title: Evidence for an IgD homologue on chicken lymphocytes.
abstract: Chicken lymphocyte membrane immunoglobulins (Ig), were precipitated with mouse monoclonal antibodies specific for heavy and light chain isotypes and analyzed by polyacrylamide gel electrophoresis. Very little or no membrane-bound IgG and IgA was detected. After sequential precipitation and removal of IgM reactive with any of three monoclonal anti-mu antibodies, anti-light chain antibody precipitated residual Ig with a relative electrophoretic mobility similar to that of IgM. Under reducing conditions, these surface Ig molecules had a heavy chain that appeared slightly larger (approximately 81,000 daltons) than mu-chain (approximately 79,000 daltons), and light chains of approximately 25,000 daltons. Complete clearance of membrane-bound IgM reactive with an anti-mu allotype antiserum left similar molecules precipitate by monoclonal anti-light chain antibody. These non-IgM molecules could be detected on the surface of lymphocytes from blood, spleen, bursa and the B cell line RAV-1, but not from thymus or blood from an agammaglobulinemic chicken. After capping of B cell surface IgM with anti-mu, immunofluorescent staining with anti-light chain antibody revealed residual Ig molecules disturbed across the surface of more than 90% of the IgM-bearing cells. The data suggest the existence of an avian homologue of mammalian IgD. Affinity-purified goat anti-mu antibodies and a fourth monoclonal anti-mu antibody reacted with both IgM and the putative IgD molecules, which suggests that the IgD homologue shares at least one common determinant with chicken IgM.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D002645:Chickens / Q000276:immunology*; D000939:Epitopes; D007072:Immunoglobulin D / Q000032:analysis*; D008214:Lymphocytes / Q000276:immunology*; D008970:Molecular Weight; D011947:Receptors, Antigen, B-Cell / Q000032:analysis
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D007072:Immunoglobulin D; D011947:Receptors, Antigen, B-Cell