The oviductal sperm reservoir in domestic mammals

Abstract

In all mammalian species studied to date, sperm cells are arrested in the caudal isthmus before ovulation to form an oviductal reservoir. When ovulation occurs, discrete numbers of sperm are released from this region and ascend to the ampulla where fertilization normally occurs. Experimental evidence indicates that the sperm reservoir is instrumental in delivering the appropriate number of sperm in the correct physiological state for normal fertilization. In this paper, we present a comprehensive review of the sperm reservoir formation and functions in mammals. Sperm reservoir manipulation as a potential tool to improve reproductive performance is also discussed.