Expression and Role of Vitellogenin Genes in Ovarian Development of Zeugodacus cucurbitae

( ) genes encode the major egg yolk protein precursor in arthropods. In this study, four were identified in (Coquillett). Sequence analysis showed that four had the conserved Vg domain. Phylogenetic analysis indicated that four were homologous to the Vgs of Tephritidae insects. The temporal and spatial expression patterns of were analyzed by quantitative real-time polymerase chain reaction (RT-qPCR), and the four showed high expression levels in female adults, especially in the fat body. The expression of and was down-regulated by a low dosage (0.5 μg) of 20-hydroxyecdysone (20E), and , , and were up-regulated by a high dosage (1.0 and 2.0 μg) of 20E. The expression of and was up-regulated by 5 μg of juvenile hormone (JH), while all of the were down-regulated by a low and high dosage of JH. Expression of was down-regulated after 24 h of starvation and recovered to normal after nutritional supplementation. After micro-injection of the gene-specific double-stranded RNA, the ' expression was significantly suppressed, and ovarian development was delayed in females. The results indicate that RNA interference of reproduction-related genes is a potential pest control method that works by manipulating female fertility.