Figure 2. (A–E) The p{dClk-15A};Clk ^out flies manifest short period behavioral rhythms.

Each panel represents the average activity of male flies for a given genotype during the third and fourth day of 12 hr light∶12 hr dark entrainment (LD) followed by 4 days of constant darkness (DD). White vertical bars represent locomotor activity during light phase and black vertical bars represent locomotor activity during dark phase in LD. Gray vertical bars represent locomotor activity during the subjective light phase in DD. White horizontal bars and black horizontal bars below each panel indicate 12 hr periods of lights-on and lights-off, respectively. Arrowheads indicate the times in a daily cycle when trough levels of activity were attained following the evening bout of activity. Standard error of the mean is indicated as dots above each bars.