04-P004 Molecular basis of attenuation of competence to respond to FGF signal in ascidian notochord induction

ences between placodes and neural crest (induction during different times of development; different developmental potential; regulation of differentiation and migration by largely nonoverlapping sets of transcription factors) this suggests that cranial placodes and neural crest cells have an independent developmental origin from non-neural and neural ectoderm, respectively. We currently perform gain and loss of function experiments in Xenopus to test whether Dlx3, Dlx5, GATA2 and/ or GATA3 genes, which are expressed throughout the non-neural ectoderm but are absent from neural ectoderm, are involved in mediating the competence of non-neural ectoderm to respond to placode inducers.