Effect of Wolbachia (wMel strain) on gene expression in Dirofilaria immitis infected-Aedes aegypti

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. MGYP2 were artificially infected with Wolbachia wMel. MGYP2.tet was maintained free of wMel infection by tetracycline treatment. OB is an original D. immitis-susceptible strain in our laboratory. OB-wMel was established by eight repeated backcrossing female progenies of OB males and MGYP2 females with OB males to obtain a D. immitis-susceptible strain infected with wMel. The differentially expressed genes between MGYP2.tet and MGYP2, OB and OB-wMel, MGYP2.tet and OB, and MGYP2 and OB-wMel were analyzed to determine the effect of Wolbachia and strain differences on gene expression in Malpighian tubules of Ae. aegypti at 2 days post infection of D. immitis.