title: Genetic diversity and selection of three nuclear genes in Schistosoma japonicum populations.
abstract: The blood fluke, Schistosoma japonicum still causes severe disease in China, the Philippines and Indonesia. Although there have been some studies the molecular epidemiology of this persistent and harmful parasite, few have explored the possibility and implications of selection in S. japonicum populations.
  
  
  
  We analyzed diversity and looked for evidence of selection at three nuclear genes (SjIpp2, SjFabp and SjT22.6) in 13 S. japonicum populations.
  
  
  
  SjT22.6 was found to exhibit high nucleotide diversity and was under positive selection in the mountainous region of mainland China. As a tegumental protein, its secondary and tertiary structure differed between S. japonicum strains from the mountainous and lakes regions. In contrast, SjIpp2 and SjFabp had relatively low levels of nucleotide diversity and did not show significant departure from neutrality.
  
  
  
  As a tegument-associated antigen-encoding gene of S. japonicum, SjT22.6 has high nucleotide diversity and appears to be under positive selection in the mountainous region of mainland China.
authors.affiliation: School of Life Science, Fudan University, Songhu Road 2005, Shanghai, China.
authors.forename: Yaqi
authors.initials: Y
authors.lastname: Li
authors.affiliation: School of Life Science, Fudan University, Songhu Road 2005, Shanghai, China. yinm@fudan.edu.cn.|MOE Key Laboratory for Biodiversity Science and Ecological Engineering, School of Life Science, Fudan University, Songhu Road 2005, Shanghai, China. yinm@fudan.edu.cn.
authors.forename: Mingbo
authors.initials: M
authors.lastname: Yin
authors.affiliation: School of Life Science, Fudan University, Songhu Road 2005, Shanghai, China.
authors.forename: Qunfeng
authors.initials: Q
authors.lastname: Wu
authors.affiliation: QIMR Berghofer Medical Research Institute, 300 Herston Road, Brisbane, QLD, 4029, Australia.
authors.forename: Donald P
authors.initials: DP
authors.lastname: McManus
authors.affiliation: College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Blair
authors.affiliation: School of Life Science, Fudan University, Songhu Road 2005, Shanghai, China.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Li
authors.affiliation: National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, 207 Rui Jin Er Road, Shanghai, 200025, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Xu
authors.affiliation: National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, 207 Rui Jin Er Road, Shanghai, 200025, China.
authors.forename: Xiaojin
authors.initials: X
authors.lastname: Mo
authors.affiliation: National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, 207 Rui Jin Er Road, Shanghai, 200025, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Feng
authors.affiliation: School of Life Science, Fudan University, Songhu Road 2005, Shanghai, China. huw@fudan.edu.cn.|National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, 207 Rui Jin Er Road, Shanghai, 200025, China. huw@fudan.edu.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Hu
mesh_terms: D000818:Animals; D000947:Antigens, Helminth / Q000235:genetics; D002681:China; D017238:Genes, Helminth; D014644:Genetic Variation; D012549:Schistosoma japonicum / Q000235:genetics*; D012554:Schistosomiasis japonica / Q000469:parasitology; D012641:Selection, Genetic; D017422:Sequence Analysis, DNA
chemical_list: D000947:Antigens, Helminth
keywords: Genetic diversity; Natural selection; Nuclear genes; Schistosoma japonicum; Tegument-associated antigen