HOMOLOGY OF A GLYCOPROTEIN OF B. arenarum EGG VITELLINE ENVELOPE WITH ZONA PELLUCIDA COMPONENTS.

BARRERA, DANIEL; LLANOS, RICARDO JAVIER; GARCÍA, VANESA; MICELI, DORA CRISTINA

Rosario, Santa Fe (Argentina)

Congreso; XLII Reunión anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2006

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

In previous work, the morphological and biochemical changes in B. arenarum eggs envelopes following passage through the oviduct were reported. The transformation of coelomic envelope (CE) into vitelline envelopes (VE) leads to the acquisition of fertilizability and involves the cleavage of glycoprotein components. The differences between electrophoretic patterns of CE and VE indicated that an oviducal protease (oviductin) digests CE glycoproteins gp84 and gp55 decreasing the relative concentrations of gp48 and gp42 with a noticeable increase in gp39. The aims of this work were to know gp39 identity and evaluate its expression pattern in the oocytes during oogenesis. In order to localize gp39 in the egg we performed immunohistochemical studies with polyclonal antibody (AB) obtained in rabbit using purified gp39 as antigen. The specificity of AB determined by Western Blot showed that AB specifically reacts with gp39 of the envelopes obtained from eggs after their passage along the oviduct. However AB recognized also gp55, 48 and 42 on envelopes obtained from eggs previous their transit through the oviduct. On the other hand three peptides from trypsin digestion of gp39 were obtained by preparative HPLC and sequenced. Bioinformatic analyses showed that these peptides have 100% identity with a deduced sequence of ZPC homologue cDNA extracted from B. arenarum ovary.