Blood feeding is required by Ae. aegypti mosquitoes to obtain the necessary protein-derived nutrients for completion of the gonotrophic cycle [32] . Understanding the biochemical and cellular regulation of blood meal metabolism will provide insights into this critical process in Ae. aegypti, as well as other blood-feeding arthropods that function as vectors of blood borne pathogens. Our objective in the studies reported here was to first determine if amino acids were sufficient to induce RER whorl unwinding, and if they were, to use a combination of proteomic and RNAi approaches to identify proteins that may be required for maintenance of RER whorls in midgut epithelial cells. It is possible that RER whorls function by providing a mechanism to rapidly activate midgut secretion pathways upon feeding, rather than expend energy maintaining them in the absence of feeding.