BOVINE OVIDUCT-SPECIFIC GLYCOPROTEIN - A POTENT FACTOR FOR MAINTENANCE OF VIABILITY AND MOTILITY OF BOVINE SPERMATOZOA IN-VITRO

In the cow, a specific glycoprotein-bovine oviduct-specific glycoprote in (BOGP)-is secreted by the epithelial cells of the oviduct at the fo llicular stage of the estrous cycle. In this study, we examined the ef fects of purified BOGP on the viability and motility of bovine spermat ozoa in culture in vitro. Frozen-thawed bovine spermatozoa were incuba ted in modified Tyrode's solution (TALP) that contained purified BOGP (TALP-BOGP). In TALP-BOGP, both the viability and motility of bovine s permatozoa were more effectively maintained than in the control medium without any added protein. The increases in both the viability and mo tility of spermatozoa were dose-dependent. Spermatozoa were also incub ated in TALP medium supplemented with bovine serum albumin, egg albumi n, lactalbumin, or gastric mucin, and their viability and motility in these media were compared with that in TALP-BOGP. Both the viability a nd motility of spermatozoa were more effectively maintained in TALP-BO GP throughout a 12-hr incubation than in other media tested. An immuno labeling study demonstrated that a monoclonal antibody specific for BO GP reacted with the posterior region of the head, the middle portion, and the tail of spermatozoa that had been incubated with TALP-BOGP, su ggesting that BOGP becomes specifically associated with particular reg ions of the spermatozoon. These results suggest that BOGP is a potent factor for maintenance of the viability and motility of sperm. On the basis of the present results, we also propose that BOGP may play an im portant role in sperm functions during the reproductive process. (C) 1 995 Wiley-Liss, Inc.