Erythrocyte alloantigen diversity and some immunological effects of the B system in related New Hampshire strains.

Chickens from the Lester J. Dreesen strain of New Hampshires and a small (SBL) and a large (LBL) bursa line derived from it were tested with previously prepared reagents for 10 erythrocyte alloantigen systems. Eight systems were shown to be segregating in one or more of the three related lines. Immunogenetic analysis of the hemagglutination reactions resulted in genotype assignments for seven of the systems. The number of alleles segregating at the respective alloantigen loci were three A, five B, three C, two D, two I, two L, and two P. All seven segregating systems displayed considerable divergence in gene frequencies among two or more of the lines. The B1B1 chicks produced significantly higher peak titers against sheep red blood cells than B6B6 chicks; in adults the order of response of genotypes was B1B1, B6B6, B5B5. Peripheral blood leukocytes from groups of adults and 5-wk old chickens responded consistently to phytohemagglutinin-M according to their B genotypes, in the order B1B1, B5B5, B6B6. Serum immunoglobulin G (IgG) concentrations determined at various ages were higher in the LBL than the SBL strain, even after bursectomy. Genes influencing serum IgG levels may be closely linked to one or more of the blood group systems.