FIGURE 1.

Effect of tau deficiency on circadian activity in Drosophila. (A,B) Averaged activity profiles across four 12 h LD cycles followed by another four DD cycles, of 7 day-old male flies from the denoted genotypes (w1118 in black and dTau^–/– in red). White rectangles represent light period (LP), or day, and black rectangles represent dark period (DP) or night. During DD cycles, subjective light period (sLP) is represented in gray, and subjective dark period (sDP) in black. Activity peaks in dTau^–/– flies show a different pattern when compared to controls, with noticeably more activity values during the “siesta” period in the light period during LD cycles, and the subjective day during the DD cycles. (C–H) Averaged activity profiles across five LD and DD cycles of the corresponding genotypes. White bars represent the light period (day), and black bars represent the dark period (night) in LD cycles (C,D). During DD cycles (F,G) subjective daytime is represented in gray. Blue dots represent SEM for each Zeitgeber time. Both in LD and DD cycles, dTau^–/– flies (D,G) were more active than controls (C,F) during the day and subjective daytime, with higher activity values and shows affection of the normal “siesta” pattern that control flies elicit during this particular period. (E,H) Total averaged locomotion activity quantification demonstrates that dTau mutant flies were significantly more active than controls, specifically during the LP in LD cycles. In DD cycles, dTau mutant flies were also significantly more active than controls during both the sLP and the sDP. However, no changes were found in total locomotor activity during DD cycles. Data represent mean and SEM analyzed with non-parametric Mann–Whitney statistical test, with ^∗p < 0.05 and ^∗∗∗p < 0.001 or NS if no statistical significance (n = 21–27 flies).