Recombination, mutation and the origin of species

Bioessays. 1995 Sep;17(9):747-9. doi: 10.1002/bies.950170902.


A major barrier to recombination between bacterial species lies in the mismatch repair system, a complex of proteins that has evolved to proof-read freshly replicated DNA. It now appears that a second system, involving an inducible DNA recombination, repair and mutagenesis pathway, also regulates interspecies recombination, but in a positive way, being required for recombination between Escherichia coli and Salmonella typhimurium. Thus the rate at which newly emerging species of bacteria diverge can be seen as a balance between a permissive state associated with inducible repair and recombination, and the proof-reading of intermediates in the recombination pathway by the mismatch correction system.

Publication types

  • Review

MeSH terms

  • Bacteria / classification
  • Bacteria / genetics*
  • Biological Evolution*
  • DNA Repair
  • DNA, Bacterial / genetics
  • Escherichia coli / genetics
  • Mutagenesis
  • Mutation*
  • Recombination, Genetic*
  • Salmonella typhimurium / genetics
  • Species Specificity
  • Transformation, Bacterial


  • DNA, Bacterial