Figure 2.
DSB repair in the absence of RecD results in altered cellular physiology. (A) Micrographs of RecBCD+ and ΔrecD cells containing or not the DNA palindrome (Pal) following 60 min of SbcCD expression. Cells harboured an array of tetO and lacO sequences on either side of the palindrome integration site (lacZ) and expressed TetR-YFP (green) and LacI-CFP (magenta) from a constitutive promoter. Scale bar shows 5 μm. (B) Distribution of cell lengths and the coefficient of variation (CV). Data are for 3 biological repeats combined. (C) Histogram showing the distribution of number of detectable LacI-CFP and TetR-YFP foci per cell and the coefficient of variation (CV). Data are the cumulative data from 3 biological repeats. (D) Cellular DNA content of >100,000 cells was measured by flow cytometry following 2 hours of exponential growth with SbcCD expression either induced or repressed in cells containing the palindrome or not. Data is from a single representative experiment. (E) Expression of green fluorescence protein (GFP) from the DNA-damage inducible promoter PsfiA as measured by flow cytometry following two hours of exponential growth with SbcCD either expressed or not. At least 100 000 cells were measured for each sample. Data is from a single representative experiment. For (B–E), data are displayed as a probability distribution function (PDF) to normalize for differences in total number of analysed cells. See also Supplementary Figure S2.