Genetic control of humoral immunity to sperm acrosomal and cell surface antigens

We have defined the nature of genetic control of humoral immunity to sperm cell surface (TSDA) and acrosome (Ac) antigens. A sperm immunization dose that distinguishes between high-responder (BALB/c) and low-responder (B10) strains of mice was identified. B10 mice were unresponsive, whereas BALB/c and F₁ hybrid mice responded to sperm of both parental strains. The ratio of nonresponder to responder mice in the B10 × F₁ backcross and F₁ × F₁ inbred generations indicates anti-TSDA or anti-Ac antibody responsiveness is controlled through more than a single gene. The significant correlation found between the anti-TSDA and anti-Ac responses is consistent with the possibility that one or more genes controls antibody responsiveness against determinants common to both the Ac and sperm cell surface. Neither anti-TSDA nor anti-Ac antibody responses were linked to the I-A subregion of the responder H-2^d MHC haplotype. In addition to a genetic difference in the control of humoral immunity to sperm, a difference in sperm immunogenicity among strains was observed. Antigens of the Ac of B10 sperm are more immunogenic than those of BALB/c sperm, and this trait is linked to the B10 Y chromosome.