INVESTIGADORES
HONORE Stella Maris
congresos y reuniones científicas
Título:
Xtwist and Sox-10: two key genes during neural crest development in Xenopus laevis
Autor/es:
HONORÉ S. M.; AYBAR M. J.; SANCHEZ S. S.
Lugar:
Valle Nevado
Reunión:
Congreso; First International Meeting of the Latinamerican Society of Developmental Biology; 2003
Institución organizadora:
Latinamerican Society of Developmental Biology
Resumen:
Neural
crest cells arise from the dorsal neural tube and migrate over precise
pathways to populate multiple organs and tissues in the developing
embryo, they differentiate into many cel1 type inc1uding melanocytes,
neurons, and glia. Numerous genes participate in the induction and
specification of the cells of the neural crest, between which
transcription factors stand out. It has been suggested that Xtwist, a
transcription factor of the helix-Ioop-helix (HLH) family also carries
out a role in the formation of the neural crests of Xenopus laevis. In
this work, we analyzed the function of Xtwist gene through the use of
inducible chimeras. The results reveal that the overexpression of
Xtwist leads to an increase of neural crest markers like Xslug and
Sox9, whereas the overexpression of a dominant negative of Xtwist
leads to a reduction in the expression of the these markers. No effect
on the express ion of the neural plate marker (Sox 2) and epidermis
marker (XK81a) was observed. On the other hand, the gene Sox 10, a
protein of HMG box family, has been considered essential for the
neural crests development in mammals and zebra fish. Mutations of
Sox10 in humans have been related to different pathological conditions
that include enteric aganglionosis, deafness and lack of pigmentation
in the skin. In our laboratory we have cloned and sequenced the
complete Sox10 mRNA of Xenopus laevis. The analysis by in situ hybridization
indicates that, Sox 10 begins to be expressed in the presumptive
ectoderm of the neural crest at the beginnings of neurulation, and
that the expression remains during crest migration. Analysis of
function experiments indicate that Sox 10 activity is important for
the specification of particularly cell lines derived from the neural
crest. These results suggest that the genes Twist and Sox 10 play key
roles in the: induction of the neural crest and in the specification
of their derivatives.