Untitled research work

During blood feeding, the protein contents of the salivary glands of Anopheles stephensi are greatly reduced. To observe the changes in salivary proteins, we analyzed the salivary glands of An. stephensi at different stages of the blood-feeding process; before probing, during probing, during feeding, and after feeding. We also investigated the midgut contents and prediuresis fluid of An. stephensi. Proteins in the salivary glands were reduced not only at the probing phase but also at the blood-feeding phase. In the midgut contents after a full blood meal, we found some proteins reacted with rabbit anti-salivary gland serum, which did not react with the midgut contents of mosquitoes before feeding. This suggests that these proteins come from the salivary glands. After feeding, we also found sporozoites in the prediuresis fluid of An. stephensi, which had been infected with Plasmodium berghei. These sporozoites may come from the salivary glands, because the density of sporozoites in the prediuresis fluid correlated with the number of sporozoites in the salivary glands. These results indicate that An. stephensi mosquitoes draw back their own saliva into their midguts when they feed blood.