Increasing the efficiency of precise genome editing with CRISPR-Cas9 by inhibition of nonhomologous end joining

摘要: Methods to introduce targeted double-strand breaks (DSBs) into DNA enable precise genome editing by increasing the rate at which externally supplied fragments are incorporated through homologous recombination. The efficiency of these methods is limited nonhomologous end joining (NHEJ), an alternative repair pathway that competes with homology-directed (HDR). To promote HDR expense NHEJ, we ligase IV, a key enzyme in NHEJ pathway, using inhibitor Scr7. Scr7 treatment increased HDR-mediated editing, Cas9 mammalian cell lines and mice for all four genes examined, up 19-fold. This approach should be applicable other customizable endonucleases, such as zinc finger nucleases transcription activator-like effector nucleases, nonmammalian cells sufficiently conserved mechanisms HDR.