SPOTLIGHT ON LISANDRA MARI

SPOTLIGHT ON... LISANDRINA MARI

BY ALEX EVANS

‘I’ve always been driven to keep learning, from new lab skills and model organisms, to different cultures.’ Having already worked on a diverse range of animal systems, Lisandrina Mari’s early career certainly illustrates this principle. She told Caroline Wood about her journey so far.

Above Lisandrina Mari holding a Green Woodpecker Photo credit: Michal Šulc G rowing up in rural Corsica, Lisandrina admits that her early childhood wasn’t necessarily conducive for a research career. ‘I come from a modest background, with my father being a construction worker, and my mum an assistant accountant. Further studies weren’t really on anyone’s radar in my community’ she says. Nevertheless, being ‘immersed in nature, surrounded by mountains and the sea’ inspired a lifelong fascination with the living world, which led to her studying a Bachelor’s degree in Physiology and Cell Biology at the Université de Corse Pascal Paoli. This was followed by a Masters in Marine Biology at the Université Côte d’Azur in Nice (France) investigating the population effects of seawater temperature changes on fish communities.

In 2015, Lisandrina continued this theme by taking up a PhD at the Alpine Center for Research on Limnic Ecosystems, (France) in Dr Emilien Lasne’s research team. This time, she focused on the effects of climate change for the Arctic Char (Salvelinus alpinus), a cold-water specialist. ‘In Europe, the southernmost edge of the Arctic Char’s distribution is restricted to high alpine lakes where the species remained following the glacier retreat after the last glaciation’ says Lisandrina. ‘As these habitats are particularly vulnerable to warming, these isolated populations can be considered as sentinels of climate change.’

Having travelled little prior to her PhD, Lisandrina has happy memories of the many field trips to remote alpine lakes in France, Switzerland and Germany to catch fish during the spawning season. Back in the lab, she investigated how changes in water temperature interacted with other stressors such as the presence of fine sediment (which affects oxygen availability and habitat quality). ‘Our key finding was that elevated temperatures and fine sediment in the water have synergistic effects on developing Arctic Char embryos. Levels of sediment that had no effect at 5 °C significantly impact development and survival at 8.5 °C’. 1

For her first postdoctoral position, Lisandrina moved again: to the Institute of Vertebrate Biology at the Czech Academy of Sciences, to join Professor Martin Reichard’s lab. Although she says this was ‘on a whim’, it’s clear that the opportunity to broaden her skillset was a key appeal. ‘The institute works on an incredibly diverse range of taxa: bats, birds, fish, even great apes. The project was also an opportunity to develop my skills in bioinformatics. In the era of “Big Data”, it is becoming increasingly important to have strong analytical skills.’

As if relocating to a new country and culture wasn’t enough of a challenge, soon after Lisandrina arrived in February 2020, the world was plunged into the first COVID-19 lockdown. ‘The pandemic certainly made it difficult to settle in. But I was lucky to be sharing a flat with three other postgraduate researchers, who understood how difficult it was to not be able to go into the lab or travel to conferences, and to feel like our careers were being held back.’ Fortunately, the Czech Republic was affected relatively lightly by the initial COVID-19 wave, and Lisandrina was soon able to immerse herself in her project.

Still working on fish, this time Lisandrina’s subject was the curious dual-parasitic relationship between Bitterling Fish (Rhodeus amarus) and unionid Mussels. ‘Bitterling lay their eggs in the gills of the mussels and, in turn, mussels require fish as a host for their parasitic larvae. However, a recently invasive mussel, Sinanodonta woodiana, is able to reject bitterling larvae but still parasitize the fish’ Lisandrina explains. ‘For my project, I was investigating what factors could help fish resist a parasitic infection. Our results indicated that genes linked to adaptive immunity were not involved, but instead, behavioural strategies might be more important. For instance, some fish could detect areas in which mussel larvae were present in high densities and avoid swimming there to minimize their infection risk.’

But even members of the same species can parasitize each other, as Lisandrina investigated for her next project as part of Professor Tomáš Albrecht’s Avian Evolutionary Ecology group. This time, her subject was the Barn Swallow (Hirundo rustica), a species where females often attempt to offload their parenting duties by laying their eggs in the nest of another female. That is, unless the potential victim recognises the intruder eggs and ejects them. ‘Our research

question was: what cues do the parent birds use to discriminate between their own eggs and those of a would-be parasite?’

To investigate this, the group mounted miniCCTV cameras by the nests of barn swallows on two farms, then infiltrated these with objects of varying shapes and colour patterns. ‘We found that swallows were much more likely to eject odd-shaped objects, whereas colour and pattern had only a minor influence on ejection decisions’ she says. ‘This indicates that swallows possess an innate template for the shape of their eggs. We believe that egg-ejection behaviour may have evolved as a by-product of nest cleaning activities, which requires the ability to recognise non-egg shaped objects in the first place’.2

Next summer, it will be all change again when Lisandrina takes up a two-year Marie Curie -Skłodowska Fellowship hosted by the University of Jyväskylä (Finland), to investigate novel biomarkers of pollution in avian models. ‘It’s a very interesting project to me because it involves a well-studied captive system, the Japanese Quail (Coturnix japonica), but also field studies on a wild forest species, the Great Tit (Parus major). Specifically, I will be looking into whether exposure to heavy metals results in epigenetic changes that are passed on from males to their offspring.’ that women support each other. You don’t have to be an activist, but being prepared to speak up for one another is a crucial first step.’ Lisandrina’s HIGH ALPINE own efforts to help break cultural stereotypes include hosting Skype a Scientist sessions LAKES ARE PARTICULARLY with secondary school children in the USA 3 – an initiative she would encourage all researchers to try. ‘It feels good to challenge their perception VULNERABLE TO WARMING, about what a researcher looks like – they don’t usually expect a 20-something woman.’ Despite enjoying the variety of her work, Lisandrina is open-minded about where her career will take her next. ‘At the moment I am trying to persevere SO THEIR ISOLATED FISH POPULATIONS CAN BE in academia, but I am aware how tough the competition always is for research funding. So whilst I would love to lead my own research group CONSIDERED AS SENTINELS one day, I am open to possibilities whether in industry, conservation, or elsewhere.’

OF CLIMATE CHANGE. For now at least, it appears that Lisandrina has found her niche. When asked what her younger self would have thought of her career now, the answer comes immediately: ‘I would be superexcited to think that I would be paid to study animals all day long. Isn’t that what every ten year old dreams of doing?’

OUR RESEARCH QUESTION WAS: WHAT CUES DO THE PARENT BIRDS USE TO DISCRIMINATE BETWEEN THEIR OWN EGGS AND THOSE OF A WOULD-BE PARASITE?

Having moved so many times, Lisandrina is acutely aware of the importance of a supportive network – especially as a woman working in STEM. ‘When it comes to the gender gap, not all countries are advancing at the same pace and cultural stereotypes still persist in some places. Men aren’t always aware that we can feel like a minority sometimes. This makes it so important

References:

1. Mari, L., Garaud, L., Evanno, G. and Lasne, E., 2016. Higher temperature exacerbates the impact of sediments on embryo performances in a salmonid. Biology Letters, 12(12), p.20160745. 2. Šulc, M., Hughes, A.E., Mari, L., Troscianko, J., Tomášek,

O., Albrecht, T. and Jelínek, V., 2022. Nest sanitation as an effective defence against brood parasitism. Animal Cognition, 25(4), pp.991-1002. 3. https://www.skypeascientist.com/

Left Lisandrina Mari holding a Great Reed Warbler Photo credit: Gabriela Štětkova.

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