Project description:Trypanosoma vivax is a vector-borne blood parasite of cattle throughout sub-saharan Africa. For some years the genome sequence of this organism has been in development at the Wellcome Trust Sanger Institute and is shortly to be completed. Analysis of the genome has revealed various putative genes encoding unknown proteins. In an effort to validate these features we will sequence mRNA transcripts from the bloodstream stage of the genome strain Y486. Most of the novel gene families identified from the genome sequence are too diverse to be validated individually, i.e. through RT-PCR, so it is necessary to sequence all cellular transcripts. We hope to confirm the transcription of one or all members of the novel gene families from the resulting transcriptome. While essential for the scientific rigour of the present genome project, this transcriptome will also provide an additional resource for the longer-term benefit of the research community.
Project description:Trypanosoma vivax is a major pathogen of domestic cattle and wildlife across sub-Saharan Africa. For many years, the WTSI has had a research interest in developing a genome sequence for T. vivax, as part of a wider programme concerning African trypanosome parasites of Humans and animals. In 2012 a draft genome sequence for T. vivax Y486 was published by the WTSI and our collaborators in comparison with related species, T. brucei and T. congolense. This study identified numerous putative genes in T. vivax that have no known affinity and are therefore species-specific. A related transcriptomic study confirmed that some of these putative genes are transcribed, but lacked accuracy and was based on a single parasite life stage only. Until recently, it has not been possible to culture different T. vivax life stages in refined media. There is now the opportunity to use new approaches to produce whole cell RNA for both insect and bloodstream parasite stages. We sequence stage-specific cDNA and identify stage-specific genes, and compare these features with similar data already available for T. brucei and T. congolense, which display substantial differences in their developmental cycles. This data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/
Project description:Trypanosoma vivax is a vector-borne blood parasite of cattle throughout sub-saharan Africa. For some years the genome sequence of this organism has been in development at the Wellcome Trust Sanger Institute and is shortly to be completed. Analysis of the genome has revealed various putative genes encoding unknown proteins. In an effort to validate these features we will sequence mRNA transcripts from the bloodstream stage of the genome strain Y486. Most of the novel gene families identified from the genome sequence are too diverse to be validated individually, i.e. through RT-PCR, so it is necessary to sequence all cellular transcripts. We hope to confirm the transcription of one or all members of the novel gene families from the resulting transcriptome. While essential for the scientific rigour of the present genome project, this transcriptome will also provide an additional resource for the longer-term benefit of the research community. ArrayExpress Release Date: 2011-02-16 Person Roles: submitter Person Last Name: Quan Person First Name: Lin Person Mid Initials: Person Email: ql3@sanger.ac.uk Person Phone: 01223 834244 Person Address: Wellcome Trust Genome Campus,Hinxton,Cambridge. CB10 1SA UK Person Affiliation: Wellcome Trust Sanger Institute Person Roles: Investigator Person Last Name: Jackson Person First Name: Andrew Person Mid Initials: P Person Email: aj4@sanger.ac.uk Person Phone: 01223 834244 Person Address: Wellcome Trust Genome Campus,Hinxton,Cambridge. CB10 1SA UK Person Affiliation: Wellcome Trust Sanger Institute Person Roles: Project Coordinator Person Last Name: Sanders Person First Name: Mandy Person Mid Initials: J Person Email: mjs@sanger.ac.uk Person Phone: 01223 834244 Person Address: Wellcome Trust Genome Campus,Hinxton,Cambridge. CB10 1SA UK Person Affiliation: Wellcome Trust Sanger Institute
Project description:Cattle trypanosomosis caused by Trypanosoma vivax is a widely distributed disease in Africa and Latin America. It causes significant losses in the livestock industry and is characterized by fever, parasitemia, anemia, lethargy, and weight loss. In this study we evaluated the virulence (capacity to multiply inside the host) and pathogenicity (ability to produce disease and/or mortality) patterns of two T. vivax strains (TvMT1 and TvLIEM176) in experimentally-infected sheep and determined the proteins differentially expressed in the proteomes of these two strains. There was a marked difference in the virulence and pathogenicity between both T. vivax strains: TvLIEM176 showed high virulence and moderate pathogenicity, whereas TvMT1 showed low virulence and high pathogenicity. In the proteomic analysis, we identified a total of 29 proteins associated with the different biological behaviour, of which 14 exhibited significant differences in their expression level between the two strains. The proteins evidenced in this study are considered potential virulence and pathogenicity biomarkers in T. vivax infections, and deserve further investigations to precise their functional role in the host-parasite interactions.
Project description:Trypanosomatid parasites undergo developmental regulation to adapt to the different environments encountered during their life cycle. In Trypanosoma brucei, a genome wide selectional screen previously identified a regulator of the protein family ESAG9, which is highly expressed in stumpy forms, a morphologically distinct bloodstream stage adapted for tsetse transmission. This regulator, TbREG9.1, has an orthologue in Trypanosoma congolense, despite the absence of a stumpy morphotype in that parasite species, which is an important cause of livestock trypanosomosis. RNAi mediated gene silencing of TcREG9.1 in Trypanosoma congolense caused a loss of attachment of the parasites to a surface substrate in vitro, a key feature of the biology of these parasites that is distinct from T. brucei. This detachment was phenocopied by treatment of the parasites with a phosphodiesterase inhibitor, which also promotes detachment in the insect trypanosomatid Crithidia fasciculata. RNAseq analysis revealed that TcREG9.1 silencing caused the upregulation of mRNAs for several classes of surface molecules, including transferrin receptor-like molecules, immunodominant proteins, and molecules related to those associated with stumpy development in T. brucei. Depletion of TcREG9.1 in vivo also generated an enhanced level of parasites in the blood circulation consistent with reduced parasite attachment to the microvasculature. The morphological progression to insect forms of the parasite was also perturbed. We propose a model whereby TcREG9.1 acts as a regulator of attachment and development, with detached parasites being adapted for transmission.
Project description:Plasmodium vivax is the most geographically widespread human malaria parasite causing approximately 130-435 million infections annually. It is an economic burden in many parts of the world and poses a public health challenge along with the other Plasmodium sp. The biology of this parasite is very little understood. Emerging evidences of severe complications due to infections by this parasite provides an impetus to focus research on the same. Investigating this parasite directly from the infected patients is the most feasible way to study its biology and any pathogenic mechanisms which may exist. Gene expression studies of this parasite directly obtained from the patients has provided evidence of gene regulation resulting in varying amount of transcript levels in the different blood stages. However, the mechanisms regulating gene expression in malaria parasites are not well understood. Discovery of natural antisense transcripts (NATs) in P. falciparum has suggested that these might play an important role in regulating gene expression. We report here the genome-wide occurrence of NATs in P. vivax parasites from patients with differing clinical symptoms. A total of 1348 NATs against annotated gene loci have been detected using a custom designed strand specific microarray. Majority of NATs identified from this study shows positive correlation with the expression pattern of the sense transcript. Our data also shows condition specific expression patterns of varying S and AS transcript levels. Genes with AS transcripts enrich to various biological processes. This is the first report detailing the presence of NATs from clinical isolates of P. vivax. The data suggests differential regulation of gene expression in diverse clinical conditions and would lead to future detailed investigations of genome regulation.
Project description:The protozoan parasites Trypanosoma brucei spp. are responsible for important human and livestock diseases in sub Saharan Africa. In the mammalian blood, two developmental forms of the parasite exist: proliferative ?slender? forms and transmissible ?stumpy? forms that are quiescent, awaiting uptake in a tsetse fly bloodmeal. The slender to stumpy differentiation is a density-dependent response that resembles quorum sensing in microbial systems and is crucial for the parasite life cycle, ensuring both infection chronicity and disease transmission. The response is triggered by an elusive ?stumpy induction factor? (SIF) whose intracellular signaling pathway is also completely uncharacterized. Laboratory-adapted (monomorphic) trypanosome strains cannot respond to SIF, but can generate forms with stumpy characteristics when exposed to cell permeable cAMP and AMP analogues. Exploiting this, we have used a genome-wide RNAi library screen to identify the signaling components driving stumpy formation. In separate screens, monomorphic parasites were exposed to cell permeable cAMP or AMP analogues to select cells that remained proliferative and so were unresponsive to these signals. Genome-wide ion torrent-based RNA interference Target sequencing (RIT-seq) identified a cohort of genes implicated in all steps of the signaling pathway, from purine metabolism, through signal transducers (kinases, phosphatases) to gene expression regulators. The identified genes at each step have been validated in cells naturally capable of stumpy formation, confirming their role in SIF-induced density sensing and cellular quiescence.