The Effects of Bovine Sperm-Bound Anti-Sperm Antibodies on Capacitation

Sperm-bound anti-sperm antibodies (ASAs) can prevent sperm capacitation resulting in decreased fertility in men. However, their effect on bovine sperm capacitation is not known. The objective of this study was to evaluate the effect of sperm-bound ASAs on bovine sperm capacitation. It was hypothesized that ASAs negatively affect the ability of bull spermatozoa to undergo capacitation in vitro. Four yearling angus bulls with satisfactory breeding potential were used. First, three ejaculates (ASA negative) were collected and cryopreserved. Then, ASAs were induced by serial immunizations with autologous spermatozoa. Three more ejaculates (ASA positive) were cryopreserved starting three weeks after the last immunization. The percentage of IgG- and IgA-bound spermatozoa was assessed at the time of semen collection using flow cytometry. On the day of the experiment, straws from each ejaculate were thawed and divided into two aliquots. Sperm capacitation was induced in one aliquot by incubation in SP-TALP with heparin (60 µg/mL) at 37 C in 5 % CO2 in air for 45 min (HEP treatment). Another aliquot incubated without heparin served as the control treatment (CON).  […]