Extended Data Fig. 8: Controls for specificity of psaA mRNA labelling in Synechocystis.

a, Variation in psaA mRNA signal intensity between cells grown under standard conditions (first row) and 3 control samples: unprobed, high light (HL)-treated cells (600 µmol photons m^-2s^-1, 1 hour) and Rifampicin-treated (400 µg ml^-1, 1 hour) cells. Confocal fluorescence micrographs showing FISH signal in green and TM in magenta. An overlay between the DAPI-stained nucleoid region (blue) and FISH signal (yellow) is shown for rifampicin-treated cells. Line profiles from representative cells are shown below the corresponding micrographs. b, comparison of mRNA FISH signals per cell in the different conditions (p=3x10^-29 for probed vs unprobed, 8x10^-25 for HL vs normal growth and 2x10^-9 for rifampicin vs untreated). Images smoothed (below optical resolution) and corrected for the background signal in the FISH channel. Error bars in the box plots indicate the range of values recorded, the centre line shows the median and the box spans the first to third quartiles. n: number of cells measured, *: significant difference from the untreated cells, at p< 0.001, measured by unpaired two-tailed Student’s t-test; scale bars: 2µm.