title: Population genomics reveals the origin and asexual evolution of human infective trypanosomes.
abstract: Evolutionary theory predicts that the lack of recombination and chromosomal re-assortment in strictly asexual organisms results in homologous chromosomes irreversibly accumulating mutations and thus evolving independently of each other, a phenomenon termed the Meselson effect. We apply a population genomics approach to examine this effect in an important human pathogen, Trypanosoma brucei gambiense. We determine that T.b. gambiense is evolving strictly asexually and is derived from a single progenitor, which emerged within the last 10,000 years. We demonstrate the Meselson effect for the first time at the genome-wide level in any organism and show large regions of loss of heterozygosity, which we hypothesise to be a short-term compensatory mechanism for counteracting deleterious mutations. Our study sheds new light on the genomic and evolutionary consequences of strict asexuality, which this pathogen uses as it exploits a new biological niche, the human population.
authors.affiliation: Wellcome Centre for Molecular Parasitology, College of Medical, Veterinary and Life Sciences, Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom.
authors.forename: William
authors.initials: W
authors.lastname: Weir
authors.affiliation: Wellcome Centre for Molecular Parasitology, College of Medical, Veterinary and Life Sciences, Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Paul
authors.initials: P
authors.lastname: Capewell
authors.affiliation: Sanger Institute, Wellcome Trust Genome Campus, Cambridge, United Kingdom.
authors.forename: Bernardo
authors.initials: B
authors.lastname: Foth
authors.affiliation: Wellcome Centre for Molecular Parasitology, College of Medical, Veterinary and Life Sciences, Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Caroline
authors.initials: C
authors.lastname: Clucas
authors.affiliation: Wellcome Centre for Molecular Parasitology, College of Medical, Veterinary and Life Sciences, Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Andrew
authors.initials: A
authors.lastname: Pountain
authors.affiliation: Wellcome Centre for Molecular Parasitology, College of Medical, Veterinary and Life Sciences, Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Pieter
authors.initials: P
authors.lastname: Steketee
authors.affiliation: West Medical Building, Office 350, University of Glasgow, Glasgow, Scotland.
authors.forename: Nicola
authors.initials: N
authors.lastname: Veitch
authors.affiliation: UFR Environnement, Laboratoire des Interactions Hôte-Microorganismes-Environnement et Evolution (LIHME), Université Jean Lorougnon GUEDE, Daloa, Côte d'Ivoire.
authors.forename: Mathurin
authors.initials: M
authors.lastname: Koffi
authors.affiliation: Institut de Recherche pour le Développement, Campus International de Baillarguet, Montpellier, France.|Centre International de Recherche-Développement de l'Elevage en zone Subhumide, Bobo-Dioulasso, Burkina Faso.
authors.forename: Thierry
authors.identifier: http://orcid.org/0000-0001-8807-241X
authors.initials: T
authors.lastname: De Meeûs
authors.affiliation: Centre International de Recherche-Développement de l'Elevage en zone Subhumide, Bobo-Dioulasso, Burkina Faso.|Université Polytechnique de Bobo-Dioulasso, UFR Sciences et Techniques, Bobo-Dioulasso, Burkina Faso.
authors.forename: Jacques
authors.initials: J
authors.lastname: Kaboré
authors.affiliation: Programme National de Lutte contre la Trypanosomiase Humaine Africaine, Conakry, Guinea.
authors.forename: Mamadou
authors.initials: M
authors.lastname: Camara
authors.affiliation: Wellcome Centre for Molecular Parasitology, College of Medical, Veterinary and Life Sciences, Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Anneli
authors.initials: A
authors.lastname: Cooper
authors.affiliation: Wellcome Centre for Molecular Parasitology, College of Medical, Veterinary and Life Sciences, Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Andy
authors.initials: A
authors.lastname: Tait
authors.affiliation: Institut de Recherche pour le Développement, Campus International de Baillarguet, Montpellier, France.|Centre International de Recherche-Développement de l'Elevage en zone Subhumide, Bobo-Dioulasso, Burkina Faso.
authors.forename: Vincent
authors.initials: V
authors.lastname: Jamonneau
authors.affiliation: Institut de Recherche pour le Développement, Campus International de Baillarguet, Montpellier, France.|Programme National de Lutte contre la Trypanosomiase Humaine Africaine, Conakry, Guinea.
authors.forename: Bruno
authors.initials: B
authors.lastname: Bucheton
authors.affiliation: Sanger Institute, Wellcome Trust Genome Campus, Cambridge, United Kingdom.
authors.forename: Matt
authors.identifier: http://orcid.org/0000-0002-9581-0377
authors.initials: M
authors.lastname: Berriman
authors.affiliation: Wellcome Centre for Molecular Parasitology, College of Medical, Veterinary and Life Sciences, Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Annette
authors.initials: A
authors.lastname: MacLeod
mesh_terms: D019143:Evolution, Molecular; D006801:Humans; D056186:Metagenomics; D009154:Mutation; D012100:Reproduction, Asexual; D014347:Trypanosoma brucei gambiense / Q000235:genetics*; D014352:Trypanosomiasis / Q000469:parasitology
keywords: Meselson effect; Trypanosoma brucei gambiense; evolutionary biology; genomics; infectious disease; microbiology; population genomics; trypanosomiasis
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