Gene expression profiling of ovary identified eggshell proteins regulated by 20-hydroxyecdysone in Bactrocera dorsalis.

The oriental fruit fly, Bactrocera dorsalis, is one of the most destructive pests worldwide. The frequent use of chemical insecticides has led B. dorsalis to develop resistance to many insecticides in recent decades. New high-throughput-sequenced transcriptomes, as well as genomes, have revealed a large number of reference genes for functional target identification. Here, we performed digital gene expression profiling of ovary and testis of B. dorsalis adults. Various genes were identified to be highly expressed in B. dorsalis ovary. The genes encoding components of eggshell, vitelline membrane proteins (Vmps) and chorion-related proteins, were identified to be tissue-specifically expressed in ovary. Five cytochrome P450 genes were also identified to be highly expressed in ovary. Three of them were ecdysone synthesis pathway genes indicating the ovary as a potential synthesis site of female. The up-regulated expression of Vmps by exogenous 20-hydroxyecdysone implied the hormonal regulation of eggshell formation during ovarian development. Many other genes with potential functions in ovarian development were also identified, including vitellogenin receptor, insulin receptor, NASP protein, and odorant binding protein. These findings should promote our understanding of the regulation of vitellogenesis and eggshell formation and enable exploration of potentially novel pest control targets.