INSIBIO   05451
INSTITUTO SUPERIOR DE INVESTIGACIONES BIOLOGICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
cAMP PARTICIPATION IN Xenopus laevis VITELLOGENIN UPTAKE
Lugar:
Santa Cruz
Reunión:
Congreso; LASDB; 2010
Resumen:
The transformation of oogonia into oocytes is commonly
described as oogenesis. In many oviparous vertebrates the growth of oocytes
from microscopic to macroscopic dimensions is mainly the result of one of the
most exciting examples of cell regulation, named vitellogenesis. This process,
general to all oviparous vertebrate species is characterized by hepatic
production of the glycoprotein vitellogenin (VTG). VTG is transported via the
bloodstream to the ovary where enters the oocytes by a receptor-mediated
endocytosis.
Previously we demonstrated that in the amphibian Xenopus laevis direct gap junctional
communication between oocytes and follicular epithelium is a requirement for
endocytic VTG uptake. This suggested that a diffusible signal molecule able to
pass through fully open gap junctions could be involved in vitellogenic
process.
In order to determine the identity of the signal
molecule, gap junctions coupling/uncoupling experiments with an endocytic
tracer were performed.
Rescue experiments demonstrated
that cAMP is one of the signal molecule involved in vitellogenin uptake during
vitellogenesis.