Fig. 6: Tk modulates dietary choice through the glucagon-like AKH signalling pathway in mated female flies.
From: Protein-responsive gut hormone tachykinin directs food choice and impacts lifespan
a,b, Dye-consumption assays for sugar (a) and yeast (b) in controls and animals with RNAi against TkR99D in APCs (a, one-way ANOVA with Dunnett’s test; b, Kruskal–Wallis with Dunn’s test). c,d, Longer-term feeding behaviour of similar animals: 6-h CAFÉ assay for sugar (Kruskal–Wallis with Dunn’s test) (c) and sugar-feeding behavioural data recorded for 22 h using the FLIC system (one-way ANOVA with Dunnett’s test) (d). e, Sugar sips in a 1-h flyPAD assay for controls and animals with APC-specific TkR99D knockdown (two-tailed Mann–Whitney U-test). f,g, Short-term dye-consumption nutrient-intake assays for sugar (f) and yeast (g) in controls and animals expressing APC-specific Akh RNAi (two-tailed Mann–Whitney U-test (f), two-tailed unpaired Student’s t-test (g)). h,i, Six-hour sugar intake in the CAFÉ assay (h) and 22-h sugar-feeding (i) behaviour (FLIC) of controls and animals expressing Akh knockdown in APCs (two-tailed Mann–Whitney U-test). j, Dye-consumption assay for sugar in animals with EEC-specific Tk-RNAi, in an Akh-loss-of-function background (two-tailed Mann–Whitney U-test). k, Schematic for l–n showing 1-h dye assays for sugar and yeast intake. l,m, Pan-neuronal (l) or fat body (m) knockdown of AkhR (two-tailed Mann–Whitney U-tests). n, AkhR knockdown in subsets of neurons targeted by their respective GAL4 drivers: interoceptive sensory neurons (ISNs) (R34G02-GAL4); insulin-producing cells (IPCs; Ilp2>); major neurosecretory cells (dimm>); neurons of the central circadian clock (tim>); and octopaminergic (Tdc2>), dopaminergic (Tyrosine hydroxylase, TH>), glutamatergic (Vesicular glutamate transporter 1, VGlut1>) and cholinergic (ChAT>) neuronal populations (two-tailed unpaired Student’s t-test). o, Feeding behaviour toward sugar measured over 22 h in the FLIC apparatus in controls and animals with RNAi against AkhR in the cholinergic cell population (Kruskal–Wallis with Dunn’s test). p, Model that is consistent with these data. Sample sizes (n) and P values are indicated in each plot. n represents animals per group. Behavioural experiments were performed following 15 h of yeast feeding. Box plots show the median, the bounds of the box (25th and 75th percentiles) and whiskers representing minimum and maximum values. Plots in d,g indicate mean ± s.e.m., and plots in e,i,o indicate the median and 95% confidence intervals. NS, P > 0.05.
