MicroRNA miR‐7‐5p|‐1|0| regulates wing development in brown planthoppers, Nilaparvata lugens

Abstract BACKGROUND MicroRNAs (miRNAs) regulate insect development; however, their roles in non‐ Drosophila wing polyphenism, such as the brown planthopper (BPH, Nilaparvata lugens ), remain unclear. Although Nlmad1 downstream of IIS‐FoxO has been shown to regulate wing morphs, its upstream control is poorly understood. RESULTS Here, we showed that the functional role of the evolutionarily conserved miR‐7‐5p|‐1|0|, miR‐7‐5p and miR‐71‐5p in N. lugens wing development and its mechanistic link to Nlmad1 . Through computational prediction, dual‐luciferase assays, and phenotypic analyses, we demonstrated that Nlu‐miR‐7‐5p|‐1|0| directly targets the 3′UTR of Nlmad1 to suppress its expression. Overexpression of Nlu‐miR‐7‐5p|‐1|0| in macropterous nymphs induced significant wing development defects, whereas inhibition of endogenous Nlu‐miR‐7‐5p|‐1|0| in the brachypterous strain only resulted in a subtle phenotype in wing development. Notably, Nlu‐miR‐7‐5p influenced Nlmad1 transcript levels but requires further validation for direct interaction, whereas Nlu‐miR‐71‐5p modulated wing development independently of Nlmad1 , suggesting distinct regulatory pathways. CONCLUSION This study is the first to establish miR‐7‐5p|‐1|0| as a post‐transcriptional regulator of Mad‐family proteins in insects, expanding our understanding of miRNA‐driven developmental plasticity. By linking conserved miRNAs to species‐specific polyphenic traits, our findings provide a framework for targeting miR‐7‐5p|‐1|0| ‐Nlmad1 interactions in novel pest management strategies aimed at disrupting wing development and population dispersal. © 2025 Society of Chemical Industry.