Project description:Doxycycline treatment affects gene expression in Wolbachia and Brugia malayi adult female worms in vivo Two biological replicates of female RNA used for hybridization, in duplicate, to examine the gene expression changes in Wolbachia and Brugia
Project description:Brugia malayi is a parasitic nematode that causes lymphatic filariasis in humans. A total of 178 novel microRNA were identified from short read transcriptional data, which when combined with known Brugia microRNAs yielded a total of 284 microRNA. Of these, 123 microRNA sequences (43%) are differentially expressed over the mammalian life stages of B. malayi that we examined. Putative targets of these microRNA were identified from inversely expressed target clusters that contain valid seed sequences for the corresponding microRNAs. The largest identified cluster is downregulated in adult females and enriched in zinc finger domains, helicase domains, and DNA binding domains suggesting this microRNA cluster may have regulatory control over a large proportion of adult female specific mRNA genes. MicroRNA-like molecules are identified as produced by the Wolbachia endosymbiont, providing evidence for direct nucleic acid-based interdomain communication between filarial nematodes and their bacterial obligate endosymbiont.
Project description:Lymphatic filarial nematodes maintain a mutualistic association with the intracellular bacterium Wolbachia. Wolbachia populations expand following infection of the mammalian host, to support larval growth and development. Utilizing transcriptomic data from Brugia malayi over the first two weeks post-infection, we present an analysis of the biochemical pathways that are involved in Wolbachia population growth and regulation in support of larval development. In Wolbachia, we observe coordinated regulation of carbon metabolism with an alternating pattern of glycolysis and TCA cycle pathways reminiscent of the ‘Warburg effect’. Wolbachia's purine, pyrimidine and haem biosynthesis and Type IV secretion pathways are also upregulated and correlate with the upregulation of the nematode’s DNA replication pathway. In the nematode we observe up-regulation of the autophagy pathway, a key regulator of Wolbachia populations. These findings support a key role for nucleotide and haem provisioning from Wolbachia in support of the larval growth and development of its nematode host.
Project description:BackgroundMost filarial nematodes contain Wolbachia symbionts. The purpose of this study was to examine the effects of doxycycline on gene expression in Wolbachia and adult female Brugia malayi.MethodsBrugia malayi infected gerbils were treated with doxycycline for 6-weeks. This treatment largely cleared Wolbachia and arrested worm reproduction. RNA recovered from treated and control female worms was labeled by random priming and hybridized to the Version 2- filarial microarray to obtain expression profiles.Results and discussionResults showed significant changes in expression for 200 Wolbachia (29% of Wolbachia genes with expression signals in untreated worms) and 546 B. malayi array elements after treatment. These elements correspond to known genes and also to novel genes with unknown biological functions. Most differentially expressed Wolbachia genes were down-regulated after treatment (98.5%). In contrast, doxycycline had a mixed effect on B. malayi gene expression with many more genes being significantly up-regulated after treatment (85% of differentially expressed genes). Genes and processes involved in reproduction (gender-regulated genes, collagen, amino acid metabolism, ribosomal processes, and cytoskeleton) were down-regulated after doxycycline while up-regulated genes and pathways suggest adaptations for survival in response to stress (energy metabolism, electron transport, anti-oxidants, nutrient transport, bacterial signaling pathways, and immune evasion).ConclusionsDoxycycline reduced Wolbachia and significantly decreased bacterial gene expression. Wolbachia ribosomes are believed to be the primary biological target for doxycycline in filarial worms. B. malayi genes essential for reproduction, growth and development were also down-regulated; these changes are consistent with doxycycline effects on embryo development and reproduction. On the other hand, many B. malayi genes involved in energy production, electron-transport, metabolism, anti-oxidants, and others with unknown functions had increased expression signals after doxycycline treatment. These results suggest that female worms are able to compensate in part for the loss of Wolbachia so that they can survive, albeit without reproductive capacity. This study of doxycycline induced changes in gene expression has provided new clues regarding the symbiotic relationship between Wolbachia and B. malayi.
Project description:We report our microarray analysis of Brugia malayi microfilariae-derived miRNA comparing parasite-derived EVs and supernatants Microarray analysis was performed using isolated RNA from three biological replicates of Brugia malayi microfilariae with a focus on the parasite-derived EVs and supernatant