RESUMO
OBJECTIVE: This study aims to contribute to the recovery of Indigenous evolutionary history in the Southern Pampas region of Argentina through an analysis of ancient complete mitochondrial genomes. MATERIALS AND METHODS: We generated DNA data for nine complete mitogenomes from the Southern Pampas, dated to between 2531 and 723 cal BP. In combination with previously published ancient mitogenomes from the region and from throughout South America, we documented instances of extra-regional lineage-sharing, and estimated coalescent ages for local lineages using a Bayesian method with tip calibrations in a phylogenetic analysis. RESULTS: We identified a novel mitochondrial haplogroup, B2b16, and two recently defined haplogroups, A2ay and B2ak1, as well as three local haplotypes within founder haplogroups C1b and C1d. We detected lineage-sharing with ancient and contemporary individuals from Central Argentina, but not with ancient or contemporary samples from North Patagonian or Littoral regions of Argentina, despite archeological evidence of cultural interactions with the latter regions. The estimated coalescent age of these shared lineages is ~10,000 years BP. DISCUSSION: The history of the human populations in the Southern Pampas is temporally deep, exhibiting long-term continuity of mitogenome lineages. Additionally, the identification of highly localized mtDNA clades accords with a model of relatively rapid initial colonization of South America by Indigenous communities, followed by more local patterns of limited gene flow and genetic drift in various South American regions, including the Pampas.
Assuntos
Genoma Mitocondrial , Humanos , Argentina , Filogenia , Genoma Mitocondrial/genética , Teorema de Bayes , América do SulRESUMO
OBJECTIVES: The study of the ancient populations of Central Argentina has a crucial importance for our understanding of the evolutionary processes in the Southern Cone of South America, given its geographic position as a crossroads. Therefore, the aim of this study is to evaluate the temporal and geographical patterns of genetic variation among the groups that inhabited the current territory of Córdoba Province during the Middle and Late Holocene. METHODS: We analyzed the mitochondrial haplogroups of 74 individuals and 46 Hypervariable Region I (HVR-I) sequences, both novel and previously reported, from archeological populations of the eastern Plains and western Sierras regions of the province of Córdoba. The HVR-I sequences were also compared with other ancient groups from Argentina and with present-day populations from Central Argentina by pairwise distance analysis and identification of shared haplotypes. RESULTS: Significant differences in haplogroup and haplotype distributions between the two geographical regions were found. Sierras showed genetic affinities with certain ancient populations of Northwestern Argentina, while Plains resembled its neighbors from Santiago del Estero Province and the Pampas region. We did not observe genetic differences among the pre 1200 and post 1200 yBP temporal subsets of individuals defined by the emergence of horticulture, considering both geographical samples jointly. CONCLUSIONS: The observed patterns of geographical heterogeneity could indicate the existence of biologically distinct populations inhabiting the mountainous region and the eastern plains of Córdoba Province in pre-Hispanic times. Maternal lineages analyses support a scenario of local evolution with great temporal depth in Central Argentina, with continuity until the present.
Assuntos
DNA Antigo , DNA Mitocondrial , Genética Populacional , Indígenas Sul-Americanos , Argentina , DNA Mitocondrial/genética , Variação Genética , Haplótipos , Humanos , Indígenas Sul-Americanos/genéticaRESUMO
The inverted triangle shape of South America places Argentina territory as a geographical crossroads between the two principal peopling streams that followed either the Pacific or the Atlantic coasts, which could have then merged in Central Argentina (CA). Although the genetic diversity from this region is therefore crucial to decipher past population movements in South America, its characterization has been overlooked so far. We report 92 modern and 22 ancient mitogenomes spanning a temporal range of 5000 years, which were compared with a large set of previously reported data. Leveraging this dataset representative of the mitochondrial diversity of the subcontinent, we investigate the maternal history of CA populations within a wider geographical context. We describe a large number of novel clades within the mitochondrial DNA tree, thus providing new phylogenetic interpretations for South America. We also identify several local clades of great temporal depth with continuity until the present time, which stem directly from the founder haplotypes, suggesting that they originated in the region and expanded from there. Moreover, the presence of lineages characteristic of other South American regions reveals the existence of gene flow to CA. Finally, we report some lineages with discontinuous distribution across the Americas, which suggest the persistence of relic lineages likely linked to the first population arrivals. The present study represents to date the most exhaustive attempt to elaborate a Native American genetic map from modern and ancient complete mitochondrial genomes in Argentina and provides relevant information about the general process of settlement in South America.
Assuntos
DNA Mitocondrial/genética , Variação Genética , Genética Populacional , Genoma Mitocondrial/genética , Migração Humana , Argentina , DNA Antigo/análise , DNA Mitocondrial/análise , DNA Mitocondrial/classificação , Geografia , Haplótipos , Humanos , Filogenia , Análise de Sequência de DNA , América do Sul , Fatores de TempoRESUMO
Human skeletal remains of an adult male (20-24 years old) and a juvenile (4-8 years old), dated to 750 ± 85 14C years BP, were found on the southern margin of Mar Chiquita Lagoon (Córdoba, Argentina). Both individuals show signs of being victims of interpersonal violence, with arrowheads associated with the remains and perimortem lesions on the juvenile, as well as an unusual form of burial, with the juvenile partially overlapped with the adult. The aim of this work is to study a possible kin relationship between these two individuals through ancient DNA analysis. Biological kinship was evaluated by autosomal and Y-chromosome STR (short tandem repeat) typing, PCR-APLP for SNP determination and hypervariable region I sequencing of the mitochondrial DNA. Genetic analyses indicated that these individuals shared the same Y-chromosomal haplotype but different mitochondrial lineages. The likelihood ratio based on autosomal loci indicates that the genetic profiles of the human remains would be more likely to be that indicating a father-son bond. The paleogenetic approach combined with forensic genetic methods applied to this study allowed us to confirm a hypothesis that originated in bioarchaeological evidence. This study constitutes a unique case in Argentina of kinship determination based on DNA profiles of human remains in an archaeological context of interpersonal violence. It is important to highlight the contribution made by these studies to address topics usually hidden in bioarchaeological studies, such as community organization, cultural customs and mortuary practices.
Assuntos
Cromossomos Humanos Y , Impressões Digitais de DNA , Repetições de Microssatélites , Linhagem , Abuso Físico , Argentina , Sepultamento , Criança , Pré-Escolar , DNA Mitocondrial/genética , Eletroforese Capilar , Antropologia Forense , Genética Forense , Haplótipos , História Antiga , Humanos , Masculino , Reação em Cadeia da Polimerase , Polimorfismo de Nucleotídeo Único , Fraturas das Costelas , Fratura do Crânio com Afundamento , Adulto JovemRESUMO
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.
Assuntos
População Negra/genética , Genoma Humano , Indígenas Sul-Americanos/genética , Casamento , Linhagem , População Branca/genética , Argentina , População Negra/etnologia , Colonialismo , DNA/genética , Escravização , Marcadores Genéticos , Variação Genética , Genética Populacional , Genótipo , Migração Humana , Humanos , Indígenas Sul-Americanos/etnologia , Modelos Genéticos , População Branca/etnologiaRESUMO
We present new data and analysis on the genetic variation of contemporary inhabitants of central Argentina, including a total of 812 unrelated individuals from 20 populations. Our goal was to bring new elements for understanding micro-evolutionary and historical processes that generated the genetic diversity of the region, using molecular markers of uniparental inheritance (mitochondrial DNA and Y chromosome). Almost 76% of the individuals show mitochondrial lineages of American origin. The Native American haplogroups predominate in all surveyed localities, except in one. The larger presence of Eurasian maternal lineages were observed in the plains (Pampas) of the southeast, whereas the African lineages are more frequent in northern Córdoba. On the other hand, the analysis of 258 male samples reveals that 92% of them present Eurasian paternal lineages, 7% carry Native American haplogroups, and only 1% of the males show African lineages. The maternal lineages have high genetic diversity homogeneously distributed throughout central Argentina, probably as result of a recent common origin and sustained gene flow. Migratory events that occurred in colonial and recent times should have contributed to hiding any traces of differentiation that might have existed in the past. The analysis of paternal lineages showed also homogeneous distribution of the variation together with a drastic reduction of the native male population.
Assuntos
Cromossomos Humanos Y , DNA Mitocondrial , Variação Genética , Genética Populacional , Alelos , Argentina , Evolução Molecular , Feminino , Frequência do Gene , Geografia , Haplótipos , Humanos , Indígenas Sul-Americanos/genética , Masculino , Herança Materna , Herança Paterna , Filogenia , Análise EspacialRESUMO
OBJECTIVES: To determine genetic differences between agriculturalist and hunter-gatherer southern Native American populations for selected metabolism-related markers and to test whether Neel's thrifty genotype hypothesis (TGH) could explain the genetic patterns observed in these populations. MATERIALS AND METHODS: 375 Native South American individuals from 17 populations were genotyped using six markers (APOE rs429358 and rs7412; APOA2 rs5082; CD36 rs3211883; TCF7L2 rs11196205; and IGF2BP2 rs11705701). Additionally, APOE genotypes from 39 individuals were obtained from the literature. AMOVA, main effects, and gene-gene interaction tests were performed. RESULTS: We observed differences in allele distribution patterns between agriculturalists and hunter-gatherers for some markers. For instance, between-groups component of genetic variance (FCT ) for APOE rs429358 showed strong differences in allelic distributions between hunter-gatherers and agriculturalists (p = 0.00196). Gene-gene interaction analysis indicated that the APOE E4/CD36 TT and APOE E4/IGF2BP2 A carrier combinations occur at a higher frequency in hunter-gatherers, but this combination is not replicated in archaic (Neanderthal and Denisovan) and ancient (Anzick, Saqqaq, Ust-Ishim, Mal'ta) hunter-gatherer individuals. DISCUSSION: A complex scenario explains the observed frequencies of the tested markers in hunter-gatherers. Different factors, such as pleotropic alleles, rainforest selective pressures, and population dynamics, may be collectively shaping the observed genetic patterns. We conclude that although TGH seems a plausible hypothesis to explain part of the data, other factors may be important in our tested populations.
Assuntos
Agricultura/história , Indígenas Sul-Americanos/genética , Indígenas Sul-Americanos/história , Polimorfismo de Nucleotídeo Único/genética , Antropologia Física , Apolipoproteínas E/genética , Antígenos CD36/genética , Genótipo , História Antiga , Humanos , Proteínas de Ligação a RNA/genéticaRESUMO
OBJECTIVES: The aim of this study was to investigate the distribution of molecular polymorphisms of the ABO gene in four population samples from the province of Córdoba, in Central Argentina, and to compare them with other worldwide populations. METHODS: A total of 110 buccal swab samples from autochthonous individuals of Córdoba were typified. Molecular characterization of the allelic variants was performed by the analysis of exons 6 and 7 of the ABO gene using PCR-RFLP analysis. Additionally, the Native American AIM O1v542 was characterized by direct sequencing. RESULTS: The four Córdoba populations did not show significant geographic structure, although the frequency of the O1v542 haplotype, detected in all the populations studied, ranged from 0.019 to 0.222. The principal component analysis based on O allele distribution showed that the populations from Córdoba clustered close to the admixed populations of Santiago and Mexico City, and at intermediate distances between European and Native American populations, while being distant from the African population. CONCLUSIONS: The results demonstrate that the analysis of the ABO system constitutes a useful tool for the study of the genetic structure and evolutionary history of human populations, reflecting accurately the relative contribution of parental continental contribution to the gene pool of admixed populations.
Assuntos
Sistema ABO de Grupos Sanguíneos/genética , Frequência do Gene , Polimorfismo Genético , Argentina , HumanosRESUMO
The possible association between finger dermatoglyphic patterns and altitude and surname distribution was analyzed in a sample of adult males from the province of Jujuy, Argentina. We also investigated the biological affinity of this population with other South American natives and admixed populations. Fingerprints were obtained from 996 healthy men, aged 18-20 years, from the highlands (HL: 2500m, Puna and Quebrada) and lowlands (LL: Valle and Selvas). Surnames were classified into native/autochthonous (A) or foreign (F), resulting in three surname classes: FF, when both paternal and maternal surnames were of foreign origin; FA, when one surname was foreign and the other was native; and AA, when both surnames were native. Frequencies of finger dermatoglyphic patterns - arches (A), radial loops (RL), ulnar loops (UL), and whorls (W) - were determined for each digit in relation to geographic location, altitude, and surname origin, resulting in the following categories: HL-FF, HL-FA, HL-AA, LL-FF, LL-FA, and LL-AA. The statistical analyses showed that UL and RL were more common in individuals of HL origin, whereas W and A were more frequent in the LL males (p<0.05). Significant associations were observed between finger dermatoglyphic patterns and surname origin when geographic altitude was considered. In the HL group, UL was associated with AA and FA; in the LL group, the presence of A was associated with FF and FA. The distribution of dermatoglyphic patterns shows that the population of Jujuy belongs to the Andean gene pool and that it has undergone differential levels of admixture related to altitude.
Assuntos
Altitude , Dermatoglifia , Nomes , Adolescente , Argentina , Análise por Conglomerados , Dermatoglifia/classificação , Humanos , Masculino , Adulto JovemRESUMO
Cândido Godói is a small Brazilian town known for high rates of twin birth. In 2011, a genetic study showed that this localized high rate of twin births could be explained by a genetic founder effect. Here we used isonymic analysis and surname distribution to identify population subgroups within 5316 inhabitants and 665 different surnames. Four clusters were constructed based on different twin rates (P < 0.001; MRPP test). Fisher's α and consanguinity index showed low and high values, respectively, corresponding with observed values in isolated communities with high levels of genetic drift. Values of A and B estimators confirmed population isolation. Three boundaries were identified with Monmonier's maximum difference algorithm (P = 0.007). Inside the isolated sections, surnames of different geographic origins, language, and religion were represented. With an adequate statistical methodology, surname analyses provided a close approximation of historic and socioeconomic background at the moment of colony settlement. In this context, the maintenance of social and cultural practices had strong implications for the population's structure leading to drift processes in this small town, supporting the previous genetic study.