Figure 2. 12 h:12 h cycles of white LED light with high and low circadian illuminance (CIL) produce robust behavioral and molecular rhythms.

Flies were exposed to conventional constant light (LL) conditions for 2 days and then were 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 flies of the indicated genotypes are shown. Each row of the actogram was double-plotted. The numbers of flies used for the analyses were 61 (CS), 60 (w¹¹¹⁸). Light blue and pink horizontal bars indicate CH and CL, respectively. (C to H) Head extracts from CS flies on day 5 of the CH/CL cycle were obtained and processed for immunoblotting with anti-PER (C), anti-TIM (D), and anti-CRY (E) antibodies. Actin served as a loading control. Relative levels of PER (F), TIM (G), and CRY (H) were determined by measuring band densities using Image J software. Three replicates were used for the calculation. Values represent mean ± SEM.