Off-target analysis of CRISPR/Cas9-edited rat model

A rat model of Cockayne syndrome is generated by using CRISPR/Cas9, a nonsense mutation is introduced into CSB gene. Despite widespread use of CRISPR, frequency and impact of Cas9-mediated off-targets in modified human cells and rodents have always been a concern. We used whole genome sequencing to comprehensively access on- and off-target mutations in the rat model, and we found that CRISPR/Cas9-based gene editing was active on the expected genomic sites without producing off-target modifications in other functional regions of the rat genome.

本研究利用CRISPR/Cas9技术构建了科凯恩综合征（Cockayne syndrome）大鼠模型，并在CSB基因中引入无义突变。尽管CRISPR技术已得到广泛应用，但Cas9介导的脱靶效应在经基因修饰的人类细胞及啮齿类动物中的发生频率与影响始终是学界关注的核心问题。本研究通过全基因组测序对该大鼠模型中的靶标突变与脱靶突变进行了全面评估，结果显示基于CRISPR/Cas9的基因编辑仅在预期的基因组位点发挥活性，未在大鼠基因组的其他功能区域产生脱靶修饰。