Novel-miR-932 targets BgNeverland to regulate 20-hydroxyecdysone synthesis in Blattella germanica: Prospective target...

miRNAs critically regulate hormonal signaling to ensure precise spatiotemporal control of metamorphosis and reproduction in insects, highlighting their potential as pest control targets. Blattella germanica, is a major indoor sanitary pest that threatens human and domestic animal health. However, the miRNA expression profiles and their systematic functions in the hormonal signaling pathways remain largely uncharacterized in B. germanica. Transcriptomic analysis of the nymph-to-adult transition in B. germanica revealed that both downregulated differentially expressed genes and the target genes of differentially expressed miRNAs were significantly enriched in insect hormone biosynthesis pathways. RNA interference (RNAi)-mediated silencing of six key 20E biosynthesis genes (BgNeverland, BgSpook, BgPhantom, BgDisembodied, BgShadow, and BgShade) resulted in molting defects and increased mortality in nymphs. Based on bioinformatic predictions and omics data, we identified miRNAs potentially targeting 20E biosynthesis genes. Subsequent dual-luciferase reporter assays, along with agomir and antagomir injection experiments, confirmed that novel-miR-932 negatively regulates BgNeverland. Both oversupply and inhibition of novel-miR-932 led to elevated nymphal mortality. Supplementation with exogenous 20E effectively rescued the increased mortality induced by novel-miR-932 agomir injection. Furthermore, either oversupply of miR-932 or silencing of BgNeverland resulted in a reduction in lipid content, consequently compromising female fecundity. These results implicate miRNAs that target 20E pathway genes as potential targets for novel pest control strategies.