Effect of peritrophic matrix C-type lectin (AdPMCTL) on blood-meal size in Anopheles dirus.

The peritrophic matrix (PM) is penetrated by Plasmodium ookinete to permit transition to oocyst in the mosquito midgut, the manner by which the ookinete interacts with glycoproteins on the PM remains poorly understood. We partially characterized peritrophic matrix C-type lectin (PMCTL) from An. gambiae (CTL10) and An. dirus (AdPMCTL). AdPMCTL protein was produced specifically in blood-fed mosquitoes. The 320 amino acid AdPMCTL exhibits 72% identity with a putative secreted An. gambiae ortholog (AGAP009316, CTL10). AdPMCTL was cloned and its expression profile determined in sugar- and blood-fed midguts. RNAi was used to determine the effect of AdPMCTL on blood meal size and on mosquito survival. AdPMCTL mRNA was present in midguts of sugar-fed mosquitoes and exhibited up-regulation following a blood meal, and AdPMCTL silencing significantly influenced the blood-meal size of engorged mosquitoes, suggesting a role for AdPMCTL as a stabilizing linker molecule, which limits PM distension after blood feeding.