Template-based genome editing directed by the SviCas3

RNA-guided genome editing based on the CRISPR-Cas system is currently the most effective genome editing technique. Here, we report that SviCas3 from the subtype I-B-Svi Cas system in Streptomyces virginiae IBL14 is an RNA-guided and DNA-guided DNA endonuclease suitable for the gene and/or base editing of prokaryotic and eukaryotic cell genomes. The genome editing efficiency of SviCas3 guided by DNA was no less than that of SviCas3 guided by RNA. It should be noted that no off-target effects or indel-formation were detected in targeted sequencing. In particular, t-DNA, as a template and a guide, does not require a proto-spacer-adjacent motif, demonstrating that CRISPR, as the basis for crRNA design, is not required for SviCas3-mediated gene and base editing. This discovery will provide important tools for the creation and modification of living things and the treatment of human genetic diseases, and will usher in a new era of DNA-guided genome editing.