Bioscientifica Proceedings

Three regions of the ruminant oviduct play different roles in the progress of sperm: the uterotubal junction, isthmus, and ampulla. The uterotubal junction acts as a point of selection of sperm, requiring that sperm are progressively motile and express specific proteins in order to enter the oviduct. The isthmus stores sperm, preserving motility and viability until ovulation. Sperm are stored in the isthmus by binding to its mucosal epithelium. In bovine sperm, binding to the ...