Fig. 2

Time course of aggregation of cells harboring a green light-inducible aggregation system. White circles show the time course of aggregation of cells grown under green light and black circles show the time course of aggregation of cells grown under red light. OD₆₀₀ or OD₅₉₅ were used as cell density indicators. a Cells harboring a green light-inducible aggregation system; b cells harboring a green light-inducible aggregation system lacking CcaS, the green light-sensor protein; c cells harboring a green light-inducible aggregation system lacking CcaR, the cognate response regulator of CcaS; d cells harboring a green light-inducible aggregation system lacking CcaS and CcaR. The experiment was performed in triplicate. The double dagger indicates statistical difference in the cell density under red light from 0 min incubation (‡P < 0.05). The asterisks indicate statistical differences from the cells exposed to red light (**P < 0.01 and ***P < 0.001 based on Dunnet’s t test)