Glycosylase Base Editors: New Tools for Genome Editing

Genome editing using the CRISPR/Cas9 system has become a staple of modern genome manipulation. In its original form, editing involved introducing double-strand breaks into DNA, which can cause genomic instability. The appearance of the first base editors in 2016 expanded the range of editing technologies and enabled single-nucleotide changes to be introduced into the genome through deamination of nucleobases, bypassing the double-strand break stage. Further development of base editors involves the incorporation of additional modules, DNA glycosylases, that can remove modified or even normal nucleobases and create non-instructive apurinic/apyrimidinic sites in DNA, significantly expanding the range of available single-nucleotide substitutions. This review examines the operating principles of the glycosylase base editors, the main limitations of these genome manipulation tools, and promising areas for the development of this technology.