Resolving a chromosome-level assembly of the Trypanosoma vivax Y486 genome sequence to identify differences with the model sequence from T. brucei.
Trypanosoma vivax causes animal trypanosomiasis across Africa and South America. An accurate genome sequence is essential to functional genetics and the design of novel diagnostics, drugs and vaccines. Our aim is to improve the existing T. vivax Y486 reference genome assembly to understand the species-specific features that could not be determined previously. We present a new core genome assembly in which many chromosomes are complete and articulated with sub-telomeres. As with T. brucei, T. vivax Variant Surface Glycoprotein (VSG) genes are arranged in sub-telomeric arrays, but that these are near-perfect repeats of intact genes, (unlike T. brucei), and we find no evidence for a VSG expression site at the telomeres or elsewhere. T. vivax Y486 expressed multiple VSG in vivo; VSG transcripts/peptides did not map to telomeric loci and indicated that multiple VSG isoforms within an active gene array are expressed simultaneously. T. vivax-specific features show how the T. brucei genome sequence is a poor guide for T. vivax. This new genome assembly will provide an accurate basis for future T. vivax genetics.
Trypanosoma vivax causes animal trypanosomiasis across Africa and South America. An accurate genome sequence is essential to functional genetics and the design of novel diagnostics, drugs and vaccines. Our aim is to improve the existing T. vivax Y486 reference genome assembly to understand the species-specific features that could not be determined previously. We present a new core genome assembly in which many chromosomes are complete and articulated with sub-telomeres. As with T. brucei, T. vivax Variant Surface Glycoprotein (VSG) genes are arranged in sub-telomeric arrays, but that these are near-perfect repeats of intact genes, (unlike T. brucei), and we find no evidence for a VSG expression site at the telomeres or elsewhere. T. vivax Y486 expressed multiple VSG in vivo; VSG transcripts/peptides did not map to telomeric loci and indicated that multiple VSG isoforms within an active gene array are expressed simultaneously. T. vivax-specific features show how the T. brucei genome sequence is a poor guide for T. vivax. This new genome assembly will provide an accurate basis for future T. vivax genetics.