Mutational spectrum of revertants in the hisD3052 allele of Salmonella typhimurium induced by hydrogen peroxide-activated benzidine.
Benzidine is mutagenic in a modified Ames (Salmonella typhimurium) assay, which uses hydrogen peroxide-dependent peroxidative activation. The mutational specificity of benzidine was investigated in tester strain TA98, which reverts by frameshifts of the hisD3052 allele. The most frequently observed mutation is a deletion of two bases from a (CG)4 run. This deletion was elevated in frequency among benzidine-induced revertants, relative to spontaneous revertants. Many other mutations were also observed, including additions, deletions, and complex events. Only small frameshifts were observed among the benzidine-induced revertants, whereas some larger deletions were observed among the spontaneous revertants.
Wallace
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Guelph-Waterloo Centre for Graduate Work in Chemistry, Department of Chemistry and Biochemistry, University of Guelph, Ont., Canada.
Josephy
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D000429:Alcohol Oxidoreductases / Q000235:genetics*; D000483:Alleles; D001483:Base Sequence; D001560:Benzidines / Q000494:pharmacology*; D017931:DNA Primers; D005798:Genes, Bacterial; D006639:Histidine / Q000235:genetics*; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009152:Mutagenicity Tests; D009154:Mutation; D012486:Salmonella typhimurium / Q000235:genetics*
D001560:Benzidines; D017931:DNA Primers; C029876:benzidine; D006639:Histidine; D006861:Hydrogen Peroxide; D000429:Alcohol Oxidoreductases; C021358:histidinol dehydrogenase