Induction and development of neural crest

R. MAYOR; S. VILLANUEVA; F. BASTIDAS; A. GLAVIC; C. TRÍBULO; M. AYBAR.

Palm Cove, Australia

Congreso; 2002 Meeting of International Research Scholars, Howard Hughes Medical Institue; 2002

Howard Hughes Medical Institue

The neural crest cell is a migratory embryonic cell population that forms at the border between the neural plate and the future epidermis. This neural plate border corresponds to the neural fold. The neural fold surrounds the entire neural plate, but only the lateral and posterior portion of the fold gives rise to neural crest cells; the anterior neural fold differentiates as forebrain. We analyzed some aspects of the specification of the neural crest at the lateral-posterior border of the neural plate. We have shown that an interaction between neural plate and epidermis is enough to induce neural crest cells, and currently this seems to be the most accepted model for neural crest induction. However, several results with amphibian and zebrafish embryos suggest a model based on a bone morphogenetic protein (BMP) gradient for neural crest specification. We have shown that levels of BMP signaling intermediate to those that specify neural plate and epidermis play a role in establishing the fate of the neural plate border, including the neural crest. Our recent results show that, to induce the neural crest properly, a posteriorizing signal from the posterior mesoderm patterns the neural plate border as anterior neural fold (forebrain) and posterior neural fold (neural crest). The molecular nature of this posteriorizing signal seems to be the same as that for posteriorization of the neural plate: FGF, Wnt-8, and retinoic acid. We propose a general model for neural crest induction and we analyze the role of the Snail/Slug genes in the development of this cell population.