Distinct roles of isoforms of the heme-liganded nuclear receptor E75, an insect ortholog of the vertebrate Rev-erb, in mosquito reproduction

► Twenty-Hydroxyecdysone (20E) plays a central role in egg development in mosquitoes. ► The nuclear receptor E75 is an essential factor in the 20E genetic hierarchy. ► We identified distinct roles of E75 isoforms in vitellogenesis of Aedes aegypti. ► Heme is required in a high level of E75-mediated expression of 20E-controlled genes. ► Heme serves as a sensor of the availability of a protein meal for egg development.