Abstract:

 Adipokinetic hormone (AKH) is one of the most important neuropeptides regulating energy homeostasis in insects by inducing mobilization of energetic substrates in the fat body to fuel energy-consuming activities. Early studies on AKH were predominant in unveiling the functions and signal transduction of AKH on promoting catabolism of nutrient reserves, such as triacylglycerol and glycogen, during insect locomotion including flight and walking. Recent studies have illustrated that AKH / AKH receptor system is involved in mobilization of nutrient stores during insect vitellogenesis and lactation. Additionally, AKHs also play important roles in homeostasis maintenance under stress conditions including antioxidant, starvation and immunity. Accumulating evidence suggested that, as a key hormone mobilizing energy stores, AKH is a pleotropic factor involved in many physiological events. Here we reviewed the functions and modes of action of AKHs in insect locomotion, reproduction and stress resistance aiming to support for further uncovering the molecular mechanism of AKH signaling pathway in regulation of insect energy homeostasis, and also for elaborating genetic basis of long-distance migration, powerful fertility and anti-stresses of pests.

Key words: adipokinetic hormone, energy homeostasis, flight, reproduction, stress adaptation