Fig. 5.

Comparison of top performing tRNA^Pro ΔC55G engineered variant with other reported systems for specific Pol-II sgRNA expression. a, b Percent reporter ECFP⁺ cells within transfected cells for the OFF state (no CMV promoter) (a) and the ON-state (with CMV promoter) (b). Points at or below the limit of detection are shown as hollow downward triangles. c Log₁₀(% ECFP⁺ cells) in the ON condition (with CMV promoter) compared to OFF condition (no CMV promoter). Thick lines represent geometric mean values (n = 3–6 independent experiments). Terminators refer to the use of alternative termination sequences to the standard poly A and include the histone 1h3h terminator, a minimal poly A sequence⁵, the MALAT 1 terminator⁵, as well as the U1 snoRNA 3′ box⁵. The ribozyme scaffold contains a gRNA flanked by hammerhead and HDV ribozymes⁷. The intron system contains a gRNA embedded within an artificial intron inside the mKate fluorphore⁶. Csy4 variants include the full Csy4 target sequence⁴, the Csy4^Nano target from¹⁹, and minimal Csy4 targets²⁷ either on its own in a transcript, or in the 3′ UTR of an iBlue transcript. (+) indicates that the Csy4 protein is present, and (−) indicates that it is absent. Source data are provided as a Source Data file