Fig. 5: Gut-derived Tk regulates glucagon-like AKH signalling in mated female flies.
From: Protein-responsive gut hormone tachykinin directs food choice and impacts lifespan
a, Confocal-microscopy image of a single preparation containing the brain and the ventral nerve cord, the gut and ovaries, stained for a Tk receptor reporter (TkR99D>GFP, yellow), AKH peptide (red), filamentous actin (phalloidin (phal), magenta) and DAPI (marking nuclei, blue). APCs are indicated and enlarged in the inset. Scale bars, 100 µm (main image) and 20 µm (inset). Similar expression and localisation patterns were observed in five independent samples. b–e, Anti-AKH staining intensity within APCs and whole-body Akh transcript levels. Scale bars 20 μm. b,c, AKH staining intensity (b) and Akh expression (c) in controls and flies with RNAi against TkR99D in APCs using Akh-GAL4 (Akh>), following 15 h of feeding on sugar or yeast medium (Kruskal–Wallis with Dunn’s test). TRiP, RNAi collection from the Harvard Transgenic RNAi Project. d, AKH staining intensity in controls and flies with knockdown of Tk in EECs (Tkgut>Tk-RNAi) after 15 h of sugar or yeast feeding (one-way ANOVA with Tukey’s test). e, AKH staining in controls and animals with RNAi against slif in Tk+ EECs (Tkgut>slif-RNAi) after 15 h of yeast feeding (two-tailed Mann–Whitney U-test). f, AKH staining in controls and animals with attenuated TOR signalling in Tk+ EECs, following 15 h of yeast feeding (Kruskal–Wallis with Dunn’s test). Sample sizes (n) and P values are indicated in each plot. In b,d–f, n represents APCs. In c, n represents APC tissue samples. Indicated central tendencies in b,c,e,f are the median and 95% confidence interval and in d are mean ± s.e.m. NS, P > 0.05.
