Figure 1.

Genomic deletion of sra locus impairs circadian locomotor behaviors. (A) Male flies homozygous or trans-heterozygous for sra mutant alleles show weaker anticipatory activity to lights-on (red arrows) and poor rhythmicity in free-running locomotor behaviors in DD. Activity profiles on the second day of LD cycles (LD2, left), on the second day of DD cycles (DD2, middle), or throughout the behavioral analyses (right) were averaged from individual flies. Averaged morning anticipation index values ± SEM are shown in red. *** P < 0.001 vs. wild-type as determined by Student’s t-test. n, the number of flies analyzed; white/black bars, LD cycles; and gray/black bars, DD cycles. (B) Rhythmicity in free-running locomotor behaviors was determined by measuring power (P) − significance (S) values from the χ² periodograms of individual flies, and averaging over each genotype. *** P < 0.001 vs. wild-type or heterozygous control, as determined by one-way ANOVA with Tukey’s post hoc test. Error bars indicate SEM (n = 29–98). (C) Percentage of flies with detectable rhythmicity (P − S > 10) was calculated per each genotype. (D) Averaged actograms of wild-type or sra^KO heterozygous flies were double-plotted (n = 93–98). Gray shade indicates constant dark. (E) Circadian periods in DD were averaged from rhythmic flies per each genotype. *** P < 0.001 vs. wild-type, as determined by Student’s t-test. Error bars indicate SEM (n = 93–94). (F) Daily total activity counts were averaged from individual flies per each genotype in LD (left) or DD (right) cycles. ** P < 0.01 and *** P < 0.001 as determined by one-way ANOVA with Tukey’s post hoc test. Error bars indicate SEM (n = 29–98). DD, constant dark; LD, 12 hr light/12 hr dark.