Sylvie Rétaux Team

Development and Evolution of the Forebrain

In brief

The vertebrate forebrain has undergone an extraordinary diversification in the course of evolution. For instance, could anyone see that the mammalian cerebral cortex, with its well-known organization into 6 layers, and the so-called everted pallium of teleost fishes, are homologous brain regions? Using an evolutionary developmental approach, we aim to understand the genetic and cellular mechanisms which govern the unity (homology) and the differences (diversification) present in the forebrains of various vertebrates. And we study the consequences of the observed developmental variations in terms of adaptive behaviors. To this end, we use an original animal model: the blind cavefish Astyanax mexicanus, which we consider as a “natural mutant”. During its adaptation to life in total and permanent darkness, this fish lost its eyes (and its pigmentation).

Our research

Projects

Astyanax mexicanus, aalso called the Mexican tetra, is a freshwater characiform fish with a large distribution in Central America. The eyed, river-dwelling forms and the eyeless, cave-dwelling forms of this species are used as models for evolutionary biology, including for the study of the evolution of the nervous system. During their adaptation to life in their dark habitat, cavefish populations have lost their eyes and their pigmentation, but they have also developed some traits that are more “useful” for cave life, such as enhanced olfaction and lateral line, large jaws and more teeth, and a series of specific behaviors which are considered as adaptive.
There are 29 known caves hosting Astyanax mexicanus cavefish populations. Some of these populations represent cases of convergent evolution, resulting from independent colonization events. They thus permit to study developmental micro-evolution and the mechanisms for generation of morphological and behavioral evolution.
In the lab, we mostly use the blind cavefish originating from the Pachón cave.

Selected Publications

> Jorge Torres-Paz*, Julien Leclercq* and Sylvie Rétaux.(2019) Maternally-regulated gastrulation as a source of variation contributing to cavefish forebrain evolution. eLife. Oct 31;8. pii: e50160. doi: 10.7554/eLife.50160. (*equal contribution). See also https://thenode.biologists.com/
Cited in Faculty of 1000, by Corinne Houart

> Carole Hyacinthe, Joël Attia, and Sylvie Rétaux (2019) Evolution of acoustic communication in blind cavefish. Nature Comms. Sep 17;10(1):4231. doi: 10.1038/s41467-019-12078-9.
See also https://natureecoevocommunity.nature.com/

> Jorge Torres-Paz#, Carole Hyacinthe#, Constance Pierre, and Sylvie Rétaux (2018). Towards an integrated approach to understand Mexican cavefish evolution. Biology Letters, 14 (8): 1-7. # equal contribution.

> Maryline Blin, Eugène Tine, Lydvina Meister, Yannick Elipot, Jonathan Bibliowicz, Luis Espinasa and Sylvie Rétaux (2018) Developmental evolution and developmental plasticity of the olfactory epithelium and olfactory skills in Mexican cavefish. Developmental Biology, 441(2):242-251.

> Julien Fumey, Hélène Hinaux, Céline Noirot, Sylvie Rétaux and Didier Casane (2018). Evidence for Late Pleistocene origin of Astyanax mexicanus cavefish BMC Evol. Biol. 18(1):43.

> Alexandre Alié#, Lucie Devos#, Jorge Torres-Paz#, Lise Prunier, Fanny Boulet, Maryline Blin, Yannick Elipot and Sylvie Rétaux. (2018) Developmental evolution of the prosencephalon in blind cavefish: origins of natural variations in neuropeptidergic patterning and their behavioral consequences. eLife, 10. 7554. # equal contribution.

> Sylvie Rétaux, Alexandre Alié, Maryline Blin, Lucie Devos, Yannick Elipot, Hélène Hinaux (2016). Neural development and evolution in Astyanax mexicanus: comparing cavefish and surface fish brains. In: The Biology and Evolution of the Mexican Cavefish. Eds AC Keen, M Yoshizawa, SE McGaugh. Elsevier, Academic Press.

> Hélène Hinaux, Lucie Devos, Maryline Blin, Yannick Elipot, Jonathan Bibliowicz and Sylvie Rétaux. (2016) Sensory evolution in blind cavefish is driven by early events during gastrulation and neurulation. Development. 143, pp 4521-4532.

> Yannick Elipot, Hélène Hinaux, Jacques Callebert, Jean-Marie Launay, Maryline Blin and Sylvie Rétaux (2014) A Mutation in the Enzyme Mono Amine Oxidase explains part of the Astyanax Cavefish Behavioural Syndrome. Nature Communications, 5:3647.

> Yannick Elipot, Laurent Legendre, Stéphane Père, Frédéric Sohm and Sylvie Rétaux (2014) Astyanax transgenesis and husbandry: how cavefish enters the lab. Zebrafish, 11(4):291-9.

> Suzanne E. McGaugh, Joshua B. Gross, Bronwen Aken, Maryline Blin, Richard Borowsky, Domitille Chalopin, Hélène Hinaux, William Jeffery, Alex Keene, Li Ma, Pat Minx, Daniel Murphy, Kelly E. O’Quin, Sylvie Rétaux, Nicolas Rohner, Steve M. J. Searle, Bethany Stahl, Cliff Tabin, Jean-Nicolas Volff, Masato Yoshizawa, Wes C. Warren (2014). The cavefish genome reveals candidate genes for eye loss. Nature Communications, Oct 20; 5: 5307.

> Yannick Elipot, Hélène Hinaux, Jacques Callebert and Sylvie Rétaux (2013) Evolutionary shift from fighting to foraging behavior in blind cavefish through developmental changes in serotonin network. Current Biology, 23: 1–10.

> Karen Pottin, Hélène Hinaux and Sylvie Rétaux (2011) Restauring eye size in Astyanax mexicanus blind cavefish embryos through modulation of the Shh and Fgf8 forebrain organizers. Development, 138: 2467-2476.

> Hélène Hinaux, Karen Pottin, Houssein Chalhoub, Stéphane Père, Yannick Elipot, Laurent Legendre, and Sylvie Rétaux (2011). A developmental staging table for Astyanax mexicanus surface fish and Pachón cavefish. Zebrafish, 8 (4):155-65. IF3

Team members

The current DECA group is composed of:

Jorge Torres-Paz, postdoc, is a developmental biologist. He studies comparative gastrulation in cavefish and surface fish embryos.

Julien Leclercq, PhD student, studies the effects of very precocious maternal factors on morphological evolution.

François Agnès, Assistant Professor at the University Paris-Saclay, focuses on the morphogenetic mechanisms underlying the (mal)formation of cavefish eyes.

Constance Pierre, PhD student, studies the phenotypic effects of a mutation in the MAO enzyme that we have discovered in the cavefish genome.

Alessandro Alunni, CNRS researcher, is interested by the developmental effects of the MAO mutation.

Maryline Blin, Ingénieure (IE CNRS), is our lab manager, is our lab manager, specialist of histological and embryological techniques. She studies olfaction.

Stéphane Père, Technicien (TCS CNRS), s’occupe en particulier de notre élevage d’Astyanax.

Sylvie Rétaux, Research Director (DR1 CNRS), is the team leader.

 

Alumni :

Vieri Failli, Bertrand Mollé, Isabelle Bachy, Arnaud Menuet, Jean-Baptiste Pénigault, Joana Osorio, Adèle Guérin, Yohann Mérot, Carole Hyacinthe, Amandine Bery, Karen Pottin, Shungo Kano, Jini Xiao, Lise Prunier, Yoni Bibliowicz, Hélène Hinaux, Yannick Elipot, Alexandre Alié, Eugène Tine, Lydvina Meister, Lucie Devos,
Victor Simon, Louise Vernier.