title: Organization and evolution of immunoglobulin VH gene subgroups.
abstract: The organization and evolution of immunoglobulin variable region genes was studied by comparing human and mouse heavy chain variable region (VH) genes. We show that a VH gene subgroup constitutes a physically linked multigene family separated from another VH subgroup. We mapped the VHIII gene subgroup to be 3' to the VHII gene subgroup based on deletion of VH genes after V-D-J rearrangement. The results indicate that the human VHIII gene subgroup underwent a significant gene expansion as compared to the mouse VHIII subgroup. Amino acid sequence data indicate that human VHIII genes correspond to only a small subset of mouse VHIII genes. Human VHIII genes contain a shorter intron and are two codons shorter than most BALB/c mouse VHIII genes. The nature of nucleotide substitutions between VH genes within a species (human) is similar to that between genes of different species (human/mouse). Both contain approximately 50% silent substitutions.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001666:Binding Sites, Antibody / Q000235:genetics*; D005075:Biological Evolution; D002874:Chromosome Mapping; D005796:Genes; D008040:Genetic Linkage; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D051379:Mice; D013045:Species Specificity
chemical_list: D007143:Immunoglobulin Heavy Chains; D007135:Immunoglobulin Variable Region