Isolation and partial characterization of mutagen-sensitive and DNA repair mutants of Chinese hamster fibroblasts
Through a new approach, we have sought to isolate ultraviolet light (UV)-sensitive and DNA repair mutant Chinese hamster fibroblasts. The procedure consisted of 1) mutation induction by 5-bromodeoxyuridine (Brd U)-blacklight and UV treatments; 2) incorporation of 3H-thymidine in repair-proficient cells at high temperature (38.5 degrees C) following UV damage; 3) cold holding (4.0 degrees C) of these cells to induce tritium killing; and 4) recovery and testing of repair-deficient and UV-sensitive cells which have survived and formed colonies at low temperature (34.0 degrees C). In our initial attempt at this protocol, we isolated 72 surviving colonies from 2 x 10(7) cells plated for selection. Of the 72 colonies, 20 demonstrated potential interest and four were selected for extensive study. One, identified as UVs-7, is slightly more sensitive to UV, but not sensitive to X rays or N-acetoxy-2-acetylaminofluorene (NAc-AAF). The mutant exhibits a highly reduced level of unscheduled DNA synthesis (UDS), as compared to the parental line. Two additional lines, UVs-40 UVs-44, are sensitive to UV, X ray, N-methyl-N-nitro-N-nitrosoguanidine (MNNG), and NAc-AAF, but exhibit normal UDS. A fourth line, UVr-23, has enhanced UDS, is resistant to UV, but exhibits no difference in sensitivity to x ray or NAc-AAf. These mutants are all stable, and should be useful for the study of mammalians DNA repair processes and mechanisms of mutagenesis.
- OSTI ID:
- 5306778
- Journal Information:
- Environ. Mutagen.; (United States), Vol. 3:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
DNA
BIOLOGICAL REPAIR
FIBROBLASTS
RADIOSENSITIVITY
BUDR
COLONY FORMATION
HAMSTERS
MUTANTS
THYMIDINE
TRITIUM COMPOUNDS
ULTRAVIOLET RADIATION
ANIMAL CELLS
ANIMALS
ANTIMETABOLITES
AZINES
BIOLOGICAL RECOVERY
BROMOURACILS
CONNECTIVE TISSUE CELLS
DRUGS
ELECTROMAGNETIC RADIATION
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
LABELLED COMPOUNDS
MAMMALS
NUCLEIC ACIDS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC BROMINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PYRIMIDINES
RADIATIONS
RECOVERY
REPAIR
RIBOSIDES
RODENTS
SOMATIC CELLS
URACILS
VERTEBRATES
560121* - Radiation Effects on Cells- External Source- (-1987)
550201 - Biochemistry- Tracer Techniques
560111 - Radiation Effects on Biochemicals- In Vitro- (-1987)