Description:
Chicken Bu-1, a product of the Bu-1a and Bu-1b alleles, is a type I transmembrane glycosylated disulfide-linked homodimer. The monoclonal antibody AV20 recognizes a monomorphic determinant on the Bu-1 B cell-associated alloantigens of both RPL 6(3) (Bu-1a) and 7(2) (Bu-1b) lines of inbred chickens. The antibody also identifies B cells in partially inbred birds. 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. The monoclonal antibody AV20 does not cross react with turkey cells when analyzed by flow cytometry.