Whole-genome mutational biases in bacteria.

ABSTRACT: A fundamental biological question is what forces shape the guanine plus cytosine (GC) content of genomes. We studied the specificity and rate of different mutational biases in real time in the bacterium Salmonella typhimurium under conditions of strongly reduced selection and in the absence of the major DNA repair systems involved in repairing common spontaneous mutations caused by oxidized and deaminated DNA bases. The mutational spectrum was determined by whole-genome sequencing of two S. typhimurium mutants that were serially passaged for 5,000 generations. Analysis of 943 identified base pair substitutions showed that 91% were GC-to-TA transversions and 7% were GC-to-AT transitions, commonly associated with 8-oxoG- and deamination-induced damages, respectively. Other types of base pair

SUBMITTER: Lind PA 

PROVIDER: S-EPMC2584707 | biostudies-literature | 2008 Nov

REPOSITORIES: biostudies-literature