FIG 5.

Whole or partial operon knockdown by CRISPRi. The knockdown effect of CRISPRi on the ccrAB operon in S. aureus N315 (A) and the era-containing operon in S. aureus NCTC 8325 (B) was determined by selectively targeting different operon genes. The relative transcription levels of different operon genes in different knockdown strains were measured by qRT-PCR. The error bars indicate the standard errors of the means of three biological replicates. Abbreviations: MSD0, N315 carrying plasmid pSD1; MSD2, N315 expressing the ccrAB sgRNA1; MSD3, N315 expressing the ccrAB sgRNA2; MSD4, N315 expressing the ccrAB sgRNA3; MSD5, N315 expressing the ccrAB sgRNA4; NSD0, NCTC 8325 carrying plasmid pSD1; NSD10, NCTC 8325 expressing the era sgRNA1; NSD11, NCTC 8325 expressing the era sgRNA2; NSD12, NCTC 8325 expressing the era sgRNA3; NSD13, NCTC 8325 expressing the era sgRNA4.