Fig. 6: AKH-dependent ICWs are regulated by dietary sugar and protein.

A Early 3rd instar fly larvae were transferred onto 2% agarose for 9 h and then onto 2% agarose + 2% sucrose for 20 min. These conditioned larvae were further transferred onto different test foods containing 2% sucrose, 2% sucrose + 10% Tryptone (protein diet), or no nutrient (starvation diet). B, C Representative Ca2+ images and Ca2+ activities of free-behaving larvae transferred between different diets. Ca2+ activities were calculated from the average signals obtained from all imaged larvae. The gap between the two diets is the larvae transfer time which is ~10 min. The result was repeated in 3 independent experiments. D Representative Ca2+ activities in the fat body of free-behaving larvae with whole-body AkhR mutant or fat-specific knockdown of AkhR. E Quantification of Ca2+ activities in the fat body of free-behaving fly larvae. N = 12 larvae for each experiment. Ca2+ intensity (arbitrary units) was presented using a linear colour scale (minimum = 0, maximum = 255) (B). Ordinary one-way ANOVA with Dunnett’s multiple comparisons was used in (E). Data were plotted as mean ± S.E.M (C, D), or mean ± SD (E). Scale bars, 2 mm (B). Source data are provided as a Source Data file.