title: Faster rates of DNA unwinding under alkaline conditions in xrs-5 cells may reflect chromatin structure alterations.
abstract: The Chinese hamster ovary (CHO) cell line xrs-5 is a radiation-sensitive mutant isolated from CHO-K1 cells. The radiation sensitivity is associated with a defect in DNA double-strand break rejoining. The DNA alkaline unwinding technique was used to measure the DNA single-strand breakage caused by gamma-rays in xrs-5 and CHO-K1 cells. Greater rates of DNA unwinding were found in xrs-5 cells as compared to CHO-K1. Independent measurement of DNA strand breakage by DNA filter elution or pulsed-field gel electrophoresis failed to show any difference between the two cell lines. The greater rate of unwinding in xrs-5 cells may reflect an alteration in chromosome structure.
authors.affiliation: Biological and Medical Research Division, Argonne National Laboratory, IL 60439.
authors.forename: J L
authors.initials: JL
authors.lastname: Schwartz
authors.forename: E
authors.initials: E
authors.lastname: Moan
authors.forename: R
authors.initials: R
authors.lastname: Mustafi
authors.forename: L
authors.initials: L
authors.lastname: Fink
authors.forename: L S
authors.initials: LS
authors.lastname: Yasui
mesh_terms: D000818:Animals; D016466:CHO Cells; D002460:Cell Line; D002843:Chromatin / Q000528:radiation effects*; D006224:Cricetinae; D004247:DNA; D004249:DNA Damage; D004277:DNA, Single-Stranded; D005720:Gamma Rays; D006863:Hydrogen-Ion Concentration
chemical_list: D002843:Chromatin; D004277:DNA, Single-Stranded; D004247:DNA