Archaeological records provide abundant evidence of an active interaction between the peoples of what are now northwestern Argentina, southern Peru, western Bolivia, and northern Chile. Likewise, DNA studies in prehispanic individuals provide direct information on the biological history and dynamics of human groups, offering new perspectives to the understanding of dispersion and variability of Native Americans. The aim of this paper is to analyze the maternal lineages present in individuals from the late period of the Puna region (1000-1450 AD) by comparing their genetic composition with other pre-Columbian groups from the south-central Andean region, described by other authors. From mtDNA HVR-I sequences, inter- and intra-sample genetic variability was determined, as well as the genetic distance between the various groups used. In the samples analyzed, A2 was found to be the most common lineage,, showing high haplotype variability, and contrasting with other studies in the Andean region, which described the prevalence of B2 lineages. At a local level, the genetic distances between the Puna population and other groups from presentday northwestern Argentina were not significant, except for Pampa Grande, which is more geographically and spatially remote. At a regional level, the differences are significant in relation to the majority of Peru ancient samples, but do not show a particular spatial or time pattern.

Las evidencias arqueológicas proporcionan abundantes pruebas de una activa interacción entre las poblaciones de lo que actualmente es el noroeste de Argentina, el sur de Perú, el oeste de Bolivia y el norte de Chile. Los estudios de ADN en individuos prehispánicos, a su vez, proveen información directa sobre la historia biológica y la dinámica de los grupos humanos, y aportan nuevas perspectivas a la comprensión de la dispersión y variabilidad de los amerindios. El objetivo de este trabajo es analizar los linajes maternos presentes en individuos del período tardío de la Puna jujeña (1000-1450 AD) mediante la comparación de su composición genética con las de otros grupos precolombinos de la región centro-sur andina descriptos por otros autores. A partir de las secuencias de HVR I del ADN mitocondrial se determinó la variabilidad genética inter e intramuestral, además de la distancia genética entre los diversos grupos utilizados. En las muestras analizadas el linaje más frecuente fue el A2, el cual mostró una gran variabilidad haplotípica. Esto lo diferencia de otros estudios de la región andina en los que se ha descripto el predominio de los linajes B2. A una escala local, las distancias genéticas entre la Puna jujeña y otros grupos poblacionales del actual noroeste argentino no fueron significativas, a excepción de Pampa Grande, de la que se encuentra más alejada geográfica y espacialmente. A nivel regional, las diferencias son significativas con respecto a la mayoría de las muestras antiguas de Perú, aunque no evidencian un patrón espacial o temporal determinado.

Pampa Grande (PG) and Los Amarillos (LA) are two archaeological sites in northwestern Argentina for which the sex of the individuals was determined and maternal and paternal lineages were analyzed by means of ancient DNA studies. PG (Salta province) is attributed to the Formative Period and LA (Quebrada de Humahuaca, Jujuy) would have been massively occupied in the Regional Developments Period. The aim of this work is to compare both sites in terms of their genetic diversity by analyzing mitochondrial haplogroups and haplotypes studied in both populations. In the analysis, 19 individuals from PG and 18 from LA were included. Studying mitochondrial lineages, we observed the absence of haplogroups B2 in LA and C1 in PG; while only A2 and D1, usually found in Native American populations, were shared by the sites. All genetic variation analyses considering the Hypervariable Region I indicate a significant genetic differentiation between the sites, with PG having the highest variability. Micro-evolutionary mechanisms associated to geographical and temporal distances may have shaped the intra and interpopulation diversity of these two Pre-hispanic sites from northwestern Argentina.

Pampa Grande (PG) y Los Amarillos (LA) son dos sitios arqueológicos del noroeste argentino (NOA), en los que el estudio de ADN antiguo ha permitido determinar el sexo de los individuos y analizar los linajes paternos y maternos presentes. PG (Salta) se ha adjudicado al Periodo Formativo y LA ubicado en la Quebrada de Humahuaca (Jujuy), habría tenido una masiva ocupación hacia el Período de Desarrollos Regionales. El objetivo de este trabajo es comparar ambos sitios en cuanto a su diversidad genética analizando los haplogrupos y haplotipos de ADN mitocondrial estudiados en dichas poblaciones. Se incluyeron en el análisis 19 individuos de PG y 18 de LA. Al analizar los linajes mitocondriales, se observa que los únicos haplogrupos compartidos entre ambas poblaciones son los haplogrupos A2 y D1, encontrados habitualmente en poblaciones amerindias. Por otro lado, no se detectó el haplogrupo B2 en LA, ni el C1 en PG. Los análisis de variación génica realizados a partir de la Región Hipervariable I indican una diferenciación genética significativa entre ambos sitios, siendo PG el más variable. Mecanismos microevolutivos asociados a la distancia geográfica y temporal parecen haber moldeado la diversidad intra e interpoblacional entre estos dos sitios prehispánicos del NOA.

In the frame of the study of the genetic composition of Argentinean cosmopolitan populations, a population sample of the city of Puerto Madryn (PM) was analyzed in order to evaluate its biological diversity using biparental and uniparental markers and compare the results with those previously obtained by our research team in six cosmopolitan populations from different regions of Argentina. The emphasis was laid on the populations of the Patagonia region. Biological samples were taken with informed consent from 82 unrelated blood donors, who attended the Regional Blood Bank and Hospital of the town and also underwent a genealogical survey. From the data obtained by analyzing autosomal markers, a European contribution of 67.2%, an Amerindian one of 29.4%, and an African one of 3.4% were estimated. The 59.9% and 8.7% of the maternal and paternal lineages, respectively, were ascribed to Native American origins, revealing an unequal gender indigenous contribution. The European contribution was mainly represented by H Hg (19.5%), and only two sub-Saharan lineages were detected. In PM, migrations from the center of the country have had a strong impact, as reflected in the greater contribution of European markers, with respect to the two samples previously studied in the province of Chubut (Comodoro Rivadavia and Esquel). These differences warn us of the necessity of accounting for the regional particularities when analyzing the genetic constitution of populations.

En el marco del estudio de la composición genética de las poblaciones cosmopolitas de Argentina, se analizó una muestra poblacional de la localidad de Puerto Madryn (PM) con la finalidad de evaluar su diversidad biológica mediante la utilización de marcadores biparentales y uniparentales y comparar los resultados con los obtenidos previamente por nuestro equipo de investigación en seis poblaciones cosmopolitas de distintas regiones de la Argentina, aunque poniendo el énfasis en las correspondientes a la Región Patagónica. Las muestras biológicas fueron tomadas con consentimiento informado a 82 dadores de sangre no emparentados que concurrieron al Banco de Sangre y al Hospital Subzonal de dicha localidad, a quienes también se les realizó una encuesta genealógica. A partir de los datos proporcionados por los marcadores autosómicos, se registró una contribución europea de 67.2%, amerindia de 29.4% y africana de 3.4%. A un origen amerindio fueron adscriptos el 59.9% y 8.7% de los linajes maternos y paternos, respectivamente, revelando un desigual aporte autóctono por género. El aporte europeo se vio representado principalmente por el Hg H (19.5%) y se detectaron sólo dos linajes subsaharianos. En PM las migraciones desde el centro del país han generado un fuerte impacto, reflejado en la mayor contribución de marcadores europeos respecto de dos muestras estudiadas previamente en Chubut (Comodoro Rivadavia y Esquel). Estas diferencias al interior de una misma provincia nos advierten que no puede abordarse el análisis de la constitución genética de las poblaciones sin dar cuenta de las particularidades regionales.

Faz já varias décadas que à antropologia biológica tem começado a usar marcadores moleculares em estudos de população. Ao começo da década de 1990, se desenvolveram técnicas diferentes em biologia molecular que permitiram obter e tipificar o ADN conservado em restos diferentes vindos de museus e sítios arqueológicos. Os estudos de ADN antigo relacionados a problemáticas arqueológicas são hoje um campo de estudo chamado de Arqueogenética. Se apresentam neste trabalho algumas das aplicações do ADN antigo. Também se discutem as vantagens e limitações desses estudos e a sua relação com assuntos éticos e legais.

For several decades, biological anthropology has employed different molecular markers in population research. Since 1990 different techniques in molecular biology have been developed allowing preserved DNA extraction and its typification in different samples from museums and archaeological sites. Ancient DNA studies related to archaeological issues are now included in the field of Archaeogenetics. In this work we present some of ancient DNA applications in archaeology. We also discuss advantages and limitations for this kind of research and its relationship with ethic and legal norms.

Desde hace varias décadas, la antropología biológica comenzó a utilizar marcadores moleculares en estudios poblacionales. A partir de la década de 1990 se desarrollaron diferentes técnicas en biología molecular que permitieron extraer y tipificar ADN conservado en diferentes restos provenientes de museos y sitios arqueológicos. Los estudios de ADN antiguo relacionados con problemáticas arqueológicas conforman hoy un campo de estudio denominado Arqueogenética. Se presentan en este trabajo algunas de las aplicaciones del ADN antiguo. Se discuten las ventajas y limitaciones de estos estudios y su relación con temas éticos y legales.

The major histocompatibility complex (MHC) is one of the biological systems of major polymorphisms. The study of HLA class II variability has allowed the identification of several alleles that are characteristic to Amerindian populations, and it is an excellent tool to define the relations and biological affinities among them. In this work, we analyzed the allelic distribution of the HLA-DRB1 class II locus in four Amerindian populations: Mapuche (n = 34) and Tehuelche (n = 23) from the Patagonian region of Argentina, and Wichi SV (n = 24) and Lengua (n = 17) from the Argentinean and Paraguayan Chaco regions, respectively. In all of these groups, relatively high frequencies of Amerindian HLA-DRB1 alleles were observed (DRB1*0403, DRB1*0407, DRB1*0411, DRB1*0417, DRB1*0802, DRB1*0901, DRB1*1402, DRB1*1406 and DRB1*1602). However, we also detected the presence of non-Amerindian variants in Mapuche (35%) and Tehuelche (22%). We compared our data with those obtained in six indigenous groups of the Argentinean Chaco region and in a sample from Buenos Aires City. The genetic distance dendrogram showed a clear-cut division between the Patagonian and Chaco populations, which formed two different clusters. In spite of their linguistic differences, it can be inferred that the biological affinities observed are in concordance with the geographic distributions and interethnic relations established among the groups studied.

The aim of this study is to estimate the gene admixture in the population of Buenos Aires City from samples of blood donors, which come from a public health centre (Hospital de Clínicas). These studies were performed on 218 unrelated people, who donated blood during the year 2002. Eight erythrocyte genetic systems and GM/KM allotypes were analysed. A survey to obtain information about place of birth, present residence and genealogical data of the donors was performed. The gene frequencies were determined using a method of maximum likelihood. The genetic admixture was calculated through the ADMIX program (trihibride). The Amerindian and African contributions were 15.8% and 4.3% respectively. These data were compared with those obtained in a previous study performed in a private centre (Hospital Italiano de Buenos Aires) and significant differences were observed, except in the KM system. The results obtained are in concordance with the demographic and historic information of Buenos Aires City.

Este estudio tiene como objetivo estimar la mezcla génica en la población de la Ciudad de Buenos Aires, a partir de muestras de dadores de sangre provenientes de un centro público de salud (Hospital de Clínicas). Los estudios se realizaron sobre 218 personas no emparentadas que donaron su sangre durante el año 2002. Se analizaron 8 sistemas genéticos eritrocitarios y los alotipos GM/KM. Se realizó una encuesta con la finalidad de obtener información sobre lugar de nacimiento, residencia actual y datos genealógicos de los dadores. Las frecuencias génicas se determinaron empleando métodos de máxima verosimilitud. Para calcular la mezcla génica se aplicó el programa ADMIX (trihíbrido). Se registró un 15.8% de aporte indígena (AI) y 4.3% de africano (AA). Estos datos se compararon con un estudio previo realizado en un centro privado (Hospital Italiano de Buenos Aires), no observándose diferencias significativas salvo en el sistema Km. Los resultados obtenidos se corresponden con la información histórica y demográfica de la ciudad de Buenos Aires.

The allelic variability of four dinucleotide microsatellites located in the HLA region (MOGc, D6S265, MIB, and TNFa) was analyzed in 67 individuals representing three Amerindian populations of the Argentine Gran Chaco: Toba, Wichi and Chorote. Genomic DNA was prepared from peripheral blood and DNA was extracted using the standard phenol-chloroform procedure. Alleles were identified by PCR, using an end-labelled reverse oligonucleotide primer (fluorescent 6 - Fam labeling). Despite the low number of samples studied, a high level of gene diversity was observed in each population and for each locus. Moreover, the mean number of alleles was 7.7, 5.3, 10.0, and 7.0 at loci MOGc, D6S265, MIB and TNFa, respectively. Differentiation tests between pairs of populations showed a clear differentiation between the Wichi and the other two groups. However, the proportion of the total genetic variability that is due to differences among populations, estimated by the Gst' index, was relatively low (6%). Almost all the genetic variation occurred at the intra-population level (96%). The high intra-populational genetic variation suggests the existence of an intensive gene flow among the Gran Chaco tribes. Historical information seems to confirm this result.

Dados relativos a fertilidade, mortalidade e migração de quatro comunidades de índios Mapuche localizadas em uma área linear na direção nordeste-sudoeste com 215 km de extensão na Província de Rio Negro, Argentina, foram associados com a informação genética fornecida por nove sistemas de grupos sangüíneos e os haplogrupos do DNA mitocondrial. Ambos os tipos de informação apontam claramente para uma dicotomia, as quatro populações sendo divididas em grupos de duas. O principal fator responsável por esta separação é provavelmente graus diferentes de mistura com não-índios. A variabilidade genética total foi muito similar em todos os grupos, aquela entre populações sendo de apenas 10% deste valor. Foi confirmada a baixa prevalência do antígeno Diego(a) entre os Mapuche. O fato de que heterogeneidade genética significativa e conjuntos populacionais diversos foram observados em uma região territorial tão pequena demonstra a sensibilidade dos enfoques demográfico e genético no esclarecimento da história humana.

Fertility, mortality and migration data from four Mapuche Indian communities located along a 215-km NE-SW linear area in the Province of Río Negro, Argentina, were collated with genetic information furnished by nine blood group systems and by mtDNA haplogroups. The demographic and genetic data indicated a clear dichotomy, which split the four populations into two groups of two. Differing degrees of non-Indian exchanges was probably the main determining factor for this separation. Total genetic variability was very similar in all groups, and the interpopulational variability accounted for only 10% of the total variability. A low prevalence of the Diego(a) antigen among the Mapuche was confirmed. The fact that significant genetic heterogeneity and population clusters were found in such a small territorial region attests to the sensitivity of demographic and genetic approaches in unraveling human history.

Haplótipos derivados de cinco sítios de restrição polimórficos presentes no agrupamento da globina beta foram investigados em 86 cromossomos da população mapuche da Argentina. Esses resultados foram analisados em conjunto com os previamente obtidos para dez tribos indígenas brasileiras. Oito haplótipos foram identificados, dos quais os mais freqüentes foram o 2 (57%) e o 6 (27%). A presença do haplótipo 3 em 2% dos cromossomos dos Mapuches é uma evidência de mistura com indivíduos de ancestralidade africana. Devido ao alto número de haplótipos, a heterozigosidade medida pelo índice Gini-Simpson é mais alta nos Mapuches do que nos índios brasileiros. A distribuição haplotípica nos Mapuches é também significativamente diferente da observada nas tribos brasileiras. Essa heterogeneidade poderia ser parcialmente explicada pela mistura com populações não-indígenas.

Haplotypes derived from five polymorphic restriction sites in the beta-globin gene cluster were investigated in 86 chromosomes from the Argentinian Mapuche. These results were integrated with those previously obtained for ten Brazilian Indian tribes. Eight haplotypes were identified, the most frequent being 2 (57%) and 6 (27%). The presence of haplotype 3 in 2% of the Mapuche chromosomes is probably an evidence of admixture with individuals of African ancestry. Due to the high number of haplotypes observed, heterozygosity as measured by the Gini-Simpson index was higher in the Mapuche than in Brazilian Indians. The haplotypic distribution in the Mapuche was also significantly different from those of all Brazilian tribes investigated. This heterogeneity could be at least partially explained by admixture with non-Indian populations.