293. Gametes alter the oviductal secretory proteome in vivo

Abstract

We sought to identify altered oviductal protein secretions in response to the presence of gametes in the oviduct in vivo at the time of ovulation. Experiments were designed to compare oviductal fluid from a gamete-stimulated oviduct to a non-gamete-stimulated oviduct within the same animal. Clips were introduced at the infundibulum of both oviducts to prevent oocytes from entering the oviducts and one uterine horn was cut to prevent sperm access to that oviduct. Sows were artificially inseminated the next day with diluted boar semen. Control sows that had undergone the same surgical procedures were inseminated with diluent (no sperm). The day after insemination oviducts were removed and oviductal fluid was collected. Two-dimensional gel electrophoresis, isotope coded affinity tag (ICAT) technology and LC-ESI-MS/MS were used to identify and quantify proteins regulated by presence of spermatozoa in the oviduct. To identify the effect of oocyte presence in the oviduct, only one oviduct was clipped at the infundibulum. This prevented oocytes from entering that oviduct. Sows were monitored for ovulation using sonography and 24 h after ovulation oviducts were removed and oviductal fluid was analysed as described above. Results indicated that in vivo, the oviduct responded to the presence of spermatozoa and oocytes by altering its secretory proteomic profile. Our surgical interventions were not responsible for any of these alterations. Many of the identified proteins are known to be involved in oocyte maturation, maintenance of sperm viability, fertilisation, and embryonic development. Our findings suggest that the oviduct responds to gametes by providing specific molecules to sustain, regulate or enhance events preceding and during fertilisation, and early embryonic development. Furthermore, it seems a gamete recognition system is present in the oviduct.

Supported by grants from the BBSRC and Sygen International PLC.