Different genetic alterations underlie dual hypersensitivity of CHO mutant UV-1 to DNA methylating and cross-linking agents
- 1 November 1985
- journal article
- research article
- Published by Springer Nature in Somatic Cell and Molecular Genetics
- Vol. 11 (6) , 523-532
- https://doi.org/10.1007/bf01534718
Abstract
CHO mutant UV-1, isolated on the basis of hypersensitivity to UV radiation (254 nm), was further characterized with respect to sensitivity to classes of DNA damaging agents in a differential cytotoxicity (DC) assay. Compared to its parental strain, Gly−A, UV-1 was dramatically (10-to 100-fold) hypersensitive to both DNA methylating and cross-linking agents. In addition, UV-1 was moderately (two- to fourfold) hypersensitive to several other classes of mutagens. DNA isolated from UV-1 or Gly− A after exposure to14C-labeled methylnitrosourea (MNU) contained similar amounts of label, thus ruling out differences in uptake or binding. Three phenotypic revertants of UV-1 were resistant to N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) and other methylating agents but retained hypersensitivity to cross-linking agents. Moreover, fusion of UV-1 with two different UV-sensitive CHO mutants also having hypersensitivity to cross-link and methylation damage produced hybrids resistant to mitomycin C (MMC) but not to methyl methane sulfonate (MMS). Since the methylation and cross-link sensitivities were uncoupled in both genetic tests, the complex phenotype of UV-1 is likely due to more than one genetic alteration.This publication has 29 references indexed in Scilit:
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