Effects of Growth Phase and Temperature on Activity within a Listeria monocytogenes Population: Evidence for RsbV-Independent Activation of at Refrigeration Temperatures
Figure 4
Activation of -dependent gene expression occurs in the absence of RsbV at 4°C. (a) Flow cytometry analyses of ΔsigB-egfp and ΔrsbV-egfp strains grown at 4°C were performed with BD AcurriC6 for cells taken at the interval of three days. The numbers in % indicate the proportion of cells within population with fluorescence above the highest autofluorenscence observed for parent WT strain. Mean fluorescence intensity (MFI) values were shown for autofluorescence range and for EGFP gate separately. Each sample was performed in biological triplicate with duplicate analyses in each replication and a minimum of 100,000 events recorded for each sample. (b) Microscopy of wT-egfp, ΔsigB-egfp, and ΔrsbV-egfp grown at 4°C and analysed in mid-exponential phase (day 6) revealed activation of in the absence of RsbV. (c) Western blotting was carried out with anti-GFP antibody (Abcam) on SDS-PAGE separated protein extracts from stationary phase cells (day 12) of wT-egfp, ΔsigB-egfp, and ΔrsbV-egfp grown at 4°C. Each strain was analysed in biological duplicates ((a) and (b)).
