Extensive repetitive DNA facilitates prokaryotic genome plasticity Academic Article uri icon


MeSH Major

  • DNA
  • Genome, Bacterial
  • Helicobacter pylori


  • Prokaryotic genomes are substantially diverse, even when from closely related species, with the resulting phenotypic diversity representing a repertoire of adaptations to specific constraints. Within the microbial population, genome content may not be fixed, as changing selective forces favor particular phenotypes; however, organisms well adapted to particular niches may have evolved mechanisms to facilitate such plasticity. The highly diverse Helicobacter pylori is a model for studying genome plasticity in the colonization of individual hosts. For H. pylori, neither point mutation, nor intergenic recombination requiring the presence of multiple colonizing strains, is sufficient to fully explain the observed diversity. Here we demonstrate that H. pylori has extensive, nonrandomly distributed repetitive chromosomal sequences, and that recombination between identical repeats contributes to the variation within individual hosts. That H. pylori is representative of prokaryotes, especially those with smaller (<2 megabases) genomes, that have similarly extensive direct repeats, suggests that recombination between such direct DNA repeats is a widely conserved mechanism to promote genome diversification.

publication date

  • November 11, 2003



  • Academic Article



  • eng

PubMed Central ID

  • PMC263856

Digital Object Identifier (DOI)

  • 10.1073/pnas.1735481100

PubMed ID

  • 14593200

Additional Document Info

start page

  • 13579

end page

  • 84


  • 100


  • 23