title: Genomic diversity in Onchocerca volvulus and its Wolbachia endosymbiont.
abstract: Ongoing elimination efforts have altered the global distribution of Onchocerca volvulus, the agent of river blindness, and further population restructuring is expected as efforts continue. Therefore, a better understanding of population genetic processes and their effect on biogeography is needed to support elimination goals. We describe O. volvulus genome variation in 27 isolates from the early 1990s (before widespread mass treatment) from four distinct locales: Ecuador, Uganda, the West African forest and the West African savanna. We observed genetic substructuring between Ecuador and West Africa and between the West African forest and savanna bioclimes, with evidence of unidirectional gene flow from savanna to forest strains. We identified forest:savanna-discriminatory genomic regions and report a set of ancestry informative loci that can be used to differentiate between forest, savanna and admixed isolates, which has not previously been possible. We observed mito-nuclear discordance possibly stemming from incomplete lineage sorting. The catalogue of the nuclear, mitochondrial and endosymbiont DNA variants generated in this study will support future basic and translational onchocerciasis research, with particular relevance for ongoing control programmes, and boost efforts to characterize drug, vaccine and diagnostic targets.
authors.affiliation: McDonnell Genome Institute, Washington University in St Louis, St Louis, Missouri 63108, USA.
authors.forename: Young-Jun
authors.initials: YJ
authors.lastname: Choi
authors.affiliation: McDonnell Genome Institute, Washington University in St Louis, St Louis, Missouri 63108, USA.
authors.forename: Rahul
authors.identifier: http://orcid.org/0000-0002-6680-8972
authors.initials: R
authors.lastname: Tyagi
authors.affiliation: McDonnell Genome Institute, Washington University in St Louis, St Louis, Missouri 63108, USA.
authors.forename: Samantha N
authors.initials: SN
authors.lastname: McNulty
authors.affiliation: McDonnell Genome Institute, Washington University in St Louis, St Louis, Missouri 63108, USA.
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Rosa
authors.affiliation: McDonnell Genome Institute, Washington University in St Louis, St Louis, Missouri 63108, USA.
authors.forename: Philip
authors.initials: P
authors.lastname: Ozersky
authors.affiliation: McDonnell Genome Institute, Washington University in St Louis, St Louis, Missouri 63108, USA.
authors.forename: John
authors.initials: J
authors.lastname: Martin
authors.affiliation: McDonnell Genome Institute, Washington University in St Louis, St Louis, Missouri 63108, USA.
authors.forename: Kymberlie
authors.initials: K
authors.lastname: Hallsworth-Pepin
authors.affiliation: Global Health Infectious Disease Research Program, Department of Global Health, University of South Florida, Tampa, Florida 33612, USA.
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Unnasch
authors.affiliation: Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892, USA.
authors.forename: Carmelle T
authors.initials: CT
authors.lastname: Norice
authors.affiliation: Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892, USA.
authors.forename: Thomas B
authors.identifier: http://orcid.org/0000-0001-6887-4941
authors.initials: TB
authors.lastname: Nutman
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St Louis, Missouri 63110, USA.
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Weil
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St Louis, Missouri 63110, USA.
authors.forename: Peter U
authors.initials: PU
authors.lastname: Fischer
authors.affiliation: McDonnell Genome Institute, Washington University in St Louis, St Louis, Missouri 63108, USA.|Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St Louis, Missouri 63110, USA.
authors.forename: Makedonka
authors.initials: M
authors.lastname: Mitreva
mesh_terms: D000354:Africa, Western; D000818:Animals; D004484:Ecuador; D051456:Gene Flow; D014644:Genetic Variation; D005838:Genotype; D017181:Onchocerca volvulus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification / Q000382:microbiology; D058974:Phylogeography; D014454:Uganda; D020577:Wolbachia / Q000145:classification* / Q000235:genetics*