Whole genome sequencing of the Escherichia coli strain АВ1157 and its mutants AB1885 uvrB5, AB2463 recA13, and AB2494 lexA1, which have deficient DNA repair, recombination, and mutagenesis systems, was performed. It was found that the genomes of the AB2463 recA13 and AB2494 lexA1 strains differ from the genome of ancestral strain in several hundred mutations which arose most probably in the course of a single treatment of AB1157 with N-methyl-N-nitro-N-nitrosoguanidine. At the same time, the genome of the strain AB1885 obtained after treatment with nitrous acid contained ten times fewer differences from its parent strain. Mutations in the AB2463 recA13 and AB2494 lexA1 genomes were predominantly represented by GC to AT transitions distributed randomly along the genomes, and their locations did not coincide in these strains. The effect of spontaneous mutations on the differences between the strains studied that appeared during the period from their isolation to the sequence experiments seems to be insignificant. Earlier known genetic and phenotypic traits are annotated on the molecular level.

中文翻译：

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大肠杆菌菌株 АВ1157、АВ2463、АВ2494 和 АВ1885 的比较基因组学

对大肠杆菌菌株 АВ1157 及其突变体 AB1885 uvrB5、AB2463 recA13 和 AB2494 lexA1 进行了全基因组测序，这些突变体具有缺陷的 DNA 修复、重组和诱变系统。发现 AB2463 recA13 和 AB2494 lexA1 菌株的基因组在数百个突变中与祖先菌株的基因组不同，这些突变最有可能发生在用 N-甲基-N-硝基-N-亚硝基胍对 AB1157 进行单次处理过程中. 同时，用亚硝酸处理后获得的菌株AB1885的基因组与其亲本菌株的差异减少了十倍。AB2463 recA13 和 AB2494 lexA1 基因组中的突变主要由沿基因组随机分布的 GC 到 AT 转变表示，并且它们的位置在这些菌株中并不重合。在从分离到序列实验期间出现的自发突变对所研究菌株之间差异的影响似乎微不足道。早期已知的遗传和表型特征在分子水平上进行了注释。