Gene admixture analysis through genetic markers and genealogical data in a sample from Buenos Aires Metropolitan Area

Abstract

In this work we analysed the degree of participation of maternal Amerindian, European and African lineages in a sample from the Buenos Aires Metropolitan Area population (BAMA). This study was performed on 211 unrelated individuals (151 males and 60 females). C-T transition in the DYS199 locus of the Y chromosome was determined and the mtDNA was examined by RFLPs to identify the four Amerindian haplogroups: A, B, C and D, and the mtDNA of European and African lineages. 102 (48 percent), 108 (51 percent), and one (0.5 percent) presented Amerindian, European and African lineages, respectively. According to the place of birth of the maternal grandmothers, the majority of the Amerindian haplogroups came from the provinces (65 percent) and the bordering countries and Peru (22 percent). The BAMA region contributed with only ten percent of these lineages. One donor (1 percent) of Asian ancestry presented haplogroup D. According to the inquiry performed, two donors (2 percent) who had European grandmothers presented Amerindian haplogroups as well. These results could be consequence of ilegitimacy of the donors misinformation regarding their grandmother’s place of birth. The European haplogroup H was the most frequent (55 percent) followed by U (12 percent), T (8 percent), K (7 percent), I-W (6 percent), V (5 percent), J (4 percent) and X (2 percent). The African maternal lineage represented less than one percent. The Amerindian paternal contribution was low (4 percent). On the basis of the genealogic data, we support the idea that the Amerindian haplogroups distribution in the BAMA was produced mainly by migrants that came from the provinces, bordering countries, and Peru, but not as a consequence of gene admixture in that area. Therefore according to the sample analysed, we can postulate that the “melting pot” has not occurred to a great extent in the BAMA. However, we are aware that the sample studied is small so more studies will be necessary to reach conclusive results.