[Structural analysis of the class II gene region of rat MHC (RT1)--a novel beta-chain gene mapped to RT1. B region].
In the present study, genomic DNAs obtained from intra-RT1 recombinant rats were subjected to restriction fragment length polymorphism (RELP) analysis, using HLA-DP beta cDNA as a probe. Out of 8 strains of rats whose haplotypes were evaluated serologically, 3 strains (NIG-III, LEJ, and DA. 1I (BI)), including 1 congenic strain, had RT1. A/B recombinant haplotypes (RT1. AqB1D1, AuBbDb, and AnBaDa, respectively). After digestion with BglII or HincII, RFLP analysis of these strains with HLA-DP beta probe showed strong bands associated with RT 1. A haplotypes, in addition to some weaker cross-hybridizing bands. That is, after BglII digestion, 4.2kb band was detected associated with RT 1. Aq, 2.1 kb band with A1 and Ab, 4.3 kb band with Au, respectively. After HincII digestion, 1.2 kb band was detected in association with RT1. Aa and 13.0 kb band with An, respectively. From these results I conclude that the recombination events have occurred within the class II region of RT1, especially between B beta gene and a novel class II beta gene which is proposed to be mapped near RT1. A region. The novel gene seems to be a candidate for DP beta-like gene in RT1, because it strongly hybridized with HLA-DP beta cDNA. As in the mouse or the man, a recombinational hotspot might be generated around this novel gene, which provides another evidence for the structural homology among the MHCs of these three species.
D000818:Animals; D005796:Genes; D005802:Genes, MHC Class II; D006239:Haplotypes; D008285:Major Histocompatibility Complex; D012150:Polymorphism, Restriction Fragment Length; D051381:Rats; D011919:Rats, Inbred Strains / Q000235:genetics*