An in situ cut-and-paste genome editing platform mediated by CRISPR/Cas9 or Cas12a

ABSTRACT Recombinant DNA technology mediated by restriction enzymes and ligases allows in vitro manipulation of a DNA segment isolated from the genome. Short overhangs generated by restriction enzymes facilitate efficient pasting together a DNA sequence and a vector. We adopted this recombinant DNA strategy to develop an in vivo recombinant-genome genome editing approach. Using the programmable endonuclease Cas9 or Cas12a as a restriction enzyme, we devised an in situ c ut- a nd- p aste (iCAP) genome editing method that was tested in both mouse germline and human cell line platforms. Mouse gene loci Slc35f2 and Slc35f6 were each edited with in-frame insertion of a large APEX2-Cre cassette and concurrent FRT3 insertion at a second location providing proof of principle for the iCAP method. Further, a de nova single nucleotide mutation associated with MED13L syndrome was efficiently corrected in patient cells. Altogether, the iCAP method provides a single genome editing platform with flexibility and multiutility enabling versatile and precise sequence alterations, such as insertion, substitution, and deletion, at single or multiple locations within a genomic segment in mammalian genomes.