Maturation and function of the hamster spermatozoon probed with monoclonal antibodies

To investigate the surface of the mammalian spermatozoon during its maturation in the epididymis, seven monoclonal antibodies were raised in mice against intact spermatozoa (and isolated sperm heads) recovered from the cauda epididymis of the golden hamster. These antibodies, which with one exception were species specific, recognized various membrane components over restricted regions of the sperm head and tail. During epididymal transit the localisation of four antigens bound by these antibodies was considerably altered. In two cases, antigens were first detected on spermatozoa in the distal corpus epididymis where sperm fertilising capacity is initially acquired. A monoclonal antibody which bound to the acrosome and midpiece specifically blocked fertilisation of intact oocytes of the hamster in vitro. Preliminary characterisation of the antigens was undertaken.