Figure 3.

CRISPRi of inhA and dfrA in M. tuberculosis. (A, D, G, J) Expression of dcas9 with and without induction of dcas9 and the sgRNA indicated. (B, E, H, K) Expression of inhA or dfrA with and without induction of dcas9 and the sgRNA indicated. (C, F, I, L) Growth curves of culture with and without induction of dcas9 and the sgRNA indicated. (M, N) Inhibition of fluorescence in the MABA at different concentrations of methotrexate (M) or isoniazid (N) with induction of the sgRNAs indicated, compared to vector control. The significance of the difference in gene-specific RNA between samples from induced and uninduced cultures is indicated by asterisks above the bar for the induced sample (*P < 0.01; **P < 0.001; ***P < 0.0001).