Supplementary Material for: Anopheles gambiae Blood Feeding Initiates an Anticipatory Defense Response to Plasmodium berghei

<p>Mosquitoes have potent innate defense mechanisms that protect them from infection by diverse pathogens. Much remains unknown about how different pathogens are sensed and specific responses triggered. Leucine-Rich repeat IMmune proteins (LRIMs) are a mosquito-specific family of putative innate receptors. Although some LRIMs have been implicated in mosquito immune responses, the function of most family members is largely unknown. We screened <i>Anopheles gambiae </i>LRIMs by RNAi for effects on mosquito infection by rodent malaria and found that LRIM9 is a <i>Plasmodium berghei </i>antagonist with phenotypes distinct from family members LRIM1 and APL1C, which are key components of the mosquito complement-like pathway. LRIM9 transcript and protein levels are significantly increased after blood feeding but are unaffected by <i>Plasmodium </i>or midgut microbiota. Interestingly, LRIM9 in the hemolymph is strongly upregulated by direct injection of the ecdysteroid, 20-hydroxyecdysone. Our data suggest that LRIM9 may define a novel anti-<i>Plasmodium </i>immune defense mechanism triggered by blood feeding and that hormonal changes may alert the mosquito to bolster its defenses in anticipation of exposure to blood-borne pathogens.</p