Figure 5.

Morphology of cells in which ftsZ or wag31 have been depleted. (A–C) Phase contrast microscopy M. tuberculosis cells containing vectors for expression of dcas9 and the ftsZ+25 sgRNA, without aTc (A) or with addition of aTc to 200 ng/ml (B and C). In each case photographs were taken at 48 h. Panel (C) shows selected images of large, multiply branched cells. (D) Measurement of cell size at 48h of CRISPRi with ftsZ+25 sgRNA. (E and F) Phase contrast microscopy M. tuberculosis cells containing vectors for expression of dcas9 and the wag31+26 sgRNA, without aTc addition (E) or with aTc addition to 200 ng/ml (F). Pictures in both panels were taken after 96h incubation. The significance of the difference in cell length and width 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; ****P < 0.00001).