title: The population genetic structure of Biomphalaria choanomphala in Lake Victoria, East Africa: implications for schistosomiasis transmission.
abstract: BACKGROUND
  The freshwater snail Biomphalaria acts as the intermediate host of Schistosoma mansoni, a globally important human parasite. Understanding the population structure of intermediate host species can elucidate transmission dynamics and assist in developing appropriate control methods.
  
  
  METHODS
  We examined levels of population genetic structure and diversity in 29 populations of Biomphalaria choanomphala collected around the shoreline of Lake Victoria in Uganda, Kenya and Tanzania, where S. mansoni is hyper-endemic. Molecular markers were utilized to estimate the degree to which snail populations are genetically differentiated from one another.
  
  
  RESULTS
  High levels of snail genetic diversity were found coupled with evidence of geographically-determined population structure but low levels of local inbreeding. The data are consistent with an effect of schistosome infection on population structure of intermediate host snails, but other factors, such as habitat and historical demographic changes, could also be important determinants of the degree of population genetic structure in Biomphalaria choanomphala.
  
  
  CONCLUSIONS
  The low stratification of populations and high genetic diversity indicates potentially less local compatibility with intermediate snail populations than previously theorized, and highlights the importance of coordinated parasite control strategies across the region.
authors.affiliation: School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD, UK. claire.standley@gmail.com.|Department of Zoology, Wolfson Wellcome Biomedical Laboratory, Natural History Museum, Cromwell Road, London, SW7 5BD, UK. claire.standley@gmail.com.|Present address: Milken Institute School of Public Health, George Washington University, Washington, D.C., 20052, USA. claire.standley@gmail.com.
authors.forename: Claire J
authors.initials: CJ
authors.lastname: Standley
authors.affiliation: School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD, UK. sara.goodacre@nottingham.ac.uk.
authors.forename: Sara L
authors.initials: SL
authors.lastname: Goodacre
authors.affiliation: School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD, UK. chris.wade@nottingham.ac.uk.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Wade
authors.affiliation: Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK. r.stothard@liverpool.ac.uk.
authors.forename: J Russell
authors.initials: JR
authors.lastname: Stothard
mesh_terms: D000351:Africa, Eastern / Q000453:epidemiology; D000818:Animals; D001700:Biomphalaria / Q000235:genetics*; D006801:Humans; D060106:Lakes; D018895:Microsatellite Repeats; D010802:Phylogeny; D012552:Schistosomiasis / Q000453:epidemiology* / Q000635:transmission*