Exposure of the mosquito vector Culex pipiens to the malaria parasite Plasmodium relictum: effect of infected blood intake on immune and antioxidant defences, fecundity and survival. Issue 1 (December 2016)

• Record Type: Journal Article
• Authors: Delhaye, Jessica; Aletti, Consolée; Glaizot, Olivier; Christe, Philippe
• Is Part Of: Parasites & vectors. Volume 9:Issue 1(2016)
• Page Start: 1
• Page End: 12
• Publication Date: 2016-12
• Subjects: Exposure -- Malaria -- Trade-off -- Vector; Parasitism -- Periodicals; Parasites -- Periodicals; Vector-pathogen relationships -- Periodicals; Animals as carriers of disease -- Periodicals; Insects as carriers of disease -- Periodicals; 616.96
• DOI: 10.1186/s13071-016-1905-7
• Languages: English
• ISSNs: 1756-3305

Abstract

Abstract Background The intake of aPlasmodium -infected blood meal may affect mosquito physiology and a series of trade-offs may occur, in particular between immune defences, reproduction and self-maintenance. We evaluated the cost of exposure toPlasmodium in the mosquito vector by investigating the effect of exposure on fecundity and survival and the implication of immune and antioxidant defences in mediating this cost. Methods We used the naturalCulex pipiens -Plasmodium relictum association. We exposed female mosquitoes to increasing levels of parasites by allowing them to feed either on uninfected canaries, Serinus canaria, (unexposed mosquitoes) or on infected canaries with low (low exposure) or high (high exposure) parasitaemia. We recorded blood meal size, fecundity (laying probability and clutch size) and survival. We quantified the expression of genes involved in immune and antioxidant defences (nitric oxide synthase, NOS; superoxide dismutase, SOD; glucose-6-phosphate dehydrogenase, G6PDH). Results We found that the laying probability of exposed females decreased with increasing exposure to the parasite and with increasing SOD expression. Clutch size of exposed females was higher compared to unexposed ones for similar blood meal size and was positively correlated to the NOS expression. We found no effect of exposure on survival. After blood meal intake, SOD increased in the three groups, NOS increased in exposed females and G6PDH increased in highly exposed females only. Conclusions Our results illustrated a trade-off between fight against the parasite and reproduction and a cost of exposure which might be mediated by the investment in immune and/or antioxidant defences. They also showed that this trade-off could lead to opposed outcome, potentially depending on the vector physiological status. Finally, they highlighted that the ingestion of aPlasmodium -infected blood meal may affect mosquito life history traits in a complex way.