Genome-wide microhomologies enable precise template-free editing of biologically relevant deletion mutations

作者：Janin Grajcarek, Jean Monlong, Yoko Nishinaka‐Arai, Michiko Nakamura, Miki Nagai, Shiori Matsuo, David R. Lougheed, Hidetoshi Sakurai, Megumu K. Saito, Guillaume Bourque, Knut Woltjen · 发表于：Nature Communications · 年份：2019 · DOI：10.1038/s41467-019-12829-8 · 被引用次数：44 · 研究领域：CRISPR and Genetic Engineering、Advanced biosensing and bioanalysis techniques、RNA and protein synthesis mechanisms

The functional effect of a gene edit by designer nucleases depends on the DNA repair outcome at the targeted locus. While non-homologous end joining (NHEJ) repair results in various mutations, microhomology-mediated end joining (MMEJ) creates precise deletions based on the alignment of flanking microhomologies (µHs). Recently, the sequence context surrounding nuclease-induced double strand breaks (DSBs) has been shown to predict repair outcomes, for which µH plays an important role. Here, we survey naturally occurring human deletion variants and identify that 11 million or 57% are flanked by µHs, covering 88% of protein-coding genes. These biologically relevant mutations are candidates for precise creation in a template-free manner by MMEJ repair. Using CRISPR-Cas9 in human induced pluripotent stem cells (hiPSCs), we efficiently create pathogenic deletion mutations for demonstrable disease models with both gain- and loss-of-function phenotypes. We anticipate this dataset and gene editing strategy to enable functional genetic studies and drug screening.