title: Paternal genetic structure of Hainan aborigines isolated at the entrance to East Asia.
abstract: BACKGROUND
  At the southern entrance to East Asia, early population migration has affected most of the Y-chromosome variations of East Asians.
  
  
  RESULTS
  To assess the isolated genetic structure of Hainan Island and the original genetic structure at the southern entrance, we studied the Y chromosome diversity of 405 Hainan Island aborigines from all the six populations, who have little influence of the recent mainland population relocations and admixtures. Here we report that haplogroups O1a* and O2a* are dominant among Hainan aborigines. In addition, the frequency of the mainland dominant haplogroup O3 is quite low among these aborigines, indicating that they have lived rather isolated. Clustering analyses suggests that the Hainan aborigines have been segregated since about 20 thousand years ago, after two dominant haplogroups entered East Asia (31 to 36 thousand years ago).
  
  
  CONCLUSIONS
  Our results suggest that Hainan aborigines have been isolated at the entrance to East Asia for about 20 thousand years, whose distinctive genetic characteristics could be used as important controls in many population genetic studies.
authors.affiliation: Department of Biology, Hainan Medical College, Haikou, Hainan, China.
authors.forename: Dongna
authors.initials: D
authors.lastname: Li
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: Caiying
authors.initials: C
authors.lastname: Ou
authors.forename: Yan
authors.initials: Y
authors.lastname: Lu
authors.forename: Yuantian
authors.initials: Y
authors.lastname: Sun
authors.forename: Bo
authors.initials: B
authors.lastname: Yang
authors.forename: Zhendong
authors.initials: Z
authors.lastname: Qin
authors.forename: Zhenjian
authors.initials: Z
authors.lastname: Zhou
authors.forename: Shilin
authors.initials: S
authors.lastname: Li
authors.forename: Li
authors.initials: L
authors.lastname: Jin
mesh_terms: D001208:Asia; D041322:Chromosomes, Human, Y; D005006:Ethnicity; D005799:Genes, Dominant; D005828:Genetics, Population; D018392:Genomic Imprinting; D006239:Haplotypes; D006801:Humans; D008297:Male; D020641:Polymorphism, Single Nucleotide; D044382:Population Groups