DEPLETION OF TOTAL SALIVARY-GLAND PROTEIN IN BLOOD-FED ANOPHELES MOSQUITOS

Reduction in total salivary gland protein from four anopheline vectors of human malaria, Anopheles stephensi Listen, An. albimanus Wiedmann, An. gambiae Giles, and An. freeborni Aitken, was quantified after mos quitoes blood-fed to repletion on human volunteers, hamsters or throug h a Baudruche artificial membrane. Total salivary gland protein from p ools of six unfed mosquitoes ranged from 4.33 to 7.91 mu g/ml. The dif ference between the total protein of glands from unfed and blood-fed m osquitoes for all species ranged from 1.77 to 3.12 (mu g/ml for six po oled salivary glands. Total salivary gland protein for mosquitoes bloo d-fed to repletion was significantly less than that of unfed controls from the same cohort. Reduction in total salivary gland protein for An . freeborni and An stephensi blood fed to repletion on human volunteer s, hamsters, and a Baudruche membrane ranged from 24 to 46%, from 43 t o 56%, and from 24 to 51%, respectively An. stephensi mosquitoes were allowed to blood feed on humans for 0 (unfed), 0.5-, 1.0-, 2.0-min tim e periods or to repletion (>2-5 min). As feeding time increased, there was a significant decrease in total amount of protein in the salivary glands. This decrease was proportional over time, indicating that sal ivation occurred continuously from the beginning (probing) of blood fe eding to withdrawal of the mosquito mouthparts at repletion. These dat a indicate that during blood feeding there was no apparent difference between species in the salivary gland output measured as amount of pro tein depleted from the salivary glands and that depletion of salivary protein from the glands occurred continuously as mosquitoes fed to rep letion.