Table 1.

Comparison of precise genome-editing strategies

Approach	Characteristic	Advantages	Limitations	References
HR	Point mutation, insertion, deletion; Dividing cells	High specificity	Extremely low efficiency	40,41,49
ZFN-HDR	Point mutation, insertion, deletion; Dividing cells	High specificity	DSB dependent; Labor intensive cloning; Low efficiency	82,83,86,87
TALEN-HDR	Point mutation, insertion, deletion; Dividing cells	High specificity	DSB dependent; Labor intensive cloning; Low efficiency	64,93–96
Cas9-HDR	Point mutation, insertion, deletion; Dividing cells	Easy to engineer	DSB dependent; PAM site necessary; Off-target effects; Low efficiency	65,99,116,118,161
Cre-loxP	Excision, Inversion, translocation; Dividing and non-dividing cells	High specificity; High efficiency	Not useful for insertion or correction; Need prior insertion of loxP sites	189,194,195,197
HITI	Insertion; Dividing and non-dividing cells	Easy to engineer	DSB dependent; PAM site necessary; Off-target effects; Low efficiency	69,161,200
BE	Point mutation; Dividing and non-dividing cells	High efficiency; non-dividing cells	PAM site necessary; Off-target effects; Only conversion of C•G to T•A, A•T to G•C, or C•G-to-G•C	25,26,161,163,206,223
PE	Point mutation, small insertion, and deletion; Dividing and non-dividing cells	Non-dividing cells	PAM site necessary; off-target effects; low efficiency; limited to small edits.	27,247
CAST	Large DNA insertion	Large DNA insertions	Low efficiency	77,78

HR homologous recombination, HDR homology-directed repair, ZFN zinc-finger nuclease, TALEN transcription activator-like effector nuclease, HITI homology-independent target integration, BE base editor, PE prime editor, CAST CRISPR-associated transposase