INVESTIGADORES
BARRERA Antonio Daniel
congresos y reuniones científicas
Título:
EFFECT OF PROTEASES ON THE ECM OF AMPHIBIAN OOCYTES AND THEIR ROLE ON FERTILIZATION
Autor/es:
LLANOS, RICARDO; VALZ-GIANINET, JORGE NELSON; BARRERA, DANIEL; MUSUMECI, HUMBERTO; MICELI, DORA CRISTINA
Lugar:
Tafí del Valle, Tucumán (Argentina)
Reunión:
Jornada; XVIII Jornadas Científicas de la Sociedad de Biología de Tucumán; 2001
Institución organizadora:
Asociación de Biología de Tucumán
Resumen:
It is known that amphibian oviducal proteases produces changes in
the oocyte´s ECM glycoproteins and that these changes would be
responsible of the fertilizability acquired by eggs after crossing the
oviduct. In previous studies, using isolated vitelline envelopes (VE)
subjected to biotin conjugation, it was observed that union of labeled
molecules to the sperm plasma membrane occured. In this
work, the ultrastructural changes in B. arenarum coelomic VE (CE)
after trypsin or oviducal pars recta fluid treatment was analyzed. It
was also made an electrophoretic study of the isolated VEs, solubilized
and then treated with trypsin. The trypsin treatment of CE
affects the 84kD protein, which disappears after 3 min treatment.
We observed that the trysin activity modifyed the proteins ranging
30 to 41 kD, giving a similar pattern to that of the uterine oocytes
VE. At the ultrastructural level, after 60 seconds treatment with
0.001% trypsin, the VEs showed dispersion of the horizontal fibrils
fascicles and disappearance of the characteristic spaces. The perpendicular fascicles to the surface are more diffuse, lossing their
interaction with the horizontal fascicles. The internal face of the
EV shows marked modifications, disappearing the reticular pattern
and acquiring a diffuse aspect. The biological essays indicate
that these transformations are related with the acquisition of the
capacity of the VE to interactuate with the sperms.