Adaptive evolution of the lactose utilization network in experimentally evolved populations of Escherichia coli.

ABSTRACT: Adaptation to novel environments is often associated with changes in gene regulation. Nevertheless, few studies have been able both to identify the genetic basis of changes in regulation and to demonstrate why these changes are beneficial. To this end, we have focused on understanding both how and why the lactose utilization network has evolved in replicate populations of Escherichia coli. We found that lac operon regulation became strikingly variable, including changes in the mode of environmental response (bimodal, graded, and constitutive), sensitivity to inducer concentration, and maximum expression level. In addition, some classes of regulatory change were enriched in specific selective environments. Sequencing of evolved clones, combined with reconstruction of individual mutations in

SUBMITTER: Quan S 

PROVIDER: S-EPMC3257284 | biostudies-literature | 2012 Jan

REPOSITORIES: biostudies-literature