We sequenced the genomes of a ~7,000 year old farmer from Germany and eight ~8,000 year old hunter-gatherers from Luxembourg and Sweden. We analyzed these and other ancient genomes1–4 with 2,345 contemporary humans to show that most present Europeans derive from at least three highly differentiated populations: West European Hunter-Gatherers (WHG), who contributed ancestry to all Europeans but not to Near Easterners; Ancient North Eurasians (ANE) related to Upper Paleolithic Siberians3, who contributed to both Europeans and Near Easterners; and Early European Farmers (EEF), who were mainly of Near Eastern origin but also harbored WHG-related ancestry. We model these populations’ deep relationships and show that EEF had ~44% ancestry from a “Basal Eurasian” population that split prior to the diversification of other non-African lineages.
The peopling of the Americas has been the subject of extensive genetic, archaeological and linguistic research; however, central questions remain unresolved1–5. One contentious issue is whether the settlement occurred via a single6–8 or multiple streams of migration from Siberia9–15. The pattern of dispersals within the Americas is also poorly understood. To address these questions at higher resolution than was previously possible, we assembled data from 52 Native American and 17 Siberian groups genotyped at 364,470 single nucleotide polymorphisms. We show that Native Americans descend from at least three streams of Asian gene flow. Most descend entirely from a single ancestral population that we call “First American”. However, speakers of Eskimo-Aleut languages from the Arctic inherit almost half their ancestry from a second stream of Asian gene flow, and the Na-Dene-speaking Chipewyan from Canada inherit roughly one-tenth of their ancestry from a third stream. We show that the initial peopling followed a southward expansion facilitated by the coast, with sequential population splits and little gene flow after divergence, especially in South America. A major exception is in Chibchan-speakers on both sides of the Panama Isthmus, who have ancestry from both North and South America.
The large and diverse population of Latin America is potentially a powerful resource for elucidating the genetic basis of complex traits through admixture mapping. However, no genome-wide characterization of admixture across Latin America has yet been attempted. Here, we report an analysis of admixture in thirteen Mestizo populations (i.e. in regions of mainly European and Native settlement) from seven countries in Latin America based on data for 678 autosomal and 29 X-chromosome microsatellites. We found extensive variation in Native American and European ancestry (and generally low levels of African ancestry) among populations and individuals, and evidence that admixture across Latin America has often involved predominantly European men and both Native and African women. An admixture analysis allowing for Native American population subdivision revealed a differentiation of the Native American ancestry amongst Mestizos. This observation is consistent with the genetic structure of pre-Columbian populations and with admixture having involved Natives from the area where the Mestizo examined are located. Our findings agree with available information on the demographic history of Latin America and have a number of implications for the design of association studies in population from the region.
We analyze the allelic polymorphisms in seven Y-specific microsatellite loci and a Y-specific alphoid system with 27 variants (ah I-XXVII), in a total of 89 Y chromosomes carrying the DYS199T allele and belonging to populations representing Amerindian and Na-Dene linguistic groups. Since there are no indications of recurrence for the DYS199CrT transition, it is assumed that all DYS199T haplotypes derive from a single individual in whom the CrT mutation occurred for the first time. We identified both the ancestral founder haplotype, 0A, of the DYS199T lineage and seven derived haplogroups diverging from the ancestral one by one to seven mutational steps. The 0A haplotype (5.7% of Native American chromosomes) had the following constitution: DYS199T, ah II, DYS19/13, DYS389a/10, DYS389b/ 27, DYS390/24, DYS391/10, DYS392/14, and DYS393/13 (microsatellite alleles are indicated as number of repeats). We analyzed the Y-specific microsatellite mutation rate in 1,743 father-son transmissions, and we pooled our data with data in the literature, to obtain an average mutation rate of .0012. We estimated that the 0A haplotype has an average age of 22,770 years (minimum 13,500 years, maximum 58,700 years). Since the DYS199T allele is found with high frequency in Native American chromosomes, we propose that 0A is one of the most prevalent founder paternal lineages of New World aborigines.
We analyzed 21 paragroup Q* Y chromosomes from South American aboriginal and urban populations. Our aims were to evaluate the phylogenetic status, geographic distribution, and genetic diversity in these groups of chromosomes and compare the degree of genetic variation in relation to Q1a3a haplotypes. All Q* chromosomes from our series and five samples from North American Q* presented the derivate state for M346, that is present upstream to M3, and determined Q1a3* paragroup. We found a restrictive geographic distribution and low frequency of Q1a3* in South America. We assumed that this low frequency could be reflecting extreme drift effects. However, several estimates of gene diversity do not support the existence of a severe bottleneck. The mean haplotype diversity expected was similar to that for South American Q1a3* and Q1a3a (0.478 and 0.501, respectively). The analysis of previous reports from other research groups and this study shows the highest frequencies of Q* for the West Corner and the Grand Chaco regions of South America. At present, there is no information on whether the phylogenetic status of Q* paragoup described in previous reports is similar to that of Q1a3* paragroup though our results support this possibility.
RESUMENSe analizó sobre la base del polimorfismo del cromosoma Y del ADN, el origen étnico de linaje paterno en dos subpoblaciones amerindias del nordeste argentino exindidas de un mismo ancestro. Una de las subpoblaciones fue obtenida en San Salvador de Jujuy ubicado a 1.200 m sobre el nivel del mar y la segunda en los habitantes de Humahuaca con una altitud que fluctúa entre 2.500 a 3.500 metros. Encontramos un porcentaje de 40,5% de integración del cromosoma Y de origen hispano en el total de muestras de amerindios. Sin embargo esta integración fue de un 64,3% en SS de Jujuy (1.200 m aproximadamente) que es el nivel andino de menor altura y de 27.6% en Humahuaca (2.500 m o más sobre el nivel del mar) definiendo una menor integración hispánica en concordancia con la altura. (P< 0.05). La subpoblación que habita a 1.200 m mostró también una variación genética del cromosoma Y significativamente alta. Estos hallazgos, tienen una buena correlación con la información histórica de la conquista de América, que fue hecha por hombres que mantenían uniones poligámicas con mujeres amerindias. SS de Jujuy es la región más noreste donde se encuentra una mezcla genética de amerindios, en Argentina.
We analyzed 391 samples from 12 Argentinian populations from the Center-West, East and North-West regions with the Illumina Human Exome Beadchip v1.0 (HumanExome-12v1-A). We did Principal Components analysis to infer patterns of populational divergence and migrations. We identified proportions and patterns of European, African and Native American ancestry and found a correlation between distance to Buenos Aires and proportion of Native American ancestry, where the highest proportion corresponds to the Northernmost populations, which is also the furthest from the Argentinian capital. Most of the European sources are from a South European origin, matching historical records, and we see two different Native American components, one that spreads all over Argentina and another specifically Andean. The highest percentages of African ancestry were in the Center West of Argentina, where the old trade routes took the slaves from Buenos Aires to Chile and Peru. Subcontinentaly, sources of this African component are represented by both West Africa and groups influenced by the Bantu expansion, the second slightly higher than the first, unlike North America and the Caribbean, where the main source is West Africa. This is reasonable, considering that a large proportion of the ships arriving at the Southern Hemisphere came from Mozambique, Loango and Angola.
We have characterized the mtDNA in normal and breast cancer tissues from seven patients. Both types of tissue showed point mutation heteroplasmies and extensive deletions of the mtDNA. The analysis of these polymorphisms allowed us to infer the mtDNA composition of the breast cell that underwent malignant transformation.
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