A 24 kb BamHI fragment of cosmid Mann 4.2, containing allele HLA-DRA1*0101 and 5' and 3' flanking sequence, and clone 11, a full-length DRB1*1501 allele cosmid encompassing extensive flanking 5' and 3' regulatory sequence, were microinjected into oocytes. Mice with this transgene express the human HLA-DR15 serotype. (J:96561)