This construct encodes an IgMa constant region with the variable specificity from BALB/c IgG1 mouse anti-human insulin monoclonal antibody, mAb125 that was the source of the immunoglobulin heavy chain VDJ sequence in this transgene. The resulting antibody binds insulin when co-expressed with a transgene encoding the light chain with the VJ of mAB125. (J:91866)