Impact of individual mutations on increased fitness in adaptively evolved strains of Escherichia coli.

ABSTRACT: We measured the relative fitness among a set of experimentally evolved Escherichia coli strains differing by a small number of adaptive mutations by directly measuring allelic frequencies in head-to-head competitions using a mass spectrometry-based method. We compared the relative effects of mutations to the same or similar genes acquired in multiple strains when expressed in allele replacement strains. We found that the strongest determinant of fitness among the evolved strains was the impact of beneficial mutations to the RNA polymerase beta and beta' subunit genes. We also identified several examples of epistatic interactions between rpoB/C and glpK mutations and identified two other mutations that are beneficial only in the presence of previously acquired mutations but that have little

SUBMITTER: Applebee MK 

PROVIDER: S-EPMC2447027 | biostudies-literature | 2008 Jul

REPOSITORIES: biostudies-literature