Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2002-5-15
pubmed:abstractText
In a system described by Cairns and Foster, starvation of a particular leaky lac mutant (lacIZ33) in the presence of lactose appears to direct mutation in non-growing cells to sites that allow growth (adaptive mutation). This behaviour requires that the lac operon be located on an F' plasmid. This position effect was investigated by placing the mutant lac operon at many sites in the genome of Salmonella enterica (Typhimurium; LT2) and testing reversion behaviour. Genomic position did not affect reversion during non-selective growth. When lac was at any of 550 chromosomal sites, starvation caused little or no enhancement of reversion. In the 28 strains with the lac on Salmonella's conjugative plasmid (pSLT), selection enhanced reversion strongly, just as seen for strains with lac on an F' plasmid. In 46 strains, the lac operon was inserted within a small chromosomal duplication, and selection stimulated RecA-dependent partial reversion by simple amplification (about 8x) of the mutant lac region. The position of lac on a conjugative plasmid is important to reversion because it allows more frequent gene duplication and amplification. These events are central to growth and reversion under selection because they increase the number of replicating lac alleles within each developing revertant clone.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
44
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1017-32
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:12010495-Adaptation, Biological, pubmed-meshheading:12010495-Chromosomes, Bacterial, pubmed-meshheading:12010495-DNA Replication, pubmed-meshheading:12010495-Escherichia coli, pubmed-meshheading:12010495-Frameshift Mutation, pubmed-meshheading:12010495-Gene Amplification, pubmed-meshheading:12010495-Gene Duplication, pubmed-meshheading:12010495-Gene Order, pubmed-meshheading:12010495-Genes, Lethal, pubmed-meshheading:12010495-Genome, Bacterial, pubmed-meshheading:12010495-Lac Operon, pubmed-meshheading:12010495-Lactose, pubmed-meshheading:12010495-Mutagenesis, pubmed-meshheading:12010495-Plasmids, pubmed-meshheading:12010495-Rec A Recombinases, pubmed-meshheading:12010495-Recombination, Genetic, pubmed-meshheading:12010495-Salmonella enterica, pubmed-meshheading:12010495-Selection, Genetic, pubmed-meshheading:12010495-Suppression, Genetic
pubmed:year
2002
pubmed:articleTitle
The effect of genomic position on reversion of a lac frameshift mutation (lacIZ33) during non-lethal selection (adaptive mutation).
pubmed:affiliation
Department of Biology, University of Utah, Salt Lake City, UT 84112, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't