title: cis-Platinum(II)diamminodichloride-induced mutagenesis in E. coli K12: crowding depression of mutagenesis.
abstract: Cis-Platinum(II)diamminodichloride (cis-PDD)-induced mutations to prototrophy were studied in Escherichia coli. Mutagenesis was not detected in a recA nor in a lexA mutant, but was greater in a uvrA strain than in a repair-proficient strain, at a given treatment of cis-PDD. Increasing the plating density above 10(5) cells per plate did not give an equivalent increase in revertants per plate [crowding depression of mutagenesis (Bockrath et al., 1980)]. Growth rates were similar at different plating densities and crowding depression of mutagenesis was observed in both excision-proficient and excision-deficient strains. A filtrate of a plate wash from crowded plates, of either treated or untreated cultures, further reduced the mutation frequencies over that due to crowding depression of mutagenesis.
mesh_terms: D002945:Cisplatin / Q000494:pharmacology*; D004260:DNA Repair; D004926:Escherichia coli / Q000235:genetics*; D008433:Mathematics; D009153:Mutagens; D009154:Mutation; D010641:Phenotype; D011995:Recombination, Genetic
chemical_list: D009153:Mutagens; D002945:Cisplatin