title: Insulin receptor regulates food intake through sulfakinin signaling in the red flour beetle, Tribolium castaneum.
abstract: Insects obtain energy and nutrients via feeding to support growth and development. The insulin signaling pathway is involved in the regulation of feeding; however, the underlying mechanisms are not fully understood. Here, we show that insulin signaling regulates food intake via crosstalk with neuropeptide sulfakinin in the red flour beetle, Tribolium castaneum. Silencing of the insulin receptor (InR) decreased the food intake in the penultimate and final instar stages, leading to a decrease of weight gain and mortality during larval-pupal metamorphosis. Interestingly, the knockdown of InR co-occurred with an increased expression of sulfakinin (sk), a gene encoding neuropeptide SK functioning as a satiety signal. In parallel, double silencing of sk and InR eliminated the inhibitory effect on food intake as induced by silencing of InR and the larvae died as prepupae. In conclusion, this study shows, for the first time, that the insulin/InR signaling regulates food intake through the sulfakinin signaling pathway in the larval stages of this important model and pest insect, indicating a novel target for pest control.
authors.affiliation: Laboratory of Agrozoology, Department of Crop Protection, Ghent University, Coupure Links 653, 9000 Ghent, Belgium.
authors.forename: Xianyu
authors.initials: X
authors.lastname: Lin
authors.affiliation: Laboratory of Agrozoology, Department of Crop Protection, Ghent University, Coupure Links 653, 9000 Ghent, Belgium.
authors.forename: Na
authors.initials: N
authors.lastname: Yu
authors.affiliation: Laboratory of Agrozoology, Department of Crop Protection, Ghent University, Coupure Links 653, 9000 Ghent, Belgium. Electronic address: guy.smagghe@ugent.be.
authors.forename: Guy
authors.initials: G
authors.lastname: Smagghe
mesh_terms: D000818:Animals; D001835:Body Weight / Q000235:genetics; D004435:Eating / Q000502:physiology*; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D007814:Larva; D008675:Metamorphosis, Biological; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism; D011972:Receptor, Insulin / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014231:Tribolium / Q000378:metabolism / Q000502:physiology*; D015854:Up-Regulation
chemical_list: D019476:Insect Proteins; D009479:Neuropeptides; D011972:Receptor, Insulin
keywords: Food intake; Insulin receptor; RNA interference; Sulfakinin; Tribolium castaneum