Gene complementation in biological crosses for humoral immune response to glutamic acid-alanine-tyrosine

Level of humoral immune response to GAT has been associated with the MHC of chickens. Matings between two unrelated lines of chickens with low antibody response to GAT (G-B1 and S1 Line B19L) resulted in progeny that were higher responders to GAT challenge (P < .05) than either of the parental lines. Progeny of matings between two related sublines that are low responders to GAT (S1 Lines B19L and B1L) had antibody responses to GAT that were not higher than the parental lines. Progeny of the between-line cross were backcrossed to S1 B19L and G-B1 (B13) parental lines, as well as mated inter se. These matings produced F2 progeny whose GAT response was significantly associated (P < .05) with their MHC (Ea-B) type. The progeny were of three MHC types (B19B19, B19B13, and B13B13) that bound 66.6, 71.9, and 4.6%, respectively, of the GAT in a radioimmunoassay. The results from these matings suggest that MHC or MHC-linked genes, as well as genes not linked to the MHC, contribute to control of humoral immune response to GAT in the lines of chicken tested.