Secretory proteins from the salivary glands of adult Aedes aegypti mosquitoes

We determined whether the salivary proteins of mosquitoes are constant throughout adult life and whether the nature of the feeding stimulus determined salivary composition. Acrylamide gel electrophoresis and subsequent silver-staining of harvested saliva yielded as many as 20 polypeptides; those precipitating silver most readily generally incorporated abundant isotope. Autoradiography revealed 12 prominant secretory polypeptide fractions, each synthesized beginning soon after ecdysis and throughout the first week of adult life. Synthesis was limited to the posterior regions of the salivary gland, mainly within the lateral lobes. Virtually all secretory polypeptides were antigenic and were secreted into hosts during blood-feeding. We concluded that the secretory salivary proteins of adult mosquitoes are continuously synthesized throughout the first week of adult life, and that most are secreted during blood-feeding.