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Resumen El Nordeste argentino se caracteriza por la presencia de diversidad étnica, cultural y lingüística; y por una historia de movimientos poblacionales ligada a variaciones geopolíticas. El objetivo de este trabajo es presentar los primeros resultados de una investigación, estructurada en tres ejes (local, regional y sudamericano), que busca explorar la historia poblacional de la región a través de la caracterización de los linajes maternos y paternos de las ciudades de Corrientes (CRR, N=151) y Formosa (FOR, N=274). Se detallan las técnicas y métodos de análisis, así como las preguntas de investigación abordadas en cada eje, y se presentan los resultados del primer eje. Se estimaron los aportes de origen nativo americano, del oeste de Eurasia y de África subsahariana. Se obtuvieron frecuencias mayoritarias de linajes nativos americanos por vía materna (FOR=85%, CRR=89,4%). Los linajes euroasiáticos (FOR=9,93%, CRR=12,41%) y africanos (FOR=2,55%, CRR=0,66%) también están presentes. Por otra parte, más del 80% de los linajes paternos resultaron de origen euroasiático, de los cuales el 55% corresponde al haplogrupo R1 (FOR=55,2%, CRR=54,7%). La fracción nativa de los linajes paternos aportó las frecuencias más bajas documentadas para Argentina (FOR= 4,9%; CRR=3,2%). Los datos moleculares se compararon con datos genealógicos y se contextualizaron con la información histórica Abstract Northeast Argentina is characterized by the presence of ethnic, cultural and linguistic diversity; and by a history of population movements linked to geopolitical variations. The aim of this paper is to present a research design, structured in three analytical axes (local, regional and South American), to explore the population history of the region through the characterization of maternal and paternal lineages of the cities of Corrientes (CRR N=151) and Formosa (FOR N=274). Analysis techniques and methods were detailed, the research questions addressed in each axis were outlined and the results of the first axis were presented. Genetic contributions of Native American, western Eurasia, and sub-Saharan Africa origin were estimated. Majority frequencies of Native American lineages were obtained through the maternal line (FOR=85%, CRR=89,4%). The Eurasian (FOR=9,93%, CRR=12,41%) and African (FOR=2,55%, CRR=0,66%) lineages were also present. On the other hand, more than 80% of the paternal lineages were of Eurasian origin, with 55% corresponding to R1 (FOR=55,2%, CRR=54,7%). The native American fraction (FOR= 4,9%; CRR=3,2%), provided the lowest frequencies documented for Argentina. Molecular data were compared with genealogical data and contextualized with historical evidence

We are at the dawn of the efforts to describe and understand the origins of genetic diversity in Argentina from high-throughput data. This knowledge is a primary step in the intent of deciphering the specific genetic bases of diseases and drug response in the country. Similarly to other populations across the Americas, genetic ancestry in Argentinean populations traces back into African, European and Native American ancestors, reflecting a complex demographic history with multiple migration and admixture events in pre- and post-colonial times. However, little is known about the sub-continental origins of these three main ancestries. We present new high-throughput genotyping data for 87 admixed individuals across Argentina. This data was combined to previously published data for admixed individuals in the region and then compared to different reference panels specifically built to run population structure analyses at a sub-continental level. Concerning the European and African ancestries, we confirmed previous results about their main origins, and we provide new insights into the presence of other origins that reflect historical records. As for the Native American ancestry, leveraging genotype data for archaeological samples in the region in order to gain temporal depth in our analyses, we could identify four Native American components segregating in modern Argentinean populations. Three of them are also found in modern South American populations and are specifically represented in Central Chile/Patagonia, Lowlands and Central Andes geographic areas. The fourth one may be specific to the Central Western region of Argentina. Identifying such component has not been straightforward since it is not well represented in any genomic data from the literature. Altogether, we provide useful insights into the multiple population groups from different continents that have contributed to present-days genetic diversity in Argentina. We encourage the generation of massive genotype data locally to further describe the genetic structure in Argentina. Author Summary The human genetic diversity in Argentina reflects demographic mechanisms during which the European colonists invaded a territory where Native American populations were settled. During colonial period, the slave trade also prompted many African people to move to Argentina. Little is known about the origins of the Native American and African components in Argentinean populations nowadays. Genotyping data for 87 admixed individuals throughout Argentina was generated and data from the literature was re-analyzed to shed light on this question. We confirmed that most of the European genetic ancestry comes from the South, although several individuals are related to Northern Europeans. We found that African origins in Argentina trace back from different regions. As for the Native American ancestry, we identified that it can be divided into four main components that correspond to Central Chile/Patagonia, Lowlands, Central Andes and Central Western region of Argentina. In order to understand the specificity of the genetic diversity in Argentina, we should not rely on knowledge generated in other populations. Instead, more effort is required to generate specific massive genomic knowledge at the local level.