Integration of miRNA and mRNA expression profiles in Asian spongy moth Lymantria dispar in response to cyantraniliprole

The Asian spongy moth, Lymantria dispar, is a worldwide forest pest that damages >500 plant species. Nowadays, chemical control is the most widely used method because of its rapidity and effectiveness, but the insecticide resistance is a growing concern for spongy moth. As important post-transcriptional regulators of gene expression, whether microRNAs (miRNAs) are involved in insecticide tolerance is little known in spongy moth. Therefore, an integrated analysis of miRNA and mRNA was performed on L. dispar larvae treated with cyantraniliprole. Compared to the control group, a total of 432 differentially expressed genes (DEGs) and 23 differentially expressed miRNAs (DEMs) were identified in L. dispar larvae under cyantraniliprole exposure. Among them, twelve DEGs encoding detoxification enzymes/proteins were further analyzed. Twenty-one genes related to insecticide tolerance were predicted by 11 DEMs, of which 25 miRNA-mRNA interactions were identified. In the miRNA-mRNA network, novel-miR-4 and mmu-miR-3475-3p were involved in the response of L. dispar to cyantraniliprole stress by regulating five genes associated with detoxification, respectively. The P450 gene CYP4C1 (c34384.graph_c0) was the only DEG related to detoxification in the network, which was regulated by novel-miR-4. The expression levels of ten DEMs were confirmed by quantitative reverse transcription PCR (RT-qPCR) and the trends were consistent with miRNA-seq. This study identified some candidate miRNAs and mRNAs related to cyantraniliprole tolerance in L. dispar, which provides valuable transcriptomic information for revealing the molecular mechanisms of insect tolerance and developing novel insecticides.