The quantitative effects of the B blood group locus and sex linked histocompatibility antigen in chickens on G-v-H reaction.

The major histocompatibility locus in the chicken is the B locus with a minor histocompatibility antigen controlled by a gene (s) on the W chromosome. This study was designed to determine the quantitative effects of the B locus and the sex linked histocompatibility gene on splenomegaly of chick embryos after inoculation with adult male lymphocytes. The embryos and male lymphocyte donors had blood group genotypes designed B9/B9, B9/B11 so that nine donor-host combinations were used. When the donor and host were homozygous for different B alleles (B9 and B11) or different by one B allele (B9 or B11) the splenomegaly was 4 and 2 times greater, respectively, than the compatible donor and host. A greater splenomegaly was produced in male to female injections than in male to male injections. However, the histocompatibility antigen controlled by a gene(s) on the W chromosome was weaker than the controlled by the B locus.