Downstream boundary of chromosomal R-loops at murine switch regions: implications for the mechanism of class switch recombination.

ABSTRACT: R-loops form at Sgamma3 and Sgamma2b Ig class switch regions in the chromosomes of stimulated murine primary B cells and are suspected to be a general feature of mammalian class switch regions. The in vivo upstream boundary of the R-loops is known to begin within the switch repeats. To determine how precisely the R-loop structure conforms to the repetitive zone of the murine Sgamma3 and Sgamma2b switch regions, a chemical probing method was used to obtain structural information on the downstream boundary. We find that only 61-67% of the R-loops terminate within the Sgamma3 and the Sgamma2b repetitive zones, and the remainder terminate downstream, usually within the first 600 bp immediately downstream of the core switch repeats. Interestingly, the nontemplate strand G density falls to the r

SUBMITTER: Huang FT 

PROVIDER: S-EPMC1458789 | biostudies-literature | 2006 Mar

REPOSITORIES: biostudies-literature