title: [Genetic polymorphisms and application of 9 STR loci of 5 ethnic groups in Gansu and Qinghai].
abstract: OBJECTIVE
  To examine the genetic polymorphism of 9 STR loci in 5 ethnic groups (including Tu, Sala, Dongxiang, Baoan and Yugu) in Gansu and Qinghai, and to evaluate its application.
  
  
  METHODS
  Nine STR loci (D3S1358, FGA, TH01, D7S820, VWA, CSF1PO, D5S818, D13S317 and TPOX) were selected as genetic markers. With STR compound amplification and genescan methods, in which STR loci were marked by fluorescence, the genotype of 5 ethnic groups were examined in 606 unrelated individuals by ABI 377 sequencer. These parameters, such as polymorphism information content (PIC), heterozygosity (H), discrimination power (DP) and probability of paternity exclusion (PPE) were calculated.
  
  
  RESULTS
  The genotype frequencies of the 9 STR loci were in accordance with Hardy-Weinberg equilibrium. PIC was within 0.6054 - 0.8735, H was within 0.6158 - 0.8736, DP was within 0.7964 - 0.9691, and PPE was within 0.4610 - 0.8838. Cluster analysis based on allele frequencies in genesis showed Tu, Sala, Dongxiang and Baoan ethnic groups were very close, but Yugu was a little bit far. There were obvious gene exchanges among the populations in north and south of China.
  
  
  CONCLUSIONS
  All the 9 STR loci are highly polymorphic in the 5 ethnic groups, which can be useful genetic markers in forensic medicine and population genetics.
authors.affiliation: Department of Forensic Science, Medical School of Xi'an Jiaotong University, Xi'an 710061, China.
authors.forename: Teng
authors.initials: T
authors.lastname: Chen
authors.forename: Tian-bo
authors.initials: TB
authors.lastname: Jin
authors.forename: Na
authors.initials: N
authors.lastname: Xin
authors.forename: Jiang-hua
authors.initials: JH
authors.lastname: Lai
authors.forename: Sheng-bin
authors.initials: SB
authors.lastname: Li
mesh_terms: D002681:China / Q000208:ethnology; D016000:Cluster Analysis; D005006:Ethnicity / Q000235:genetics; D005787:Gene Frequency; D005828:Genetics, Population; D005838:Genotype; D006801:Humans; D011110:Polymorphism, Genetic; D020080:Tandem Repeat Sequences / Q000235:genetics*