PROJECT SUMMARY There has been a continuous demand for development of insect control methods that are target-specific. Juvenile hormone (JH) and ecdysteroids (20-hydroxyecdysone, 20E is the most active form) are the major hormones that regulate many physiological and developmental processes in insects. Since these hormones are not present in vertebrates, they represent attractive targets for development of insect control methods. Hindering this effort is the lack of understanding on the molecular basis of action of these hormones. There has been excellent recent progress in understanding the molecular basis of 20E and JH action. Key players, including receptors, co-activators, response elements and target genes involved in the action of these hormones have been identified. Non-steroidal ecdysone agonists and JH analogs have been discovered, and commercialized for the control of pests and disease vectors. Research supported by this program showed that epigenetic modifications, especially acetylation levels of histones regulated by histone acetyltransferases (HAT) and histone deacetylases (HDAC) modulate JH and 20E action. Hormone action requires multiple layers of regulation because the same circulating levels of hormones exert diverse functions in different tissues and under different physiological conditions. Based on the published literature and preliminary data included in this application, we hypothesize that epigenetic regulators HDACs, HATs, histone lysine methyltransferases (HKMT) and histone demethylases (HDM) modulate JH and 20E action in the regulation of postembryonic development and reproduction. The main goal of this proposal to test this hypothesis by studying the mechanisms of action of epigenetic modifiers in JH and 20E action using T. castaneum, TcA cells, Ae. aegypti and Aag2 cells as model systems. The two Specific Aims of the proposal are 1. To identify and characterize epigenetic modifiers required for 20E and JH regulation of postembryonic development and female reproduction and 2. To study mechanisms of action of epigenetic modifiers required for 20E and JH regulation of postembryonic development and female reproduction. In the first Specific Aim, RNAi, CRISPR/Cas9 genome editing methods, RNA sequencing, bioinformatics, RT-qPCR, enzyme assays and cell culture approaches will be used to identify and characterize HATs, HDACs, HKMTs and HDMs required for postembryonic development and female reproduction in T. castaneum and Ae. aegypti. In the second Specific Aim, the mechanisms of action of 10-12 epigenetic modifiers will be studied using western blots and ChIP, reporter, Two-hybrid and pull-down assays, and mass spectrometry approaches. Results from the proposed research will impact medicine by providing information for the development of vector control methods. This information could help in understanding epigenetics of human diseases such as cancer. The results from the proposed research may help to transform our understand...