Evidence That Stationary-Phase Hypermutation in the Escherichia coli Chromosome Is Promoted by Recombination

Adaptive (or stationary-phase) mutation is a group of phenomena in which mutations appear to occur more often when selected than when not. They may represent cellular responses to the environment in which the genome is altered to allow survival. The best-characterized assay system and mechanism is r...

Full description

Saved in:
Bibliographic Details
Published in:Genetics (Austin) 2000-04, Vol.154 (4), p.1427-1437
Main Authors: Bull, Harold J, McKenzie, Gregory J, Hastings, P. J, Rosenberg, Susan M
Format: Article
Language:English
Subjects:
Bacteria
Bacterial Proteins - genetics
Biological Evolution
Chromosomes, Bacterial
Escherichia coli
Escherichia coli - genetics
Escherichia coli Proteins
Evolution
Exodeoxyribonuclease V
Exodeoxyribonucleases - genetics
Genes
Genetics
laac gene
Mutation
recD gene
recG gene
Recombination, Genetic
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Adaptive (or stationary-phase) mutation is a group of phenomena in which mutations appear to occur more often when selected than when not. They may represent cellular responses to the environment in which the genome is altered to allow survival. The best-characterized assay system and mechanism is reversion of a lac allele on an F' sex plasmid in Escherichia coli, in which the stationary-phase mutability requires homologous recombination functions. A key issue has concerned whether the recombination-dependent mutation mechanism is F' specific or is general. Hypermutation of chromosomal genes occurs in association with adaptive Lac(+) mutation. Here we present evidence that the chromosomal hypermutation is promoted by recombination. Hyperrecombinagenic recD cells show elevated chromosomal hypermutation. Further, recG mutation, which promotes accumulation of recombination intermediates proposed to prime replication and mutation, also stimulates chromosomal hypermutation. The coincident mutations at lac (on the F') and chromosomal genes behave as independent events, whereas coincident mutations at lac and other F-linked sites do not. This implies that transient covalent linkage of F' and chromosomal DNA (Hfr formation) does not underlie chromosomal mutation. The data suggest that recombinational stationary-phase mutation occurs in the bacterial chromosome and thus can be a general strategy for programmed genetic change.
ISSN:0016-6731
1943-2631
1943-2631
DOI:10.1093/genetics/154.4.1427