Figure 4. TRPA1 is required for circadian entrainment by temperature.

(A–C) Average actograms of flies that were entrained to 12-h:12-h LD cycles for 3 days at 25°C followed by 6 days of DD and 12-h:12-h temperature (25°C/16°C) cycles in which warm and cold phase were in antiphase to the previous light/dark (LD) cycle. After temperature entrainment, the flies were kept at 25°C for free running. Each genotype was denoted on the double plot. Asterisks indicate ectopic peaks that were not detected in controls. Blue and red bars indicate cryophase and thermophase, respectively. (D) Relative locomotor activity during the last 6-h cold phase. The p-values are relative to wild-type (** p-value < 0.01, * p-value < 0.05).