Highly efficient base editing in rabbit by using near-PAMless engineered CRISPR/Cas9 variants

Dear Editor,Base editors can achieve targeted C-to-T and A-to-G conversion without the generation of DNA double-strand breaks（DSBs） or the requirement of a donor template, showing the potential to generate new mutations or to correct pathogenic mutations （Gaudelli et al., 2018）. However, for conventional base editors, efficient base editing requires the presence of an NGG protospacer adjacent motif （PAM） that lies 12–16 nt downstream of the target bases, which generally limits the application of these base editors （Gaudelli et al., 2018）.