Synergism of Feeding and Digestion Regulated by the Neuropeptide F System in Ostrinia furnacalis Larvae.

Feeding is crucial for the growth and survival of animals, including humans, but relatively little is known about how it is regulated. Here, we show that larval feeding in is regulated by neuropeptide F (NPF, the homologous peptide of mammalian NPY) via the insulin signalling pathway in the midgut. Furthermore, the genes and in the insulin pathway positively regulate α-amylase and lipase of the midgut by recruiting the transcription factors and for binding to the promotors of these two enzymes. Importantly, we find that the feeding behaviour and the digestive system of midgut in larvae are closely related and interactive in that knocking down α-amylase or lipase induces a reduction in larval feeding, while food-deprived larvae lead to fewer expressions of and . Importantly, it is the gut NPF that regulates the α-amylase and lipase, while variations of α-amylase and lipase may feed back to the brain NPF. This current study reveals a molecular feedback mechanism between feeding behaviour and the digestive system that is regulated by the conserved NPF via insulin signalling systems in the midgut of larvae.