title: DNA repair in a UV-sensitive mutant of a mouse cell line.
abstract: A UV-sensitive mutant, Q31, isolated from mouse-lymphoma L5178Y cells, was studied for excision and post-replication repairs. A nearly equal number of UV endonuclease-sensitive sites was induced by UV in L5178Y, Q31, and human Raji cells. L5178Y cells irradiated with 10 J/m2 removed 18% of sensitive sites from DNA of detection, whereas Raji cells eliminated about 60% of the sites. These results during incubation for 24 h, and Q31 cells removed 3% of the sites, a fraction less than the limit indicate that mouse-lymphoma cells are capable of excision repair to a limited extend as compared with human cells and that mutant Q31 cells are essentially devoid of dimer excision. The newly synthesized DNA was of smaller size in UV-irradiated and unirradiated Q31 cells than that in the corresponding L5178Y cells, but the DNAs in both cell strains increased to comparable sizes after a 2-h chase.
mesh_terms: D000818:Animals; D004260:DNA Repair; D007940:Leukemia L5178 / Q000235:genetics*; D007942:Leukemia, Experimental / Q000235:genetics*; D051379:Mice; D009154:Mutation; D010641:Phenotype; D011740:Pyrimidine Dimers / Q000235:genetics; D011836:Radiation Tolerance; D014466:Ultraviolet Rays
chemical_list: D011740:Pyrimidine Dimers