期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1979
卷号：76
期号：8
页码：3982-3986
DOI：10.1073/pnas.76.8.3982
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The UV induction of diphtheria toxin-resistant (DTr) mutants in normal and xeroderma pigmentosum human fibroblasts has been quantitatively characterized. A concentration of diphtheria toxin at which DTr cells are cross-resistant to Pseudomonas aeruginosa exotoxin A was determined and used in the selection of resistant mutants. Recovery of mutants was not influenced by the presence of wild-type cell densities of 1-8 x 10(5) per 9-cm plate, indicating no metabolic cooperation exists, in contrast to what is seen in the selection of some other variant phenotypes. Expression periods for UV-induced mutations differed with the severity of mutagen treatment and cell strain used. A relatively long (10-15 days after UV treatment) expression period was required for the maximum recovery of DTr mutants. Maximum recovery was followed by a decrease in mutation frequency on subsequent days evaluated. An apparent linear dose response within the dose range used was observed for UV-induced mutations in both normal and xeroderma pigmentosum fibroblasts. Our results indicate that xeroderma pigmentosum fibroblasts have higher UV-induced mutation frequencies per unit UV dose but similar frequencies per unit survival compared to normal cells within the range of UV doses tested.
