Immunodetection of epithelial cadherin in cow oviductal cepithelial cells and in vitro matured cumulus-oocyte complexes (COCs).

CABALLERO J; DALVIT G; CETICA P; VAZQUEZ-LEVIN MH

Buenos Aires, Argentina

Congreso; VIII Jornadas Multidisciplinarias de la Sociedad Argentina de Biologia; 2006

Sociedad Argentina de Biologia

 After mating, few spermatozoa reach the cow oviduct to form a sperm reservoir; there, the plasma membrane overlaying the acrosome interacts with the cilliated surface of oviductal epithelial cells until signals associated to ovulation cause sperm release, possibly by capacitation-related events. At the site of fertilization, sperm initially make contact with the cumulus cells, and then interact with the oocyte zona pellucida (ZP) and the oolemma. Epithelial cadherin (Ecad) is a Ca+2 dependent cell-cell adhesion molecule present on the surface of non-capacitated, capacitated and acrosome reacted bull spermatozoa in cell regions proposed to participate in the interaction with oviductal cells and oocyte envelopes (1). The aim of the study was to evaluate localization of Ecad in oviductal tissue sections, as well as in cumulus cells and oocytes from in vitro matured COCs. Immunohystochemical analysis of sections from different regions of the oviduct during the periovulatory period, immunocytochemistry of in vitro matured oocytes and their surrounding cells, and Western immunoblotting (WIB) of denuded oocytes was done using a specific anti Ecad antibody (sc#7870; Sta Cruz Biotech). Presence of Ecad was revealed in oviductal epithelial cells and their secretions, in the surrounding cells accompanying the matured oocyte, in the ZP and in the oocyte plasma membrane; a 120 KDa form was immunodetected by WIB of whole oocyte protein extracts. Altogether, these results suggest the involvement of Ecad in the interaction between bull spermatozoa with the oviductal epithelial cells in the formation and release from the sperm reservoir, as well as during gamete interaction leading to fertilization.