title: The dose-response relationship for ultraviolet-light-induced mutations at the hypoxanthine-guanine phosphoribosyltransferase locus in Chinese hamster ovary cells.
abstract: Exposure of Chinese hamster ovary (CHO) cells clone K1BH4 to ultraviolet (UV) light at doses up to 86 ergs/mm2 did not significantly reduce cell survival, but UV doses of 86-648 ergs/mm2 produced an exponential cell killing. Observed mutation frequency ro 6-thioguannine resistance induced by UV increases approximately in proportion to increasing doses up to 260 ergs/mm2 in a range of 5-648 ergs/mm2 examined. The pooled data of mutation frequency f(X) as a function of dose X from 0-260 ergs/mm2 is adequately described by f(X)=10(-6) (13.6 + 2.04 X). That the UV-induced mutations to 6-thioguanine resistance affects the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) locus is supported by the observation that all randomly isolated drug-resistant colonies contained highly reduced or undetectable HGPRT activity.
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival; D002874:Chromosome Mapping; D002875:Chromosomes / Q000528:radiation effects*; D006224:Cricetinae; D004307:Dose-Response Relationship, Radiation; D004351:Drug Resistance; D007041:Hypoxanthine Phosphoribosyltransferase / Q000096:biosynthesis*; D066298:In Vitro Techniques; D009154:Mutation; D011336:Probability; D013866:Thioguanine / Q000494:pharmacology; D014466:Ultraviolet Rays
chemical_list: D007041:Hypoxanthine Phosphoribosyltransferase; D013866:Thioguanine