congresos y reuniones científicas
Vgl4b, a novel member of Xenopus Vestigial like gene family
Congreso; VI International Meeting of the Latin American Society for Developmental Biology; 2012
Institución organizadora:
Latin American Society for Developmental Biology (LASDB)
Vestigial (Vg) belongs to a class of transcription cofactor genes that were first described in Drosophila and whose functions are to govern the fates of cells within the embryo. In mammals were reported four Vestigial like genes (Vgl1-4) that display distinct patterns of expression in both embryonic and adult tissues. Vgl genes encode proteins with amino acid conserved regions named TONDU (TDU) motif. As in mammals, in Xenopus laevis were characterized four Vgl genes that are highly conserved within their TDU motif and that are differently expressed in a complex pattern during development. Unlike other members of the Vestigial family, Vgl4 has two tandem TDU motifs. We have identified a new paralog of Vgl4 who carries the two TDU motifs. We called this gene Vgl4b, and the previously found Vgl4a. The comparison of protein sequences showed that Vgl4a is more similar than Vgl4b to the mammalian Vgl4. However, strong Vgl4 homology was observed in TDU motifs which are completely conserved between human, mouse, zebrafish and Xenopus. Despite the low overall identity of Vgl4b and other Vgl4 proteins, conservation in specific regions is sufficient to assign orthology to Vgl4. Then, we analyzed the temporal and spatial expression of Vgl4b by in situ hybridization and RT-PCR and compared it with the expression of FoxD3, Sox2 and XK81a. By neurula stage, the main expression of Vgl4b is located in the inner layer of the ectoderm corresponding to the epidermis and the neural crest. At tailbud stages, Vgl4b is expressed strongly in the CNS, branchial arches, otic vesicle and trunk epidermis. To determine the regulatory relationship between Vgl4b and DNp63, another gene expressed in the inner layer of the ectoderm, we carried out gain- and loss-of-function experiments. When DNp63 was overexpressed we observed an increase in Vgl4b expression while the DNp63 inhibition led to a disruption in Vgl4b expression. Taken together, these results show that Vgl4b is a new member of Vestigial like genes family with differential expression in the ectoderm, and could be involved in the development of this tissue.