Figure 3

Growth-dependent analysis of the expression of AI-regulated genes at the single cell level. V. harveyi conjugants that carried one of the plasmids pCA2, pCA3, pCA4, pCA5, and pCA1 containing a promoter::gfp fusion driven by the luxC (blue), vhp (green), vscP (red), luxS (grey), or recA (dark grey) promoter, respectively, were cultivated, and at the indicated times the optical density (OD₆₀₀) was determined (A) and single cell analysis was performed (B-F). At each time point the average fluorescence of the population was determined (A). The activity of luxC (B), vhp (C), vscP (D), luxS (E), and recA (F) promoters was followed in a growing population over time. Fluorescence levels were normalized for cell size and expressed in arbitrary units.