Fig. 1. Initial discovery and characterization of the compact type V Al3Cas12f nuclease.
a, Phylogenetic tree showing representative members of the Cas12f-MG119 family of compact type V systems (including the Al3Cas12f clade) in relation to other Cas12 and TnpB nucleases in the literature. b, Schematic representing the cut sites for Al3Cas12f on the TS and NTS. Shown is the U40 spacer, which would be bound at the 3′ end of the gRNA. c, gRNA screen of Al3Cas12f across two loci in K562 cells using the 134-nt gRNA scaffold and a 20-nt spacer. Editing efficiency is represented as the mean percentage (n = 3 independent biological replicates) of indels detected in NGS reads. Top-performing 27 gRNAs targeting the AAVS1 locus (dark blue) and the APOA1 locus (light blue). d, Comparison of mammalian cell activity among Al3Cas12f, OsCas12f and LbCas12a across eight different loci. Editing efficiency is represented as the mean percentage of indels detected in NGS reads (n = 3 independent biological replicates). e, Box-and-whisker plot showing the data in d. The box outlines denote the first and third quartiles, the median is represented by the center line and the whiskers encompass the full data range. Individual data points are shown as dots. Significance was determined using a paired t-test.