In most animals, the female reproductive tract can store sperm for longer times than semen extenders. For example, poultry semen in extenders is usually only stored for up to 48 hours before insemination compared to the 2-3 week storage in the hen. Clearly, the female reproductive tract has capabilities unmatched by artificial extenders. Based on supportive preliminary results, the investigators hypothesize that adding specific oviduct glycans to bovine sperm will prolong sperm lifespan ex vivo. The studies supported by this award are designed to address the NSF BREAD Challenge topic of developing a cold-chain-free artificial insemination process. Sperm storage by cryopreservation in liquid nitrogen has revolutionized transportation of bovine semen in developed countries. But cryopreservation techniques are impractical for small herdowners in developing countries due to technical and infrastructure constraints. A more practical alternative would allow semen from valuable males to be transported at ambient temperature, maximizing the genetic impact of valuable animals.
The characteristics of the mammalian oviduct that enable sperm to live an extended lifespan are unclear but there is a developing paradigm that oviductal glycans are involved in sperm retention and that the glycans extend sperm cell viability. These hypotheses will be addressed in 3 specific aims: 1) identification of glycan motifs that bind bovine sperm and determine their location in the oviduct; 2) determination of whether oviduct glycans that bind sperm prolong sperm lifespan and function in standard culture medium (dmTALP); and 3) determination of whether oviduct glycans can prolong sperm lifespan and function in an optimized semen diluent at normal room temperatures. In addition to the research findings, this project will train a postdoctoral fellow and several undergraduates, including underrepresented minority students recruited through the many diversity-oriented programs at the University of Illinois. An interactive web site that teaches the importance of semen analysis that will be developed and used in laboratories for a class of 175 students each year. Results from the study will be published in peer-reviewed journals and disseminated through scientific conferences.
