The H2dm1 mutation is unique among all described H-2 mutations in that two transplantation antigens, the H-2Dd and the H-2Ld, are affected. H2dm1 is formed by fusion of the 5' part of the Dd gene and the 3' part of the Ld gene, with the region in between deleted. The recombination junction is located in the third exon, which encodes the alpha 2 region of the protein. When the hybrid gene is transfected into mouse L cells, serological and biochemical analyses indicate the Ddm1 antigen expressed in the transformant line is identical to the mutant molecule in Ddm1 spleen cells.
Embryos were cryopreserved in 1995.