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 these signaling cascades is redeployed throughout development for the patterning and formation of various tissues has been rather astonishing. Elaboration of interaction between these signals, which include Wnt, hedgehog (Hh), fibroblast growth factor (FGF), transforming growth factor beta (TGFß), bone morphogenic protein (BMP), retinoic acid (RA) and Delta/Notch, has been proposed as one of the key events marking the diversification of first metazoan and subsequently bilaterian animals. In our team, we are very actively involved in studying the developmental functions of two intercellular signaling cascades, 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. 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 members of our team use comparative approaches to assess the evolution of Wnt and RA signaling functions and their interactions during deuterostome development.
Biography Updated on 13 May 2013