Solute carriers affect Anopheles stephensi survival and Plasmodium berghei infection in the salivary glands.

Malaria is caused by mosquito-borne Plasmodium spp. parasites that must infect and survive within mosquito salivary glands (SGs) prior to host transmission. Recent advances in transcriptomics and the complete genome sequencing of mosquito vectors have increased our knowledge of the SG genes and proteins involved in pathogen infection and transmission. Membrane solute carriers are key proteins involved in drug transport and are useful in the development of new interventions for transmission blocking. Herein, we applied transcriptomics analysis to compare SGs mRNA levels in Anopheles stephensi fed on non-infected and P. berghei-infected mice. The A. stephensi solute carriers prestinA and NDAE1 were up-regulated in response to infection. These molecules are predicted to interact with each other, and are reportedly involved in the maintenance of cell homeostasis. To further evaluate their functions in mosquito survival and parasite infection, these genes were knocked down by RNA interference. Knockdown of prestinA and NDAE1 resulted in reduction of the number of sporozoites in mosquito SGs. Moreover, NDAE1 knockdown strongly impacted mosquito survival, resulting in the death of half of the treated mosquitoes. Overall, our findings indicate the importance of prestinA and NDAE1 in interactions between mosquito SGs and Plasmodium, and suggest the need for further research.

The Anopheles gambiae transcriptome - a turning point for malaria control.

Mosquitoes are important vectors of several pathogens and thereby contribute to the spread of diseases, with social, economic and public health impacts. Amongst the approximately 450 species of Anopheles, about 60 are recognized as vectors of human malaria, the most important parasitic disease. In Africa, Anopheles gambiae is the main malaria vector mosquito. Current malaria control strategies are largely focused on drugs and vector control measures such as insecticides and bed-nets. Improvement of current, and the development of new, mosquito-targeted malaria control methods rely on a better understanding of mosquito vector biology. An organism's transcriptome is a reflection of its physiological state and transcriptomic analyses of different conditions that are relevant to mosquito vector competence can therefore yield important information. Transcriptomic analyses have contributed significant information on processes such as blood-feeding parasite-vector interaction, insecticide resistance, and tissue- and stage-specific gene regulation, thereby facilitating the path towards the development of new malaria control methods. Here, we discuss the main applications of transcriptomic analyses in An. gambiae that have led to a better understanding of mosquito vector competence.