Complex chromosomal neighborhood effects determine the adaptive potential of a gene under selection.

ABSTRACT: How the organization of genes on a chromosome shapes adaptation is essential for understanding evolutionary paths. Here, we investigate how adaptation to rapidly increasing levels of antibiotic depends on the chromosomal neighborhood of a drug-resistance gene inserted at different positions of the Escherichia coli chromosome. Using a dual-fluorescence reporter that allows us to distinguish gene amplifications from other up-mutations, we track in real-time adaptive changes in expression of the drug-resistance gene. We find that the relative contribution of several mutation types differs systematically between loci due to properties of neighboring genes: essentiality, expression, orientation, termination, and presence of duplicates. These properties determine rate and fitness effects

SUBMITTER: Steinrueck M 

PROVIDER: S-EPMC5526668 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature