The direct regulation ofAalbdsxonAalVgRis indispensable for ovarian development inAedes albopictus

BACKGROUND Aedes albopictus is an important vector with an extensive worldwide distribution. Only female mosquitoes play a significant role in the transmission of pathogens. Doublesex ( dsx ) is a central nexus gene in the insect somatic sex determination hierarchy. RESULTS In this study, we characterized the full-length sex-specific splicing forms of the Ae. albopictus dsx gene ( Aalbdsx ). Then, we identified 15 direct target genes of DSX in adult females using digital gene expression (DGE) combined with qPCR following a chromatin immunoprecipitation assay (ChIP) with specific DSX antibodies. The knockdown of Aalbdsx suppressed ovarian development, and the transcript levels of the Aalbdsx target vitellogenin receptor ( VgR ) gene decreased, whereas vitellogenin ( Vg ) expression showed an increase in the fat body. Genes in the major Vg regulatory pathway were also upregulated. Our results suggest that the effects of Aalbdsx RNAi on ovarian development are exerted mainly via VgR rather than Vg . CONCLUSION The results of our study not only provide a reference for the further elucidation of the sex determination cascade and comparative analyses of dsx target interactions in mosquitoes but also reveal potential molecular targets for application to the development of sterile male mosquitoes to be released for vector control.