Transcriptomic and reverse genetic analysis of gene expression in the juvenile hormone dependent post-eclosion development of the adult female mosquito, Aedes aegypti

Mosquito egg development is controlled by alternating peaks of two major insect hormones – juvenile hormone (JH) and 20-hydroxyecdysone (20E). JH regulates the post-eclosion (PE) development of mosquito females, preparing them for blood-meal activated events driven by 20E. The fat body (FB), the insect tissue central to metabolism, immunity and reproduction, undergoes a dramatic PE development controlled by JH. However, this development has not been characterized molecularly. Our microarray transcriptome analysis has revealed three major gene clusters in Aedes aegypti FB expressed in temporal manner over PE development: early, mid, and late PE (EPE, MPE, and LPE). The EPE cluster mainly contains genes responsible for carbohydrate metabolism reflecting needs of the FB of the nectar-feeding post-eclosed mosquito. Another set of predominantly metabolic genes is expressed as the MPE cluster. The LPE cluster is enriched in genes of amino acid metabolism genes as well as more transcriptional and translational process genes. Met is a putative JH receptor (Riddiford, 2008). Mosquitoes with Met RNAi depletion exhibit the same phenotype of ovarian follicle growth arrest as those deprived of JH. Depletion of Met results in down-regulation of Kruppel-h1, Hairy and Sodium/solute Symporter1 but up-regulation of Hexamerin 2β and bHLH-PAS factor Cycle. However, Hairy, a bHLH transcription factor, has an opposite effect from Met, activating Hexamerin 2β, AAEL002049 and inhibiting Cycle. This study serves as a stepping stone for advancing our understanding of JH action in the mosquito reproductive maturation.