Fig.1 Effect of gRNA sequence on RNA knock-down efficiency. (A) The CRISPR/Cas13 RNA targeting system. (B) A gradient curve for the efficiency of Cas13b and Cas13d. Luc/Rluc plasmids are in a constant volume, abscissa is the amount of Cas13b and Cas 13d, ordinate represents the relative cutting efficiency of Cas13b and Cas13d. (C, D) Different efficiency of 33 gRNAs is showed on the histogram. The abscissa is ordered according to the location of gRNA on the mRNA. The sequences of each corresponding gRNA are identical in Cas13b and Cas13d systems. The red columns represent the first batch of gRNAs (Among them, gRNA 2, 16, 29 represent up, mid, down gRNAs in figure.2A,2B), blue columns represent the second batch of gRNAs, yellow columns represent the third batch of gRNAs. All results are representative of at least three independent experiments. (E) The relationship between GC content and Cas13 efficiency.