Fig. 4

TOLL 11 activity protects mosquitoes against infection with P. falciparum. Gene silencing of TOLL 11 followed by parasite challenge causes increased P. falciparum oocyst infection prevalence in A. gambiae. Silencing of TOLL 10 does not significantly alter infection phenotypes. a Prevalence of oocyst infection for Fd03 colony individuals treated with control dsRNA (dsGFP) or with dsRNA directed against TOLL 11 (dsTOLL11) and challenged with P. falciparum in 3 replicate experiments (replicate number in grey box). Green bars, proportion of uninfected mosquitoes (0 midgut oocysts), red bars, proportion of mosquitoes with ≥ 1 midgut oocyst. P-values are calculated using a χ ² test across treatments. b Intensity of infection measured by the number of oocysts in midguts after dsRNA treatment and infection challenge. Intensity is only analyzed in mosquitoes with ≥1 midgut oocyst. Significance is calculated by the non-parametric Wilcoxon rank-sum test. For both infection prevalence and intensity, P-values across replicates for intensity were combined by the method of Fisher (see Methods). (c) and (d) as in (a) and (b), but with dsRNA directed against TOLL 10 (dsTOLL10). The number of replicates shown for oocyst intensity is less than for oocyst prevalence, because oocyst intensities were only statistically compared when the infection prevalences were above 30 % for both control and target gene silencing conditions. This cut-off provides for adequate statistical power for detecting differences in infection intensity