State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
University of Chinese Academy of Sciences, Beijing, China.
Insect Sci. 2023 Dec;30(6):1663-1676. doi: 10.1111/1744-7917.13201. Epub 2023 May 18.
Energy metabolism is essential for insect metamorphosis. The accumulation and utilization of energy is still not completely clear during larval-pupal metamorphosis of holometabolous insects. We used metabolome and transcriptome analysis to reveal key metabolic changes in the fat body and plasma and the underlying metabolic regulation mechanism of Helicoverpa armigera, an important global agricultural insect pest, during larval-pupal metamorphosis. During the feeding stage, activation of aerobic glycolysis provided intermediate metabolites and energy for cell proliferation and lipid synthesis. During the non-feeding stages (the initiation of the wandering stage and the prepupal stage), aerobic glycolysis was suppressed, while, triglyceride degradation was activated in the fat body. The blocking of metabolic pathways in the fat body was probably caused by 20-hydroxyecdysone-induced cell apoptosis. 20-hydroxyecdysone cooperated with carnitine to promote the degradation of triglycerides and the accumulation of acylcarnitines in the hemolymph, allowing rapid transportation and supply of lipids from the fat body to other organs, which provided a valuable reference for revealing the metabolic regulation mechanism of lepidopteran larvae during the last instar. Carnitine and acylcarnitines are first reported to be key factors that mediate the degradation and utilization of lipids during larval-pupal metamorphosis of lepidopteran insects.
能量代谢对于昆虫变态至关重要。在完全变态昆虫的幼虫-蛹变态过程中，能量的积累和利用仍不完全清楚。我们使用代谢组学和转录组学分析来揭示鳞翅目重要农业害虫棉铃虫幼虫-蛹变态过程中脂肪体和血浆中关键代谢变化及其潜在的代谢调控机制。在取食阶段，有氧糖酵解的激活为细胞增殖和脂质合成提供了中间代谢物和能量。在不取食阶段（ wandering 期和预蛹期的开始），有氧糖酵解受到抑制，而脂肪体中的甘油三酯降解被激活。脂肪体中代谢途径的阻断可能是 20-羟基蜕皮酮诱导细胞凋亡引起的。20-羟基蜕皮酮与肉碱协同作用促进甘油三酯的降解和酰基肉碱在血液中的积累，使脂肪体中的脂质能够快速运输并供应给其他器官，这为揭示鳞翅目幼虫最后一龄期的代谢调控机制提供了有价值的参考。肉碱和酰基肉碱首次被报道为介导鳞翅目昆虫幼虫-蛹变态过程中脂质降解和利用的关键因素。
