Identification of membrane antigens of goat epididymal spermatozoa

Purified goat sperm plasma membrane was used as antigen to raise the antibody in rabbit. Using this antisera four groups of antigenic membrane polypeptides are determined in caput and cauda epididymal sperm. The immunoresponsiveness of the polypeptides in caput and cauda sperm differs significantly. In case of cauda epididymal sperm, the polypeptides of region A (96KDa, 82KDa, 78KDa, 68KDa) and region D (24KDa, 20KDa, 18KDa) are highly immunoresponsive whereas in case of caput epididymal sperm the same antisera recognized the polypeptides of region B, C and D. By surface labelling with lactoperoxidase iodination and subsequent immunoprecipitation in the iodinated cell extract we demonstrate eight of these above polypeptides (96KDa, 82KDa, 68KDa, 50KDa, 29KDa, 24KDa, 20KDa and 18KDa) as surface antigen. The 96KDa, 82KDa and 68KDa surface polypeptides are highly immunoresponsive than the other lower molecular weight surface antigens in cauda epididymal goat spermatozoa.