17 April 2018
Yuichiro Miyaoka, PhD, (Regenerative Medicine Project) published a paper on “New way to enhance precise genome editing via HDR induced by CRISPR/Cas9.” in Nucleic Acids Research.
CRISPR/Cas9 allows for genetic manipulations in basically all species, which has a great potential in therapeutic and agricultural applications. CRISPR/Cas9 specifically cuts target genomic DNA sequences to activate the two DNA repair pathways, NHEJ and HDR. NHEJ induces DNA insertions and deletions, whereas HDR precisely repairs the genome via recombination between the genomic DNA and template DNA. However, CRISPR/Cas9 always generates NHEJ along with HDR. Therefore, we investigated how the balance between HDR and NHEJ is determined by CRISPR/Cas9.
We utilized our original methods to detect single nucleotide substitutions and knock-ins of a multi-kb gene fragment mediated by HDR, and found that Cas9 variants and modified gRNAs with altered interactions with the genomic DNA exhibited higher HDR/NHEJ ratios. Our results indicate that alterations in the interactions between CRISPR/Cas9 and the genomic DNA can lead to more precise and efficient genome editing mediated by HDR.