Cross-reaction of antibodies present in sera of vasectomized mice with human swollen spermheads.
Vasectomy induced anti-sperm antibodies in mice were seen to cross react with human spermatozoa. Similarly anti-sperm antibodies in an infertile human male subject were found not only to react with human but also with bovine, porcine and murine sperm. Both observations made with preparations of swollen spermatozoa demonstrate the cross-reactivity of anit-sperm protamine activity of different species. Therefore in spite of known species dependent differences in amino acid composition and sequence of protamines, they appear to have common antigenic determinants.