Fig. 1.
Sik3 is essential for proper MSDR. (A) Males in which Sik3 expression was knocked down by RNAi in fruM-positive neurons (bar 3), show a low rhythmicity and short period in MSDR but not in SLR. Period length is completely restored and rhythmicity is mostly restored by Sik3 expression in clock neurons (bar 4). (B) Males in which Sik3 expression was knocked down by RNAi in Pdf+ LNvs (bars 3 and 5), in DN1 neurons (bars 7 and 9), and in a majority of clock cells (bar 11) show a short MSDR period. SIk3 knockdown produces a slight extension of the SLR period in LNvs and a shortening of the SLR period in DN1 neurons. Black bars represent experimental genotypes; white bars represent control genotypes. Numbers within the bars denote total number of flies in “Rhythmic flies” and total number of rhythmic flies in “Period.” Error bars represent the SEM. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001 in rhythmic flies (χ2 test) and period (one-way ANOVA followed by Tukey’s multiple comparison test). (A′ and B′) Behavior actograms for MSDR and SLR of the experimental genotypes in A and B, respectively. Averaged activity traces for MSDR and SLR are double plotted. Complex trough phases in MSDR are observed with Sik3 reduction in M cells (B′). All measurements were done under DD. Gray and black bars below the graphs denote subjective day and night, respectively. The numbers below the graphs indicate the averaged period with SEM. RNAi is abbreviated as “i.”