Figure 7. FLP-18 plays a role in modulating bout durations in the presence of weak disturbances.

(A) Posture analysis of undisturbed flp-18(gk3063) mutants revealed wild-type-like overall quiescence but reduced correlations between subsequent bouts. R = 0.33 ± 0.06, N = 12 animals. These correlations were significantly different (p < 0.05) from those of wild-type and npr-1 mutants shown in Figures 2A and 5A, respectively. (B) Frame subtraction analysis of flp-18 mutants during L4leth in the presence of weak blue light stimuli (15 s, 20 mW/cm²). All stimuli were initiated at t = 0. The dynamics of locomotion revealed defects in the ability of flp-18 mutants to compensate for the motion induced by the stimulus with enhanced quiescence. Left: the locomotion responses during lethargus of each of the two alleles tested and its wild-type control group shown on a semi-log scale. Shaded area denotes mean ± s.e.m. Asterisks denote that during the trough in locomotion, the fraction of quiescence of the mutant allele was significantly lower than that of its respective wild-type control (p < 0.01). Right: for each strain, the quiescence fraction was calculated during 1 min intervals centered at the times of the peak and trough of the L4leth responses, as well as for their respective pre-stimulus baselines. Plots and bars depict mean ± s.e.m obtained from datasets of N = 40–50 animals per condition. Asterisks and double asterisks denote p < 0.05 and p < 0.01, respectively.

DOI: http://dx.doi.org/10.7554/eLife.04380.015

Figure 7—figure supplement 1. A fluorescent reporter of FLP-18 in VC motor neurons and head neurons.

Top: sample images of the same animal during the late L4int stage (left) and the first half of L4leth (right). Arrows point to VC motoneurons in which expression of the Pflp-18::flp-18::SL2::gfp reporter was visibly upregulated. Arrowheads point to head neurons in which changes in expression were not detected. Bottom: the mean fluorescence, before and during lethargus, from reporter expressed in VC motoneurons (left) and head neurons (right). When VC neurons fluorescence prior to lethargus was low (dark grey), it increased more than twofold during the first half of lethargus (p < 0.05). When VC neurons fluorescence prior to lethargus was high (light grey), it did not change significantly afterward. The number of animals assayed is denoted in parentheses, error bars depict ±s.e.m, and asterisks denote p < 0.05.

DOI: http://dx.doi.org/10.7554/eLife.04380.016

Figure 7—figure supplement 2. Bout correlations in undisturbed flp-18 mutants.

Pairwise bout correlations in wild-type animals and flp-18 mutants during the first and second halves of L4leth. The behavior of the mutants differed from wild-type only during the first half of L4leth, corresponding to the period of upregulation of the expression reporter. Error bars depict 95% confidence intervals and asterisks denote p < 0.05.

DOI: http://dx.doi.org/10.7554/eLife.04380.017