Molecular Analysis of Edn1/Ednra Pathway in Xenopus Neural Crest Development

MARCELA BONANO; CELESTE TRÍBULO; JAIME DE CALISTO; ROBERTO MAYOR; MANUEL AYBAR; SARA S. SÁNCHEZ

Guarujá

Congreso; Second International Meeting of the Latin American Society of Developmental Biology; 2005

Latin American Society of Developmental Biology

The neural crest develops at the border between neural plate and the prospective epidermis in all vertebrate embryos. NC cells are highly migratory and generate a variety of cells, including neurons, pigment cells, smooth muscle, craniofacial cartilage, bone, endocrine cells, etc. Numerous studies in chick, zebrafish and amphibian embryos have demonstrated that the signals BMP4, Wnt, FGF, Notch/Delta and retinoic acid participate in the initial induction of this tissue. However, the involvement in neural crest development of other cell signaling pathways has not been established. In this work, we have analyzed the expression and participation of components of the Endothelin-1/Endothelin Receptor cell signaling pathway during the embryonic development of the amphibian Xenopus laevis. We report the isolation of a 2.8 kb-length transcript corresponding to the cDNA of Endothelin Receptor A (Ednra) and a detailed analysis by whole mount in situ hybridization of its expression pattern during early embryonic development. Results showed that Ednra is expressed at the neural plate border from stage 13 (early neurula). During neural crest migration, Ednra expression is mainly located in the cephalic migratory streams, while in the postmigratory neural crest cells Ednra labels branchial arches and the otic vesicle. The participation of Edn1/Ednra pathway during development was analyzed by conditional gain of function through the overexpression of Ednra mRNA, while the loss of function approach was performed using a specific inhibitor of Ednra dubbed BQ123, and by the microinjection of specific Ednra morpholino antisense oligonucleotides. Our results suggest that Edn1/Ednra signaling pathway is required for the induction and migration of neural crest cells in Xenopus embryos. Funding: CIUNT, Foncyt PICT02-10623, ICM P02-050, Fund. Antorchas, UNSTA.