Dilp6 produced by the fat body regulates ERK for HAB during the hungry state.

Abstract

(A) dilp6 loss-of-function mutant flies (dilp6LOF) showed increased HAB when hungry (Satiety: P-values: 0.6176, 0.4785, 0.8634, and 0.7292 from left to right; Hunger: P-values: 0.0003, 0.0029, 0.0222, and 0.4018 from left to right). (B) α′β′ MBn showed increased hot response in dilp6LOF mutant background specifically when hungry but not when sated (P = 0.2043 for satiety; P = 0.0002 for hunger). (C) Adult-stage-specific knockdown of dilp6 in the fat body increased HAB in hungry but not in sated flies (Satiety: P-values: 0.7112, 0.4332, 0.748, and 0.4753 from left to right; Hunger: P-values: 0.0006, 0.0002, 0.0332, and 0.0732 from left to right). (D) Genetic knockdown of dilp6 in the fat body increased hot response of α′β′ MBn specifically in the hungry state (P = 0.8682 for satiety; P = 0.0328 for hunger). (E) Adult-stage-specific expression of dilp6 in the fat body decreased HAB in the hungry state (Satiety: P-values: 0.2437, 0.2066, 0.3148, and 0.2978 from left to right; Hunger: P-values: F) Genetic expression of dilp6 in the fat body decreased hot response of α′β′ MBn in the hungry state (P = 0.5214 for satiety; P = 0.002 for hunger). (G) Adult-stage-specific knockdown of Erk in α′β′ MBn increased HAB during hunger (Satiety: P-values: 0.9053, 0.6805, 0.4785, and 0.2593 from left to right; Hunger: P-values: H) Genetic knockdown of Erk in α′β′ MBn increased hot responses of α′β′ MBn during hunger but not during satiety (P = 0.2155 for satiety; P = 0.0361 for hunger). (I) Adult-stage-specific expression of Erk in α′β′ MBn decreased HAB during the hungry state (Satiety: P-values: 0.6868, 0.7727, 0.7495, and 0.0552 from left to right; Hunger: P-values: 0.001, 0.0003, 0.0002, and 0.0121 from left to right). (J) Genetic expression of Erk in α′β′ MBn decreased the hot response of α′β′ MBn in the hungry state (P = 0.4394 for satiety; P = 0.0003 for hunger). The arrows under each calcium response curve indicate the time points at which the hot stimulus was applied. Each N represents either a group of 15 flies analyzed together in the behavioral assay (A, C, E, G, I) or a single fly in calcium imaging experiments (B, D, F, H, J). Data are represented as mean ± SEM with dots representing individual values. The data underlying this figure can be found in S1 Data. Data were analyzed by one-way ANOVA followed by Tukey’s test (C, E, G, I) or the unpaired two-tailed t test (A, B, D, F, H, J). *P < 0.05; ns, not significant. HAB, hot avoidance behavior; MBn, mushroom body neuron; SEM, standard error of mean.</p