Stress-induced mutagenesis in bacteria.
The evolutionary significance of stress-induced mutagenesis was evaluated by studying mutagenesis in aging colonies (MAC) of Escherichia coli natural isolates. A large fraction of isolates exhibited a strong MAC, and the high MAC variability reflected the diversity of selective pressures in ecological niches. MAC depends on starvation, oxygen, and RpoS and adenosine 3',5'-monophosphate regulons; thus it may be a by-product of genetic strategies for improving survival under stress. MAC could also be selected through beneficial mutations that it generates, as shown by computer modeling and the patterns of stress-inducible and constitutive mutagenesis. We suggest that irrespective of the causes of their emergence, stress-induced mutations participate in adaptive evolution.
Bjedov
Ivana
I
INSERM U571, Faculté de Médecine Necker-Enfants Malades, Université ParisV, 156 rue Vaugirard, 75730 ParisCedex 15, France.
Tenaillon
Olivier
O
Gérard
Bénédicte
B
Souza
Valeria
V
Denamur
Erick
E
Radman
Miroslav
M
Taddei
François
F
Matic
Ivan
I
D000222:Adaptation, Physiological; D000391:Air Microbiology; D000483:Alleles; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D005075:Biological Evolution; D003198:Computer Simulation; D004260:DNA Repair; D012321:DNA-Directed RNA Polymerases / Q000235:genetics; D004926:Escherichia coli / Q000145:classification / Q000235:genetics* / Q000254:growth & development / Q000502:physiology*; D004927:Escherichia coli Infections / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D005243:Feces / Q000382:microbiology; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D019015:Geologic Sediments; D006801:Humans; D007763:Lac Operon; D008954:Models, Biological; D016296:Mutagenesis; D018384:Oxidative Stress; D010100:Oxygen / Q000378:metabolism; D010641:Phenotype; D010802:Phylogeny; D011938:Rec A Recombinases / Q000378:metabolism; D018085:Regulon; D013014:SOS Response, Genetics; D012641:Selection, Genetic; D012808:Sigma Factor / Q000235:genetics / Q000378:metabolism; D014871:Water Microbiology
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria; D011938:Rec A Recombinases; D012321:DNA-Directed RNA Polymerases; C105078:RNA polymerase beta subunit; D010100:Oxygen