Genetic structure characterization of Chileans reflects historical immigration patterns

Nat Commun. 2015 Mar 17;6:6472. doi: 10.1038/ncomms7472.

Abstract

Identifying the ancestral components of genomes of admixed individuals helps uncovering the genetic basis of diseases and understanding the demographic history of populations. We estimate local ancestry on 313 Chileans and assess the contribution from three continental populations. The distribution of ancestry block-length suggests an average admixing time around 10 generations ago. Sex-chromosome analyses confirm imbalanced contribution of European men and Native-American women. Previously known genes under selection contain SNPs showing large difference in allele frequencies. Furthermore, we show that assessing ancestry is harder at SNPs with higher recombination rates and easier at SNPs with large difference in allele frequencies at the ancestral populations. Two observations, that African ancestry proportions systematically decrease from North to South, and that European ancestry proportions are highest in central regions, show that the genetic structure of Chileans is under the influence of a diffusion process leading to an ancestry gradient related to geography.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • African Continental Ancestry Group
  • Chile
  • Cluster Analysis
  • Emigration and Immigration*
  • Ethnic Groups
  • Europe
  • European Continental Ancestry Group
  • Female
  • Gene Frequency
  • Genetics, Population*
  • Genome, Human
  • Genotype
  • Geography
  • Haplotypes
  • Humans
  • Indians, North American
  • Male
  • Oligonucleotide Array Sequence Analysis
  • Polymorphism, Single Nucleotide*
  • Sex Factors
  • Software

Associated data

  • dbSNP/1062069