Cross-talk of insulin-like peptides, juvenile hormone, and 20-hydroxyecdysone in regulation of metabolism in the mosquito .

Female mosquitoes feed sequentially on carbohydrates (nectar) and proteins (blood) during each gonadotrophic cycle to become reproductively competent and effective disease vectors. Accordingly, metabolism is synchronized to support this reproductive cyclicity. However, regulatory pathways linking metabolism to reproductive cycles are not fully understood. Two key hormones, juvenile hormone (JH) and ecdysteroids (20-hydroxyecdysone, 20E, is the most active form) govern female mosquito reproduction. genome codes for eight insulin-like peptides (ILPs) that are critical for controlling metabolism. We examined the effects of the JH and 20E pathways on mosquito ILP expression to decipher regulation of metabolism in a reproducing female mosquito. Chromatin immunoprecipitation assays showed genomic interactions between genes and the JH receptor, methoprene-tolerant, a transcription factor, Krüppel homolog 1 (Kr-h1), and two isoforms of the ecdysone response early gene, E74. The luciferase reporter assays showed that Kr-h1 activates , , and , but represses and The 20E pathway displayed the opposite effect in the regulation of E74B repressed and , while E74A activated and Combining RNA interference, CRISPR gene tagging and enzyme-linked immunosorbent assay, we have shown that the JH and 20E regulate protein levels of all eight ILPs. Thus, we have established a regulatory axis between ILPs, JH, and 20E in coordination of metabolism during gonadotrophic cycles of .