Figure 1. HPL-2 and MUT-7 Act at the Time of Odor Exposure in the AWC Neurons to Promote Adaptation to Butanone (A) Olfactory adaptation paradigm. Animals exposed to buffer alone (naive) or butanone (adapted) for 80 min are placed at the ''origin'' of an agar-lined 10 cm Petri dish. Butanone is placed at the red and ethanol at the black ''X.'' Sodium azide (to paralyze the worms) was also placed at each ''X.'' Animals roam plates 2 hr before counting. The CI is calculated by subtracting the number of animals at the diluent from the number at the odor and dividing this by the number of animals that left the origin. (B) Initial screen of mutant strains defective for siRNA pathways. Bars represent mean CIs of strains of the indicated genotype that had either been incubated with buffer (-) or buffer-diluted butanone (+) for 80 min. Bars for wild-type represent the mean CI of pooled controls for all the strains. All error bars are SEM. The sideby- side comparisons of each strain with wild-type controls are shown in Figure S1A. ** = p < 0.005, * = p < 0.05, and ''n.s.'' = p > 0.05. Unless otherwise noted, all tests were two-tailed Student's t test, and all assays were performed on separate days with >100 animals per assay.
drsh-1,
alg-2,
dcr-1: n=4;
rde-1 mut-7: n = 6;
hpl-2: n = 5.(C) HPL-2 and MUT-7 are expressed in AWCs. Fluorescent confocal images of wild-type animals expressing the putative
hpl-2 (top) or
mut-7 (bottom) promoters driving GFP-tagged versions of each protein. AWC is marked with ceh-36prom3 promoter driving mCherry. Anterior is at the left for both images. Figure S1B is associated with this panel. (D) Expression of HPL-2 or MUT-7 inAWC rescued the adaptation defects of each mutant. HPL-2 (left graph, third pair of bars) or GFP-tagged MUT-7 (right graph, third pair of bars) was expressed in AWC from pceh-36prom3 in
hpl-2(
tm1489) or
mut-7(
pk204), respectively. **p = 0.002, *p = 0.0035, and n > 5 for each. (E) Expression of HPL-2 or MUT-7 at the time of odor exposure rescued adaptation defects.
hpl-2(
tm1489) (left) or
mut-7(
pk204) (right) transgenic for the respective cDNA under the control of the heat shock promoter (phsp16-2) were heated (+) 1 hr before odor exposure. Heat-treated animals' exposed CI's were significantly different from either before heating (p = 0.02,
hpl-2; p < 0.005,
mut-7) or from nontransgenic animals that had been heated (p = 0.005,
hpl-2; p < 0.005,
mut-7), n > 5 for each. (F) HPL-2 and MUT-7 act in the same genetic pathway for adaptation. Mean naive () and exposed (+) CIs of animals of the indicted genotype. The adaptation defects of the
fbf-1(
ok91) strain are due to loss of the translational control pathway (Kaye et al., 2009) that acts in parallel with
hpl-2. (G) Expression of NRDE-3 in AWC rescued the adaptation defects of the
nrde-3 mutant strain. Mean CI of naive () and exposed (+) wild-type,
ndre-3(
gg66), and NRDE-3 expressed in AWC (pceh-36prom3) of the
nrde-3(
gg66) mutant strain. Figure S1D is associated with this figure. Error bars for each panel are SEM.