Molecular analysis of the components of banded Hedgehog cell signaling pathway during Xenopus laevis development

AGUERO, TRISTÁN; AYBAR, MANUEL; SÁNCHEZ, SARA

Tafi del Valle, Tucumán

Congreso; XXI Annual Scientific Meeting of Tucumán Society Biology; 2005

Asociación de Biología de Tucumán

The vertebrate homologs of Drosophila hedgehog are sonic hedgehog, cephalic hedgehog and banded hedgehog. They encode a family of secreted cell signaling proteins involved in the embryonic patterning. In the present work we analyzed the expression of banded hedgehog (bhh) and the components of the intracelular signaling cascade during early development of Xenopus laevis. Our results showed that bhh is expressed during neurulation stages at the lateral border of neural plate in territories partially correlated with the expression of Gli transcription factors, that are expressed in overlapping ectodermal domains. We carried out a gain-of function approach by the microinjection of in vitro transcribed bhh mRNA in one blastómere of 4-8 cells developing embryos. At stages 14-17 embryos were fixed and processed for whole mount in situ hybridization. Results showed that an experimental increase in bhh signaling leads to an increased expression of neural crest markers (Slug, Snail, FoxD3) and transcription factors. Additionally, the overexpression of Gli3, mimics the effect produced by bhh gain of function. Our results showed that bhh signaling and Gli transcription factors are involved in the early neural crest development.