Gene silencing in mosquito salivary glands by RNAi

Abstract

Salivary glands are the ultimate site of development in the insect of mosquito born pathogens such as Plasmodium. Mosquito salivary glands also secrete components involved in anti-haemostatic activities and allergic reactions. We investigated the feasibility of RNAi as a tool for functional analysis of genes expressed in Anopheles gambiae salivary glands. We show that specific gene silencing in salivary glands requires the use of large amounts of dsRNA, condition that differs from those for efficient RNAi in other mosquito tissues. Using this protocol, we demonstrated the role of AgApy, which encodes an apyrase, in the probing behaviour of An. gambiae.

Collagen-binding protein, Aegyptin, regulates probing time and blood feeding success in the dengue vector mosquito, Aedes aegypti

“…Instead they perform complementary functions to optimize successful feeding. Our data and conclusions are supported further by data on the partial silencing of salivary apyrase and gSG6 genes in A. gambiae, which resulted in reduced mosquito feeding efficiency (33,34). Finally, our results support transgenic approaches for studies of gain and loss of salivary functions.…”

Use of chromatin remodeling ATPases as RNAi targets for parental control of western corn rootworm (Diabrotica virgifera virgifera) and Neotropical brown stink bug (Euschistus heros)

“…In other orders such as Diptera, generally higher doses are needed to achieve an effective RNAi response. For example, in the African malaria mosquito, Anopheles gambiae, doses on the order of 1 μg/g to 10 μg/g are necessary to achieve an effective RNAi response (Boisson et al, 2006); and Lepidoptera needs a vast range of concentrations that span from <0.01 μg/g to > 1 μg/g depending on the species (Terenius et al, 2011). Drosophila lack systemic RNAi (Roignant et al, 2003), and therefore are not as sensitive to injection or oral administration of dsRNAs (e.g., most RNAi assays in D. melanogaster are performed with transgenic flies designed to express hairpin RNAs (Dietzl et al, 2007)).…”

Olfaction in vector-host interactions

“…This has been aptly demonstrated in mosquitoes where feeding time has been related to the quantity of apyrase in the glands of different anopheline mosquitoes (Ribeiro et al 1985). More recently, Boisson and colleagues (Boisson et al 2006) confirmed the role of apyrase in efficient mosquito feeding using gene silencing to reduced the expression of the apyrase gene AgApy. Saliva from mosquitoes injected with ds-AgAyp exhibited reduced enzyme activity and was less efficient at inhibiting platelet activity.…”