Genetic Mutations That Drive Evolutionary Rescue to Lethal Temperature in Escherichia coli.

Evolutionary rescue occurs when adaptation restores population growth against a lethal stressor. Here, we studied evolutionary rescue by conducting experiments with Escherichia coli at the lethal temperature of 43.0 °C, to determine the adaptive mutations that drive rescue and to investigate their effects on fitness and gene expression.

Adaptive Mutations in RNA Polymerase and the Transcriptional Terminator Rho Have Similar Effects on Escherichia coli Gene Expression.

Modifications to transcriptional regulators play a major role in adaptation. Here, we compared the effects of multiple beneficial mutations within and between Escherichia coli rpoB, the gene encoding the RNA polymerase β subunit, and rho, which encodes a transcriptional terminator. These two genes have harbored adaptive mutations in numerous E.

The phenotypic signature of adaptation to thermal stress in Escherichia coli.

Background: In the short-term, organisms acclimate to stress through phenotypic plasticity, but in the longer term they adapt to stress genetically. The mutations that accrue during adaptation may contribute to completely novel phenotypes, or they may instead act to restore the phenotype from a stressed to a pre-stress condition. To better understand the influence of evolution on the diversity and direction of phenotypic change, we used Biolog microarrays to assay 94 phenotypes of 115 Escherichia coli clones that had adapted to high temperature (42.