title: [Analysis for spatial distribution of Oncomelania snail in mainland China by geographic information system(GIS) database].
abstract: OBJECTIVE
  To analyze spatial distribution of Oncomelania snail populations in mainland China by geographic information system (GIS) database.
  
  
  METHODS
  Genetic variation experiment data and experimental data of susceptibility of 34 snail populations were collected from nine provinces in China, to set up a database. A world digital map was linked with the database in a software ArcView Release 3.0 a to be used to divide zones with ArcView spatial analyze function and GIS overlaying function. AVHRR NDVI satellite images were collected to form a new one for prevalent season, which were overlaid with distribution maps of heterozygous indices of snail populations, polymorphic locus percentage and infection rates of snail population with schistosome for classifying the images.
  
  
  RESULTS
  Spatial analysis showed that distribution maps of genetic heterozygous indices of snail, percentage of polymophic loci and infection rate of snail can be divided into two large zones, i.e., east zone and west zone, both with varied pictures. Analysis for overlaying three-stratum distribution map with AVHRR NDVI satellite image showed four distinctly different spatial zones, including west Sichuan zone, west Yunnan zone, middle zone of river, lake and marshland, and southeast coastal zone.
  
  
  CONCLUSIONS
  It is the first time using GIS to analyze data of Oncomelania population genetics and confirmed the population structure of Oncomelania snails presented discrete sub-population model, which supports the theory of sub-species of Oncomelania spp. Exited in mainland China.
authors.affiliation: Jiangsu Institute of Parasitic Diseases, Wuxi 214064.
authors.forename: X
authors.initials: X
authors.lastname: Zhou
authors.forename: T K
authors.initials: TK
authors.lastname: Kristensen
authors.forename: Q
authors.initials: Q
authors.lastname: Hong
authors.forename: L
authors.initials: L
authors.lastname: Sun
mesh_terms: D000818:Animals; D002681:China; D003710:Demography; D004199:Disease Vectors; D004463:Ecology; D040362:Geographic Information Systems; D011110:Polymorphism, Genetic / Q000235:genetics; D012554:Schistosomiasis japonica / Q000635:transmission*; D012908:Snails / Q000235:genetics / Q000469:parasitology