title: Trypanosoma vivax displays a clonal population structure.
abstract: African animal trypanosomiasis, or Nagana, is a debilitating and economically costly disease with a major impact on animal health in sub-Saharan Africa. Trypanosoma vivax, one of the principal trypanosome species responsible for the disease, infects a wide host range including cattle, goats, horses and donkeys and is transmitted both cyclically by tsetse flies and mechanically by other biting flies, resulting in a distribution covering large swathes of South America and much of sub-Saharan Africa. While there is evidence for mating in some of the related trypanosome species, Trypanosoma brucei, Trypanosoma congolense and Trypanosoma cruzi, very little work has been carried out to examine this question in T. vivax. Understanding whether mating occurs in T. vivax will provide insight into the dynamics of trait inheritance, for example the spread of drug resistance, as well as examining the origins of meiosis in the order Kinetoplastida. With this in mind we have identified orthologues of eight core meiotic genes within the genome, the presence of which imply that the potential for mating exists in this species. In order to address whether mating occurs, we have investigated a sympatric field population of T. vivax collected from livestock in The Gambia, using microsatellite markers developed for this species. Our analysis has identified a clonal population structure showing significant linkage disequilibrium, homozygote deficits and disagreement with Hardy-Weinberg predictions at six microsatellite loci, indicative of a lack of mating in this population of T. vivax.
authors.affiliation: Wellcome Centre for Molecular Parasitology, Glasgow Biomedical Research Centre, Faculty of Veterinary Medicine, University of Glasgow, Glasgow G12 8TA, United Kingdom.
authors.forename: Craig W
authors.initials: CW
authors.lastname: Duffy
authors.forename: Liam J
authors.initials: LJ
authors.lastname: Morrison
authors.forename: Alana
authors.initials: A
authors.lastname: Black
authors.forename: Gina L
authors.initials: GL
authors.lastname: Pinchbeck
authors.forename: Robert M
authors.initials: RM
authors.lastname: Christley
authors.forename: Andreas
authors.initials: A
authors.lastname: Schoenefeld
authors.forename: Andy
authors.initials: A
authors.lastname: Tait
authors.forename: C Michael R
authors.initials: CM
authors.lastname: Turner
authors.forename: Annette
authors.initials: A
authors.lastname: MacLeod
mesh_terms: D000818:Animals; D002417:Cattle / Q000469:parasitology; D003307:Copulation; D018397:Equidae / Q000469:parasitology; D005714:Gambia; D005838:Genotype; D006041:Goats / Q000469:parasitology; D006736:Horses / Q000469:parasitology; D058507:Host Specificity; D006801:Humans; D058751:Livestock / Q000469:parasitology; D018895:Microsatellite Repeats / Q000235:genetics*; D016133:Polymerase Chain Reaction; D016689:Trypanosoma vivax / Q000235:genetics*