INVESTIGADORES
AYBAR Manuel Javier
artículos
Título:
Amphibian Bufo arenarum vitronectin-like protein: its localization during oogenesis
Autor/es:
MANUEL J. AYBAR; SUSANA B. GENTA; EVELINA I. VILLECCO; ALICIA SÁNCHEZ RIERA; SARA S. SÁNCHEZ
Revista:
INTERNATIONAL JOURNAL OF DEVELOPMENTAL BIOLOGY
Editorial:
Basque Country University Press
Referencias:
Lugar: Bilbao, España; Año: 1996 vol. 40 p. 997 - 1008
ISSN:
0214-6282
Resumen:
In the present study, we analyzed the localization of vitronectin-like
protein in oocytes during oogenesis as well as in the serum and liver
tissue of the amphibian Bufo arenarum. Vitronectin-like protein was
purified from serum by heparin-affinity chromatography and showed to
have the two biological properties in common with most animal
vitronectins (VN): heparin binding activity and an RGD-dependent
cell-spreading activity. SDS-PAGE of vitronectin-like protein revealed
that it consists of two bands of 64 kDa and 72 kDa, while
immunoblotting analyses showed that this protein strongly cross-reacts
with two monoclonal antibodies against human VN. No immunofluorescent
staining of vitronectin-like protein was observed in previtellogenic
oocytes (stages I and II). In vitellogenic oocytes (stages III, IV and
V) fluorescence was observed in the cortical cytoplasm localized in
yolk platelets, extending concomitantly with the vitellogenic process.
When we examined the yolk platelet formation pathway by immunoelectron
microscopy, gold particles indicated that vitronectin-like protein was
located on the yolk platelet precursors: multivesicular bodies and
primordial yolk platelets. Gold particles also were seen sparsely
distributed in all oocyte investing layers. The mean serum
vitronectin-like protein concentration in amphibian animals was 127.8
+/- 11.6 micrograms/ml in adult males and 181.5 +/- 14.3 micrograms/ml
in adult females. Serum vitronectin-like protein of males and females
was susceptible to hormonal stimulation (17-beta estradiol). These
results suggest that vitronectin-like protein is stored in the yolk
platelets and may be involved in the later events of amphibian
development.