Figure 3. CH/CL-cycle–induced circadian locomotor activity is dependent on core circadian-clock genes.

Flies were exposed to conventional constant light (LL) conditions for 2 days and then maintained on 12 h:12 h cycles of 10,000 K white LED light with high CIL (CH) and 2,000 K white LED light with low CIL (CL) for 11 days. (A and B) Averaged actograms of clock mutants w; per⁰¹ (A) and Clk^out(B) flies are shown. Each row of the actogram was double-plotted. The numbers of flies used for the analyses were 30 (per⁰¹) and 27 (Clk^out). Light blue and pink horizontal bars indicate CH and CL, respectively. (C) Daily average activity profiles of flies of indicated genotype on days 5 and 6 of 12 h:12 h CH/CL cycles are shown. The numbers of flies used for the analyses were 61 (CS), 60 (w¹¹¹⁸), 30 (per⁰¹) and 27 (Clk^out). Light gray vertical bars represent activity during the CH period and black vertical bars represent activity during the CL period. (D and E) Entrainment indices were calculated for flies of each genotype under CH/CL cycles using time windows ZT6–12 (D) and ZT9–15 (E). ZT, zeitgeber time. Values represent mean ± SEM and are compared by pairwise t-test. ***p < 0.0001.