Theodore Roth

In trans paired nicking triggers seamless genome editing without double-stranded DNA cutting
Chen X1, Janssen JM1, Liu J1, Maggio I1, 't Jong AEJ1, Mikkers HMM1, Gonçalves MAFV2.
Nat Commun. 2017 Sep 22;8(1):657. doi: 10.1038/s41467-017-00687-1.
September 22, 2017
Department of Molecular Cell Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, The Netherlands. Department of Molecular Cell Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, The Netherlands. [email protected]
Precise genome editing involves homologous recombination between donor DNA and chromosomal sequences subjected to double-stranded DNA breaks made by programmable nucleases. Ideally, genome editing should be efficient, specific, and accurate. However, besides constituting potential translocation-initiating lesions, double-stranded DNA breaks (targeted or otherwise) are mostly repaired through unpredictable and mutagenic non-homologous recombination processes. Here, we report that the coordinated formation of paired single-stranded DNA breaks, or nicks, at donor plasmids and chromosomal target sites by RNA-guided nucleases based on CRISPR-Cas9 components, triggers seamless homology-directed gene targeting of large genetic payloads in human cells, including pluripotent stem cells. Importantly, in addition to significantly reducing the mutagenicity of the genome modification procedure, this in trans paired nicking strategy achieves multiplexed, single-step, gene targeting, and yields higher frequencies of accurately edited cells when compared to the standard double-stranded DNA break-dependent approach.CRISPR-Cas9-based gene editing involves double-strand breaks at target sequences, which are often repaired by mutagenic non-homologous end-joining. Here the authors use Cas9 nickases to generate coordinated single-strand breaks in donor and target DNA for precise homology-directed gene editing.
Date: 
November 8, 2017
Where: 
HSW 1057 at noon