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.
Project description:Deep sequencing of the transcriptome of P. vivax parasite populations from vivax malaria patients with scarce parasitemia from the low transmission Brazilian Amazonian endemic region we the aim of better understanding the molecular mechanisms behind this cytoadherence and rosetting phenotypes by identifying proteins, especially parasitic ligands, which might be important for the P. vivax adhesion capacity within the human host. We used RNA-seq coupled with parasite enrichment from field samples and cytoadherence and rosetting assays to privilege the sequence of the whole transcriptome of parasite populations with distinct adhesive characteristics and, also assess the human host immune-related expression profile in the context of vivax malaria disease.
Project description:The parasitic flagellate Trypanosoma vivax is a cause of animal trypanosomiasis across Africa and South America. The parasite has a digenetic life cycle, passing between mammalian hosts and insect vectors, and a series of developmental forms adapted to each life cycle stage. Transcriptomic and proteomic studies of the related parasites T. brucei and T. congolense have shown how gene expression is regulated during their development. New methods for in vitro culture of the T. vivax insect stages have allowed us to describe global gene expression throughout the complete T. vivax life cycle for the first time. We combined transcriptomic and proteomic analysis of each life stage using RNA-seq and mass spectrometry respectively, to identify genes with patterns of preferential transcription or expression. While T. vivax is similar to related species in several ways, (e.g. developmental regulation of energy metabolism, restricted expression of a dominant variant antigen, and expression of ‘Fam50’ proteins in the insect mouthparts), we identify significant differences in gene expression affecting metabolism in the fly and a suite of T. vivax-specific genes with predicted cell-surface expression that are preferentially expressed in the mammal (‘Fam29, 30’) or the vector (‘Fam34, 35, 43’). Thus, T. vivax differs significantly from other African trypanosomes in the developmentally-regulated proteins it expresses on its cell surface and thus, in the structure of the host-parasite interface. These unique features may yet explain the species differences in life cycle and could, in the shape of bloodstream-stage proteins that do not undergo antigenic variation, provide targets for therapy.