Targeted Large-Scale Deletion of Bacterial Genomes Using CRISPR-Nickases

ACS Synth Biol. 2015 Nov 20;4(11):1217-25. doi: 10.1021/acssynbio.5b00132. Epub 2015 Oct 25.


Programmable CRISPR-Cas systems have augmented our ability to produce precise genome manipulations. Here we demonstrate and characterize the ability of CRISPR-Cas derived nickases to direct targeted recombination of both small and large genomic regions flanked by repetitive elements in Escherichia coli. While CRISPR directed double-stranded DNA breaks are highly lethal in many bacteria, we show that CRISPR-guided nickase systems can be programmed to make precise, nonlethal, single-stranded incisions in targeted genomic regions. This induces recombination events and leads to targeted deletion. We demonstrate that dual-targeted nicking enables deletion of 36 and 97 Kb of the genome. Furthermore, multiplex targeting enables deletion of 133 Kb, accounting for approximately 3% of the entire E. coli genome. This technology provides a framework for methods to manipulate bacterial genomes using CRISPR-nickase systems. We envision this system working synergistically with preexisting bacterial genome engineering methods.

Keywords: CRISPR; Cas9 nickase; chromosome deletion; direct repeats; genome engineering; recombination.

Publication types

  • Letter
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Clustered Regularly Interspaced Short Palindromic Repeats*
  • Gene Deletion*
  • Genome, Bacterial*
  • Recombination, Genetic
  • Synthetic Biology