Wnt 6 and Wnt 11-R regulate paraxis expresión in Xenopus laevis paraxial mesoderm.

SÁNCHEZ R.S.; MÓNACO M.E.; SÁNCHEZ S.S.

Carlos Paz, Córdoba, Argentina

Congreso; XLIV Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology (SAIB); 2008

SAIB

In all vertebrates the Paraxial Mesoderm (PM) segmentation involves the formation of metameric units called somites through a Mesenchymal-Epithelial Transition (MET). However this morphogenetic process is different in the amphibian Xenopus laevis because it does not form an epithelial somite but rather undergoes a complex cell arrangement. The molecular mechanisms that control these cell behaviours underlying somite formation remain elusive. Paraxis is a bHLH transcription factor expressed in vertebrate PM and later is localized in the somite. In mouse and chick embryos their expression is regulated by Wnt signalling pathway and is implicated in the somite MET.In order to establish if Wnt signalling pathway regulates paraxis expression and is involved in the rearrangement of Xenopus PM, we carried out experiments using an inhibitor of the Wnt signaling pathway, the Valproic Acid (AV). In vivo experiments show that AV produces a decrease of the paraxis expression in treated embryos. Also we carry out experiments of gain function by Wnt-6 and Wnt11-R mRNA microinjection. We find that the overexpression of these molecules produces an increment of the paraxis expression, suggesting that this gene could be regulated by Wnt-6 and Wnt11-R signal molecules.