Figure 1.
Relative sizes of Brugia malayi developmental stages that occur within compatible mosquito hosts: An example of cyclo-developmental transmission.
A. microfilariae are ingested during blood feeding; B. parasites differentiate into non-feeding, first-stage larvae within mosquito indirect flight muscle cells; C. following the first molt, second-stage larvae remain intracellular parasites which ingest cellular material into their newly developed digestive tract. D. third-stage larvae leave the muscle cells and migrate to the mosquito's head and proboscis where they will exit through the mosquito cuticle during blood feeding.
Figure 2.
Global transcriptional analysis of the response of a compatible mosquito infected with successfully developing Brugia malayi.
A. Regulated (differentially expressed above a 1.7-fold threshold) genes for each experimental group. (+) indicates up-regulated in infected mosquitoes and (−) indicates down-regulated. Assayable genes (those that gave signal intensities above a standard cutoff threshold) are indicated below the graph. Functional group distributions are the same to those used in Nene et al., 2007 and Xi et al., 2008: IMM: immunity, R/S/M: redox, stress, mitochondrial, CSR: chemosensory reception, DIG: blood digestive, PRT: proteolysis, C/S: cytoskeletal, structural, TRP: transport, R/T/T: replication, transcription, translation, MET: metabolism, DIV: diverse, UKN: unknown. B. Percent distribution of functional group for each up- and down-regulated experimental group. Transcription data are presented in Table S5.
Table 1.
Cluster analysis of Aedes aegypti immunity genes transcribed by Brugia malayi-infected mosquitoes.
Table 2.
Few Aedes aegypti genes are differentially transcribed in multiple stages of the infection response to Brugia malayi.
Figure 3.
Gene knockdown of Ae. aegypti Caspar does not affect B. malayi development.
A, B. Gene knockdown of Ae. aegypti Caspar at the time of parasite ingestion did not affect mosquito mortality (A; P = 0.23) or B. malayi development (B; P = 0.10), in comparison to control mosquitoes. C, D. Gene knockdown of Ae. aegypti Caspar at the time of the parasite's first molt (L1 to L2) did not affect mosquito mortality (C; P = 0.32) or B. malayi development (D; P = 0.72). Bars indicate the mean intensity (total number of L3s recovered per infected individual) and standard deviation (B and D). Log-rank and Mann-Whitney tests were used to compare mosquito mortality curves and parasite mean intensities, respectively. Arrow: dsRNA was injected intrathoracically two days following infective blood meal.
Figure 4.
Gene knockdown of Ae. aegypti MyD88 does not affect B. malayi development.
A, B. Gene knockdown of Ae. aegypti MyD88 during parasite ingestion did not affect mosquito mortality (A; P = 0.94) or B. malayi development (B; P = 0.14), compared to control mosquitoes. C, D. Knockdown of Ae. aegypti MyD88 when parasites first molt (L1 to L2) did not affect mosquito mortality (C; P = 0.30) or B. malayi development (D; P = 0.77). Bars indicate the mean intensity (total number of L3s recovered per infected individual) and standard deviation (B and D). Log-rank and Mann-Whitney tests were used to compare mosquito mortality curves and parasite mean intensities, respectively. Arrow: dsRNA was injected intrathoracically two days following infective blood meal.
Figure 5.
Gene knockdown of Ae. aegypti Cactus decreases mosquito survival but does not affect B. malayi development (until death of the host).
A. Cactus-silenced mosquitoes showed a greater mortality compared to the GFP dsRNA treated controls (P<0.001). B. Mortality of Cactus-silenced mosquitoes fed on uninfected blood displayed a similar mortality rate to those that ingested parasite infected blood (4A). C. Cactus-silenced mosquitoes were dissected at 6 d post blood meal to observe parasite development. D. Gene silencing of Ae. aegypti Cactus did not affect the development of B. malayi (no difference in L2 mean intensities, P = 0.16). Bars indicate the mean intensity (total number of L3s recovered per infected individual) and standard deviation (D). Log-rank and Mann-Whitney tests were used to compare mosquito mortality curves and parasite mean intensities, respectively. Arrows indicate dsRNA was injected intrathoracically two days following the infective blood meal.