Figure 7
Single-cell cultivation under various lighting conditions. A: LL (continuous light) condition. PAR was 200 μmol m-2 s-1. Cell volume is normalized to the initial cell volume. The white arrowhead indicates the time at which the cell enters the division phase. The solid line indicates an exponential fit; μ L is the volume increase rate given by μ L = (1/T L )ln(V(T L )/V(0)). B: LD condition. PAR was the same as in panel A. The light exposure was stopped at the time indicated by the black arrow; T L is the duration of the light exposure period. The cells entered the division phase at the time indicated by the white arrowhead. T LD is the interdivision phase duration under the LD condition, and μ L is the volume increase rate during the light period calculated as in panel A. C: LDL condition. PAR was the same as in panels A and B. The light exposure was stopped (black arrow) and restarted (white arrow) before the target single cell entered the division phase. The cell entered the division phase at the time indicated by the white arrowhead, before reaching 4.1 times its initial volume. T L is the first light period duration, T LDL is the interdivision phase duration under the LDL condition, and μ L is the volume increase rate during the light period. D: L1L2 illumination condition (i.e., first 200 μmol m-2 s-1 and then 100 μmol m-2 s-1). The cell entered the division phase at the time indicated by the white arrowhead before reaching 4.1 times its initial volume. T L1 is the duration of the first light exposure period (L1), T L1L2 is the interdivision phase duration under the L1L2 condition, and μ L1 is the rate of cell volume increase during L1 period.