Zhao_2023_Cells_12_

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 Ostrinia furnacalis is regulated by neuropeptide F (NPF, the homologous peptide of mammalian NPY) via the insulin signalling pathway in the midgut. Furthermore, the genes pi3k and mtor in the insulin pathway positively regulate alpha-amylase and lipase of the midgut by recruiting the transcription factors c-Myc and PPARgamma for binding to the promotors of these two enzymes. Importantly, we find that the feeding behaviour and the digestive system of midgut in O. furnacalis larvae are closely related and interactive in that knocking down alpha-amylase or lipase induces a reduction in larval feeding, while food-deprived larvae lead to fewer expressions of alpha-amylase and lipase. Importantly, it is the gut NPF that regulates the alpha-amylase and lipase, while variations of alpha-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 O. furnacalis larvae.