Anopheles gambiaematernal age and parous state control offspring susceptibility toPlasmodium falciparum

Abstract

Maternal effects have been reported in many organisms whereby exposure to environmental stress, either toxics or pathogens will impact on progeny response to these stresses. Here we show that Anopheles gambiae susceptibility to Plasmodium falciparum is dependent upon maternal effects driven by females not previously exposed to the parasite. The maternal effect involved both mother age and reproductive state. Offspring of old females or from a 4 th gonotrophic cycle are more susceptible than offspring from young females. These maternal effects also contribute to overall better fitness of the offspring. As mosquito population age structure contributes heavily shaping malaria transmission, consequences of this novel finding should be taken into account in further strategies for controlling malaria transmission. Main Text:Malaria transmission is dependent on the bioecology and bionomics of Anopheles mosquitoes. Malaria transmission modelling relies on estimating mosquito vectorial capacity C (1, 2) which includes estimation of several entomological indices such as the number of mosquitoes, their daily biting rate and the extrinsic incubation period that quantifies the length of parasite development within the mosquito before it can be transmitted. One parameter that is not clearly defined in the estimation of C is vector competence, which corresponds to the ability of a mosquito to sustain Plasmodium development up to the production of infective sporozoites in her