title: Molecular mapping of murine I region recombinants: crossing over in the E beta gene.
abstract: The parental origin of genomic DNA from two independently derived murine I-region recombinants, B10.ASR7 [as3] and B10.BASR1 [as4], was determined by Southern blot hybridization by using DNA probes corresponding to A beta, A alpha, 5'-E beta, 3'-E beta, and A alpha genes. New E beta gene probes were specifically constructed to make analysis of the E beta gene region definitive. Although the immune response phenotypes of the recombinants had suggested an I-A subregion cross-over, a number of restriction fragment length polymorphisms distinguishing the k and the s haplotypes showed that both recombinations mapped within a 7-kb segment of the E beta gene. The validity of these results was tested by analysis of two other H-2k/s recombinants. One of them, B10.S(8R) [as1], mapped within the same 7-kb region of the E beta gene, whereas the other, B10.BASR2 [as5], mapped outside the I-region as expected. Including those studied here, there are a dozen I region recombinants whose cross-over positions have been determined at a molecular genetic level, and all of the cross-overs occurred within the E beta gene.
mesh_terms: D000483:Alleles; D000818:Animals; D003001:Cloning, Molecular; D003434:Crossing Over, Genetic; D004262:DNA Restriction Enzymes; D005802:Genes, MHC Class II; D006238:Haploidy; D006649:Histocompatibility Antigens / Q000235:genetics*; D000949:Histocompatibility Antigens Class II / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009693:Nucleic Acid Hybridization; D011110:Polymorphism, Genetic; D011995:Recombination, Genetic
chemical_list: D006649:Histocompatibility Antigens; D000949:Histocompatibility Antigens Class II; C024138:I-E-antigen; D004262:DNA Restriction Enzymes