Autosomal and X chromosome Alu insertions in Bolivian Aymaras and Quechuas: two languages and one genetic pool

Analysis of 21 X-chromosome polymorphisms in urban and rural populations in Salta province (north-western Argentina)

Population genetic data for 21 X-chromosome markers (Alu insertions and STRs) are reported for two populations (rural and urban) in Salta province (north-western Argentina). New variants are described, confirming the complexity and variability of some markers in this set. Results reveal Salta populations harbor a high Native American component, despite their self-recognized European ancestry. Notwithstanding the high genetic similarity of both populations, the rural sample seems to have maintained a larger Amerindian legacy. Data further show these X-linked markers, especially STRs, are highly informative in Salta populations and, therefore, can contribute to the development of a local database for forensic purposes in north-western Argentina.

Genetic Differentiation of North-East Argentina Populations Based on 30 Binary X Chromosome Markers

Alu insertions, INDELs, and SNPs in the X chromosome can be useful not only for revealing relationships among populations but also for identification purposes. We present data of 10 Alu insertions, 5 INDELs, and 15 SNPs of X-chromosome from three Argentinian north-east cities in order to gain insight into the genetic diversity of the X chromosome within this region of the country. Data from 198 unrelated individuals belonging to Posadas, Corrientes, and Eldorado cities were genotyped for Ya5DP62, Yb8DP49, Ya5DP3, Ya5NBC37, Ya5DP77, Ya5NBC491, Ya5DP4, Ya5DP13, Yb8NBC634, and Yb8NBC102 Alu insertions, for MID193, MID1705, MID3754, MID3756 and MID1540 Indels and for rs6639398, rs5986751, rs5964206, rs9781645, rs2209420, rs1299087, rs318173, rs933315, rs1991961, rs4825889, rs1781116, rs1937193, rs1781104, rs149910, and rs652 SNPs. No deviations from Hardy-Weinberg equilibrium were observed for Posadas and Corrientes. However, Eldorado showed significant values, and it was found to have an internal substructuring with two groups of different origin, one showing higher similarity with European countries, and the other with more similarities to Posadas and Corrientes. F_st pairwise genetic distances emerged for some markers among the studied populations and also between our data and those from other countries and continents. Of particular interest, Alu insertions demonstrated the most differences, and could be of use in ancestry studies for these populations, while INDELs and SNPs variation were informative for differentiation within the country.

Genetic Variations in the TP53 Pathway in Native Americans Strongly Suggest Adaptation to the High Altitudes of the Andes

The diversity of the five single nucleotide polymorphisms located in genes of the TP53 pathway (TP53, rs1042522; MDM2, rs2279744; MDM4, rs1563828; USP7, rs1529916; and LIF, rs929271) were studied in a total of 282 individuals belonging to Quechua, Aymara, Chivay, Cabanaconde, Yanke, Taquile, Amantani, Anapia, Uros, Guarani Ñandeva, and Guarani Kaiowá populations, characterized as Native American or as having a high level (> 90%) of Native American ancestry. In addition, published data pertaining to 100 persons from five other Native American populations (Surui, Karitiana, Maya, Pima, and Piapoco) were analyzed. The populations were classified as living in high altitude (≥ 2,500 m) or in lowlands (< 2,500 m). Our analyses revealed that alleles USP7-G, LIF-T, and MDM2-T showed significant evidence that they were selected for in relation to harsh environmental variables related to high altitudes. Our results show for the first time that alleles of classical TP53 network genes have been evolutionary co-opted for the successful human colonization of the Andes.