Wolbachia-driven host miRNAs mediate arthropod reproduction in a Wolbachia density-dependent manner

Wolbachia is a widespread endosymbiont and a promising tool for pest control due to its ability to manipulate arthropod reproduction. However, how Wolbachia shapes host microRNA regulation remains poorly understood. Here, we profile the Wolbachia-driven host miRNAs using small RNA-seq in spider mite Tetranychus truncatus to uncover their roles in reproduction and symbiosis. Enrichment analyses of predicted miRNA targets suggest that Wolbachia-driven miRNAs may be involved in Wolbachia-host interactions. Functional assays show that several Wolbachia-driven miRNAs influence host fecundity, with some also affecting Wolbachia density. Inhibition of novel-33 or novel-40 reduces host fecundity and is accompanied by reduced Wolbachia density, whereas inhibition of novel-65 reduces fecundity without altering density. These findings indicate that specific miRNAs contribute to the regulation of reproduction and Wolbachia density in T. truncatus, highlighting host miRNAs regulated by Wolbachia as a mechanism of host manipulation and offering opportunities for Wolbachia-based pest management.