Divided genomes: negotiating the cell cycle in prokaryotes with multiple chromosomes

Mol Microbiol. 2005 Jun;56(5):1129-38. doi: 10.1111/j.1365-2958.2005.04622.x.


Historically, the prokaryotic genome was assumed to consist of a single circular replicon. However, as more microbial genome sequencing projects are completed, it is becoming clear that multipartite genomes comprised of more than one chromosome are not unusual among prokaryotes. Chromosomes are distinguished from plasmids by the presence of essential genes as well as characteristic cell cycle-linked replication kinetics; unlike plasmids, chromosomes initiate replication once per cell cycle. The existence of multipartite prokaryotic genomes raises several questions regarding how multiple chromosomes are replicated and segregated during the cell cycle. These divided genomes also introduce questions regarding chromosome evolution and genome stability. In this review, we discuss these and other issues, with particular emphasis on the cholera pathogen Vibrio cholerae.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Bacteria / cytology*
  • Bacteria / genetics*
  • Biological Evolution
  • Cell Cycle*
  • Chromosome Segregation
  • Chromosomes, Bacterial / physiology*
  • DNA Replication Timing
  • DNA Replication*
  • Genome, Bacterial*
  • Vibrio cholerae / physiology