Bu-1b Products

Chicken Bu-1b, a product of the Bu-1b allele, is expressed on the cell surface as a disulfide-linked homodimer. In 10-week-old H.B15 and H.B2 chickens, Bu-1 is found on 85-90% of bursal cells, 2-8% of thymocytes, 15-27% of spleen cells, and 2-18% of peripheral blood cells. It is also expressed on subsets of macrophages and monocytes, but not on granulocytes, erythrocytes or thrombocytes. In chickens heterozygous for the Bu-1 alleles (Bu-1a/b), Bu-1a does not exhibit allelic exclusion. The monoclonal antibody 5-11G2 reacts with lymphoid cells from CHA and H.B14Ab strains but does not react with cells from H.B14Aa. (1-2)