MFPL - 2016 RESEARCH GROUPS
FLORIAN RAIBLE
Origin and diversification of hormone systems We are interested in the origin and evolution of hormone systems. Central to our work is the exploration of a novel invertebrate model system, Platynereis dumerilii.
University of Vienna Research Platform (“Rhythms of Life”) that allows us to interact with colleagues from the Analytical Chemistry and Neurobiology. Together, we have recently gained critical insight into one of the enigmatic hormones involved in the synchronized reproduction of the animal.
Our past work has shown that this marine worm exhibits a unique combination of ancestral-type genomic characteristics not found in insect and nematode model species. Moreover, we have identified numerous components of ancestral-type hormone pathways in Platynereis. Therefore, Platynereis is highly interesting for comparison with other animal hormone systems - including the ones of vertebrates - and for our understanding of marine life.
Exploring a new marine model system Over the past years, Platynereis has emerged as a very promising “next-generation” model system. We have pioneered transgenic technology in Platynereis that allows us to mark and interrogate cell types with unprecedented precision. Likewise, we have helped to establish targeted mutagenesis in the worm, allowing us to test if a given gene is required for regeneration or reproductive timing. Finally, we make use of the remarkable transparency of Platynereis to observe neurons and stem cells in the living animal. These approaches provide entry points into the fascinating biology of a new marine model species. Besides the action of hormones, we are actively investigating the evolution of gene-regulatory logic and the orchestration of cellular processes involved in the sculpting of bristles. Our vision is to firmly establish Platynereis as a reference species for marine biology.
The hormonal control of reproduction and regeneration What could be the function of ancestral-type hormones in Platynereis? One of the systems that we dissect is the hormonal machinery orchestrating reproduction and regeneration. Platynereis is an excellent object for this analysis, as it has been a central model for the link between chronobiology and reproduction. Our bioinformatic analyses, as well as transcriptomic, proteomic and targeted biochemical analyses, have revealed a spectrum of hormones present in Platynereis. Thanks to the establishment of new molecular tools, we are now able to systematically assess the impact of these candidates on the development and maturation of the animals. These experiments are supported by an ERC starting grant (HOR.MOON), as well as a
Hormonal orchestration of regeneration and reproduction by the medial Platynereis brain. (A) Classical transplantation studies revealed that immature Platynereis heads are the source for an endocrine brain hormone inhibiting maturation and supporting regeneration. (B) Implantations of small brain fragments (blue) map the source of the brain hormone to the medial Platynereis brain. Recent work has allowed us to gain first insight into the molecular identity of the brain hormone.
SELECTED PUBLICATIONS Bannister S, Antonova O, Polo A, Lohs C, Hallay N, Valinciute A, Raible F, Tessmar-Raible K. TALENs Mediate Efficient and Heritable Mutation of Endogenous Genes in the Marine Annelid Platynereis dumerilii. Genetics 2014;197(1):77-89. PMID: 24653002 Backfisch B, Veedin Rajan VB, Fischer RM, Lohs C, Arboleda E, Tessmar-Raible K, Raible F. Stable transgenesis in the marine annelid Platynereis dumerilii sheds new light on photoreceptor evolution. P Natl Acad Sci USA 2013;110(1):193-8. PMID: 23284166 Tessmar-Raible K, Raible F, Arboleda E. Another place, another timer: Marine species and the rhythms of life. BIOESSAYS 2011;33(3):165-72. PMID: 21254149
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Florian Raible
TEAM Stephanie Bannister Andrej Belokurov Caroline Broyart Carola Jaunecker Roger Revilla-i-Domingo Sven Schenk Clara Schmidt Karim Pyarali Vadiwala Martin Zurl
Ancestral-type hormones in a simple invertebrate. Individual hormone-producing cells are visualized (green colour) in an adult Platynereis brain. Whereas cell bodies (“mc”) localize to the medial brain, neuronal projections (np) project into the region of the infracerebral gland, an annelid neurohemal organ.