IDENTIFICATION OF CLASS-II MAJOR HISTOCOMPATIBILITY COMPLEX POLYMORPHISMS PREDICTED TO BE IMPORTANT IN PEPTIDE ANTIGEN PRESENTATION

Chickens of the B2, B-5, B-15, B19, and B21 B-congenic haplotypes diff er in disease resistance. Complementary DNA from B-congenic chicken st rains have been analyzed for allelic diversity of expressed Class II M HC genes. The predicted amino acid sequences of eight genes from five haplotypes were subjected to Wu-Kabat variability analysis. The B-L ge ne polymorphic regions and conserved regions are highly similar to the human leukocyte antigen Class II genes. Therefore, the present analys is reveals candidate polymorphisms important in determining the spectr um of antigenic peptides presented to T helper cells, and allelic diff erences possibly important in resistance to avian disease.