Molecular mapping of murine I region recombinants: Crossing over in the E sub( beta ) gene

• Published in: The Journal of immunology (1950) Vol. 136; no. 3; pp. 1112 - 1116
• Main Authors: Saha, B K, Cullen, SE
• Format: Journal Article
• Language: English
• Published: 01.01.1986
• ISSN: 0022-1767

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 sub( beta ), A sub( alpha ), 5'-E sub( beta ), 3'-E sub( beta ), and A sub( alpha ) genes. New E sub( beta ) gene probes were specifically constructed to make analysis of the E sub( 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 Kappa and the s haplotypes showed that both recombinations mapped within a 7-kb segment of the E sub( beta ) gene. 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 sub( beta ) gene.