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Equipes de recherche - Biologie du Développement de Villefranche sur mer
Unité Mixte de Recherche CNRS 7009

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Evolution de la Signalisation Intercellulaire Embryonnaire

http://biodev.obs-vlfr.fr/fr/evoinside

Responsable de l'Equipe

Michael Schubert

 

Developmental biology studies a highly complex question: how to create an entire organism from a single cell? Although it does not come as a surprise that this process relies on very well coordinated intercellular signals in metazoan animals, the discovery that a relatively small toolkit of signaling cascades is being co-opted repeatedly throughout development for the patterning and formation of various tissues is rather astonishing. Elaboration of the interaction between these signaling pathways, which include Wnt, hedgehog (Hh), fibroblast growth factor (FGF), transforming growth factor beta (TGFβ), bone morphogenic protein (BMP), retinoic acid (RA) and Delta/Notch, has been proposed as one of the key events marking the diversification of metazoan animals. Developmental functions of intercellular signaling cascades and their interactions have been particularly well studied in vertebrates, but it has now become evident that these cascades are also involved, outside vertebrates, in a multitude of other processes, which have received significantly less attention in the past.
In the EvoInSiDe team, we are very actively involved in studying the developmental functions of two particular intercellular pathways, Wnt and RA signaling, in three animal models located at key phylogenetic positions within the deuterostome phylum. Namely, we are working on sea urchin (Paracentrotus lividus), amphioxus (Branchiostoma lanceolatum) and lamprey (Petromyzon marinus), respectively, a xenambulacrarian, an invertebrate chordate and an agnathan vertebrate (Fig. 1). Importantly, all three models are amenable for experimental developmental studies, with controllable spawning and external fertilization. The embryos are suitable for pharmacological treatments as well as for microinjection, allowing the creation of transient transgenic animals and the specific functional knockdown or overexpression of targeted genes. Thus, taking advantage of these three animal models, the EvoInSiDe team uses comparative approaches to assess the evolution of Wnt and RA signaling functions and of their interactions during deuterostome development.

 

Figure 1. Simplified phylogeny of metazoan animals (modified from Campo-Paysaa et al., 2008, Genesis, 46:640-656).

 

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