Targeted dual base editing with Campylobacter jejuni Cas9 by single AAV-mediated delivery

Abstract

Genome editing: Novel editors for CRISPR-Cas9 technology Tiny genome editors that can fit inside a single delivery system could potentially improve the efficiency and specificity of the editing technology known as CRISPR-Cas9. This technology is used to edit parts of the genome and shows promise for disease therapeutics. Cas9 is a bacterial enzyme that acts as molecular scissors to edit DNA and is guided to the correct DNA region by specific RNA segments (gRNAs). Yongsub Kim at the University of Ulsan in Seoul, South Korea, and co-workers used one of the smallest known Cas9 enzymes, sourced from Campylobactor jejuni, to create two ‘base editors’ (BEs), capable of specific base substitutions. Results suggest the BEs are highly efficient, covering more potential targets than previous Cas9-based BEs. One of the BEs can be packaged, alongside two gRNAs, into a single viral vector for targeted delivery.