Ethnic Contributions to the Extant Population of Argentina: as shown by uniparentally inherited genetic markers

DANIEL CORACH, ANDREA SALA AND MIGUEL MARINO.

Ponta Delgada, Azores

Congreso; 21 st Congress International Society for Forensic Genetics; 2005

International Society for Forensic Genetics

The population of Argentina is the result of three major ethnic contributions. The original population of  South America is of Amerindian ancestry and its arrival from Asia to the New World is accepted to had occurred over 18.000 years ago. A second contribution was provided by the Spanish conquerors who arrived to the now a days territory of Argentina in 1536 and maintained their migration since then. A third contributor was introduced during the seventh century, as a working force, the slaves imported from West Africa. At present, it is not possible to distinguish the presence of African phenotypes in our population, however its genetic contribution can be traced. Finally, during the late XIX and early XX centuries an intense migration wave from Europe and Near East occurred. The history of the admixed Argentina can be traced back to 19 generations and a big deal of admixture might had taken place. In order to investigate the ethnic contribution to the extant population of Argentina  a set of 322 unrelated males inhabiting 10 provinces of Argentina were selected at random from samples of routine forensic casework. Three major geographic regions were considered: Northeastern (Formosa, Chaco, Corrientes and Misiones Provinces, N=102), Center (Buenos Aires, Santa Fe and Entre Rios Provinces, N=120) and  South Southwestern (Mendoza, Rio Negro and Chubut Provinces, N=100). DNA was extracted from blood samples. Each sample was analyzed by 15 autosomal STRs included in PowerPlex16 and the uniparentally inhereted genetic markers including: the SNP DYS199, nine Y-STRs (DYS19, DYS385a/b, DYS389I/II, DYS390, DYS391, DYS392 and DYS393); mtDNA D-Loop sequence at HVR I and II; and the ins/del of 9bp at Region V. The use of well defined Amerindian uniparentally inhereted genetic markers could determine the ancestry of the individuals that belong to aboriginal or non-aboriginal patri or matrilineages. Mitochondrial DNA analysis allowed us to detect the presence of the main four Amerindian specific as well as European and African haplogroups. The analysis of Y-chromosome markers allowed to find Amerindian specific polymorphism (such as DYS199 T). The results were analyzed considering the geographical regions from where the samples were obtained in order to assess their similarities. The overall results suggest that 58% of the individuals belong to one of the major Amerindian mtDNA haplogroups (A: 13,44%, B: 35,48%; C: 34,4% and D: 16,66%),  18% showed the DYS199 T variant; 12% belongs to both Amerindian matri and patri lineages and 36% of the total exhibit non-Amerindian lineages. The analysis of these results by geographical areas showed a good correlation with historical and geographical records. The results presented in this work supports previous investigations based on blood groups and autosomal  genetic markers analyzed in urban population of different cities of Argentina.