Genetic diversity in maternal amerindian lineages in Argentinian Patagonia

CRESPO C.M.; POSTILLONE M.B.; RUSSO M.G.; BRAVI C.M.; AVENA S.A.; DUBOIS C.F.; HAJDUK A.; ARRIGONI G.; LANATA J.L.; DEJEAN C.B.

Burgos

Congreso; XVII Mundial Congress of Prehistoric and Protohistoric Sciences 2014; 2014

Introduction:Recentlynew approaches about American regional peopling are being producedfrom several disciplines and contribute to explain different socialand biological aspects from ancient populations. Patagonia, thesouthern region of South America, presents evidence of earlyarchaeological sites, with an accepted chronology of 14,500cal BP in Chile and13,900 ? 12,800cal BP for Argentinian locations.Thestudy of mitochondrial DNA can be used to determine the geneticstructure and the evolutionary history of human groups. Differentclades have been described so far in South America. They exhibitdifferent mutations and sometimes a geographic specific dispersion.For example: B2 haplogroup is more frequently found in the Andeanregion, A2 in extant samples of Argentinian Mesopotamia, and C1, D1,D4h3a and some of their variants in ancient Patagonian groups. Theaim of this study is to provide new data about the maternal lineagesthat inhabited Patagonia during the Late Holocene and determine theirregional distribution.Materialsand Methods:Atotal of 58 human samples were analyzed, their chronology go from4800 ybp to contact period, they  belong to museum collectionsor archaeological sites from different locations in Patagonia. DNAwas extracted after demineralization, proteinase K digestion, organicsolvent extraction and concentration with silica columns and/or withQIAamp DNA Investigator kit (Qiagen). Haplogroups were typified byPCR-RFLP and sequencing of the hipervariable region I (HVR I).Analyses were performedto calculate genetic diversity, their association with the geographicdistribution (Mantel Test) and the differentiation among Patagoniapopulations (AMOVA).Results:Sofar DNA of 33/58 samples (57.0%) could be assigned by RFLP, 19(57.6%) samples belong to D haplogroup, 12 (36.4%) to C and 2 (6.0%)to A. HVR-I sequences were obtained in 20/33 individuals. Thefollowing lineages were identified: A2, C1, D1, D1g, D1jand D4h3a.Statistical analysis revealed that no genetic differentiation wouldexist among the studied groups.Conclusions:Aspreviously described, most of the individuals analyzed werecharacterized C1 and D1. We also detected D1j, D1g and D4h3a on theAtlantic coast, traditionally accepted as founder lineages comingsouth by a Pacific coastal route, and present in extant natives. Thisraises the question about whether the initial peopling occurred fromthe Pacific coast with a subsequent expansion or it came from theNorth through an Atlantic route, or both. Finally, we could postulatea reduced genetic diversity and no population structure, perhaps theresult of founder effect and/or genetic flow among the Patagoniannatives.