Hairy genes family in developing neural crest of Xenopus laevis

VEGA LÓPEZ, GUILLERMO A.; AYBAR, MANUEL J.

Toulon (Giens Peninsula), France

Conferencia; Xenopus International Conference; 2012

In the formation of the neural crest (NC) several cell signaling pathways were involved in its development. The Notch/Delta signaling pathway has been involved in the induction of the NC of Xenopus laevis. The Hairy family genes (Hairy1, Hairy2a and Hairy2b)have been postulated as direct targets of Notch/Delta signaling pathway in vertebrates and invertebrates. In this work was determined by in vivo overexpression in embryos of the inducible proteins and dominant negative, by microinyeción mRNA or antisense oligonucleotides showed that Hairy genes are required for the induction and migration of NC. Blocking Hairy genes resulted in a decreased expression of NC genes marker, as well as higher levels of apoptosis and inhibition of the development of derived from the NC. Furthermore, analysis by use of inducible chimeric proteins transcriptional activator or repressor gene Hairy, indicate that these genes function as transcriptional repressors during the induction process of the NC in Xenopus laevis. Furthermore, we examined the regulation of Hairy genes expression by different cell signaling pathways. Hairy genes are down-regulated by BMP-Smad pathway, while having a positive regulation from Notch/Delta-Su (h) and Ihh-Gli3 cell signaling pathway. The results obtained in this study showed that Hairy genes have unique characteristics that differentiate the functions previously described in other species, which have a functional equivalence between different Hairy genes and that they are different processes required for early development of the NC: initial induction, maintenance of the specification, migration and differentiation of some of its derivatives.