Genome-wide hypermutation in a subpopulation of stationary-phase cells underlies recombination-dependent adaptive mutation

Stationary‐phase mutation in microbes can produce selected (‘adaptive’) mutants preferentially. In one system, this occurs via a distinct, recombination‐dependent mechanism. Two points of controversy have surrounded these adaptive reversions of an Escherichia coli lac mutation. First, are the mutati...

Full description

Saved in:
Bibliographic Details
Published in:The EMBO journal 1997-06, Vol.16 (11), p.3303-3311
Main Authors: Torkelson, Joel, Harris, Reuben S., Lombardo, Mary-Jane, Nagendran, Jayan, Thulin, Carl, Rosenberg, Susan M.
Format: Article
Language:English
Subjects:
Adaptation, Biological - genetics
adaptive mutation
Base Sequence
Biological Evolution
Chromosomes, Bacterial
directed mutation
Escherichia coli
Escherichia coli - genetics
Escherichia coli - growth & development
evolution
F Factor - genetics
Genome, Bacterial
Lac Operon - genetics
Models, Genetic
Molecular Sequence Data
Mutagenesis
recombination
Recombination, Genetic
Selection, Genetic
stationary phase
Time Factors
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Stationary‐phase mutation in microbes can produce selected (‘adaptive’) mutants preferentially. In one system, this occurs via a distinct, recombination‐dependent mechanism. Two points of controversy have surrounded these adaptive reversions of an Escherichia coli lac mutation. First, are the mutations directed preferentially to the selected gene in a Lamarckian manner? Second, is the adaptive mutation mechanism specific to the F plasmid replicon carrying lac ? We report that lac adaptive mutations are associated with hypermutation in unselected genes, in all replicons in the cell. The associated mutations have a similar sequence spectrum to the adaptive reversions. Thus, the adaptive mutagenesis mechanism is not directed to the lac genes, in a Lamarckian manner, nor to the F′ replicon carrying lac . Hypermutation was not found in non‐revertants exposed to selection. Therefore, the genome‐wide hypermutation underlying adaptive mutation occurs in a differentiated subpopulation. The existence of mutable subpopulations in non‐growing cells is important in bacterial evolution and could be relevant to the somatic mutations that give rise to cancers in multicellular organisms.
ISSN:0261-4189
1460-2075
1460-2075
DOI:10.1093/emboj/16.11.3303