Polymorphism of minor histocompatibility genes in wild mice.

H-2b-restricted cytolytic T lymphocytes (CTL) were generated against H-1, H-3, and H-4 antigens and tested against target cells of F1 hybrids between wild mice and inbred H-2b mice. The congenic strain combinations for the CTL production were such that they tested one allele each at the H-1 and H-4 loci and four alleles at the H-3 locus. Most of the wild mice tested came from Southern Germany, but a few mice came from other European countries and Egypt and Israel. Virtually all wild mice typed as positive with CTL directed against H-3b and H-4b antigens; 32% of the F1 hybrids tested reacted with anti-H-1c CTL and 9% reacted with anti-H-3d CTL. The positive results were not caused by cross-reaction with allogeneic H-2 antigens controlled by the major histocompatibility complex (Mhc) genes of the wild mice. At least some of the H-3 and H-4 antigens detected by the CTL in the F1 hybrid were not identical with antigens of the immunizing strains. These results suggest a relatively low degree of polymorphism of the tested minor H loci in wild mice and further support the notion that minor H loci are unrelated to the Mhc.