Neutral mutations and neutral substitutions in bacterial genomes

Mol Biol Evol. 2003 Dec;20(12):2091-6. doi: 10.1093/molbev/msg229. Epub 2003 Aug 29.


Molecular evolutionary biologists usually assess the underlying spectrum of mutations within a bacterial genome by examining substitutions that occur at sites believed to be under no selective constraints. Alternatively, bacterial mutation rates can also be estimated in a variety of experimental systems. The two classes of changes occurring in DNA sequences-i.e., mutations and neutral substitutions-are, in theory, identical; however, the rates and patterns of mutations in bacteria, as inferred from sequence comparisons, often differ significantly from those derived experimentally. These differences have resulted in conflicting interpretations of the nonselective forces that affect mutation rates.

Publication types

  • Comparative Study
  • Review

MeSH terms

  • Amino Acid Substitution
  • Chromosomes, Bacterial
  • Escherichia coli / genetics
  • Evolution, Molecular
  • Genome, Bacterial*
  • Mutation*
  • Salmonella enterica / genetics
  • Transcription, Genetic