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U.S. Department of Energy
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Effects of radiations on DNA and repair of the damage. Progress report, May 1, 1974--June 30, 1977. [Gamma and UV radiation, Escherichia coli, lambda phage]

Technical Report ·
DOI:https://doi.org/10.2172/7210876· OSTI ID:7210876
Repair of DNA double-strand breaks produced by gamma rays takes place in E. coli. Such repair requires recA function and the presence of another DNA molecule of the same base sequence, so it may involve a recombination-like event. Ultraviolet light acting on DNA containing bromouracil produces doublestrand breaks by single photochemical events, and a simple model can explain this, as well as other results. Bromouracil mutagenesis of either E. coli or lambda phage does not involve the recA or red functions. Bromouracil mutagenesis is greatly increased in E. coli mutants such as uvrE, mutL, mutR and mutS, which are defective in mismatch repair. This, and other results, suggest that bromouracil mutagenesis occurs when cell enzymes fail to remove mismatched bases. Ultraviolet mutagenesis of lambda phage may be a useful model for the study of mutagenesis in cells, because the effects of lesions in the gene mutated (i.e. in the phage) and changes in enzyme systems (by treating the host cells) can be examined separately. Quantitative data support this approach.
Research Organization:
Yale Univ., New Haven, CT (USA)
OSTI ID:
7210876
Report Number(s):
COO-3571-18
Country of Publication:
United States
Language:
English