Plasma free amino acids and protein-bound amino acids in vertebrate blood provide the raw materials for energy conversion and reproduction [19, 20, 21] , and also function to initiate signaling through the target of rapamycin (TOR) signal transduction pathway [22, 23] . Moreover, an artificial amino acid meal is sufficient to induce translation of early trypsin mRNA using the TOR signaling pathway in midgut epithelial cells, however amino acids alone do not induce the transcription and translation of the late phase trypsin protein [24] . It is possible that amino acid signaling through the TOR pathway also stimulates RER reorganization in mosquito midgut epithelial cells.