Effects of pair bonding and monogamy on epididymal sperm characteristics in prairie voles (Microtus ochrogaster)

Abstract

Prairie Voles are a social, monogamous species which have gained traction in the fields of neurobiology, neuroendocrinology, and psychology as a potential model species for studying human social behavior and associated biology, due to similarities in brain chemistry and social tendencies as well as the similarities between rodent and human physiology. Reproductive work in prairie voles is somewhat limited, with more emphasis placed on behavior than physiology. The female prairie vole estrus cycle is unique in that the females do not begin estrus cycling until exposed to a non-relative male. It is unknown if/how female exposure and pair bonding affect male sperm characteristics and/or production. Here we utilize male prairie voles as a study model for if/how pair bonding and monogamy affect sperm production and characteristics. Prior to comparing sperm characteristics between mated and unmated males, we establish an effective methodology for epididymal sperm extraction and analysis utilizing established techniques in other rodents, modern theriogenology concepts, and trial and error. This methodology displays statistical significance and consistency based on established reproductive parameters in mammals, and is thus appropriate to utilize for study group comparisons moving forward. We now turn our attention to the differences between unmated males and mated monogamous males. Preliminary data indicates a likely statistical difference in sperm characteristics between these groups, but more data is needed to reach an objective conclusion.