Fig 1.
Schematic of the CRIPSR/Cas9 approach to viral inactivation and generation of escape mutants.
CRISPR/Cas9 endonuclease can be used to cut a viral genome within an essential target gene using either a single gRNA (A) or multiple gRNAs (B). With a single gRNA, a base substitution or InDel mutation may occur on repair of the double-strand DNA break by error-prone non-homologous end-joining (NHEJ), which inactivates the virus. However, it is also possible that cleavage at a single site and error-prone NHEJ may also allow the occurrence and selection of escape mutants (A). However, when multiple gRNAs are used, this allows the creation of a large deletion with no protein produced and no possibility of escape mutations occurring (B).
Table 1.
Human viral targets of CRISPR/Cas9.