abstract |
Provided is a genome editing system for site-directed modification of a target sequence in the genome of a cell, which comprises a Cas9 nuclease variant having higher specificity as compared with the wild-type Cas9 nuclease or its expression construct, and an expression construct comprising the coding sequence of tRNA-gRNA fusion or ribozyme-gRNA fusion, or comprises an expression construct comprising the coding sequences of the Cas9 nuclease variant and tRNA-gRNA or ribozyme-gRNA both. Also provided is a method for genetically modifying a cell by introducing the genome editing system, which has high efficiency and high specificity. |