Mechanism for induction of adaptive mutations in Escherichia coli

Mol Microbiol. 1990 Apr;4(4):597-601. doi: 10.1111/j.1365-2958.1990.tb00628.x.


When bacterial cells are subjected to a strong selective pressure it often induces specific mutations. Here a model is considered in which errors are introduced at random in one of the strands of the DNA molecule: a nick in one of the strands can initiate strand displacement rendering a region of the chromosome single-stranded. Upon conversion back to double-stranded DNA there is a certain probability of introducing errors creating a heteroduplex. If an error results in the production of an mRNA molecule encoding a product which provides a selective advantage, growth will be stimulated and the mutation can be immortalized by chromosomal replication. Otherwise, the error can be corrected by the DNA 'proof-reading' enzymes.

MeSH terms

  • Adaptation, Physiological*
  • DNA Replication*
  • DNA, Bacterial / biosynthesis*
  • DNA-Directed DNA Polymerase / genetics*
  • Escherichia coli / genetics*
  • Escherichia coli / growth & development
  • Methylation
  • Models, Molecular
  • Mutation*
  • RNA, Messenger / biosynthesis


  • DNA, Bacterial
  • RNA, Messenger
  • DNA-Directed DNA Polymerase