Genetic effects on quantitative variation in serologically detected H-Y antigen.

We have examined effects of an autosomal gene on the expression of serologically detectable H-Y, a male-specific minor histocompatibility antigen for which a role in primary sex determination has been postulated. Quantitative immunoabsorption studies using three different male specific antisera revealed variation in the level of H-Y among inbred mouse strains and mice bearing variants of the T/t complex. Two patterns of expression in inbred strains were observed; high, C57BL/6J (B6) and low, which included A/J (A), C3H/ DiSn and DBA/2J. In F1 hybrids between A (female parent) and B6 (male parent), the F1 expressed H-Y levels indistinguishable from A, the low parent. Among T/t complex variants, mice bearing T or t0 showed high expression whereas those of the t12 haplotype showed low expression. The co-segregation of H-Y expression types with these T/t complex variants provided further evidence for the location of a gene determining the level of H-Y antigen on the proximal portion of chromosome 17.