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El empleo de los polimorfismos del ADN mitocondrial para caracterizar a las poblaciones humanas ha permitido distinguir patrones geográficos de distribución de linajes, detectando posibles rutas de poblamiento. En Argentina existen regiones clásicamente identificadas como libres de pueblos originarios, quedando espacios vacíos de información en cuanto a la distribución de linajes nativos. Sin embargo, los pueblos de las regiones del centro-oeste y noroeste no fueron exterminados sino que fueron asimilados biológicamente primero, a la sociedad colonial y luego, a la sociedad estatal. Los procesos de mestizaje tuvieron una tendencia sexo asimétrica permitiendo la conservación de los linajes maternos nativos en elevadas proporciones. En este trabajo se analizan 1951 muestras obtenidas en centros de salud de catorce localidades del centro-oeste y noroeste de Argentina y se comprueba que el 90% de los haplogrupos mitocondriales son propios de América. La agrupación de localidades en base a la distribución de frecuencias de haplogrupos nativos mediante AMOVA indica que las localidades de Maimará y La Quiaca constituyen una entidad claramente diferenciada, en coincidencia con los datos arqueológicos y lingüísticos. Las elevadas frecuencias de haplogrupo D en La Rioja y de haplogrupo A en Villa Tulumaya pueden representar fenómenos poblacionales prehispánicos. Se postula entonces la utilidad de abordar a la población actual como vía de acceso al conocimiento del origen de los linajes mitocondriales nativos y su distribución espacial.

El título nobiliario de Marqués del Valle del Toxo, conocido comúnmente como Marqués de Yavi, era el más importante en el territorio del virreinato del Río de la Plata y se extendía por toda la Puna argentina y diversos municipios de Bolivia. Hubo cuatro marqueses desde su creación en 1708 por la Real Cédula emitida por Felipe V, rey de España, hasta su disolución en 1820 luego del fallecimiento del cuarto marqués Juan José Feliciano Fernández Campero. La abundancia de referencias históricas sobre el Marquesado de Yavi, el reciente interés político por recuperar la figura histórica del último Marqués sumado al encuentro social de sus descendientes ofreció la extraordinaria posibilidad de realizar una reconstrucción detallada de la genealogía de la familia Campero y relacionarla con el estudio molecular de sus descendientes. Se analizaron muestras de 30 individuos Campero a través de 6 microsatélites del cromosoma Y (DYS:19, 389a y b, 390,392,393) Se encontraron 8 linajes paternos bien definidos, 16 muestras comparten un linaje único, el segundo linaje congrega a 5 individuos, el tercero y cuarto linaje cuentan con 2 individuos cada uno y en 5 muestras se encontraron linajes individuales no relacionados con los anteriores. De estos resultados se interpreta que en la Genealogía Campero coexisten linajes diferentes, de los cuales uno de ellos, el mayoritario, probablemente sea el linaje fundador de esta genealogía. Se discuten estos resultados a la luz de la información genealógica e histórica.

De acuerdo a la teoría isonímica, se espera que dentro de una población los individuos con el mismo apellido tengan ancestros comunes. El objetivo de este trabajo fue evaluar la concordancia entre apellidos y haplotipos holándricos en individuos del NOA. Se analizaron muestras de 92 varones seleccionados al azar provenientes de Salta, Tucumán y Catamarca, abarcando 34 apellidos distintos. Los haplotipos del cromosoma Y se establecieron a través de 7 microsatélites (DYS 19, 389 a y b, 390, 391, 392 y 393). Se identificaron 87 haplotipos, 83 (95,4%) fueron únicos y 4 (4,6%) compartidos. Tres individuos compartieron el mismo apellido y haplotipo y este fue de origen nativo americano. Seis individuos se agruparon de a dos en tres haplotipos, con apellidos distintos (trans-apellidos), uno de ellos fue de origen nativo americano y los otros dos europeo. Aún cuando las muestras fueron seleccionadas al azar, el 3,3% de los individuos compartieron apellido y haplotipo del cromosoma Y, denotando una concordancia entre los dos sistemas. El alto porcentaje de haplotipos únicos revela la magnitud de la migración pasada y reciente en la región. Estos resultados demuestran la importancia de los procesos de disrupción étnica y transmisión irregular de los apellidos, que influyen sobre la compleja antroponimia de esta región.

En comunidades pequeñas o aisladas es posible identificar relaciones de parentesco paterno a través de marcadores moleculares del cromosoma Y. En este trabajo se analiza la correlación entre apellidos e identidad molecular de los cromosomas Y en 14 muestras provenientes de individuos de una genealogía extensamente documentada de La Rioja (Aicuña), 59 de una población aislada y pequeña de Catamarca (Azampay) y 92 provenientes de 3 capitales del NOA (Salta, Catamarca y Tucumán). Se utilizaron 11 marcadores SNP y 7 microsatélites (DYS19, 389 a y b, 390, 391, 392 y 393) del cromosoma Y para caracterizar haplogrupos y haplotipos, que otorgan alta definición para identificar linajes emparentados. La concordancia entre apellidos y haplotipos en la genealogía fue del 60%, en la población aislada fue del 27% y en las 3 ciudades del NOA tomadas en conjunto fue el 3.3%. Los tres grupos se diferenciaron en frecuencia y número de apellidos y de haplotipos. La diversidad de haplotipos fue mayor al 76% en las tres poblaciones. La diversidad de apellidos fue 0.36 en la genealogía, 0.87 en la población aislada y 0.97 en el NOA. Estos resultados muestran que el aumento del tamaño poblacional y fenómenos migratorios disminuyen las posibilidades de encontrar concordancias entre apellidos y linajes paternos. Posiblemente mecanismos como el bautismo y la herencia materna del apellido también contribuyan a esta discordancia.

The settlement of the Americas has been the focus of incessant debate for more than 100 years, and open questions regarding the timing and spatial patterns of colonization still remain today. Phylogenetic studies with complete human Y chromosome sequences are used as a highly informative tool to investigate the history of human populations in a given time frame. To study the phylogenetic relationships of Native American lineages and infer the settlement history of the Americas, we analyzed Y chromosome Q Haplogroup, which is a Pan-American haplogroup and represents practically all Native American lineages in Mesoamerica and South America. We built a phylogenetic tree for Q Haplogroup based on 102 whole Y chromosome sequences, of which 13 new Argentine sequences were provided by our group. Moreover, 1,072 new single nucleotide polymorphisms (SNPs) that contribute to its resolution and diversity were identified. Q-M848 is known to be the most frequent autochthonous sub-haplogroup of the Americas. The present is the first genomic study of Q Haplogroup in which current knowledge on Q-M848 sub-lineages is contrasted with the historical, archaeological and linguistic data available. The divergence times, spatial structure and the SNPs found here as novel for Q-Z780, a less frequent sub-haplogroup autochthonous of the Americas, provide genetic support for a South American settlement before 18,000 years ago. We analyzed how environmental events that occurred during the Younger Dryas period may have affected Native American lineages, and found that this event may have caused a substantial loss of lineages. This could explain the current low frequency of Q-Z780 (also perhaps of Q-F4674, a third possible sub-haplogroup autochthonous of the Americas). These environmental events could have acted as a driving force for expansion and diversification of the Q-M848 sub-lineages, which show a spatial structure that developed during the Younger Dryas period. [ABSTRACT FROM AUTHOR]

We analyzed 21 paragroup [Q.sup.*] 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 Qla3a haplotypes. All [Q.sup.*] chromosomes from our series and five samples from North American [Q.sup.*] presented the derivate state for M346, that is present upstream to M3, and determined [Q1a3.sup.*] paragroup. We found a restrictive geographic distribution and low frequency of [Q1a3.sup.*] 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.sup.*] and Qla3a (0.478 and 0.501, respectively). The analysis of previous reports from other research groups and this study shows the highest frequencies of [Q.sup.*] 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.sup.*] paragoup described in previous reports is similar to that of [Q1a3.sup.*] paragroup though our results support this possibility. KEY WORDS Y chromosome; SNP; microsatellites; south America DOI 10.1002/ajpa.21133

Similarly to other populations across the Americas, Argentinean populations trace back their genetic ancestry into African, European and Native American ancestors, reflecting a complex demographic history with multiple migration and admixture events in pre- and post-colonial times. However, little is known about the sub-continental origins of these three main ancestries. We present new high-throughput genotyping data for 87 admixed individuals across Argentina. This data was combined to previously published data for admixed individuals in the region and then compared to different reference panels specifically built to perform population structure analyses at a sub-continental level. Concerning the Native American ancestry, we could identify four Native American components segregating in modern Argentinean populations. Three of them are also found in modern South American populations and are specifically represented in Central Andes, Central Chile/Patagonia, and Subtropical and Tropical Forests geographic areas. The fourth component might be specific to the Central Western region of Argentina, and it is not well represented in any genomic data from the literature. As for the European and African ancestries, we confirmed previous results about origins from Southern Europe, Western and Central Western Africa, and we provide evidences for the presence of Northern European and Eastern African ancestries. [ABSTRACT FROM AUTHOR]

Copyright of Revista Argentina de Antropología Biológica is the property of Revista Argentina de Antropologia Biologica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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. [ABSTRACT FROM AUTHOR]

Copyright of Intersecciones en Antropología is the property of Universidad Nacional del Centro de la Provincia de Buenos Aires, Facultad de Ciencias Sociales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Reduced representation sequencing methods such as genotyping-by-sequencing (GBS) enable low-cost measurement of genetic variation without the need for a reference genome assembly. These methods are widely used in genetic mapping and population genetics studies, especially with non-model organisms. Variant calling error rates, however, are higher in GBS than in standard sequencing, in particular due to restriction site polymorphisms, and few computational tools exist that specifically model and correct these errors. We developed a statistical method to remove errors caused by restriction site polymorphisms, implemented in the software package GBStools. We evaluated it in several simulated data sets, varying in number of samples, mean coverage and population mutation rate, and in two empirical human data sets (N = 8 and N = 63 samples). In our simulations, GBStools improved genotype accuracy more than commonly used filters such as Hardy-Weinberg equilibrium p-values. GBStools is most effective at removing genotype errors in data sets over 100 samples when coverage is 40X or higher, and the improvement is most pronounced in species with high genomic diversity. We also demonstrate the utility of GBS and GBStools for human population genetic inference in Argentine populations and reveal widely varying individual ancestry proportions and an excess of singletons, consistent with recent population growth. [ABSTRACT FROM AUTHOR]

There is great scientific and popular interest in understanding the genetic history of populations in the Americas. We wish to understand when different regions of the continent were inhabited, where settlers came from, and how current inhabitants relate genetically to earlier populations. Recent studies unraveled parts of the genetic history of the continent using genotyping arrays and uniparental markers. The 1000 Genomes Project provides a unique opportunity for improving our understanding of population genetic history by providing over a hundred sequenced low coverage genomes and exomes from Colombian (CLM), Mexican-American (MXL), and Puerto Rican (PUR) populations. Here, we explore the genomic contributions of African, European, and especially Native American ancestry to these populations. Estimated Native American ancestry is in MXL, in CLM, and in PUR. Native American ancestry in PUR is most closely related to populations surrounding the Orinoco River basin, confirming the Southern America ancestry of the Taíno people of the Caribbean. We present new methods to estimate the allele frequencies in the Native American fraction of the populations, and model their distribution using a demographic model for three ancestral Native American populations. These ancestral populations likely split in close succession: the most likely scenario, based on a peopling of the Americas thousand years ago (kya), supports that the MXL Ancestors split kya, with a subsequent split of the ancestors to CLM and PUR kya. The model also features effective populations of in Mexico, in Colombia, and in Puerto Rico. Modeling Identity-by-descent (IBD) and ancestry tract length, we show that post-contact populations also differ markedly in their effective sizes and migration patterns, with Puerto Rico showing the smallest effective size and the earlier migration from Europe. Finally, we compare IBD and ancestry assignments to find evidence for relatedness among European founders to the three populations. [ABSTRACT FROM AUTHOR]

The development of online software designed for genetic studies has been exponentially growing, providing numerous benefits to the scientific community. However, they should be used with care, since some require adjustments. The efficiency of two programs for haplogroup prediction was tested with 119 samples of known haplotypes and haplogroups from Argentine populations. Quantitative estimates of the predictive quality of both software systems were computed with the uncertainty coefficient; and sensitivity, specificity, positive, and negative likelihood ratios were also calculated to assert the reliability of both programs, showing high probabilities of assigning an incorrect haplogroup. [ABSTRACT FROM AUTHOR]