Uniparental origins of the admixed Argentine Patagonia

CAMILA TAMBURRINI; MICHELLE DE SAINT PIERRE; CLAUDIO MARCELO BRAVI; LAURA JURADO MEDINA; GRACIELA BAILLET; IRINA FLORENCIA VELÁZQUEZ; NÉSTOR GUILLERMO BASSO; LUCIANO ESTEBAN REAL; J. ALFREDO HOLLEY; CLAUDIA MARCELA TEDESCHI; MARÍA LAURA PAROLIN

AMERICAN JOURNAL OF HUMAN BIOLOGY

WILEY-LISS, DIV JOHN WILEY & SONS INC

Lugar: New York; Año: 2021

1042-0533

Objetives:From a multidisciplinary approach this study aimed to analyze the geographic origins of the uniparental inheritance markers in an admixed Central Patagonian Argentina population. Results obtained were analyzed together with genealogical, demographic and historical data. Also, results were contrasted with modern and ancient DNA information to evaluate genetic affinities among other Patagonian population and to evaluate the presence of current mtDNA Hg variants in ancient population of the same region. Additionally, uniparental results obtained were contrasted with autosomal continental ancestry previously estimated in the same sample set.Methods:The entire mtDNA D-Loop was typified in 89 individuals from Trelew city, located at Northeast of Chubut province. From this data set, 66 males were analyzed by 12 Y-chromosome STR and 15 Y-SNP. AMOVA and Median-joining networks were carried out to analyze possible sub-structuration and population differences. Differences on continental origins estimated by uniparental and biparental markers were tested using ad hoc scripts.Results:As expected for admixed Latin-American populations, a prevalence of mtDNA Native American haplotypes (53.9%) was observed, while most of the paternal lineages were allochthone (89.4%). Genealogical information showed that autochthone mtDNA lineages increased when maternal ancestors were born in North (81.8%) or South (58.5%) regions of the country, or even in Chile (77.8%). For Y-chromosome, European lineages prevailed (89.4%) regardless the geographical origin of the paternal ancestors. Population sub-structure was observed only for Y-chromosome haplotypes but not for mtDNA haplogroups when performing AMOVA analysis among North/Center/South regions of Argentina. Moreover, strong genetic affinities were observed among Argentinian and Chilean Patagonian population in both maternal and paternal markers. Consistency between mtDNA haplogroups found in ancient and modern populations Patagonia region was registered. D1g and D1g4, present in the current population were also observed in ancient studies of the region for at least the last ca 2762-2430 and ca 500 years, respectively. C1b and C1c were also reported in ancient individuals confirming their presence in the area from at least ca 6736-7167 and ca 6620 YBP, respectively. On the other hand, sub-lineage such as B2i2 and C1b13 registered in TW population, were not yet found in ancient studies of the region. This could be indicating the emergence of new lineage in recent times in the area. Significant differences in the continental ancestry estimation was observed when uniparental and biparental markers are independently analyzed.Conclusions:The analysis of lineage specific markers in an admixed Patagonian population, revealed a biased gender admixture process with marked preservation of autochthone maternal roots, which is strongly correlated with the birthplace of the female ancestors. Population comparisons showed a heterogeneity for the autochthonous and allochthone contributions through different regions of the country, and even among localities of a same province, as Chubut. Continuity for certain sub-lineage were observed when analyzing ancient studies of the area meanwhile other ones are hypothesize to be the result of migration events and emergence of lineages in recent times. Finally, our study showed the need to combine uni-parental and bi-parental inheritance markers together with local genealogical and historical information to achieve an integral overview of the genetic structure of a population, which is essential for the correct interpretation of genetic information in medicine, anthropology and forensic researches.