Figure 6
Ornithine decarboxylase (ODC) influences susceptibility to P. falciparum infection.
(A) ODC gene silencing efficiency, as measured by qRT-PCR of mRNA abundance in whole mosquitoes; bars represent the standard error of the mean (SEM). (B) P. falciparum infection intensity of OCD gene-silenced mosquitoes (N = 33, P = 0.419) compared to GFP dsRNA-treated control mosquitoes (N = 36). (C) P. falciparum infection intensity of sugar control groups (N = 50), fungus filtrate-exposed mosquitoes (N = 47), L-Arg-fed mosquitoes (N = 50) and fungus filtrate plus L-Arg–exposed mosquitoes (N = 35). Each dot represents a single midgut and bars represent the median infection intensity of three independent experiments, *P < 0.05, ***P < 0.001, ****P ≤ 0.0001; two-tailed Mann-Whitney test. (D) L-Arg is a substrate for polyamine synthesis and nitric oxide (NO) production. Pe. chrysogenum-secreted factors shift the balance toward polyamine synthesis, resulting in decreased parasite killing.
