title: Adaptive mutation in Escherichia coli: a role for conjugation.
abstract: When subjected to selective conditions that impose starvation, a bacterial population can accumulate mutations, called adaptive, that allow colony formation. Here, the reversion of a lac allele under selective conditions, in a model system using Escherichia coli with the lac mutation on an F' plasmid, was shown to require the conjugational capacity of the plasmid. Reversion associated with transfer was shown, and when the same lac allele was chromosomal, reversion to Lac+ was 25 to 50 times less frequent. Postplating reversion was 25 times less when mating was inhibited by the presence of detergent. Mutability associated with conjugation provides new ways of thinking about the origin of adaptive mutations.
authors.affiliation: Department of Biology, Massachusetts Institute of Technology, Cambridge 02139, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Radicella
authors.forename: P U
authors.initials: PU
authors.lastname: Park
authors.forename: M S
authors.initials: MS
authors.lastname: Fox
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D000483:Alleles; D001426:Bacterial Proteins / Q000235:genetics; D003227:Conjugation, Genetic; D003470:Culture Media; D004261:DNA Replication; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development; D029968:Escherichia coli Proteins; D005144:F Factor; D016368:Frameshift Mutation; D007763:Lac Operon; D056968:Lac Repressors; D007785:Lactose / Q000378:metabolism; D009154:Mutation; D012097:Repressor Proteins / Q000235:genetics; D012641:Selection, Genetic
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D029968:Escherichia coli Proteins; D056968:Lac Repressors; C539064:LacI protein, E coli; D012097:Repressor Proteins; D007785:Lactose