Genetic analysis of the H-2D region using a new intra-D-region recombinant mouse strain.
A rare D-region recombination event which gave rise to the B10.RQDB major histocompatibility complex haplotype has been examined to ascertain the nature of the crossover and to determine which class I genes are present in the new alignment of D-region genes. Serologic analysis have shown that the B10 . RQDB major histocompatibility complex recombinant mouse inherited the H-2Dd gene from the B10.T(6R) parental line and the H-2Db gene from the B10.A(2R) parental line, representing the first example of an intra-D-region crossover resulting from an intercross. Previous molecular genetic analyses of the d and b haplotypes revealed structural diversity in the organization of their D-region gene clusters. Hence, the D region is comprised of five class I genes in the d haplotype and only one in the b haplotype. Because allelic relationships among the various D-region genes are not defined, either a homologous or nonhomologous alignment of genes has generated the RQDB crossover. Therefore, the possibility that all three D-region antigen-presenting molecules (Dd, Ld, and Db) might be encoded by the RQDB haplotype was examined. Fluorescence-activated cell sorter and cytotoxic T lymphocyte analyses revealed no detectable levels of H-2Ld cell-surface expression, confirming earlier studies with antibody-mediated cytotoxicity and immunoprecipitation. Southern blot analysis localized the recombination point to within a 1-kb region at the centromeric end of the H-2Ld gene on the B10 . T(6R) chromosome in a region of high homology to the H-2Db gene on the B10 . A(2R) chromosome. Together, these studies define the D region of the RQDB haplotype as containing the five class I genes: Dd, D2d, D3d, D4d, and Db. In addition to providing insight into rare recombination events in the D region, the B10.RQDB mouse should be a useful tool for exploring the function of D-region genes.
Duran
L W
LW
Department of Immunology, Mayo Medical School, Rochester, MN 55905.
Zeller
J C
JC
Lundy
J K
JK
Chang-Miller
A
A
Krco
C J
CJ
David
C S
CS
Pease
L R
LR
D000818:Animals; D000911:Antibodies, Monoclonal; D002874:Chromosome Mapping; D003602:Cytotoxicity, Immunologic; D005455:Fluorescent Antibody Technique; D005805:Genes, MHC Class I; D006183:H-2 Antigens / Q000032:analysis / Q000235:genetics*; D006239:Haplotypes; D008285:Major Histocompatibility Complex; D051379:Mice; D011995:Recombination, Genetic; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
D000911:Antibodies, Monoclonal; D006183:H-2 Antigens