Inferring Continental Ancestry of Argentineans from Autosomal, Y‐Chromosomal and Mitochondrial DNA

TLDR

The study is relevant to any region where people of diverse continental ancestries live in close proximity. The authors aimed to investigate the biogeographic ancestry of Argentineans and quantify their genetic admixture. They analyzed 246 unrelated male individuals from eight provinces across three Argentinean regions using ancestry‑sensitive DNA markers from autosomal, Y‑chromosomal and mitochondrial genomes. European ancestry dominates the Y‑chromosomal (94.1%) and autosomal (78.5%) genomes of Argentineans, while mitochondrial DNA is largely Native American (53.7%) and African ancestry is minor (<4%) across all systems; inter‑individual heterogeneity is high, provincial substructure is negligible, and these results highlight the necessity of using autosomal, Y‑chromosomal and mitochondrial markers together to assess geographic origins and admixture.

Abstract

Summary We investigated the bio‐geographic ancestry of Argentineans, and quantified their genetic admixture, analyzing 246 unrelated male individuals from eight provinces of three Argentinean regions using ancestry‐sensitive DNA markers (ASDM) from autosomal, Y and mitochondrial chromosomes. Our results demonstrate that European, Native American and African ancestry components were detectable in the contemporary Argentineans, the amounts depending on the genetic system applied, exhibiting large inter‐individual heterogeneity. Argentineans carried a large fraction of European genetic heritage in their Y‐chromosomal (94.1%) and autosomal (78.5%) DNA, but their mitochondrial gene pool is mostly of Native American ancestry (53.7%); instead, African heritage was small in all three genetic systems (&lt;4%). Population substructure in Argentina considering the eight sampled provinces was very small based on autosomal (0.92% of total variation was between provincial groups, p = 0.005) and mtDNA (1.77%, p = 0.005) data (none with NRY data), and all three genetic systems revealed no substructure when clustering the provinces into the three geographic regions to which they belong. The complex genetic ancestry picture detected in Argentineans underscores the need to apply ASDM from all three genetic systems to infer geographic origins and genetic admixture. This applies to all worldwide areas where people with different continental ancestry live geographically close together.