RECOMBINATION BETWEEN GENES CODING FOR IMMUNE-RESPONSE AND SEROLOGICALLY DETERMINED ANTIGENS IN CHICKEN B-SYSTEM

Evidence is presented for a crossover between the genes coding for the serologically determined (SD) antigens on erythrocytes and an immune response gene (Ir-GAT) controlling immune response to the synthetic polypeptide GAT within the B complex, the MHC of chickens. The Ir-GAT1 and Ir-GAT19 alleles control low and high immune response to GAT, respectively. Both low and high responders were recovered as recombinants from B1B1 and B19B19 birds. The low-responder haplotypes are homozygous for the Ir-GAT1 allele and the high-responder haplotypes carry the Ir-GAT19 allele. Mortality for B1B1 nonresponder birds was 39%, compared with 19% for the B1B1 high responders; this suggests the possibility that genes located within the immune response region of the B complex exert some genetic control over viability and survival. © 1978 Springer-Verlag New York Inc.