Paraxis regulate the cell adhesion of paraxial mesoderm during somite formation in Xenopus laevis

SANCHEZ R.S.; SANCHEZ S.S.

Santa Cruz

Congreso; V International Meeting of the Latin American of Developmental Biology; 2010

LSADB

In all vertebrates the Paraxial Mesoderm (PM) segmentation involves the formation of metameric units called somites through a Mesenchymal-Epithelial Transition. However this morphogenetic process is different in the amphibian Xenopus laevis because it does not form an epithelial somite, it rather undergoes a complex cell rearrangement. The molecular mechanisms that control these cell behaviours underlying somite formation remain elusive. Paraxis is a bHLH transcription factor expressed in vertebrate PM and in the somite. To establish the role of paraxis in this model organism, we carried out experiments of gain and loss of function by using a hormone-inducible construct. In vivo and in vitro experiments showed that the overexpression of this gene resulted in defects in the cell adhesion and in the somite formation. Alterations in the expression molecular markers of somitic differentiation were observed.  These results suggest that paraxis could play an important role in the cell rearrangement during Presomitic to Somitic Transition through the regulation of the cell adhesion.