03-P074 The relationship between specification and migration of neural crest progenitors

anism would thus be a new way to form a tube. As the generation of the lumen and of the tube itself requires the apparition of an apical domain, we decided to investigate how part of the lateral domain becomes apical. Our first results, using transgenes driven by brachyury regulating sequences, show that several proteins classically involved in antero-posterior and planar polarities could be involved in this process.