Structure and expression of genes encoding murine Qa-2 class I antigens.
DNA structural analysis of the Qa region in two BALB/c mouse substrains with different Qa-2 phenotypes reveals that a deletion of DNA has occurred in BALB/cBy (Qa-2-) mice relative to BALB/c (Qa-2+) mice. We propose that this deletion arises from unequal crossing-over and recombination between adjacent BALB/c class I genes and results in the generation of a hybrid class I gene in BALB/cBy mice. Furthermore, we suggest that this is a direct cause of the change in Qa-2 phenotype. Further support for this model was obtained from transfection experiments in which cloned genes from the equivalent part of the Qa region in C57BL/10 mice were introduced into L cells. Four C57BL/10 genes, arranged in two almost identical pairs, encode polypeptides that are precipitated from lysates of transfectants with anti-Qa-2/3 antiserum. Although loss of one pair of these genes in BALB/c mice has no qualitative effect on Qa-2 phenotype, the loss of both pairs of genes via gene fusion leads to the loss of the Qa-2+ phenotype in BALB/cBy mice.
D000818:Animals; D000954:Antigens, Surface / Q000235:genetics*; D002872:Chromosome Deletion; D003001:Cloning, Molecular; D005786:Gene Expression Regulation; D005796:Genes; D015395:Histocompatibility Antigens Class I; D007739:L Cells; D008285:Major Histocompatibility Complex; D008565:Membrane Proteins / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C / Q000235:genetics*; D010957:Plasmids; D014162:Transfection
D000954:Antigens, Surface; D015395:Histocompatibility Antigens Class I; D008565:Membrane Proteins; C032907:Q surface antigens