Figure 1.

Food Conditions Control Sleep Amount in C. elegans across Stages

(A–I) Individual RIS calcium imaging and sleep measurements. RIS activity is shown in red and locomotion speed in black; blue shading shows sleep bouts as defined by a locomotion cessation threshold. At the onset of a sleep bout, RIS activated and locomotion ceased.

(A) An adult worm feeding on OP50 bacteria with bacterial growth medium.

(B) An adult worm feeding on OP50 without bacterial growth medium.

(C) An adult worm feeding on dead OP50 with growth medium.

(D) An adult that was starved for 24 hr.

(E) An L1 larva in the presence of food, 8 hr after hatching and prior to lethargus.

(F) An L1 larva before and during lethargus as defined as the non-feeding period (starting at 0 hr) prior to the molt in the presence of food.

(G) An arrested L1 larva that was starved for 24 hr.

(H) A 3-day-old dauer larva in the absence of food.

(I) An adult feeding on OP50 without growth medium in the presence of dauer pheromone.

(J–O) RIS activity increased significantly with locomotion cessation at the onset of sleep bouts in all conditions. The increase of Δ F/F of the calcium sensor signal was (J) 126.1% ± 20.2%, n = 24 worms, ^∗∗∗p < 0.001 for adults on growing OP50; (K) 32.5% ± 5.4%, n = 20 worms, ^∗∗p < 0.01 for starving adults; and (L) 22.0% ± 0.9%, n = 14 worms, ^∗p = 0.014 for developing L1 worms during lethargus.

(M–O) 58.7% ± 4.9% (M), n = 33 worms, ^∗∗∗p < 0.001 for arrested L1 larvae; 36.8% ± 7.9% (N), n = 13 worms, ^∗∗p = 0.002 for dauer larvae; 45.7% ± 19.8% (O), n = 12 worms, ^∗p = 0.02 for adults on stationary OP50 with dauer pheromone.

For all statistical comparisons, the paired Wilcoxon rank test was used. See also Figures S1 and S2.