(A) A matrix of strains was constructed, each of which contains a chromosomally integrated CFP reporter for one sigma factor (colored boxes) and a chromosomally integrated YFP reporter for another (second set of colored boxes), along with mCherry under the control of σA (schematic).
(B) Filmstrip from a mother machine movie, showing a single lane at 15 min intervals. PB-CFP is shown in red, overlaid with PW-YFP in the green channel (see Movie S3). Anti-correlations between the sigma factors are apparent from the lack of cells showing similar intensities in green and red channels (i.e., the lack of yellow cells).
(C) Example traces showing the activity dynamics of different pairs of alternative sigma factors, including strains with two reporters for the same sigma factor (top), and other pairs (lower two panels). See also Figure S6.