Analysis of the murine sperm surface with monoclonal antibodies

Hybridomas secreting monoclonal antibodies reactive with murine spermatozoa were produced by fusion of myeloma cells with spleen cells from C57BL/6J mice immunized with spermatozoa from mice of the same strain. All antisperm antibodies were of the mu (mu) immunoglobulin heavy chain class; only one (MS-1) bound S. aureus protein A. Antibody MS-1 recognized an antigen present on the sperm acrosomal cap, on the surface of cells from liver and kidney and from some cultured cell lines. The subunit molecular weight (69000) of the polypeptide reactive with MS-1 was determined by SDS-PAGE analysis of sperm membrane proteins followed by their electrophoretic transfer to nitrocellulose.