(A) Schematic of chemotaxis assay setup. (B) Chemotaxis index of wild-type animals and mutants with different alleles of lite-1 that have defects in diacetyl response. P-values are from unpaired two-tailed t-tests, n = 4 biological replicates, each an average of 4 plates. (C) Chemotaxis index of wild-type and lite-1 (yum2880) animals with different diacetyl concentrations (5 μl). P-values are from unpaired two-tailed t-tests, n = 3 biological replicates, each an average of 4 plates. (D) Time series of wild-type (blue line) animals and mutants with different alleles of lite-1 (orange line) when stimulated with blue light (blue shaded box). n = 3 biological replicates, each an average of 12 wells.

(A) Confocal image of labelled sensory neurons and calcium imaging traces showing the responses of three neurons when exposed to high concentrations of diacetyl. (B) Neuronal activity of wild-type controls with lite-1 mutants. (C) Neuronal activity of wild-type controls to unc-13 mutants. Grey shaded box denotes the presence of diacetyl. Shaded area around the activity dynamics denotes standard error. (D) Chemotaxis index of wild-type animals and rescue mutants expressing lite-1 cDNA from the srh-220 promoter in ADL neuron. P-values are from unpaired two-tailed t-tests, n = 4 biological replicates, each an average of 4 plates.

(A) Percent of worms that are swimming at ten seconds after exposure to buffer untreated or to diacetyl. Wild-type animals continue swimming in buffer and diacetyl (WT, left) whereas worms expressing LITE-1 in body wall muscles (Pmyo-3::LITE-1, right) are mostly paralysed when treated with diacetyl. (B) Sample midline trajectories from wild-type and Pmyo-3::LITE-1 animals showing difference in motion (each trajectory shows 6 seconds of swimming). (C) Worm body length over time after treatment. Wild-type animals do not show a significant length difference in either buffer or diacetyl treatments (left) whereas worms expressing LITE-1 in body-wall muscles show a significant contraction in response to diacetyl (insert showing the average contraction). P-values from paired two-tailed t-test, n ≥ 15 worms. (D) Image of a Pmyo-3::LITE-1 animal that ejected eggs within ten seconds of diacetyl treatment (white arrow). (E) Molecular docking of diacetyl into the AlphaFold-predicted structure of LITE-1 with predicted micromolar affinity.

(A) Chemotaxis index of wild-type animals and lite-1 mutants for known odorants. P-values are from unpaired two-tailed t-tests, n = 4 biological replicates each an average of 4 plates. (B) Molecular docking of 2,3-pentanedione into the AlphaFold-predicted structure of LITE-1 with predicted micromolar affinity. (C) Image of a Pmyo-3::LITE-1 animal that ejected eggs within ten seconds of 2,3-pentanedione treatment (white arrow). (D) Percent of worms that are swimming at ten seconds after exposure to buffer untreated or to 2,3-pentanedione. Wild-type animals continue swimming in buffer and 2,3-pentanedione (WT, left) whereas worms expressing LITE-1 in body-wall muscles (Pmyo-3::LITE-1, right) are mostly paralysed when treated with 2,3-pentanedione. (E) Worm body length over time after treatment. Wild-type animals do not show a significant length difference in either buffer or 2,3-pentanedione treatments (left) whereas worms expressing LITE-1 in body-wall muscles show a significant contraction in response to 2,3-pentanedione (insert showing the average contraction). P-values from paired two-tailed t-test, n ≥ 15 worms.

(A) Chemotaxis index of wild-type and lite-1 (yum2880) animals with undiluted diacetyl in the presence and absence of ambience light. P-values are from unpaired two-tailed t-tests, n=3 biological replicates, each an average of 3-4 plates. (B) Chemotaxis index of wild-type, lite-1 (yum2880), odr-10 (yum2055) and lite-1odr-10 (yum2880; yum2055) with undiluted diacetyl or 2,3-pentannedione. P-values are from unpaired two-tailed t-tests, n=5 biological replicates, each an average of 3-4 plates.

Chemotaxis index of wild-type and tax-4 (p678) animals with undiluted diacetyl.

P-values are from unpaired two-tailed t-tests, n=3 biological replicates, each an average of 4 plates.

Scatter plot of calcium imaging responses across 11 pairs of sensory neurons following a pulse of diacetyl.

(A) ADL and ASK neurons show significant differences in activity in the presence versus absence of LITE-1. (B) No significant differences in neuronal activity between wild-type and unc-13 mutants across the different sensory neuron pairs. P-values were calculated using two-sided t-test with FDR correction, *p < 0.01.

(A) Percent of worms that are swimming at ten seconds after exposure to buffer containing diacetyl (lite-1 (ce314), left) whereas worms expressing LITE-1 in body-wall muscles (lite-1 (ce314) Pmyo-3::LITE-1, right) are mostly paralysed when treated with diacetyl. (B) Image of lite-1 (ce314) Pmyo-3::LITE-1 animals that ejected eggs after ten seconds of diacetyl treatment (white arrows). (C) Worm body length over time after treatment. lite-1 (ce314) worms expressing LITE-1 in body wall muscles show a significant contraction in response to diacetyl (right; insert showing the average contraction). P-values from paired two-tailed t-test, n ≥ 15 worms.

DynamicBind and Gninna predicted ligand binding affinities of different odorants to the putative LITE-1 binding pocket.

For Dynamicbind, affinity is reported as -log(IC50), where higher values indicate stronger predicted binding and the corresponding Kd values(µM) were converted from - log(IC50), with lower values indicating stronger binding. For Gnina, affinity is reported as kcal/mol where higher values indicate higher binding interactions.

(A) Percent of worms that are swimming at ten seconds after exposure to buffer containing 2,3-pentanedione (lite-1 (ce314), left) whereas worms expressing LITE-1 in body-wall muscles (lite-1 (ce314) Pmyo-3::LITE-1, right) are mostly paralysed when treated with 2,3-pentanedione. (B) Image of lite-1 (ce314) Pmyo-3::LITE-1 animals that ejected eggs after ten seconds of 2,3-pentanedione treatment (white arrows). (C) Worm body length over time after treatment. lite-1 (ce314) worms expressing LITE-1 in body-wall muscles show a significant contraction in response to 2,3-pentanedione (right; insert showing the average contraction). P-values from paired two-tailed t-test, n ≥ 15 worms.