Modulation of Midgut Peritrophins' Expression during Plasmodium Infection in Anopheles stephensi (Diptera:Culicidae)

The peritrophic matrix (PM) serves as a barrier to pathogens in many disease vectors including mosquitoes. The Plasmodium ookinete has to cross the PM barrier for its successful establishment in the mosquito midgut and subsequent transmission. It is conceived that alterations to PM may lead to a block in infection. Peritrophins which are the major constituents of PM are yet to be elucidated at molecular level. The present study demonstrates Anopheles stephensi midgut peritrophins' expression during Plasmodium berghei infection. Eight peritrophin genes (Per 10, Per 16, Per 22, Per 25, Per 26, Per 28, Per 30 & Per 43) of A. stephensi were identified from vectorbase, isolated from the adult midgut, and expression pattern monitored in real-time, in normal and infected blood meal conditions. Temporal expression of peritrophins in the midgut was monitored every 6 h till 24 h post blood meal. Results showed that the Per 10, Per 16, Per 22, Per 25 and Per 26 expression was significantly downregulated during Plasmodium infection whereas Per 30 and Per 43 expression was markedly up-regulated. The Per 28 expression was low initially but elevated later. This data clearly indicates that peritrophins are differentially modulated in infected midgut. The significance of differential expression of peritrophins' in parasite transmission is discussed further.