Figure 1. The temporal order of stress responses observed at the population level does not necessarily reflect the temporal order in every single cell.

1. Green line: Normalized population expression level averaged over all OxyR, and SoxS‐regulated promoters; red line: average over all LexA‐regulated promoters (Mitosch et al, 2017), as measured with a promoter‐GFP plasmid library (Zaslaver et al, 2006) in a plate reader. Oxidative stress promoters clearly precede SOS response promoters in response to NIT stress, when measured at the population level (Mitosch et al, 2017). Lines show the mean and error bars show the standard deviation over seven oxidative stress and SOS promoters, respectively (Materials and Methods). It is not clear if this temporal order correctly reflects the temporal order in single cells.
2. Schematic showing response of two different genes (green and red) in three different cells (solid, dashed, and dotted line). The temporal order observed at the population level correctly reflects the temporal order in each individual cell.
3. As (B) but here, the temporal order at the population level is not the same in every single cell: Although in most cells, the green gene responds before the red one, one cell expresses the red gene before the green one (solid lines).