title: Demonstration of recovery from the potentially mutagenic effects of ultraviolet light by replication-inhibited Chinese hamster V79 cells.
abstract: The effects of replication-inhibiting conditions on the ability of Chinese hamster (V79) cells to recover from the potentially mutagenic effects of ultraviolet (UV) light were investigated. V79 cells were synchronized by a new technique using a low concentration of hydroxyurea (0.2 mM), which provided a mildly-toxic, nonmutagenic method for producing large quantities of synchronized cells needed for these studies. The protocol developed for this study involved UV-irradiation of synchronized V79 cells which were blocked at the Gl/S boundary. Following UV-irradiation, the cells were either allowed to enter S phase immediately or were blocked for increasing periods of time by the addition of more hydroxyurea. The former cells contained the highest frequencies of ouabain-resistant mutants, while cells whose replication was blocked following UV-irradiation showed decreasing mutation frequencies with respect to time. Therefore, V79 cells are able to demonstrate liquid holding recovery from potentially mutagenic UV-lesions. Since the UV-induced mutation frequency was reduced by almost 50% following 6 h of 'liquid holding', the mutagenic lesions seem to be removed at a faster rate than has previously been reported for the removal of pyrimidine dimers from these cells.
mesh_terms: D000818:Animals; D002453:Cell Cycle; D002455:Cell Division; D002460:Cell Line; D002470:Cell Survival / Q000528:radiation effects*; D006224:Cricetinae; D003412:Cricetulus; D004351:Drug Resistance; D005819:Genetic Markers; D008168:Lung; D010042:Ouabain / Q000494:pharmacology; D010641:Phenotype; D014466:Ultraviolet Rays
chemical_list: D005819:Genetic Markers; D010042:Ouabain