CONICET | Buscador de Institutos y Recursos Humanos

The human population genetic structure of the southernmost part of the American continent hasbeen mainly approached from the diversity of uniparental lineages, or the use of a few autosomalgenetic markers. The use of massive genomic data to address this problem has recently begun.Here, we used high-throughput genotype data from 94 Argentinians with Native American mtDNAhaplotypes. An extended meta-dataset compiling genome-wide genotype data from South-American native and the 1KGP populations was built.PCA results show that Argentinians are distributed along a ?gradient? of American vs Europeanancestry, similar to other Latin American populations. Individuals from Misiones exhibit the highestEuropean ancestry, while samples from the northwest have the highest native component. Africanancestry is low in our samples, with the highest proportions observed in the center of Argentina.ADMIXTURE reveals a northern European component in Misiones, but Argentinians in generalhave two predominant ancestries: southern European and native American. The Africancomponent seems to have two origins: South and West Africa. When we include other SouthAmerican native populations, the Argentinean native ancestry splits in three distinct components: (i) a?Central-Patagonic ancestry? recently described in Chile and present throughout Argentina, withhighest proportion in the center and southern areas; (ii) , a "Gran Chaco" component also present throughout Argentina with highest proportion in the north east area; and (iii) a ?North-Andean component?, highest inthe Argentinian northwest, but also present throughout Argentina.Finally, local ancestry analyses identified chromosome regions of African, European or Americanancestry. This, in turn, allowed us to evaluate for each individual its origin within each continent ona fine geographic scale.