RNA interference targeting neuropeptide F inhibits the lipid metabolism and reproduction in Drosophila suzukii.

Neuropeptide F (NPF) is an important signaling molecule that acts as a neuromodulator to regulate diverse physiological and behavioral processes across vertebrates and invertebrates. However, the role of NPF in the globally invasive pest of soft-skinned fruits, Drosophila suzukii, remains unknown. Here, we identified and characterized cDNA encoding one NPF precursor from D. suzukii. DsNPF was most highly expressed during the adult stage and showed the highest expression levels in the midgut. Three-dimensional models of the DsNPF-DsNPFR complex generated by AlphaFold 3 revealed that three residues in DsNPF and four residues in DsNPFR play critical roles in mediating their interaction. RNA interference (RNAi)-mediated silencing of DsNPF led to a marked reduction in whole-body triacylglycerol (TAG) levels and intestinal lipid content. These metabolic defects were accompanied by decreased starvation resistance and compensatory hyperphagia. DsNPF silencing significantly upregulated lipid metabolism genes and downregulated insulin-like peptides. Furthermore, DsNPF knockdown significantly reduced fecundity in females, and impaired male mating behavior. Silencing of DsNPF significantly downregulated vitellogenin (DsVg) expression in the fat body and Vg receptor (DsVgR) expression in the ovary. Exogenous NPF administration effectively rescued the metabolic and reproductive defects caused by DsNPF knockdown. These results indicate that the DsNPF signaling pathway not only plays a pivotal role in the regulation of lipid metabolism and reproduction, but also provides a valuable reference for the development of potential agonists or antagonists targeting this pathway in D. suzukii.