Molecular analysis of the hotspot of recombination in the murine major histocompatibility complex.
Biological and serological assays have been used to define four subregions for the I region of the major histocompatibility complex (MHC) in the order I-A, I-B, I-J, and I-E. The I-J subregion presumably encodes the I-J polypeptide of the elusive T-cell suppressor factors. Restriction enzyme site polymorphisms and DNA sequence analyses of the I region from four recombinant mouse strains were used to localize the putative I-B and I-J subregions to a 1.0-kilobase (kb) region within the E beta gene. Sequencing this region from E beta clones derived from the two mouse strains: B10.A(3R), I-Jb and B10.A(5R), I-Jk initially used to define the I-J subregion revealed that these regions are identical, hence the distinct I-Jb and I-Jk molecules cannot be encoded by this DNA. In addition, the DNA sequence data also refute the earlier mapping of the I-B subregion. Analysis of the DNA sequences of three parental and four I region recombinants reveals that the recombinant events in three of the recombinant strains occurred within a 1-kb region of DNA, supporting the proposition that a hotspot for recombination exists in the I region. The only striking feature of this hotspot is a tetramer repeat (AGGC)n that shows 80 percent homology to the minisatellite sequence which may facilitate recombination in human chromosomes.
D000818:Animals; D001483:Base Sequence; D004262:DNA Restriction Enzymes; D005802:Genes, MHC Class II; D008285:Major Histocompatibility Complex; D051379:Mice; D011995:Recombination, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D013491:Suppressor Factors, Immunologic / Q000235:genetics
D013491:Suppressor Factors, Immunologic; D004262:DNA Restriction Enzymes