Effects of Plasmodium gallinaceum on hemolymph physiology of Aedes aegypti during parasite development

Insect disease vectors show diminished fecundity when infected with Plasmodium. This phenomenon has already been demonstrated in laboratory models such as Aedes aegypti, Anopheles gambiae and Anopheles stephensi. This study demonstrates several changes in physiological processes of A. aegypti occurring upon infection with Plasmodium gallinaceum, such as reduced ecdysteroid levels in hemolymph as well as altered expression patterns for genes involved in vitellogenesis, lipid transport and immune response. Furthermore, we could show that P. gallinaceum infected A. aegypti presented a reduction in reproductive fitness, accompanied by an activated innate immune response and increase in lipophorin expression, with the latter possibly representing a nutritional resource for Plasmodium sporozoites.

Figure optionsDownload as PowerPoint slideResearch highlights▶ Fecundity effect by modulation of 20E hemolymph levels in infected Aedes aegypti. ▶ Mosquitoes may counterbalance parasite spoliation with reproductive output. ▶ Costs incurred by resistance mechanisms, is similar to those imposed by infection. ▶ Varying rates of reproductive output may be a successful strategy. ▶ Evolutionary strategy should be manifest as plasticity in reproductive physiology.