Repair of DNA double-strand breaks in colcemid-arrested mitotic Chinese hamster cells.
Chinese hamster V79 cells blocked in mitosis were irradiated with 60Co gamma-rays and incubated for repair in the presence of colcemid. DNA strand breaks were measured using neutral sucrose gradient centrifugation or the alkaline unwinding technique. It was found that mitotic cells repair DNA double-strand breaks (as well as single-strand breaks) efficiently, with a rate similar to exponentially growing asynchronous cells. It is argued that the dense packing of the chromatin in the mitotic chromosome makes a recombinational repair mechanism unlikely.
D000818:Animals; D002453:Cell Cycle / Q000187:drug effects; D002460:Cell Line; D003037:Cobalt Radioisotopes; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000528:radiation effects*; D004260:DNA Repair; D003703:Demecolcine / Q000494:pharmacology; D005720:Gamma Rays; D008938:Mitosis
D003037:Cobalt Radioisotopes; D004247:DNA; D003703:Demecolcine