Table 2.

Panel of Cas9-fusion variants assessed in this study.

Cas9 variant		Description
Cas9	Cas9	Wild-type Cas9
Cas9-hGem	Cas9-hGem	hGeminin is degraded by the APC/Cdh1 complex during G1 phase when the NHEJ pathway is selectively active over HDR (Gutschner et al., 2016)
Cas9-hCtIP	Cas9-hCtIP Cas9-GSG-CtIP* Cas9-TGS-CtIP**	hCtIP “HDR enhancer element” is involved in the DNA end resection. Involved in recruiting other factors to initiate repair (Charpentier et al., 2018).
	Cas9-hGem-hCtIP
Cas9-UL12	Cas9-UL12	UL12 increases recombination by the single-strand annealing (SSA) pathway and inhibits NHEJ (Balasubramanian et al., 2010).
	Cas9-hGem-UL12
Cas9-dn53BP1	Cas9-dn53BP1	A mouse dominant negative 53BP1 is expected to reduce accumulation of 53BP1 at the DSB site, thus suppressing NHEJ (Paulsen et al., 2017)
	Cas9-DN1S Cas9-GSG-DN1S*	Amino acids 1,231–1,644 of human 53BP1; (Jayavaradhan et al., 2019)

^*GSG—signifies a 12 amino acid linker made up of repeating Gly-Ser-Gly residues (GGGS)×3.

^**TGS—signifies a 12 amino acid linker made up of repeating Tyr-Gly-Ser residues (TGS)×4.