IMMUNOGENETICS OF THE A-E ALLOANTIGEN COMPLEX

The close linkage (0.5%) between the A and E erythrocyte alloantigen l oci present a special challenge in the production of locus-specific ty ping antisera. The objective of the investigation was to determine imm unogenetically the A-E haplotypes (genetically linked combinations of A and E antigens) existing in the locally maintained individuals of th e New Hampshire (NH) and White Plymouth Rock (WR) breeds. The A and E alloantigens in these populations were identified using reference anti sera previously produced in White Leghorns. A total of four A-E haplot ypes were identified within each of the two breeds; A2E1, A6E2, A6E4, and, A8E2 in WR and A2E1, A3E7, A7E4, and A8E2 in NH. Individuals of t hese two brown-egg breeds were backcrossed over several generations to a line of Ancona chickens homozygous at the A and E loci. Genetic seg regation occurring over four generations resulted in nonrecombinant an d recombinant progeny that were immunized reciprocally with the blood of siblings to raise antibodies reactive with the individual A and E a ntigens of the NH and WR stocks. The antisera resulting from the withi n-family alloimmunizations confirmed the haplotypes deduced in the WR and NH lines from the initial tests with the A and E reference antiser a.