CRISPR/Cas-Mediated Base Editing: Technical Considerations and Practical Applications

Genome editing with CRISPR/Cas has rapidly gained popularity. Base editing, a new CRISPR/Cas-based approach, can precisely convert one nucleotide to another in DNA or RNA without inducing a double-strand DNA break (DSB). A combination of catalytically impaired nuclease variants with different deaminases has yielded diverse base-editing platforms that aim to address the key limitations such as specificity, protospacer adjacent motif (PAM) compatibility, editing window length, bystander editing, and sequence context preference. Because new base editors significantly reduce unintended editing in the genome, they hold great promise for treating genetic diseases and for developing superior agricultural crops. We review here the development of various base editors, assess their technical advantages and limitations, and discuss their broad applications in basic research, medicine, and agriculture.