Some characteristics of the zona pellucida antigen in the hamster

Abstract

Abstract Antibody prepared in rabbits against saline extracts of hamster ovary forms a precipitate on the zona pellucida surface of oviducal eggs and immature oocytes of adult and prepubertal females. The precipitate appears in a net‐like arrangement on the outer surface only and reflects the heterogeneity of the zona. The antibody diffuses through the cumulus cells of oviducal eggs but not the cumulus cells of ovarian oocytes. Trypsin digests the inner nonprecipitated portion of the antibody treated zona but not the outer precipitated region. An important role for the zona antigen in sperm to zona attachment and in zona penetration is indicated by: (a) the failure of sperm to attach to the zona pellucida surface following treatment of eggs with antibody; (b) the polarity of the distribution of antigen in the zona; (c) the species‐specificity of the antigen; (d) the attachment of sperm to only the outer surface of zona ghosts; (e) and the concentration of the antigen at the surface of the sperm slits in the zona.