Accumulation of mutants in "aging" bacterial colonies is due to growth under selection, not stress-induced mutagenesis

Marie Wrande, John R. Roth, Diarmaid Hughes

Research output: Contribution to journalArticle

56 Scopus citations

Abstract

Several bacterial systems show behavior interpreted as evidence for stress-induced mutagenesis (adaptive mutation), a postulated process by which nongrowing cells temporarily increase their general mutation rate. Theoretical considerations suggest that periodic stress-induced general mutagenesis would not be advantageous in the long term, due to the high cost of deleterious mutations. Alternative explanations have been tested for very few of the systems used as evidence for stress-induced mutation. In one prominent system, mutants resistant to rifampicin (RifR; rpoB; RNA polymerase) accumulate in cell populations that "age" on solid medium with little net growth. Mutant accumulation was initially attributed to stress-induced general mutagenesis in nongrowing cells. Evidence is presented that these Rif R mutants accumulate because they grow faster than parent cells during the aging period. Direct tests revealed no increase in the frequency of other mutant types during the aging period.

Original languageEnglish (US)
Pages (from-to)11863-11868
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume105
Issue number33
DOIs
StatePublished - Aug 19 2008

ASJC Scopus subject areas

  • Genetics
  • General

Fingerprint Dive into the research topics of 'Accumulation of mutants in "aging" bacterial colonies is due to growth under selection, not stress-induced mutagenesis'. Together they form a unique fingerprint.

  • Cite this