Extended Data Fig. 4: Controls for specificity of psbA mRNA-labelling in Synechococcus.

a, Comparison of psbA mRNA signals in cells grown under standard conditions (first row) and unprobed and rifampicin-treated cells. Micrographs of the mRNA FISH signal (green) and TM (magenta). b, Mean fluorescence intensity per cell of the mRNA signal in cells from the different samples: p=6x10^-41 for probed vs unprobed, 5x10^-40 for rifampicin vs untreated. Analysis was done after smoothing the images (below optical resolution) and correcting the background signal in the FISH channel (detail in Methods). Error bars in the box plots indicate the range of values recorded, the centre line shows the median and the box spans the interquartile range. Images are representative of at least 2 independent experiments. n: number of cells measured, *: significant difference, at p< 0.001, measured by unpaired two-tailed Student’s t-test; scale bar: 2µm.