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Open Access Highly Accessed Research article

The impact of modern migrations on present-day multi-ethnic Argentina as recorded on the mitochondrial DNA genome

María Laura Catelli1, Vanesa Álvarez-Iglesias2, Alberto Gómez-Carballa2, Ana Mosquera-Miguel2, Carola Romanini1, Alicia Borosky3, Jorge Amigo2, Ángel Carracedo2, Carlos Vullo13 and Antonio Salas2*

Author affiliations

1 Equipo Argentino de Antropología Forense, Independencia 644 - 5C, Edif. EME1, Córdoba, Argentina

2 Unidade de Xenética, Instituto de Medicina Legal and Departamento de Anatomía Patolóxica e Ciencias Forenses, Calle San Francisco sn, Facultade de Medicina, Universidade de Santiago de Compostela, CIBERER, Santiago de Compostela, 15782, Galicia, Spain

3 Laboratorio de Inmunogenética y Diagnóstico Molecular, Independencia 644 - 4, Edif EME1, Córdoba, Argentina

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Citation and License

BMC Genetics 2011, 12:77  doi:10.1186/1471-2156-12-77

Published: 30 August 2011

Abstract

Background

The genetic background of Argentineans is a mosaic of different continental ancestries. From colonial to present times, the genetic contribution of Europeans and sub-Saharan Africans has superposed to or replaced the indigenous genetic 'stratum'. A sample of 384 individuals representing different Argentinean provinces was collected and genotyped for the first and the second mitochondrial DNA (mtDNA) hypervariable regions, and selectively genotyped for mtDNA SNPs. This data was analyzed together with additional 440 profiles from rural and urban populations plus 304 from Native American Argentineans, all available from the literature. A worldwide database was used for phylogeographic inferences, inter-population comparisons, and admixture analysis. Samples identified as belonging to hg (hg) H2a5 were sequenced for the entire mtDNA genome.

Results

Phylogenetic and admixture analyses indicate that only half of the Native American component in urban Argentineans might be attributed to the legacy of extinct ancestral Argentineans and that the Spanish genetic contribution is slightly higher than the Italian one. Entire H2a5 genomes linked these Argentinean mtDNAs to the Basque Country and improved the phylogeny of this Basque autochthonous clade. The fingerprint of African slaves in urban Argentinean mtDNAs was low and it can be phylogeographically attributed predominantly to western African. The European component is significantly more prevalent in the Buenos Aires province, the main gate of entrance for Atlantic immigration to Argentina, while the Native American component is larger in North and South Argentina. AMOVA, Principal Component Analysis and hgs/haplotype patterns in Argentina revealed an important level of genetic sub-structure in the country.

Conclusions

Studies aimed to compare mtDNA frequency profiles from different Argentinean geographical regions (e.g., forensic and case-control studies) should take into account the important genetic heterogeneity of the country in order to prevent false positive claims of association in disease studies or inadequate evaluation of forensic evidence.