Project description:Wolbachia pipientis is an intracellular symbiotic bacterium found in insects and arthropods. Wolbachia can decrease the vectorial capacity for various pathogens, such as the dengue virus, in Aedes aegypti. The purpose of this study was to determine the effect of Wolbachia (wMel strain) on the vectorial capacity of Ae. aegypti for Dirofilaria immitis. We analyzed gene expression patterns by RNA-seq in addition to the D. immitis infection phenotype in Ae. aegypti infected with and without wMel. Four Ae. aegypti strains, MGYP2.tet, MGYP2, Liverpol (LVP)-Obihiro (OB), and LVP-OB-wMel (OB-wMel) were analyzed for transcriptome comparison in Malpighian tubule at 2 days post infection. The correlation between Wolbachia infection, D. immitis infection phenotype and immune-related genes expression in Ae. aegypti was investigated.
Project description:Certain strains of the intracellular endosymbiont Wolbachia can strongly inhibit or block the transmission of viruses such as dengue by Aedes mosquitoes, and the mechanisms responsible are still not well understood. Direct infusion and liquid chromatography FT-ICR mass spectrometry based lipidomicse DIMS and LCMS analyses were conducted using Aedes albopictus Aa23 cells that were infected with the wMel and wMelPop strains of Wolbachia compared to uninfected cells. Substantial shifts in the cellular lipid profile were apparent in the presence of Wolbachia. Most significantly, sphingolipids were depleted across all classes, and some reduction in diacylglyerol fatty acids and phosphatidylcholines was also observed. These lipid classes have previously been shown to be selectively enriched in DENV-infected mosquito cells, suggesting that Wolbachia may produce a cellular lipid environment that is antagonistic to viral replication. The data improve understanding of the intracellular interactions between Wolbachia and mosquitoes.
Project description:Wolbachia is a vertically transmitted intracellular bacteria that infect most than 60% of insect species. The strains wMelPop and wMel were introduced in the dengue virus vector Aedes aegypti, naturally not infected by Wolbachia. Recently, it was shown that those two strains inhibit dengue virus replication into their new host, A. aegypti (Moreira et al. 2009 and Walker et al. in preparation). The aim of this project is to look at the transcriptional response of Aedes aegypti to infection with wMel and wMelPop and try to find some genes or pathway potentially involved in the viral interference.Four laboratory lines of A. aegypti were used throughout this study. The PGYP1 and Mel2 lines were generated by transinfection with wMelPop and wMel strains respectively. PGYP1.tet and Mel2tet lines were treated with the antibiotic tetracycline and cured from Wolbachia infection (McMeniman et al., 2009 and Walker et al in preparation). The Mosquitoes were reared under standard laboratory conditions (26 ± 2 °C, 12:12 light/dark cycle, 75% relative humidity). Mosquito larvae were fed 0.1mg/larvae of TetraMin Tropical Tablets once a day. Adults were transferred to cages (measuring 30 x 30 x 30 cm) at emergence at 400 individuals per cage. Adults were supplied with a basic diet of 10% sucrose solution (Turley et al., 2009).
Project description:Wolbachia, an endosymbiotic bacterium, is being investigated as a vector control agent in several insect species. Along with the well known classical reproductive parasitism Wolbachia employs against its host to spread within the population, it is emerging that the bacteria can protect the host against pathogens and reduced pathogen transmission. Anopheles mosquitoes, which transmit malaria, have never been found to harbour Wolbachia in nature, and despite numerous transinfection attempts, no stable line has been developed. However recently, two strains of Wolbachia, wAlbB from Aedes albopictus, and wRi from Drosophila simulans were cultured in Anopheles gambiae Sua5B cells. These cell lines provides an amenable system to study Wolbachia-Anopheles interaction in the absence of a stable transinfected line. It has been proposed that the compromised vector competence of Wolbachia infected insects is due to an up regulation of the basal immune state. We therefore completed a genome wide expression profile of Wolbachia infected Anopheles, assessing both wAlbB and wRi infected cells in parallel against uninfected Sua5B cells.