Fig. 1.

KaiC represses circadian rhythms of promoter activities. Approximately 640 clones carrying random promoter::luxAB reporters were isolated by promoter-trapping from IPTG-inducible kaiC cells. The circadian bioluminescence rhythms of these clones and the PkaiBC::luxAB reporter strain were analyzed on solid media under continuous light (LL) conditions of 46 μmol·m^–2·s^–1 at 30°C in the absence or presence of 1 mM IPTG (administered at the time point indicated by arrows). The bioluminescence profiles of nine representative clones are shown here. Maximum bioluminescence intensity during the experiment, normalized to the sample colony numbers, is shown for each rhythm. Rhythmic and nonrhythmic components are shown with yellow and blue backgrounds, respectively. Abscissa, hours in LL.