Expression pattern of xpax1, xpax9 and xunc genes and their participation in the sclerotome of the amphibian Xenopus laevis

SANCHEZ R. S.; SANCHEZ S. S.

Tafi del Valle, Tucumán

Jornada; XXVIII Jornadas Científicas Asociación de Biología de Tucumán Tafí del Valle, Tucumán; 2011

Asociacion de Biologia de Tucumán

The anurans body plan diverges from that of other vertebrates. With respect to the skeleton, the frogs are characterized by a truncated axial skeleton (AS) with absence of discrete caudal vertebrae (CV). However, the ability to form elements of the CV is present in some anurans, suggesting that the molecular machinery that regulates their formation is still present in this group and the absence of these elements could be due to alterations in the expression of a set of genes in the caudal region of the embryo. The AS develops from the sclerotome, a cell mass derived from the somites. Those cells take up positions around the notochord and neural tube for later differentiation to cartilage and bone of the spine. Studies in fish, birds and mammals showed that pax1, pax9 and uncx play a central role in the development of AS promoting the proliferation of sclerotome and the formation of cartilaginous condensations. Loss of function of these genes results in severe abnormalities in the spine with absence of vertebral elements. In this work we characterize the expression pattern of the Xpax1, Xpax9 and Xunc genes in Xenopus by in situ hybridization and RT-PCR. We found that these factors are expressed in the sclerotome. The gain of function approaches by overexpressing the pax genes suggest their potential role in the development of the X. laevis spine.