Coupling of growth with nutritional status: the roles of novel
Abstract: Animals need to coordinate growth with nutritional availability for proper development and physiology, which leads to better survival. Nutritional information is mostly perceived by peripheral organs, particularly metabolic organs such as adipose tissue and gut, before being relayed to the brain, which modulates physiological responses. Hormonal signaling ensures this organ-to-organ communication, and defects in this endocrine regulation in humans often cause diseases including obesity and diabetes. Here we show that Drosophila peptide hormone, CCHamide-2 (CCHa2) plays important roles in the coupling of growth with nutritional status. CCHa2 is a 13-amino acid peptide, which is predominantly expressed in adipose tissue (the “fat body”) and gut. The expression of CCHa2 is nutrient-dependent; it is particularly sensitive to glucose. The CCHa2 peptide signals to neuroendocrine cells in the brain that produce Drosophila insulin-like peptides (Dilps) through its receptor (CCHa2-R) and promotes the production of Dilps. Dilps are equivalent to mammalian insulin/IGF, which control tissue growth as well as sugar metabolism. Mutants of both CCHa2 and CCHa2-R display severe growth retardation during larval stages. These results demonstrate that CCHa2 and CCHa2-R functionally connect peripheral tissues with the brain, and that CCHa2/CCHa2-R signaling coordinates the animal’s growth with its nutritional conditions by regulating the production of insulin-like peptides.
Contact: Division of Neurogenetics, Prof. Dr. Daisuke Yamamoto 022-217-6220 （代理 佐藤耕世）