induction of chromosomal aberrations and sister-chromatid exchanges ( sces ) was studied in wild-type chinese hamster ovary ( cho-k1 ) cells and its 2 x-ray-sensitive mutants xrs 5 and xrs 6 ( known to be deficient in repair of dna double-strand breaks ( dsbs ] by restriction endonucleases ( res ) and inhibitors of dna topoisomerase ii known to induce dna strand breaks .
C0037211
sister-chromatid exchanges
C0007634
cells