DNA methyltransferases have an essential role in female fecundity in brown planthopper, Nilaparvata lugens

DNA methylation is an ancient epigenetic modification present in all three domains of life. However, the understanding of DNA methylation in insects is limited. Here, we amplified the full-length transcripts of the DNA methyltransferases Nlu-Dnmt1 and Nlu-Dnmt3, indicating that a complete DNA methylation toolkit exists in the brown planthopper, Nilaparvata lugens, a destructive pest in rice production. Nlu-DNMT1 and Nlu-DNMT3 had the conserved motifs and domains of the DNA methyltransferase family. Nlu-Dnmt1 and Nlu-Dnmt3 were highly expressed in the mated and gravid female adults but weakly expressed in larvae, male adults, and virgin female adults. Silencing Nlu-Dnmt1 and Nlu-Dnmt3 in gravid brachypterous female adults led to fewer offspring, suggesting that DNA methylation regulates female fecundity in insects.