INVESTIGADORES
AYBAR Manuel Javier
congresos y reuniones científicas
Título:
Vgl4b, a novel member of Xenopus Vestigial like gene family
Autor/es:
MARÍA GUADALUPE BARRIONUEVO; MANUEL J. AYBAR; CELESTE TRÍBULO
Lugar:
Uruguay. 26-29 Abril de 2012.
Reunión:
Congreso; 6th International Meeting of the Latin American Society of Developmental Biology; 2012
Institución organizadora:
Latinamerican Society for Developmental Biology
Resumen:
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 ΔNp63, another gene expressed in the inner layer of the ectoderm,
we carried out gain- and loss-of-function experiments. When ΔNp63 was overexpressed we observed an
increase in Vgl4b expression while
the ΔNp63 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.