PROJECT SUMMARY / ABSTRACT This supplement is responsive to the Notice of Special Interest, NOT-AI-22-049, “Administrative Supplements for NIAID Regional Biocontainment Laboratories (RBL) and other NIH Grantees Conducting Research at RBL- affiliated Sites” and the scope of our NIAID grant, (fund R01AI151166), entitled, “Metabolic basis of mosquito- endosymbiont-virus interactions.” Here, we will accelerate and advance Specific Aims 1-3 of the parent award through two primary supplementary aims; SA 1-3.supp1: Assess how modification of cellular lipids alters the composition of the viral envelope and required structural transitions for maturation and infectivity in Ae. Aegypti. The data generated from SA 1-3.supp1 will significantly enhance the parent award data outcomes as it provides biophysical insight into how lipid modulation might alter virus structure and function and thus impact the viral life cycle in Ae. aegypti. SA 2.supp2: Assess how Wolbachia-mediated lipid changes alter ZIKV and CHIKV infection and virus-associated lipid modulations. The data generated from SA 2.supp2 will significantly enhance the parent award data outcomes by providing additional insight into the metabolic state of the vector following infection with all three vectored viruses. The studies will enhance our understanding of metabolic choke points that may be applicable to all three viruses, and/or significant differences that might hinder biocontrol efforts. Both efforts synergize with the goals of the RBL in (diagnostics, therapeutics, vaccines, and transmission control methods for Arboviruses vectored by Ae. aegypti); and has the full support of the Scientific Director of the RMRBL.