Project description:Female reproductive potential is crucial for a population to multiply. MicroRNAs (miRNAs) have been demonstrated to be critical regulators in the post-transcriptional regulation of numerous biological processes, including reproduction. However, these studies mainly focus on model species. The oriental fruit fly, Bactrocera dorsalis, is a highly invasive pest in East Asia and the Pacific. Thus, it is of great significance to identify miRNAs involved in reproduction in this notorious pest. In this study, high-throughput sequencing was carried out to identify miRNAs potentially involved in reproductive development in female B. dorsalis. Eight miRNA libraries were established in the ovary and fat body from four developmental stages [1 days (d), 5 d, 9 d, and 13 d post-eclosion]. 116 and 84 miRNAs were found to be differentially expressed in ovary and fat body, respectively, during sexual maturation of female adults. The Gene Ontology analysis of the target genes involved in oogenesis and lipid particle accounted for 33% and 15% respectively . Among these differentially expressed miRNAs, we found five highly expressed miRNAs that are shared in the ovary and fat body that comprised four (miR-305-3p, miR-317-3p, miR-2779, and miR-305) conserved and one novel (Bdo-pc-3p-116) miRNA. Quantitative polymerase chain reaction results revealed that Bdo-pc-3p-116 was found to be specifically expressed in the ovary and down-regulated during sexual maturation. Injection of agomir-pc-3p-116 resulted in arrested ovarian development, and reduced egg deposition and progeny viability in B. dorsalis. CYP6a14 and endophilin B were confirmed to be the targets of pc-3p-116 via dual-luciferase assay and expression profiling. RNAi depletion of CYP6a14 led to reproductive defects similar to those caused by the injection of pc-3p-116 agomir. Thus, pc-3p-116 might play a critical role in female reproduction by targeting CYP6a14 and endophilin B and serve as a monitor to control CYP6a14 and endophilin B1 mRNA levels. Our data will not only provide abundant miRNAs as well as target genes for molecular research in female reproduction but also promote environment-friendly control strategies for this agricultural pest.
