Genome-wide analysis in Brazilian Xavante Indians reveals low degree of admixture

PLoS One. 2012;7(8):e42702. doi: 10.1371/journal.pone.0042702. Epub 2012 Aug 10.

Abstract

Characterization of population genetic variation and structure can be used as tools for research in human genetics and population isolates are of great interest. The aim of the present study was to characterize the genetic structure of Xavante Indians and compare it with other populations. The Xavante, an indigenous population living in Brazilian Central Plateau, is one of the largest native groups in Brazil. A subset of 53 unrelated subjects was selected from the initial sample of 300 Xavante Indians. Using 86,197 markers, Xavante were compared with all populations of HapMap Phase III and HGDP-CEPH projects and with a Southeast Brazilian population sample to establish its population structure. Principal Components Analysis showed that the Xavante Indians are concentrated in the Amerindian axis near other populations of known Amerindian ancestry such as Karitiana, Pima, Surui and Maya and a low degree of genetic admixture was observed. This is consistent with the historical records of bottlenecks experience and cultural isolation. By calculating pair-wise F(st) statistics we characterized the genetic differentiation between Xavante Indians and representative populations of the HapMap and from HGDP-CEPH project. We found that the genetic differentiation between Xavante Indians and populations of Ameridian, Asian, European, and African ancestry increased progressively. Our results indicate that the Xavante is a population that remained genetically isolated over the past decades and can offer advantages for genome-wide mapping studies of inherited disorders.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Brazil / ethnology
  • Cross-Sectional Studies
  • Ethnicity / genetics
  • Genetic Variation*
  • Genetics, Population
  • HapMap Project
  • Humans
  • Indians, South American / genetics*
  • Models, Genetic
  • Polymorphism, Single Nucleotide
  • Population Groups / genetics

Grants and funding

This study was funded by grants from Fundação de Amparo à Pesquisa do Estado de São Paulo (Fapesp), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and INCT- Obesidade e Diabetes. The funders have no rule in study design, data coletion and analysis, decision to publish, or preparation of the manuscript.