Insertion-sequence-mediated mutations both promote and constrain evolvability during a long-term experiment with bacteria.

ABSTRACT: Insertion sequences (IS) are ubiquitous bacterial mobile genetic elements, and the mutations they cause can be deleterious, neutral, or beneficial. The long-term dynamics of IS elements and their effects on bacteria are poorly understood, including whether they are primarily genomic parasites or important drivers of adaptation by natural selection. Here, we investigate the dynamics of IS elements and their contribution to genomic evolution and fitness during a long-term experiment with Escherichia coli. IS elements account for ~35% of the mutations that reached high frequency through 50,000 generations in those populations that retained the ancestral point-mutation rate. In mutator populations, IS-mediated mutations are only half as frequent in absolute numbers. In one population, an excep

SUBMITTER: Consuegra J 

PROVIDER: S-EPMC7881107 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature