CRISPR-Cas systems in bacteria and archaea: versatile small RNAs for adaptive defense and regulation.

  title={CRISPR-Cas systems in bacteria and archaea: versatile small RNAs for adaptive defense and regulation.},
  author={Devaki Bhaya and Michelle Davison and Rodolphe Barrangou},
  journal={Annual review of genetics},
Bacteria and archaea have evolved defense and regulatory mechanisms to cope with various environmental stressors, including virus attack. This arsenal has been expanded by the recent discovery of the versatile CRISPR-Cas system, which has two novel features. First, the host can specifically incorporate short sequences from invading genetic elements (virus or plasmid) into a region of its genome that is distinguished by clustered regularly interspaced short palindromic repeats (CRISPRs). Second… 

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