METTL3/METTL14‐mediated RNA m6A modification is involved in male reproductive development in Bactrocera dorsalis

Abstract RNA N 6 ‐methyladenine (m 6 A) modification represents a pivotal epigenetic modification that facilitates the remodeling of gene expression and regulates a variety of biological processes via certain post‐transcriptional mechanisms. However, the specific function of RNA m 6 A modification in insect male reproduction remains unclear. In this study, we explored the molecular mechanism by which METTL3/METTL14‐mediated RNA m 6 A modification regulates male reproduction in the invasive pest Bactrocera dorsalis . The results showed that BdMettl3 and BdMettl14 were highly expressed in fat body (FB) and male accessory glands (MAGs). Knockout of BdMettl3 or BdMettl14 decreased the expression level of m 6 A in B. dorsalis , resulting in testicular deformities and a significant reduction of viable sperm number. Specifically, BdMettl3 or BdMettl14 knockout reduced the titer of 20‐hydroxyecdysone (20E, the active form of ecdysone) in males. The messenger RNA (mRNA) of Disembodied , one of the 20E synthesis genes, was modified by m 6 A, and its expression increased the titer of 20E. The mRNA m 6 A level of Disembodied obviously decreased after the knockout of BdMettl3 or BdMettl14 , suggesting that RNA m 6 A modification regulates testis development and fecundity by modulating 20E synthesis. Taken together, this study indicates that METTL3/METTL14‐mediated RNA m 6 A modification presents a new regulatory mechanism for male reproduction in B. dorsalis , serving as a potential target for the control of B. dorsalis .