title: The genetic diversity and geographical separation study of Oncomelania hupensis populations in mainland China using microsatellite loci.
abstract: BACKGROUND
  Oncomelania hupensis is the unique intermediate host of Schistosoma japonicum, which plays a crucial role in the transmission of schistosomiasis. The endemic area of S. japonicum is strictly consistent with the geographical distribution of O. hupensis.
  
  
  METHODS
  A total of 24 populations of O. hupensis from four ecological landscapes were selected for analysis of genetic diversity by screening eight microsatellite DNA polymorphic loci.
  
  
  RESULTS
  The number of alleles per locus ranged from 29 to 70 with an average of 45.625 and that of effective alleles were 18.5 to 45.8 with an average of 27.4. The observed (Ho) and expected (He) heterozygosities varied from 0.331 to 0.57 and from 0.888 to 0.974, respectively. The mean of polymorphism information content (PIC) for all populations was 0.940, appearing polymorphic for all loci. For the fixation index of F-Statistics, Fit and Fst were 54.95 and 37.62%, respectively. Variation of O. hupensis chiefly exists among individuals, accounting for 60.58% of the total variation determined by Analysis of Molecular Variation (AMOVA). Variation among individuals within populations, among populations within groups and among groups only accounted for 26.60, 8.04 and 4.78%, respectively. This distribution of variation suggests that genetic differences principally originate from within-populations rather than among-populations. Moreover, UPGMA cluster analysis showed that the populations spreading within middle and lower reaches of the Yangtze River (HBWH, JSYZ, JXNC, HNHS, JXJJ, AHWW, HBJL, JXDC, HNNX, JSYZJZ, ZJJH, AHNG and AHWJ) clustered together first, then gathered with the populations in the high mountains (SCMS, SCYA, SCPJ, YNEY, SCLS, YNWS and SCXC), coastal hills (FJFQ and FJFZ) and Karst landform (GXBS and GXYZ) successively.
  
  
  CONCLUSIONS
  This study provides novel insight into the theoretical source of genetic differentiation of Oncomelania hupensis in mainland China, which is critical for the epidemiological investigation and surveillance of S. japonicum.
authors.affiliation: National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025, People's Republic of China. sg690287@sina.cn.|Key Laboratory of Parasite and Vector Biology, Ministry of Health, WHO Collaborating Center for Malaria, Schistosomiasis and Filariasis, Shanghai, 200025, People's Republic of China. sg690287@sina.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Guan
authors.affiliation: National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025, People's Republic of China. Lisz@chinacdc.cn.
authors.forename: Shi-Zhu
authors.initials: SZ
authors.lastname: Li
authors.affiliation: Department of Zoology, Federal University Lafia, P.M. B 146, Lafia, Nasarawa State, Nigeria. abeeniola11@gmail.com.
authors.forename: Eniola Michael
authors.initials: EM
authors.lastname: Abe
authors.affiliation: Wolfson Wellcome Biomedical Laboratories, Department of Zoology, Natural History Museum, Cromwell Road, London, SW7 5BD, UK. bonw@nhm.ac.uk.
authors.forename: Bonnie L
authors.initials: BL
authors.lastname: Webster
authors.affiliation: Wolfson Wellcome Biomedical Laboratories, Department of Zoology, Natural History Museum, Cromwell Road, London, SW7 5BD, UK. dr@nhm.ac.uk.
authors.forename: David
authors.initials: D
authors.lastname: Rollinson
authors.affiliation: National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025, People's Republic of China. zhouxn1@chinacdc.cn.|Key Laboratory of Parasite and Vector Biology, Ministry of Health, WHO Collaborating Center for Malaria, Schistosomiasis and Filariasis, Shanghai, 200025, People's Republic of China. zhouxn1@chinacdc.cn.
authors.forename: Xiao-Nong
authors.initials: XN
authors.lastname: Zhou
mesh_terms: D000818:Animals; D002681:China / Q000453:epidemiology; D056426:Genetic Loci; D014644:Genetic Variation; D005843:Geography; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D060885:Multiplex Polymerase Chain Reaction / Q000379:methods*; D011110:Polymorphism, Genetic / Q000235:genetics*; D012549:Schistosoma japonicum / Q000502:physiology*; D012554:Schistosomiasis japonica / Q000453:epidemiology* / Q000469:parasitology; D012908:Snails / Q000235:genetics* / Q000469:parasitology