Knock-in of large reporter genes in human cells via CRISPR/Cas9-induced homology-dependent and independent DNA repair

X He, C Tan, F Wang, Y Wang, R Zhou… - Nucleic acids …, 2016 - academic.oup.com
X He, C Tan, F Wang, Y Wang, R Zhou, D Cui, W You, H Zhao, J Ren, B Feng
Nucleic acids research, 2016academic.oup.com
Abstract CRISPR/Cas9-induced site-specific DNA double-strand breaks (DSBs) can be
repaired by homology-directed repair (HDR) or non-homologous end joining (NHEJ)
pathways. Extensive efforts have been made to knock-in exogenous DNA to a selected
genomic locus in human cells; which, however, has focused on HDR-based strategies and
was proven inefficient. Here, we report that NHEJ pathway mediates efficient rejoining of
genome and plasmids following CRISPR/Cas9-induced DNA DSBs, and promotes high …
Abstract
CRISPR/Cas9-induced site-specific DNA double-strand breaks (DSBs) can be repaired by homology-directed repair (HDR) or non-homologous end joining (NHEJ) pathways. Extensive efforts have been made to knock-in exogenous DNA to a selected genomic locus in human cells; which, however, has focused on HDR-based strategies and was proven inefficient. Here, we report that NHEJ pathway mediates efficient rejoining of genome and plasmids following CRISPR/Cas9-induced DNA DSBs, and promotes high-efficiency DNA integration in various human cell types. With this homology-independent knock-in strategy, integration of a 4.6 kb promoterless ires-eGFP fragment into the GAPDH locus yielded up to 20% GFP+ cells in somatic LO2 cells, and 1.70% GFP+ cells in human embryonic stem cells (ESCs). Quantitative comparison further demonstrated that the NHEJ-based knock-in is more efficient than HDR-mediated gene targeting in all human cell types examined. These data support that CRISPR/Cas9-induced NHEJ provides a valuable new path for efficient genome editing in human ESCs and somatic cells.
Oxford University Press