Repair of DNA single-strand breaks in radiation-sensitive mutants of mouse cells.
The radiation-sensitive mutant M10 of mouse lymphoma L5178Y cells was examined for its ability to rejoin DNA single-strand breaks induced by gamma-rays. The alkaline sucrose gradient sedimentation analysis revealed that M10 cells repaired single-strand breaks but simultaneously produced increasing amounts of small DNA fragments with time of postirradiation incubation, something which was not observed in L5178Y cells. Since small fragments did not appear in M10 cells irradiated at room temperature, DNA fragmentation may result from cold treatment during irradiation followed by incubation at 37 degrees C. This indicates that the cold susceptibility is characteristic of M10 cells and is not related to radiation sensitivity of this mutant. This conclusion is supported by the finding that no DNA degradation takes place after cold treatment with a subsequent incubation in the other radiosensitive mutant LX830 that belongs to the same complementation group as M10.
D000818:Animals; D002460:Cell Line; D004247:DNA / Q000528:radiation effects*; D004260:DNA Repair; D005720:Gamma Rays; D008223:Lymphoma; D051379:Mice; D009154:Mutation / Q000528:radiation effects*
D004247:DNA