Mutagenesis and DNA repair in mammalian cells
Two aspects of DNA damage and repair in mammalian cells were investigated. Using a lambda phage shuttle vector, a system was developed to study mutations arising in the DNA of mammalian cells. This system was used to determine the spectrum of mutations induced in cellular DNA by ultraviolet light. Also, the repair of base pair mismatches in DNA was studied by the development of a method to detect a DNA mismatch repair activity in extracts made from cultured human cells. In order to study mutations arising in mammalian cells, stable mouse L cell lines were established with multiple copies of lambda phage vector which contains the supF gene of E. coli as a target for mutagenesis. Rescue of viable phage from high molecular weight mouse cell DNA using lambda in vitro packaging extracts was efficient and yielded a negligible background of phage with mutations in the supF gene. From mouse cells exposed to 12 J/m/sup 2/ of 254 nm ultraviolet (UV) light, 78,510 phage were rescued of which eight were found to have mutant supF genes. DNA sequence analysis of the mutants suggests that the primary site of UV mutagenesis in mammalian cells is at pyrimidine-cytosine (Py-C) sequences, and that the most frequent mutation at this site is a C to T transition.
- Research Organization:
- Yale Univ., New Haven, CT (USA)
- OSTI ID:
- 6289528
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ANIMAL CELLS
DNA REPAIR
MUTATIONS
RADIOINDUCTION
ULTRAVIOLET RADIATION
MUTAGENESIS
DNA MISMATCH
DNA SEQUENCING
GENETIC RADIATION EFFECTS
MICE
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
ELECTROMAGNETIC RADIATION
GENETIC EFFECTS
MAMMALS
RADIATION EFFECTS
RADIATIONS
RECOVERY
REPAIR
RODENTS
STRUCTURAL CHEMICAL ANALYSIS
VERTEBRATES
560120* - Radiation Effects on Biochemicals
Cells
& Tissue Culture