show that this nutrient depletion is associated with enrichment of cellular starvation responses, amino acid biosynthesis, apoptotic signalling, and endoplasmic reticulum stress response. Alterations in mitochondrial respiration using Seahorse extracellular flux analysis were also observed. Taken together, these results exemplify the metabolic considerations for Plasmax use, highlighting that cell culture in Plasmax requires daily media exchange.

ORGANISED BY: DAVID EVANS (OXFORD BROOKES UNIVERSITY), CHRISTOPHE TATOUT (UNIVERSITY OF CLERMONT AUVERGNE) CP7 THE UPS AND DOWNS OF BEING AN OUTDOOR PLANT Thursday 7th July 2022

15:35pm-16:05pm

Robyn Emmerson, University of Essex Tracy Lawson, University of Essex, Nicolae Radu Zabet, Queen Mary University of London, Ulrike Bechtold, Durham University re19493@essex.ac.uk Plants must cope with the highly dynamic nature of light to survive and thrive, a process referred to as acclimation. Although acclimation to different light intensities has been well studied, there has been little research into the effects of dynamic lighting regimes on this process.

Natural fluctuating light in field grown crops, can limit photosynthesis through slow stomatal opening in response to increasing light, whilst slow stomatal closure can erode water use efficiency (McAusland et al, 2016). It has been reported that both biochemical and stomata limitation on photosynthesis can lead to wheat yield losses of upto 21% (Taylor and Long, 2017).Previously dynamic growth light has been shown to effect the photosynthetic abilities of Arabidopsis thaliana, reducing maximum photosynthetic capacity and light absorption and altering light use efficiency along with changes in photoprotection (Vialet-Chabrand et al., 2017). To understand changes in gene expression resulting from acclimation to fluctuating light, Whole Genome Bisulfite Sequencing (WGBS) was utilised to examine changes in DNA methylation. Genome-wide changes were noted, with differentially methylated regions observed across a range of protein coding genes, transposable elements, and non-coding RNAs, as well as multiple regulatory sequences. RNAseq analysis demonstrated that some of these genes with changed methylation state impacted transcription, although many more changes in transcript levels were noted beyond the WGBS data. This could provide a new set of gene targets for improved photosynthetic efficiency and ultimately crop yield, which could be incorporated into on-going crop breeding programmes.

CP8 REGULATION OF NUCLEAR ORGANIZATION BY CHROMATIN REMODELING AND COHESIN-COMPLEX PROTEINS IN ARABIDOPSIS Thursday 7th July 2022

11:00am-11:30am

Daniel Schubert, Freie Universität Berlin, Claire Jourdain, Freie Universität Berlin, Kalyani Krishna, Freie Universität Berlin dan.schubert@fu-berlin.de Epigenetic regulation is essential to ensure the correct deployment and transcriptional stability of the genome at different stages of plant development. Polycomb-group (PcG) proteins mediate epigenetic gene regulation by depositing the H3K27me3 mark via Polycomb Repressive Complex 2 (PRC2). Proteins associated with the nuclear envelope play essential roles in chromatin organization and transcriptional repression, in addition to maintaining nuclear morphology, but their interaction with PcG-mediated gene regulation is largely unclear.

We have previously identified the PWO1 (PWWP INTERACTOR OF POLYCOMBS1) protein which links PcG proteins and the nuclear laminaassociated protein CRWN1 (CROWDED NUCLEI 1) and regulates nuclear size and stress-responsive genes. Using PWO1 as a bait we identified further highly conserved proteins of chromatin-remodelling- and cohesin-complexes. We reveal physical and genetic interactions of these proteins to regulate nuclear organization, Arabidopsis development and stress responses. We further present a dissection of the subnuclear localization of these proteins, their role in regulating specific nuclear compartments and their interaction with specific histone modifications.

Altogether, this work presents a framework linking diverse chromatin regulating proteins to regulate nuclear organisation in Arabidopsis .

P8 MATHEMATICAL MODELLING OF THE CELL CYCLE AND CELL SIZE CONTROL IN PLANTS Friday 8th July 2022

10:15am-10:30am

Daniel Williamson, University of Nottingham d.e.williamson94@gmail.com Populations of cells must maintain a fairly consistent size, as excessively large or small cells will be non-viable. However, cell division is not necessarily symmetrical, generally leading to the formation of daughter cells of unequal volume. Cells must therefore possess a mechanism of “size control,” by which variation in cell volume at birth may be evened out across the cell cycle. While the basis of size control has been studied in other organisms, such as yeast, it is not yet clear how this mechanism functions in plants.

It is our view that, while progress through the cell cycle is regulated by a network of many interacting proteins, there exists a handful of key “sizer” proteins which control cell cycle progression and provide

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an internal scale against which cell size may be measured. Depending upon their rates of synthesis, these proteins may accumulate over time, or be diluted as the cell grows. Activators of cell cycle progression accumulate, while inhibitors are diluted, until a critical point is reached and there is a change of cell phase.

This talk will consider the mathematical modelling of the cell cycle in Arabidopsis thaliana. In particular, it will focus on the use of differential equations to study size control as an emergent property of a network of interacting proteins.

CP9 GBPL3 IS A NOVEL PLANT NUCLEOPORIN THAT RECRUITS RNA PROCESSING AND TRANSCRIPTION MACHINERY AT THE NUCLEAR BASKET BY PROMOTING CONDENSATES FORMATION Thursday 7th July 2022

15:05pm-15:35pm

Yangnan Gu, University of California, Berkeley, Yu Tang, University of California, Berkeley guyangnan@berkeley.edu The basket of nuclear pore complex (NPC) is an assembly of flexible protein filaments and acts as a dynamic scaffold at the nucleoplasmic side that regulates various essential cellular processes, including nuclear transport, RNA processing, chromatin organization, and gene expression. However, the mechanisms behind the regulation are still poorly understood, especially in plants. Here, we identified a guanylatebinding protein (GBP)-like GTPase (GBPL3) as a specific component of the NPC basket in Arabidopsis. GBPL3 is located at the nuclear rim and confers robust physical and genetic interactions with various NPC and nucleoskeleton constituents. Proximity labeling proteomics experiment suggests that GBPL3 is predominantly distributed at the NPC basket and that it is intimately associated with chromatin remodelers, transcription regulators, and RNA processing machinery. Importantly, we found that GBPL3 promotes the formation of biomolecular condensates at the NPC basket, which is capable of recruiting its interactors. Loss of GBPL3 led to severely stunted plant growth, aberrant transcription of abiotic and biotic stress-related genes, and retention of total mRNA in the nucleus. These results suggest that GBPL3 is a plant-specific NPC basket component and can recruit transcription and RNA processing machinery through condensate formation to modulate gene expression and subsequent RNA processing, which is required for plant growth and stress responses.

C14 THE DYNAMICS OF CHROMATIN CHANGES DURING BARLEY SEED DEVELOPMENT Friday 8th July 2022

11:45am-12:15pm

Ales Pecinka, Institute of Experimental Botany, Czech Academy of Sciences pecinka@ueb.cas.cz Cereal grains are among the most important sources of energy for humans and domestic animals, owing to large and nutritious endosperm tissues. We study nuclear organization and chromatin

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in seeds of cereals using cultivated barley (Hordeum vulgare subsp. vulgare) - a diploid temperate zone model cereal used for both food and feed. Barley has a large genome (2n = 2x = 14, 1C = 5.1 Gbp) with interphase chromosomes organized in Rabl configuration with centromeres and telomeres clustering at opposite nuclear poles. Though considered to be typical for large cereal genomes, observations of Rabl configuration are based mostly on nuclei from meristematic tissues.

We explored interphase chromosome organization in different tissues of developing barley grains and will show that Rabl chromosome organization is not a general rule in barley and it diminishes with the increasing nuclear DNA content and seed age. Furthermore, we performed transcriptome profiling of different barley grain tissues that allowed determining roles of different biological processes and also chromatin regulatory pathways during this critical stage of development. In summary, all these facets of our barley chromatin research create a fruitful environment for future functional analyses of nuclear organization and epigenetic regulation of gene expression in this agriculturally important species.

C20 LINKER HISTONE DYNAMICS AT THE ONSET OF PLANT GERMLINE INITIATION Thursday 7th July 2022

16:50pm-17:20pm

Célia Baroux, University of Zürich Yanru Li, University of Zürich, Danli Fei, University of Zürich, Jasmin Schubert, University of Zürich cbaroux@botinst.uzh.ch Germline separation from the soma is key to sexual reproduction in multicellular organisms. This process occurs at drastically different times during development in animals and plants. While the germline is set aside during embryogenesis in animals, plant precursors differentiate de novo during the adult phase, in floral organs. Despite these very distinct developmental strategies, we found a remarkable conservation of large-scale chromatin reprogramming in plant spore mother cells (SMC) (She et al., Development 140, 2013) and animal primordial germ cells (PGC) (Hajkova et al., Nature 452, 2008). One striking similarity is the eviction of somatic linker histones that precedes a breadth of changes in chromatin structure and composition in SMC. In a quest for potential post-translational modifications regulating H1 eviction, we found evidence for a citrullination-ubiquitination module to operate specifically in the SMC. Furthermore, and interestingly, premeiotic eviction of H1 seems to serve post-meiotic fate and to control gametophytic competence. This suggests an essential role for H1 eviction in SMC to unlock pluripotency in the plant reproductive lineage.

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C23 PNET2 IS A COMPONENT OF THE PLANT NUCLEAR LAMINA AND IS REQUIRED FOR PROPER GENOME ORGANIZATION AND ACTIVITY Friday 8th July 2022

09:00am-09:30am

Yu Tang, University of California, Berkeley, Yangnan Gu, University of California, Berkeley

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non-MNase assays such as ATAC-seq. Motif analysis of 145,000 maize earshoot MFs led to the detection of 215 sequence motif families, which were merged into non-overlapping regions numbering just above 100,000 loci and covering just below 0.1% of the maize genome.

We also used MOA-seq to examine genomic response to hypoxia in human cells. From these initial studies, we conclude that MOA-seq is ideal for genome-wide identification of cistrome occupancy at high resolution using a single antibody-free assay. The technology adds a valuable method to the genomic toolkit for pinpointing cis-regulatory candidates in agriculture and medicine.

yutang@berkeley.edu The interaction between chromatin and the nuclear lamina (NL) is intrinsically important to the establishment of three-dimensional chromatin architecture and spatiotemporal regulation of gene expression. However, critical regulators involved in this process are poorly understood in plants. Here, we report that Arabidopsis PNET2 and its two homologs are bona fide inner nuclear membrane proteins and integral components of the NL. PNET2s physically interact with the plant nucleoskeleton and engage nucleosome-enriched chromatin at the nuclear periphery. Loss of all three PNET2s leads to severely disrupted growth and development, concomitant activation of abiotic and biotic stress responses, and ultimate lethality in Arabidopsis.

The pnet2 triple mutant also displays drastic transcriptome changes accompanied by a globally altered chromatin architecture revealed by HiC analysis. Our study identified PNET2 as an inner nuclear membrane (INM) component of the NL, which associates with chromatin and plays a critical role in orchestrating gene expression and chromatin organization in plants.

C24 MNASE-BASED MOA-SEQ PINPOINTS NATIVE CISTROME OCCUPANCY AT 30BP RESOLUTION AMID ACCESSIBLE CHROMATIN Thursday 7th July 2022

09:00am-09:30am

Hank W. Bass, Florida State University, Thomas Hartwig, Max Planck Institute, Savannah D. Savadel, Florida State University, Shivansh Singh, Florida State University, Mark N. Gillespie, University of South Alabama, Jonathan H. Dennis, Florida State University hbass@fsu.edu Elucidating transcriptional regulatory networks requires knowledge of transcription factor (TF) binding sites and their occupancy, ideally in a native chromatin context. Towards this goal, we have adapted the use of micrococcal nuclease (MNase) as a biochemical probe of fixed chromatin structure with emphasis on small DNA fragments from sub-nucleosome-sized particles. Specifically, we developed MNase-defined cistrome-Occupancy Analysis (MOA-seq) to achieve high-resolution genome-wide detection of TF-bound sites within accessible chromatin regions, illustrated with a proof of concept study on field-grown maize ear shoots (Savadel, Hartwig, et al., 2021; PLOS Genetics). Fragment center plotting focused the footprint detection down to small particles with an average peak size of ~30bp. These MOA footprints (MFs) exhibited (1) expression-correlated associations with gene promoters, (2) enrichment at known TF-binding sites, (3) enrichment at known long-range chromatin interaction sites, and (4) enrichment at known open chromatin regions defined by other

C25 EXPLORING THE FUNCTION OF COMPONENTS OF THE NUCLEAR PORE COMPLEX DURING MEIOSIS: SAR1 (NUP160) AND SAR3 (NUP96) Thursday 7th July 2022

09:45am-10:15am

Mónica Pradillo, Universidad Complutense de Madrid Nadia Fernández-Jiménez, Universidad Complutense de Madrid, Félix Gil-Donés, Universidad Complutense de Madrid pradillo@bio.ucm.es Nuclear Pore Complexes (NPCs) are large macromolecular assemblies embedded into the nuclear envelope (NE). They are involved in the selective nucleocytoplasmic transport of macromolecules, chromatin organization, and DNA repair. NPCs are organized into sub-complexes composed of repetitions of about 30 highly conserved nucleoporins (NUPs). The NUP107–160 complex (also known as Y complex) is located in the outer ring and is conserved between distantly related eukaryotes such as yeast and mammals. Here, we are going to focus on two Arabidopsis mutants deficient for this sub-complex: Atnup160 and Atnup96, also known as suppressor of auxin resistance1 (sar1) and sar3, respectively. NUP160 and NUP96 are critical for the nucleocytoplasmic transport of mRNAs and play important functions in auxin signalling, plant growth and flowering time regulation, as well as in immune defence and cold stress tolerance. In the context of our global study about the possible role of NPCs during meiosis (the specialised cell division that leads to gamete formation), we decided to explore the potential function of NUP160 and NUP96 during this cell division because the corresponding mutants show reduced fertility. The results of our study have demonstrated that meiosis is altered in a percentage of the meiocytes from these mutants, which would explain the reduction in the number of seeds. Our observations have revealed that the alteration of the Y complex causes problems in meiotic recombination, the formation of meiotic structures (such as the synaptonemal complex), and viability of the meiocytes. The possible origins of these problems will be discussed.

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C26 ANCHOR: A TECHNICAL APPROACH TO MONITOR SINGLE-COPY LOCUS LOCALIZATION IN PLANTA... AND MUCH MORE Thursday 7th July 2022

11:45am-12:15pm

Frédéric Pontvianne, CNRS, Laboratoire Génome et Développement des Plantes (LGDP), Université de Perpignan Via Domitia frederic.pontvianne@univ-perp.fr Together with local chromatin structure, gene accessibility, and the presence of transcription factors, gene positioning is implicated in gene expression regulation. Although the basic mechanisms are expected to be conserved in eukaryotes, less is known about the role of gene positioning in plant cells, mainly due to the lack of a highly resolutive approach. I will present the ANCHOR system that allows real-time single locus detection in planta. ANCHOR is a DNA-labeling tool derived from the chromosome partitioning system found in many bacterial species.

This approach is suitable to monitor a single locus in planta and we use this approach to track chromatin mobility during cell differentiation in Arabidopsis thaliana root epidermal cells. I will also discuss how this technique can help us investigate key biological questions about gene expression, but also transposable elements life cycle.

C27 SEGMENTATION OF 3D PLANT NUCLEI USING DEEP LEARNING – A GUIDE FOR BIOLOGIST USERS Thursday 7th July 2022

09:45am-10:15am

Guillaume Mougeot, Université Clermont Auvergne guillaume.mougeot@tuta.io When working on the cell nucleus, biologists often use microscopy images, usually 3D. They are then sometimes interested in extracting quantitative information characterizing their set of nuclei, such as the volume or surface area of each nucleus. The recent evolution of microscopy techniques now allows them to quickly capture thousands of nuclei and then need to automate these measurements. A preliminary step is required: to segment the image, which consists in locating the regions of the image (group of pixels) containing the nuclei. This step is difficult to automate and is the core of many recent publications in the booming sector of deep learning (part of artificial intelligence).

Despite the profusion of such methods, their performance promises are often not fulfilled. Our work consists in, first, alerting the biologists regarding accessibility problems and then, guiding those who would like to use a deep learning method to segment their 3D images. We expose some of the main criteria required for a method to properly be made available and we show that only a small set follows these minima. We then present 6 deep learning methods for 3D nucleus segmentation. We evaluate them with handmade segmentations of 3D plant nuclei and list their pros and cons. Finally, we present our recent deep learning method that can segment both plant nuclei and chromocenters.

SCIENCE ACROSS BOUNDARIES ABSTRACTS 168

P57 GLOBAL INCREASE OF THE NUCLEAR TRANSCRIPTIONAL REGIME DURING ARABIDOPSIS PHOTOMORPHOGENESIS: A CHROMATIN PERSPECTIVE Thursday 7th July 2022

14:20pm-14:50pm

Fredy Barneche, IBENS, CNRS, Clara Bourbousse, IBENS, CNRS UMR 8197, Geoffrey Schivre, IBENS, CNRS UMR 8197 , Lorenzo Concia, IBENS, CNRS UMR 8197, Gianluca Teano, IBENS, CNRS UMR 8197, Stefan Grob, Zurich-Basel Plant Science Center, University of Zurich, Alessandra Carbone, Sorbonne Université, CNRS, IBPS, UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), Célia Baroux, Zurich-Basel Plant Science Center, University of Zurich barneche@biologie.ens.fr Seedling de-etiolation involves massive change in genome expression, many light-responsive genes undergoing pioneering rounds of transcription within minutes. In previous studies we reported that Arabidopsis photomorphogenesis indeed associates with a ~3-fold increase of global RNA Polymerase II elongation activity in most cotyledon nuclei (1), which, together with more recent studies (2), suggests that light induces a switch from a relatively quiescent to a more active transcriptional status during the transition. Studies from others and us focusing on nuclear and chromatin dynamics also unveiled that de-etiolation involves genome-wide variations nuclear architecture and in chromatin hallmarks of transcription elongation status at thousands' protein-coding genes (1, 3-4), which are controlled by DET1 and other light signaling components (3). Yet, because of data normalization practices, the functional consequences of these multilevel adaptations of the chromatin status to an elevated transcriptional regime are not observed when analyzing transcriptomic profiles obtained with classical microarray or RNA-seq analyses.

We therefore developed a new methodological setup enabling an absolute quantification of RNA-seq data to explore the functional impact of transcription intensification on gene expression. We will present how this approach can be used to assess to which extent, and for which genes, a global increase of RNA Pol 2 activity is reflected at the transcript level during photomorphogenesis. This new standpoint should help revisiting how signaling paths and chromatin machineries modulate plant genome expression in response to the environment.

References: 1 Bourbousse et al, PNAS (2015) 112(21) e2836-44 2 Godoy Herz, et al. Mol Cell (2019) PMID: 30661982 3 Nassrallah, Rougee et al, eLife (2018) e37892 4 Charron et al, Plant Cell (2009) 21:3732-48

ANNUAL CONFERENCE MONTPELLIER 2022

P58 THERE IS MORE THAN ONE WAY TO FORM A HOLOCENTROMERE – LESSONS FROM THE LILIOID CHIONOGRAPHIS JAPONICA AND OTHER PLANTS Friday 8th July 2022

11:00am-11:30am

Andreas Houben, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Yi-Tsu Kuo, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, André Marques, Max Planck Institute for Plant Breeding Research houben@ipk-gatersleben.de The centromere is the region on a chromosome where the kinetochore assembles and spindle microtubules attach. In addition to monocentric chromosomes, species with holocentromeres exist with a centromere distribution along the entire chromatids. As holocentricity has arisen multiple times during evolution, a striking question is whether the organization and dynamics of centromeres differs in species having independently evolved holocentromeres. To address this question we compared the holocentromeres of the lilioid Chinongraphis japonica, the rush Luzula elegans and sedge Rhynchospora pubera. Striking differences were found in the organization and dynamics of their holocentromeres. Thus, different types of holocentromeres exist. In addition, comparative analysis of holocentric C. japonica and their closest monocentric relative, Camalerium luteum demonstrate that transition to holocentricity affected the genome architecture by amplification of centromeric satellite DNA and distributing centromere function to heterochromatic megabase-sized CENH3-positive satellite arrays.

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that it is the free dsDNA ends that serve as the substrate for random integration. Here I report that capped structures containing a GFP reporter gene have been successfully transformed into plant cells via Agrobacterium and GFP expression detected on confocal microscopy.

This demonstrates that these structures get into the plant cell nucleus and do not hinder enzymatic access to the gene, an important milestone in developing this technology. To test the nanostructure’s ability to improve GT efficiencies and reduce off target effects, an assay was established to measure GT rates with or without nanostructures. GT events have been successfully visualised by GFP expression in plant cells using confocal microscopy and flow cytometry. Next steps are to assay the rates of random integration using the nanostructure caps via qPCR-based assays and to design, build and test the next generation of DNA nanostructures for prevention of random integration using DNA origami nanotechnology as a transgene delivery vehicle. Overall, this project brings together two exciting technologies to address the need for continued improvement in GT frequencies and preventing random integration. This will facilitate the improvement of plant genome engineering tools that can deliver vital improvements to crops required to bring sustainable agriculture into the 21st Century.

C21 MODULATING MEIOTIC RECOMBINATION IN BREAD WHEAT BY APPLYING DNA DAMAGING AGENTS Wednesday 6th July 2022

POSTER SESSION

Francesco Blasio, Universidad Complutense de Madrid, Mónica Pradillo, Universidad Complutense de Madrid, Bianca Martín, Universidad Complutense de Madrid franblas@ucm.es

POSTER SESSION P7 GM PLANTS 2.0: CAN DNA NANOTECHNOLOGY ENHANCE PLANT GENOME ENGINEERING? Wednesday 6th July 2022

POSTER SESSION

Rosalind Latham, University of Leeds bsrml@leeds.ac.uk Gene targeting (GT) is a method of precise genome engineering that can facilitate crop improvements that are central to meeting growing global food demands. Yet GT frequencies are very low in higher plants, mainly due to the low frequency of homologous recombination (HR) upon which GT relies, hindering realisation of the technology’s potential. Despite advancements, routine GT frequencies remain ~ <1% and random integration of donor DNA and GT machinery causes problematic off-target effects; therefore, further improvements in GT frequency and accuracy are required. Here, a novel approach to address these problems is described, based on the application of DNA nanotechnology to GT in plants. In this approach random integration of the GT template will be prevented by concealing the free dsDNA ends of the repair template with nanostructure ‘caps’, as we propose

Reciprocal exchanges of genetic information between homologous chromosomes (known as crossovers, COs) are critical to the success of meiosis, the specialised cell division that leads to the production of gametes. CO formation in plants is an extremely controlled process, which imposes a number of limitations for plant breeding since agronomical important traits cannot be separated from undesirable features. COs form at a low frequency, concentrate in distal euchromatic regions, and are suppressed at and near the centromeres in most plant species. Since COs are dependent on the formation of DNA doublestrand breaks (DSBs), we wondered whether the patterning of COs could be modified by artificially increasing the number of DSBs in bread wheat. Bread wheat (2n=6x=42, AABBDD) is an allohexaploid that behaves as a diploid during meiosis. COs are restricted to homologous chromosomes despite the presence of homoeologues in the nucleus.

Here, we present our results on analysing the consequences of applying two DSB-inducing agents at different concentrations into bread wheat meiocytes. We have treated spikes from three different genotypes: the common wheat landrace Chinese Spring, a line carrying a mutation at the Ph1 (Pairing Homologus 1) locus which exhibits high levels of homoeologous COs, and a wheat-rye disomic addition line in which a pair of rye chromosomes has been added to the full complement of wheat. We will discuss the consequences of the extra production of DSBs on the formation of COs in these different genetic backgrounds.

ANNUAL CONFERENCE MONTPELLIER 2022

C22 A PREDICTED PROTEIN–PROTEIN INTERACTION (PPI) NETWORK AT THE ARABIDOPSIS THALIANA NUCLEAR PERIPHERY Thursday 7th July 2022

POSTER SESSION

Christophe Tatout, Université Clermont Auvergne christophe.tatout@uca.fr Protein-protein interactions (PPI) are at the heart of molecular processes in all living organisms. We are studying protein networks specifically localized at the periphery of the nucleus of the model plant Arabidopsis thaliana (1), in particular interactions occurring between the Nuclear Pore Basket and the nucleoskeleton that involved KAKU4, CRWNs, NUP136 proteins (2). PPIs prediction have been performed using a Recurent Convolutional Neural Network (RCNN) called ProteinProtein Interaction Prediction (PIPR) (3). The model was trained with multi-species PPI datasets and with a specific Arabidopsis dataset that we have gathered from publications, PPI databases and unpublished data. This new predicted interactome of Arabidopsis nuclear periphery will be illustrated through a PPI network constructed with Cytoscape.

The new network will be centered on our three candidate proteins to predict the most robust potential partners to be validated in wet lab experiments. The predicted interactome should enable us to identify new PPIs and improve our knowledge of the Plant nuclear periphery.

References: 1. A. Poulet, A. V. Probst, K. Graumann, C. Tatout, D. Evans, Nucleus. 19, 1–14 (2016).

2. S. Mermet et al., BioXriv, (2021) doi:10.1101/2021.03.20.435662.

3. M. Chen et al., Bioinformatics. 35, i305–i314 (2019).

P22 GENOTYPIC VARIATION IN HEAT TOLERANCE IN AUS RICE DURING THE FLOWERING STAGE Thursday 7th July 2022

POSTER SESSION

Dalal Alonazy, University of Aberdeen, Adam H. Price, University of Aberdeen, Gareth Norton, University of Aberdeen, Martin Barker, University of Aberdeen d.alonazy.20@abdn.ac.uk Rice (Oryza sativa L.) is one of the important cereal grains and a staple food for more than 50% of the world’s population. Increases in global temperatures have a negative impact on crop productivity.

Plants undergo a variety of physiological and biochemical changes as a result of temperature stress in order to adapt to higher temperatures.

In this study, we have used 204 accessions from the Bengal and Assam Aus Panel (BAAP). A total of eight replicate plant per accession were grown. All plants were grown in the greenhouse until maturity; thereafter, five replicate plants were randomly selected, their panicles at anthesis stage marked and were transferred to large growth room at 38°C for 24 hours to assess high-temperature treatments. Three replicates plants were not heat treated. Fertility was assessed as the proportion of flowers filled. Heat treatment significantly (P&lt;0.0001) reduced fertility by 17.4% on average and there was a significant (P&lt;0.0001) differences among accessions. In addition to that, there was a significant (P&lt;0.001) interaction between accession and treatment. Heat tolerant cultivars have been identified including

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the aus reference cultivar DJ123. Genome Wide Association Studies (GWAS) using 2 million SNPs will be used to identify QTLs and candidate genes associated with heat tolerance in the BAAP.

P35 GENOME-WIDE ASSOCIATION MAPPING AND TRANSCRIPTOMIC STUDIES REVEAL CANDIDATE GENES FOR NITROGEN USE EFFICIENCY IN AUS RICE Wednesday 6th July 2022

POSTER SESSION

Yehia Hazzazi, University of Aberdeen, Adam Price, University of Aberdeen, Gareth Norton, University of Aberdeen r01yh19@abdn.ac.uk In many countries, rice feeds over 50% of the population. Between 2013 and 2050, global rice demand will increase by 85%. Large-scale nitrogen (N) applications in rice fields have increased yields. However, only 40% of the applied N goes to rice crops, leaving the rest to cause environmental issues like increased greenhouse gas production and eutrophication of water bodies. Therefore, increasing the rice plants' nitrogen use efficiency (NUE) is required. In this context, we conducted a greenhouse experiment on 230 six-week-old rice genotype accessions from the Bengal and Assam Aus Panel to assess plant height, tiller number, nitrogen balance index (NBI), and shoot biomass related to NUE of rice under 0% and 100% N application (recommended dose of N application). The 100% nitrogen application resulted in increases in all the traits, and all were under strong genetic control. Tiller number, nitrogen balance index, and shoot biomass displayed a high genotype by treatment interaction. Genome-wide association studies (GWAS) revealed some potential candidate genes for example, OsI-BAK1 and OsNAC42 for relative plant height, CDK D-1 and CycU3;1 for relative tiller number, OsRGB1 and KNOX for NBI, and OsIDHc;2 and OsNAR2.1 for shoot biomass. In addition, ongoing RNA-seq analyses of N-responsive and N-unresponsive accessions aims to validate genes found in the GWAS will be reported. The study will be helpful to understand the genetic variation for NUE in rice cultivars and candidate genes with potential to improve NUE in rice.

Keywords: Nitrogen, rice, nitrogen use efficiency, GWAS, NBI, RNA-seq.

P36 CHARACTERISTICS AND FITNESS ANALYSIS OF INTERSPECIFIC HYBRIDIZATION BETWEEN BRASSICA RAPA L. SSP. AND TRANSGENIC BRASSICA NAPUS Thursday 7th July 2022

POSTER SESSION

Soo In Sohn, Rural Development Administration sisohn88@gmail.com Interspecific hybridization between transgenic crops and their relatives is a major concern for transgene dispersal in the environment. In order to assess the hybridization potential and the fitness of interspecific hybrids between Brassica rapa and genetically modified (GM) Brassica napus under controlled environment, artificial hand pollination experiments

ANNUAL CONFERENCE MONTPELLIER 2022

were performed. Initially six subspecies of B. rapa were hybridized with GM B. napus through hand pollination. Among the different combinations, the F1 hybrids with B. rapa ssp. rapa (♀) (F1 selfing) was found to be effective in producing viable future generations with highest crossability index (1.6±0.69) than other subspecies.

Consequently, they were used for the generation of F2 and F3 progenies.

The 18 different morphological characteristics among the parental cross combinations and F1 hybrid progenies were measured and visualized through hierarchical clustering. Different generations were found to grouped based on their different morphological characteristics. The chromosome numbers among the interspecific hybrids were ranged from 2n=29 to 2n=40. Assessment of relative fitness can prove the rational for the chromosome number variations in the interspecific hybrids. Further the SSR markers, revealed the presence of genomic portions in the hybrids in comparison with their parental lines. The study, concluded that the interspecific hybrids between B. napus to B. rapa can be viable and actively hybridizing up to F3 generations and more. Suggesting that GM B. napus can disperse transgene into B. rapa through interspecific hybridization and that can pass through for several generations.

P56 THE ROLE OF SPT AS A MEDIATOR OF CLV1 AND GCN5 INTERACTION IN GYNOECIUM DEVELOPMENT IN ARABIDOPSIS Thursday 7th July 2022

POSTER SESSION

Konstantinos Vlachonasios, Aristotle University of Thessaloniki, Stylianos Poulios, Aristotle University of Thessaloniki kvlachon@bio.auth.gr The Arabidopsis gynoecium is a complex structure composed of different tissues. Development is regulated by hormone interactions, especially auxin and cytokinin, as well as the spatiotemporal action of transcription factors and chromatin dynamics, including epigenetic modifications of core histones. SPT is bHLH transcription factor involved in gynoecium development, specifically affecting both auxin and cytokinin responses. GCN5 is a histone acetyltransferase with pleiotropic biological roles including auxin and cytokinin responses in the gynoecium. CLV1 is a receptor kinase, part of the CLAVATA signaling pathway which suppresses the expression of WUS in apical and floral meristems. Previous work has shown that clv1gcn5 double mutants exhibit a plethora of phenotypes including fasciated meristems and abnormal flowers with increased number of stamen and elongated gynoecia with enlarged apical regions and reduced ovaries. In the double mutants, the stem-cell-promoting transcription factor WUS is ectopically overexpressed in the gynoecia. To elucidate genetic interactions between SPT, CLV1 and GCN5 we created all genetic combination between spt, clv1 and gcn5 mutants. We show here that spt mutations largely suppress the phenotypes of clv1gcn5 gynoecia.

The enlarged stigma and style and ovary formation are restored in sptclv1gcn5 plants compared to clv1gcn5 plants. The spt mutation also reverses the WUS ectopic overexpression in clv1gcn5 gynoecia.

Interestingly spt gynoecia have also reduced WUS expression compared to wild type. These results suggest that SPT mediates the CLV1-GCN5 synergistic interaction during gynoecium development, potentially acting as a positive regulator of WUS expression in the gynoecium.

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C4 - SYSTEMS APPROACHES TO CELLULAR DECISION-MAKING

ANNUAL CONFERENCE MONTPELLIER 2022

C31 MODELLING GA TRANSPORT WITHIN THE ARABIDOPSIS ROOT Thursday 7th July 2022

14:50pm-15:05pm

, Kristian Kiradjiev, University of Nottingham, Jenia Binenbaum, Tel Aviv University, Nikolai Wulff, University of Copenhagen, Hussam H. Nour-Eldin, University of Copenhagen, Eilon Shani, Tel Aviv University, Leah Band, University of Nottingham

ORGANISED BY: GEORGE BASSEL (UNIVERSITY OF WARWICK), LEAH BAND (UNIVERSITY OF NOTTINGHAM)

kristian.kiradjiev@nottingham.ac.uk

AC2 PROBLEM SOLVING IN ACELLULAR SLIME MOLDS Thursday 7th July 2022

11:00am-11:30am

Audrey Dussutour, CNRS audrey.dussutour@univ-tlse3.fr Decision making have hitherto been investigated almost exclusively in multicellular neural organisms. Yet, evidence for decision making have been described in single celled organisms such as acellular slime molds. In the last 20 years, slime molds have become a model system, with multiple experiments seeking to reproduce behavioural predictions from neuroscience, animal behaviour and psychology In this talk, I will focus on decision making in slime molds and explore various frameworks: nutritional geometry, speed versus accuracy trade-off, magnitude-sensitive reaction times, Weber's law and social influence. Hopefully by the end of my talk, you will be convinced that slime molds are an ideal model system in which to investigate fundamental mechanisms underlying the ground-floor of decision making abilities.

we hypothesized that SUMOylation suppresses wounding-induced regulator(s) and searched for early acting players underlying the stressinduced cellular reprogramming. By analyzing the transcriptome of wounded plants, we found that HEAT SHOCK FACTOR A1s (HSFA1s) are activated after wounding. Mutant and overexpression analysis showed that HSFA1s, also known to be activated by heat stress, promote shoot regeneration in Arabidopsis. Furthermore, the regulation of HSFA1s appeared independent of transcription and biochemical analysis revealed that they are subject to SUMOylation in response to stress.

Here, I will discuss how key stress-induced transcription factors regulate cellular reprograming and how SUMOylation modulates this regenerative response in plants.

C30 MORPHOGENETIC DETERMINANTS OF MMC FORMATION IN ARABIDOPSIS Thursday 7th July 2022

09:30am-09:45am

Inès Ouedraogo, Institut de Recherche pour le Développement (IRD) ines.ouedraogo@ird.fr

CP10 THE ROLE OF SUMOYLATION DURING SHOOT REGENERATION IN ARABIDOPSIS Thursday 7th July 2022

15:20pm-15:35pm

Duncan Coleman, RIKEN Center for Sustainable Resource Science, Yokohama, Akira Iwase, RIKEN CSRS, Yokohama, Ayako Kawamura, RIKEN CSRS, Yokohama, Momoko Ikeuchi, Niigata University, David Favero, RIKEN CSRS, Yokohama, Alice Lambolez, University of Tokyo, Takamasa Suzuki, Chubu University, Keiko Sugimoto, RIKEN CSRS, Yokohama and University of Tokyo duncan.coleman@riken.jp During in vitro tissue culture, plants form callus and regenerate organs by reprogramming developmental pathways. In addition to hormonal signals, stress-induced cues, such as those from wounding, can trigger and promote cellular reprogramming. Conjugation of the small ubiquitin-related modifier (SUMO) to target transcriptional regulators is thought to rapidly and precisely modulate their activity in response to stress. We previously investigated if SUMOylation is involved in wound-induced reprogramming and showed that loss of the E3 ligase SIZ1 causes a hyper-active wound response and enhances shoot regeneration (Coleman et al, 2020). Based on these observations,

The plant hormone gibberellin (GA) is involved in many developmental processes, however, how GA is distributed within plant tissues is not yet understood. In this talk, we present a multi-cellular mathematical model for GA transport within the Arabidopsis root. We consider both passive and facilitated modes of transport through the symplast and the apoplast. In particular, we model the effects of the NPF cytoplasm importers, localised in different layers of the root. In addition, we consider the effect of a vacuole as a possible storage mechanism for GA within each cell and model the role of transport across the tonoplast. We assume an effective GA source coming from the stele and constant degradation rate of GA within the whole root. We also present results on the values of the various transporter permeabilities, estimated from a model and oocyte experimental data. We discuss the governing equations and show numerical results predicting the spatial and temporal distribution of GA. Our results provide insights into the role of the vacuole in regulating the amount of GA in the cell, and how this contributes to GA distributions and cellular decision making.

In angiosperms, female meiosis takes place in a single cell per ovule, the MMC (Megaspore Mother Cell, or female Spore Mother Cell). The MMC is formed in apical sub-epidermal position in the ovule, as an enlarged anisotropic cell. Recent data generated by our groups suggest that MMC identity in Arabidopsis is determined by the geometrical and mechanical parameters of the ovule. Moreover, developmental plasticity exists within ovule primordia: several candidate MMCs initiate differentiation, then a gradual fate restriction occurs to form a single MMC where meiosis will occur. The penetrance and timing of this process depends on the genetic background. However, neither the precise developmental trajectory of candidate MMCs nor their coordination with ovule tissue growth are resolved in 3D. To address this, we exploit 4D imaging data (time lapse) focusing on early primordia, and 3D static images reporting on candidate markers of MMC identity. We developed a semi-automatic workflow combining image segmentation, cell annotation and cell tracking during development. We undertake a quantitative analysis of cellular parameters, over time, such as cell division, cell growth, cell shape and cell contacts, to identify features best characterizing and discriminating candidate MMCs from their neighbors, and their gradual fate restriction during primordia growth.

Overall, our goal is to improve our understanding of the geometry and organ topology patterns predictive of the plasticity of MMC formation at ovule emergence.

C32 MODELLING REVEALS POSTTRANSCRIPTIONAL REGULATION OF GA METABOLISM ENZYMES IN RESPONSE TO DROUGHT AND COLD Thursday 7th July 2022

15:05pm-15:20pm

Leah Band, University of Nottingham, Hilde Nelissen, Center for Plant Systems Biology, VIB, Simon Preston, University of Nottingham, Hamada Abd Elgawad, University of Antwerp, Bart Rymen, KU Leuven Plant Institute, Gerrit Beemster, University of Antwerp leah.band@nottingham.ac.uk The hormone gibberellin (GA) controls plant growth and regulates growth responses to environmental stress. In roots and monocotyledonous leaves, GA controls growth by regulating the size of the division zone - regulating the cell's decision to cease division and begin rapid elongation. We used a systems approach to investigate the establishment of the GA distribution in the maize leaf growth zone to understand how drought and cold alter leaf growth. By developing and parameterizing a multiscale computational model that includes cell movement, growth-induced dilution and metabolic activities, we revealed that the GA distribution is predominantly determined by variations in GA metabolism. Considering wild-type and UBI::GA20OX-1 leaves, the model predicted the peak in GA concentration, which has been shown to determine division-zone size. Drought and cold modified enzyme transcript levels, although the model revealed that this did not explain the observed GA distributions. Instead, the

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model predicted that GA distributions are also mediated by posttranscriptional modifications increasing the activity of GA20oxidase in drought and of GA2oxidase in cold, which we confirmed by enzyme activity measurements. This work provides a new, mechanistic understanding of the GA metabolism in plant growth regulation.

C33 INFORMATION PROCESSING IN PLANT ORGANS Thursday 7th July 2022

11:30am-11:45am

George Bassel, University of Warwick gbassel@gmail.com Extensive efforts have revealed genetic programs plants use to control their development in response to the environment. Much less is known about how the output of these programs is impacted by the multicellular context they operate within. In order to better understand how collections of cells in plants process information, we are taking a computational perspective of development and examining parallels between these naturally evolved biological organisms and engineered computational systems. More specifically, whether the control principles of distributed computation apply to plants. In an effort to address this, we are viewing plant organs as integrated systems of interacting cells, and mapping intercellular connectivity into networks. This provides a quantitative approach to understanding cellular patterning, while mapping the multicellular “circuitry” plants use to perform computation. By integrating these topological templates with mathematical models describing the genetic programs that operate within individual cells, the impact of each cell organization and communication on developmental outputs is being examined. This is providing insight into the extent to which development is controlled beyond intracellular genetic mechanisms.

C34 GENE-FREE LANDSCAPE MODELS FOR DEVELOPMENT Thursday 7th July 2022

11:45am-12:15pm

Meritxell Saez Cornellana, IQS, Universitat Ramon Llull meritxell.saez@iqs.url.edu Fate decisions in developing tissues involve cells transitioning between a set of discrete cell states. Geometric models, often referred to as Waddington landscapes, are an appealing way to describe differentiation dynamics and developmental decisions. We consider the differentiation of neural and mesodermal cells from pluripotent mouse embryonic stem cells exposed to different combinations and durations of signalling factors. We developed a principled statistical approach using flow cytometry data to quantify differentiating cell states. Then, using a framework based on Catastrophe Theory and approximate Bayesian computation, we constructed the corresponding dynamical landscape. The result was a quantitative model that accurately predicted the proportions of neural and mesodermal cells differentiating in response to specific signalling regimes. Taken together, the approach we describe is broadly applicable for the quantitative analysis of differentiation dynamics and for determining the logic of developmental cell fate decisions.

ANNUAL CONFERENCE MONTPELLIER 2022

C35 FLUX AND POLARITY IN THE OTHER VASCULAR SYSTEM Thursday 7th July 2022

phase boundaries, and that the adaptation of cell size to changing conditions appears to be an emergent property of the overall system of cell cycle control.

09:00am-09:30am

Christian S. Hardtke, University of Lausanne christian.hardtke@unil.ch Higher animals and plants are two evolutionary outcomes of complex multicellularity. An important driver of cellular specialization and body plan expansion in both phyla was the evolution of vascular distribution networks. Most prominently, the cardiovascular network of mammals distributes oxygen and nutrients throughout the body, driven by the pumping action of the heart. By comparison, the vascular transport systems of the dominant group of higher plants, the angiosperms, are fundamentally different. For instance, transport of photosynthates in the phloem network is governed by dynamic source-sink relations and driven by a pressure differential that builds up through locally controlled cellular osmolarity. The conducting phloem channels are the so-called sieve tubes, which not only transport nutrients but also developmental signals such as the phytohormone auxin. Sieve tubes are formed from interconnected individual sieve elements that are meticulously aligned in cell files as they develop. Sieve elements represent a cellular between-life-and-death state, because they lack numerous organelles, including the nucleus, and are nurtured by their neighboring, so-called companion cells. The peculiar sieve element differentiation process can be observed in growth apices. For example, in the root meristem of Arabidopsis thaliana seedlings their development from stem cell into mature sieve element is laid out in a spatiotemporal gradient. My lab has characterized a molecular network that guides this differentiation process through the interplay between controlled transcellular auxin transport across developing sieve element cell files and autocrine receptor kinase signaling pathways that respond to small peptide ligands. Key players in this network constitute a molecular rheostat that finetunes transcellular auxin flux and maintains its pronounced cellular polarity through a self-reinforcing mechanism. Our research suggests that this module is intimately connected to the evolution of phloem, which enabled plants to effectively colonize land and thereby had a major impact on the extant biosphere.

C36 DECISIONS, DECISIONS, DECISIONS: CELL DIVISION AND CELL SIZE CONTROL IN ARABIDOPSIS Thursday 7th July 2022

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16:50pm-17:20pm

Jim Murray, Cardiff University MurrayJA1@cardiff.ac.uk Plants grow continuously throughout their life cycle. Plant cells within meristems- the actively growing regions at the tips of shoots and roots- undergo repeated division cycles to provide the cells needed for growth. Division must be coordinated with cell growth because cells within a meristem maintain their average size when conditions are constant. However in response to changes in environmental conditions or in different genotype backgrounds, cell size is reset to a new average. Using combined modeling and imaging approaches, we have been studying the relationship between cell size control and cell cycle progression and we find evidence for two cell size control points within the Arabidopsis cell cycle at both the G1/S phase and G2/M

C37 DECIPHERING THE SUMO CODE FOR ADAPTIVE RESPONSES IN ROOTS Thursday 7th July 2022

15:35pm-15:50pm

ANNUAL CONFERENCE MONTPELLIER 2022

to relative positional information. A major challenge is to accurately capture the multicellular 3 dimensional (3D) microenvironment. To further study systemic behavior of these stem cells within a defined microenvironment, we established the framework of 3D bioprinting with plant cells to study cell viability, cell division, and cell identity.

Within our designed microenvironment, the deposited Arabidopsis and soybean cells re-entered the cell cycle, which led to the formation of microcalli. Furthermore, we showed that the identity of isolated cells of Arabidopsis roots expressing endodermal markers maintained longer periods of time. We believe that the 3D bioprinting framework paves the way for a general use of 3D bioprinting for studying the rules governing developmental decisions.

Ari Sadanandom, Durham University ari.sadanandom@durham.ac.uk SUMO conjugation is emerging as an important mechanism to transduce environmental cues into cellular signaling. We present evidence to show that SUMOylation of key transcriptional regulators such as DELLA and BZR1, provides a conduit for environmental influence of root growth and development during salt stress. SUMOylation stabilizes BZR1 in the nucleus by inhibiting its interaction with BIN2 kinase. During salt stress, Arabidopsis plants arrest growth through deSUMOylation of BZR1 in the cytoplasm by promoting the accumulation of the BZR1 targeting SUMO protease, ULP1a. ULP1a mutants are salt tolerant and insensitive to the BR inhibitor, brassinazole with regards to root growth.

BR treatment stimulates ULP1a degradation, allowing SUMOylated BZR1 to accumulate and promote growth. This study uncovers a mechanism for integrating environmental cues into BR signaling to shape root growth.

Intriguingly an interacting partner of BZR1, the growth repressing DELLA proteins are also SUMOylated. We demonstrate that a proportion of DELLAs are conjugated to SUMO, the extent of conjugation increases during salt stress. We identify a SUMO interacting motif (SIM) in the GA receptor GID1 and demonstrate that SUMO-conjugated DELLA binds to this motif in a GA-independent manner. The consequent sequestration of GID1 by SUMO-conjugated DELLAs leads to an accumulation of non-SUMOylated DELLAs resulting in repression of root growth in salinity. We present a model depicting how SUMO decodes environmental cues to shape root growth and development.

P42 COORDINATED REGULATION OF GENE EXPRESSION AMONG STEM CELLS Thursday 7th July 2022

14:20pm-14:50pm

Ross Sozzani, NC State University ross_sozzani@ncsu.edu Capturing the rules governing developmental decisions in multicellular organisms is key to study cellular functions, including reprogramming of cell differentiation and function. To understand how different genes coordinately regulate developmental decisions towards cell function, we used a multi-scale hybrid model integrating ordinary differential equations (ODEs) and agent-based modeling. This model allowed us to gain a deeper understanding in the coordinate function of key developmental genes, including WUSCHEL-RELATED HOMEOBOX 5 (WOX5) and SHORTROOT (SHR), to regulate stem cell divisions. We predicted cell-type-specific expression dynamics of SHR, SCARECROW, WOX5, AN3 and CYCLIND6;1, and showed an interdependency between CEI and QC divisions. At present, we know these stem cell populations divide, differentiate and display functions in response

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POSTER SESSION C29 3D QUANTITATIVE ANALYSIS OF OVULE PRIMORDIUM ARCHITECTURE AND FEMALE GERM CELLS PRECURSORS FORMATION IN MAIZE Wednesday 6th July 2022

P59 CONVERGENCE OF HORMONAL SIGNALLING DURING RADIAL GROWTH OF ARABIDOPSIS ROOT Thursday 7th July 2022

09:45am-10:15am

Ari Pekka Mähönen, University of Helsinki AriPekka.Mahonen@helsinki.fi Vascular cambium provides radial growth in plants. This lateral meristem produces secondary xylem inwards and secondary phloem outwards.

Our earlier studies revealed that both xylem and phloem originate from a single bifacial stem cell. Next to to stem cells, xylem identity is defined by an auxin maximum, and consequential expression of HD-ZIP III transcription factors. Clonal activation of high auxin signalling in phloem parenchyma led to differentiation of the clone as xylem vessel.

Cells adjacent to clone obtained cambium stem cell identity. Based on these studies, we proposed that cells with auxin maximum define an organizer, which positions stem cells in the adjacent cells. During my presentation, I will explain how a few other cambial factors connect to the regulatory network defining the stem cell organizer. Previous studies have shown that Gibberellic acid (GA) promote secondary xylem production in vascular cambium. By combining molecular genetics and confocal imaging, we discovered that GA promotes polar auxin transport along the root. Subsequently, auxin signalling levels increase and broaden in cambium. This broadened auxin maximum forces larger number of cells in cambium to differentiate as xylem, thus explaining the enhanced xylem production after GA treatment.

Additionally, I will explain how peptide gradient originating from the phloem converge with the auxin signalling to position the stem cells.

Together, our studies reveal how various hormonal pathways converge in cambium to position the stem cells and regulate their differentiation into xylem and phloem.

POSTER SESSION

Daphné Autran, IRD, Research Unit DIADE, CIRAD, IRD, University of Montpellier, Inès Ouedraogo, IRD - French Institute for Sustainable Development. Geneviève Conéjéro, Research Unit IPSIM, CNRS, INRAE, Institut Agro, University of Montpellier, Matthieu Dejean, Research Unit AGAP Institute, CIRAD, INRAE, Institut Agro, University of Montpellier, Marc Lartaud, Research Unit AGAP Institute, CIRAD, INRAE, Institut Agro, University of Montpellier, JeanLuc Verdeil, Research Unit AGAP Institute, CIRAD, INRAE, Institut Agro, University of Montpellier, Luciana Delgado, IICAR, CONICET, University of Rosario daphne.autran@ird.fr In higher plants, the formation of female gametes is a crucial step in the plant reproductive cycle and determines seed formation, hence participating in crop yields. The plant female germline initiates in the ovule primordium, with the specification of the MMC, the Megaspore Mother Cell, the only cell which will undergo meiosis to produce gametes. However, reproductive cell fate in the early ovule appears flexible. Genetic variants and apomictic species show that somatic cells neighboring the MMC can enter the MMC identity program or even directly produce female gametophytes without meiosis.

Moreover, this developmental plasticity is at least partially controlled by ovule tissue growth, as shown recently in Arabidopsis. However, we don’t know if such model is conserved in grasses ovules, and could be part of the mechanisms explaining the shift from sexual to apomictic reproductive mode in these species. To set up a framework to study ovule morphogenesis and MMC formation in grasses, in 3D and at cellular level, we use maize as a sexual plant model and multiphoton microscopy to monitor step by step ovule primordium development. Such 3D quantitative atlas allows to correlate organ level morphogenetic changes with a first precise cellular description of gradual MMC formation, and will be further used as a reference to explore reproductive fate plasticity in aposporous ovules.

PLANT BIOLOGY ABSTRACTS

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P3 - ACCESS AND BENEFIT SHARING RIGHTS AND DIGITAL SEQUENCE INFORMATION: BUILDING AWARENESS FOR PLANT SCIENTIST ORGANISED BY: ISABEL MENDOZA POUDEREUX (UNIVERSITY OF VALENCIA), JANE ANDERSON (NEW YORK UNIVERSITY & ENGELBERG CENTRE FOR INNOVATION LAW AND POLICY), KC BANSAL (NATIONAL ACADEMY OF AGRICULTURAL SCIENCE P1 PLANT AND ANIMAL GENOMICS RESEARCH FOR AND WITH INDIGENOUS COMMUNITIES: A EUROPEAN SCIENTIST’S PERSPECTIVE Tuesday 5th July 2022

16:00pm-16:30pm

David Chagne, The New Zealand Institute for Plant & Food Research Ltd, david.chagne@plantandfood.co.nz Genomics provide researchers with solutions to better predict the phenotypic characteristics, economic value and adaptive potential of species, and improves our understanding of the diversity present in wild populations. I will reflect on our work to develop high-quality genome assemblies and associated analyses for plant and animal species of importance to New Zealand (Aotearoa), including species that are considered as treasures (taonga) by indigenous Māori people. Specifically, I will present my perspectives and experiences as a European biologist who works in a government-owned research institution, alongside Māori communities, academics and commercial enterprises, to reflect on my journey to achieve positive impact and shared benefits with Māori using genomics research.

P63 EXAMINING GLOBAL PATTERNS OF DSI SHARING AND USE TO INFORM POLICY Tuesday 5th July 2022

14:00pm-14:30pm

Andrew Hufton, Leibniz DSMZ andrew.hufton@dsmz.de New access & benefit sharing regulations for digital sequence information (DSI) could have a dramatic impact on DSI-based research for decades to come. Many researchers are concerned that the complex

reality of global DSI research is not being fully accounted for in ongoing policy discussions. Using a data-driven approach and open data sources, we have been studying how DSI is generated and used around the world, revealing findings that challenge common policy narratives. In partnership with a network of international scientists, and informed by these findings, we are working to give the scientific community a greater voice in policy discussions. In my talk, I will outline some of the findings that have been made as part of the ongoing WiLDSI project (https://www.dsmz.de/collection/nagoya-protocol/digital-sequenceinformation), and explain why we feel scientists need multilateral policy solutions that preserve openness, promote biodiversity research, and create meaningful benefit sharing. I will also share initial data from new work underway exploring plant DSI and the use of DSI in public patent documents.

P64 NAGOYA PROTOCOL AND ACCESS TO GENETIC RESOURCES Tuesday 5th July 2022

14:30pm-15:00pm

Brad Sherman, The University of Queensland b.sherman@law.uq.edu.au Recent changes to the legal frameworks regulating genetic resources – including the expanding reach of ABS under the Nagoya Protocol, and the growing number of non-State institutions developing their own ABS schemes – are having a negative impact on the collection, transfer, and use of genetic resources. The talk argues that while these are challenging issues that the stakes are too high not to attempt to find a solution, and that there is potential for researcher driven solutions to the legal uncertainty created by the Nagoya Protocol.

ANNUAL CONFERENCE MONTPELLIER 2022

P65 INTRODUCING THE TRADITIONAL KNOWLEDGE AND BIOCULTURAL LABELS AND NOTICES: SUPPORTING ACCESS AND BENEFIT SHARING PATHWAYS WITHIN DATA INFRASTRUCTURES Tuesday 5th July 2022

15:00pm-15:30pm

Jane Anderson, New York University & Engelberg Centre for Innovation Law and Policy, ja77@nyu.edu Concerns over Indigenous Data Sovereignty and Indigenous rights under the Nagoya Protocol underpin the development and application of Traditional Knowledge and Biocultural Labels/Notices. The Local Contexts system which delivers the Labels and Notices, is focused on implementing Indigenous provenance, protocols, and permissions into digital infrastructures. The Labels and Notices are designed to provide a persistent and durable connection between collaborating Indigenous communities and researchers, research projects, genetic resources, Digital Sequence Information (DSI), and associated traditional knowledge, that exist as metadata in sample/data repositories. The Biocultural Labels support Nagoya Protocol expectations around the disclosure and origins of genetic resources (i.e., Provenance Label) and help to define and communicate Indigenous community expectations and consent about appropriate and future use of genetic resources and derived benefits. Importantly BC Labels may only be applied by an Indigenous community, and they are both human readable and machine readable. The Notices are a distinct tool for researchers who can use this mechanism to disclose Indigenous rights and interests.

This presentation will introduce the Labels and Notices and explore the responsibilities that universities and researchers have to practically implement mechanisms that enable transparency around Indigenous rights and interests in support of Indigenous Data Sovereignty.

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P4 - INCLUSIVE NUTRITION FOR A SUSTAINABLE AGRICULTURE

ANNUAL CONFERENCE MONTPELLIER 2022

P71 PHOSPHATE-SENSING SPX PROTEINS CONTROL ARBUSCULE LIFETIME IN MEDICAGO Wednesday 6th July 2022

09:30am-10:00am

Erik Limpens, Wageningen University & Research

ORGANISED BY: BENOIT LACOMBE (INSTITUT DES SCIENCES DES PLANTES DE MONTPELLIER), HATEM ROUACHED (MICHIGAN STATE UNIVERSITY) P66 REGULATORY NETWORK BEHIND SYSTEMIC NITROGEN SIGNALING IN ARABIDOPSIS Tuesday 5th July 2022

09:00am-09:30am

Sandrine Ruffel, INRAE sandrine.ruffel@inrae.fr Rapid adjustment of plant physiology and development to external fluctuations is critical for sessile organism, giving a singular interest to network signaling controlling these mechanisms. Among many adaptation processes, root plasticity is primordial to optimize nutrient acquisition but relies on a complex network integrating local and systemic signaling. Indeed, locally, plants invest resource in soil area where nutrients are available and systemically they adjust nutrient acquisition to the whole plant demand.

Our main goal is to decipher systemic signaling underlying the perception of nitrate heterogeneous provision, in Arabidopsis. Using the split-root system, in which physically isolated root systems of the same plant were challenged with different environments, we previously demonstrated that cytokinin biosynthesis constitutes one critical component of root-shoot-root communication. By combining the use of cytokinin mutants with hormone measurements, transcriptomic analysis, nitrate uptake assays, and root growth measurements, we show that root to shoot trans-zeatin (tZ) translocation is likely crucial for long distance signaling controlling rapid sentinel gene regulation and long-term functional acclimation to heterogeneous nitrate supply. Interestingly, shoot transcriptome profiling revealed that glutamate/glutamine metabolism is likely a target of tZ root-toshoot translocation, prompting us to revisit the hypothesis of the role of amino acids into systemic nitrogen signaling.

P68 UNRAVELLING THE ROLE OF NITRATE IN THE SIGNALING PATHWAYS CONTROLLING SYMBIOTIC N-FIXATION ACTIVITY IN LEGUME NODULES Tuesday 5th July 2022

10:00am-10:30am

Maurizio Chiurazzi, IBBR-CNR, Vladimir Totev Valkov, IBBR-CNR maurizio.chiurazzi@ibbr.cnr.it Nitrogen-fixing nodules are new organs formed on legume roots as a result of the beneficial interaction with the soil bacteria, rhizobia.

Nodule functioning requires high amounts of carbon and energy, and therefore legumes have developed finely tuned mechanisms to cope with changing external environmental conditions. The investigation of the role of nitrate as regulator of the N2-fixation activity in the symbiotic nodules has been mainly limited to the inhibitory effects exerted by high external concentrations of this nutrient on nodule formation, development and functioning. We describe here a nitratedependent pathway acting at low external concentrations that become crucial in hypoxia conditions to ensure an efficient nodule functionality.

The reported phenotypic characterizations of knock out mutants of Lotus japonicus NITRATE-PEPTIDE-TRANSPORTER-FAMILY (NPF) and NRT2 members indicate a combined action of these transporters in the control of a nitrate route toward the invaded cells of the nodules to support the energetic status required for an efficient N2-fixation.

P69 CHLOROPLASTIC RETROGRADE SIGNALING PATHWAY TO ADAPT PHOTOSYNTHESIS TO NUTRIENT AVAILABILITY Tuesday 5th July 2022

10:30am-11:00am

Hatem Rouached, Michigan State University rouached@msu.edu Plants rely on a constant supply of macro- and micronutrients to perform photosynthesis. For example, iron is an important micronutrient for photosynthesis, which is supported by longstanding observations that link iron deficiency and chlorosis. However, in the late 1970s, DeKock et al. (1979) reported the development of chlorotic leaves under high-phosphorus conditions despite replete iron levels, challenging the causal connection between iron concentration and chlorosis.

More recently, we showed that iron-induced chlorosis in monocots is phosphorus-dependent, in which plants grown under combined iron and phosphorus deficiency display an intriguing “stay green” phenotype. These observations highlight a gap in our understanding of the interdependent effects of nutrient availability on photosynthesis regulation, and raise the question: how do plants integrate nutrient cues to control photosynthesis? Our results show that iron-induced chlorosis is phosphorus-dependent in both monocots and eudicots. By combining genome-wide gene expression changes and genome-wide association studies (GWAS) with molecular physiology in Arabidopsis thaliana, we identified and validated a signaling pathway involved in the regulation of photosynthesis under combined iron and phosphorus stresses. This newly identified mechanism includes genes coding for chloroplastic (PHT4

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It demonstrated to be very efficient in phenotyping several, large, genetically segregating Arabidopsis populations and diversity panels, under different growth conditions. The observed genotypic variation was used to identify quantitative trait loci (QTL) for ΦPSII, reflecting genetic variation residing on the nuclear genome. In addition, we have investigated the effect of variation residing on the chloroplast genome of A. thaliana, through analysis of so-called cybrids, or cytoplasmic swaps, which carry new combinations of nuclear and cytoplasmic genomes, not found in nature.

erik.limpens@wur.nl Arbuscules are considered to be the main structures where nutrient exchange between plants and arbuscular mycorrrhizal (AM) fungi takes place inside root cortex cells. These structures are relatively short lived and can be controlled by the plant in a nutrient-dependent manner. If the fungus does not deliver sufficient nutrients, such as phosphate (Pi), the arbuscules are prematurely degraded. To get insight into how the plant can monitor how much phosphate it gets from the fungus in the arbuscule-containing cells we focussed on SPX proteins as key phosphate sensors in plants. We identified two SPX proteins in Medicago truncatula, SPX1 and SPX3, that are induced upon Pi starvation but who’s expression becomes restricted to arbusculecontaining cells upon the establishment of the symbiosis. SPX1 and SPX3 negatively regulate the plants phosphate starvation response and under Pi-limiting conditions, facilitate the production of strigolactones to increase fungal branching and initial root colonization. Later, in arbuscule-containing cells, SPX1 and SPX3 redundantly control arbuscule degradation. Knock-out of both SPX1 and SPX3 increased the life-time of arbuscules, while overexpression caused their premature degradation. This regulation of arbuscule life-time does not involve the PHOSPHATE STARVATION RESPONSE regulator PHR2, which interacts with SPX1 and SPX3 in a phosphate dependent manner. Interaction studies suggest that SPX1/3 may control the activity of aquaporins.

P72 ARABIDOPSIS THALIANA AS MODEL TO STUDY HOW TO IMPROVE PLANT PRODUCTION Wednesday 6th July 2022

10:00am-10:30am

Mark Aarts, Wageningen University & Research, Thu-Phuong Nguyen, Wageningen University & Research, Tom Theeuwen, Wageningen University & Research, Roel van Bezouw, Wageningen University & Research, Louise Logie, Wageningen University & Research, René Boesten, Wageningen University & Research, Jeremy Harbinson, Wageningen University & Research mark.aarts@wur.nl The ability to perform photosynthesis is a major driver of plant evolution.

Despite a very long history of selection for optimal photosynthesis, evolution is still ongoing, as evidenced by the genetic variation for photosynthesis efficiency that can be observed when comparing different plant species or different genotypes of the same species.

Such variation may be selected for to improve crop photosynthesis and, potentially, to improve crop yield. We have explored the opportunities to characterize the genetic variation for photosynthesis efficiency in the model species Arabidopsis thaliana. One of the challenges in investigating such genetic variation is the ability to adequately phenotype photosynthesis parameters. For this purpose, we developed and used the Phenovator, a phenotyping platform for high-throughput imaging of light use efficiency of photosystem II electron transport (ΦPSII or Fq’/Fm’) through chlorophyll fluorescence measurements.

P73 A SYSTEMS VIEW OF NITROGEN SIGNALING INTERACTIONS Wednesday 6th July 2022

10:30am-11:00am

Gabriel Krouk, CNRS gkrouk@gmail.com Plants need to adapt to a myriad of combined signals coming from i) their environment and ii) their own metabolism1. Gene Regulatory Networks (GRNs) leading to these adaptations and signal integration are the central point of our research. Here, I will show that by focusing on Nitrate (NO3-) regulated transcription factors (TFs) and their genome wide activity, using a technique called TARGET (Transient Assay Reporting Genome wide Effect of Transcription factors2), we were able to identify several important signaling cross-talks between NO3-, Phosphate (PO43-) 3,7 and Reactive Oxygen Species (ROS) pathways4. These studies open perspectives at the same time on i) applied biotechnology [since we discovered genotypes with an enhanced NO3- transport activity] 4, as well as on ii) basic understanding of large GRN function, dynamics5,6, emerging properties, and topology in plants6. These recent works will be presented and discussed as well as a new kind of GWAS we have been “cooking" for a long time 8.

References: 1. Krouk Plant Mol Biol 2016.

2. Bargmann et al. Mol Plant 2013.

3. Medici, et al . Nature communications 2015.

4. Safi, et al. JEB, 2021.

5. Para et al. PNAS 2014. 111:10371-10376 6. Carre, Mas & Krouk NPJ systems biol. and applications 2017.

7 Medici, Szponarski et al. Plant Cell 2019 8 Carre, Carluer, et al. in preparation

SOCIETY FOR EXPERIMENTAL BIOLOGY