Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
1.
Nature ; 538(7624): 238-242, 2016 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-27654910

RESUMO

High-coverage whole-genome sequence studies have so far focused on a limited number of geographically restricted populations, or been targeted at specific diseases, such as cancer. Nevertheless, the availability of high-resolution genomic data has led to the development of new methodologies for inferring population history and refuelled the debate on the mutation rate in humans. Here we present the Estonian Biocentre Human Genome Diversity Panel (EGDP), a dataset of 483 high-coverage human genomes from 148 populations worldwide, including 379 new genomes from 125 populations, which we group into diversity and selection sets. We analyse this dataset to refine estimates of continent-wide patterns of heterozygosity, long- and short-distance gene flow, archaic admixture, and changes in effective population size through time as well as for signals of positive or balancing selection. We find a genetic signature in present-day Papuans that suggests that at least 2% of their genome originates from an early and largely extinct expansion of anatomically modern humans (AMHs) out of Africa. Together with evidence from the western Asian fossil record, and admixture between AMHs and Neanderthals predating the main Eurasian expansion, our results contribute to the mounting evidence for the presence of AMHs out of Africa earlier than 75,000 years ago.


Assuntos
Genoma Humano/genética , Genômica , Migração Humana/história , Grupos Raciais/genética , África/etnologia , Animais , Ásia , Conjuntos de Dados como Assunto , Estônia , Europa (Continente) , Fósseis , Fluxo Gênico , Genética Populacional , Heterozigoto , História Antiga , Humanos , Havaiano Nativo ou Outro Ilhéu do Pacífico/genética , Homem de Neandertal/genética , Nova Guiné , Dinâmica Populacional
2.
3.
Am J Hum Genet ; 82(1): 236-50, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18179905

RESUMO

Progress in the mapping of population genetic substructure provides a core source of data for the reconstruction of the demographic history of our species and for the discovery of common signals relevant to disease research: These two aspects of enquiry overlap in their empirical data content and are especially informative at continental and subcontinental levels. In the present study of the variation of the Y chromosome pool of ethnic Russians, we show that the patrilineages within the pre-Ivan the Terrible historic borders of Russia have two main distinct sources. One of these antedates the linguistic split between West and East Slavonic-speaking people and is common for the two groups; the other is genetically highlighted by the pre-eminence of haplogroup (hg) N3 and is most parsimoniously explained by extensive assimilation of (or language change in) northeastern indigenous Finno-Ugric tribes. Although hg N3 is common for both East European and Siberian Y chromosomes, other typically Siberian or Mongolian hgs (Q and C) have negligible influence within the studied Russian Y chromosome pool. The distribution of all frequent Y chromosome haplogroups (which account for 95% of the Y chromosomal spectrum in Russians) follows a similar north-south clinal pattern among autosomal markers, apparent from synthetic maps. Multidimensional scaling (MDS) plots comparing intra ethnic and interethnic variation of Y chromosome in Europe show that although well detectable, intraethnic variation signals do not cross interethnic borders, except between Poles, Ukrainians, and central-southern Russians, thereby revealing their overwhelmingly shared patrilineal ancestry.


Assuntos
Povo Asiático/genética , Cromossomos Humanos Y , População Branca/genética , Etnicidade , Genética Populacional , Humanos , Federação Russa
4.
Nat Ecol Evol ; 3(6): 966-976, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31036896

RESUMO

The indigenous populations of inner Eurasia-a huge geographic region covering the central Eurasian steppe and the northern Eurasian taiga and tundra-harbour tremendous diversity in their genes, cultures and languages. In this study, we report novel genome-wide data for 763 individuals from Armenia, Georgia, Kazakhstan, Moldova, Mongolia, Russia, Tajikistan, Ukraine and Uzbekistan. We furthermore report additional damage-reduced genome-wide data of two previously published individuals from the Eneolithic Botai culture in Kazakhstan (~5,400 BP). We find that present-day inner Eurasian populations are structured into three distinct admixture clines stretching between various western and eastern Eurasian ancestries, mirroring geography. The Botai and more recent ancient genomes from Siberia show a decrease in contributions from so-called 'ancient North Eurasian' ancestry over time, which is detectable only in the northern-most 'forest-tundra' cline. The intermediate 'steppe-forest' cline descends from the Late Bronze Age steppe ancestries, while the 'southern steppe' cline further to the south shows a strong West/South Asian influence. Ancient genomes suggest a northward spread of the southern steppe cline in Central Asia during the first millennium BC. Finally, the genetic structure of Caucasus populations highlights a role of the Caucasus Mountains as a barrier to gene flow and suggests a post-Neolithic gene flow into North Caucasus populations from the steppe.


Assuntos
Povo Asiático , Fluxo Gênico , Geografia , Humanos , Federação Russa
5.
Genome Biol ; 19(1): 139, 2018 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-30241495

RESUMO

BACKGROUND: The genetic origins of Uralic speakers from across a vast territory in the temperate zone of North Eurasia have remained elusive. Previous studies have shown contrasting proportions of Eastern and Western Eurasian ancestry in their mitochondrial and Y chromosomal gene pools. While the maternal lineages reflect by and large the geographic background of a given Uralic-speaking population, the frequency of Y chromosomes of Eastern Eurasian origin is distinctively high among European Uralic speakers. The autosomal variation of Uralic speakers, however, has not yet been studied comprehensively. RESULTS: Here, we present a genome-wide analysis of 15 Uralic-speaking populations which cover all main groups of the linguistic family. We show that contemporary Uralic speakers are genetically very similar to their local geographical neighbours. However, when studying relationships among geographically distant populations, we find that most of the Uralic speakers and some of their neighbours share a genetic component of possibly Siberian origin. Additionally, we show that most Uralic speakers share significantly more genomic segments identity-by-descent with each other than with geographically equidistant speakers of other languages. We find that correlated genome-wide genetic and lexical distances among Uralic speakers suggest co-dispersion of genes and languages. Yet, we do not find long-range genetic ties between Estonians and Hungarians with their linguistic sisters that would distinguish them from their non-Uralic-speaking neighbours. CONCLUSIONS: We show that most Uralic speakers share a distinct ancestry component of likely Siberian origin, which suggests that the spread of Uralic languages involved at least some demic component.


Assuntos
Povo Asiático/genética , População Branca/genética , Demografia , Genes , Variação Genética , Genoma Humano , Humanos , Linguística , Dinâmica Populacional
6.
PLoS One ; 10(9): e0135820, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26332464

RESUMO

The Slavic branch of the Balto-Slavic sub-family of Indo-European languages underwent rapid divergence as a result of the spatial expansion of its speakers from Central-East Europe, in early medieval times. This expansion-mainly to East Europe and the northern Balkans-resulted in the incorporation of genetic components from numerous autochthonous populations into the Slavic gene pools. Here, we characterize genetic variation in all extant ethnic groups speaking Balto-Slavic languages by analyzing mitochondrial DNA (n = 6,876), Y-chromosomes (n = 6,079) and genome-wide SNP profiles (n = 296), within the context of other European populations. We also reassess the phylogeny of Slavic languages within the Balto-Slavic branch of Indo-European. We find that genetic distances among Balto-Slavic populations, based on autosomal and Y-chromosomal loci, show a high correlation (0.9) both with each other and with geography, but a slightly lower correlation (0.7) with mitochondrial DNA and linguistic affiliation. The data suggest that genetic diversity of the present-day Slavs was predominantly shaped in situ, and we detect two different substrata: 'central-east European' for West and East Slavs, and 'south-east European' for South Slavs. A pattern of distribution of segments identical by descent between groups of East-West and South Slavs suggests shared ancestry or a modest gene flow between those two groups, which might derive from the historic spread of Slavic people.


Assuntos
Cromossomos Humanos Y/genética , DNA Mitocondrial/genética , Pool Gênico , Variação Genética , Idioma , População Branca/genética , Europa (Continente) , Humanos , Filogenia , Polimorfismo de Nucleotídeo Único
7.
Eur J Hum Genet ; 20(2): 203-10, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21829225

RESUMO

There is a great deal of interest in a fine-scale population structure in the UK, both as a signature of historical immigration events and because of the effect population structure may have on disease association studies. Although population structure appears to have a minor impact on the current generation of genome-wide association studies, it is likely to have a significant part in the next generation of studies designed to search for rare variants. A powerful way of detecting such structure is to control and document carefully the provenance of the samples involved. In this study, we describe the collection of a cohort of rural UK samples (The People of the British Isles), aimed at providing a well-characterised UK-control population that can be used as a resource by the research community, as well as providing a fine-scale genetic information on the British population. So far, some 4000 samples have been collected, the majority of which fit the criteria of coming from a rural area and having all four grandparents from approximately the same area. Analysis of the first 3865 samples that have been geocoded indicates that 75% have a mean distance between grandparental places of birth of 37.3 km, and that about 70% of grandparental places of birth can be classed as rural. Preliminary genotyping of 1057 samples demonstrates the value of these samples for investigating a fine-scale population structure within the UK, and shows how this can be enhanced by the use of surnames.


Assuntos
Genótipo , Nomes , População/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Feminino , Frequência do Gene , Genética Populacional , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade , Reino Unido , Adulto Jovem
8.
Eur J Hum Genet ; 18(8): 924-32, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20354563

RESUMO

The HLA region on chromosome 6 is gene-rich and under selective pressure because of the high proportion of immunity-related genes. Linkage disequilibrium (LD) patterns and allele frequencies in this region are highly differentiated across broad geographical populations, making it a region of interest for population genetics and immunity-related disease studies. We examined LD in this important region of the genome in six European populations using 166 putatively neutral SNPs and the classical HLA-A, -B and -C gene alleles. We found that the pattern of association between classic HLA gene alleles and SNPs implied that most of the SNPs predated the origin of classic HLA gene alleles. The SNPs most strongly associated with HLA gene alleles were in some cases highly predictive of the HLA allele carrier status (misclassification rates ranged from <1 to 27%) in independent populations using five or fewer SNPs, a much smaller number than tagSNP panels previously proposed and often with similar accuracy, showing that our approach may be a viable solution to designing new HLA prediction panels. To describe the LD within this region, we developed a new haplotype clustering method/software based on r(2), which may be more appropriate for use within regions of strong LD. Haplotype blocks created using this proposed method, as well as classic HLA gene alleles and SNPs, were predictive of a northern versus southern European population membership (misclassification error rates ranged from 0 to 23%, depending on which independent population was used for prediction), indicating that this region may be a rich source of ancestry informative markers.


Assuntos
Genética Populacional/métodos , Antígenos HLA/genética , Desequilíbrio de Ligação , Polimorfismo de Nucleotídeo Único , População Branca/genética , Mapeamento Cromossômico , Cromossomos Humanos Par 6 , Europa (Continente) , Frequência do Gene , Variação Genética , Genótipo , Haplótipos , Humanos
9.
J Physiol Anthropol Appl Human Sci ; 24(4): 375-82, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16079584

RESUMO

It has been proposed that the Delta32 mutation in the chemokine receptor gene, inducing resistance to HIV-1 and, probably, to other virus infections, has undergone selection in historical times. The frequency of this mutant allele has changed rapidly both in time (during the last two millennia) and in space (across Eurasia). We compiled a global database on Delta32 allele frequencies in 300 populations. Nearly 10 percent of them are our data on 35 East European populations analyzed here for the first time. A detailed map of Delta32 frequency distribution was constructed and statistically analysed. We found a linearly decreasing trend with a maximum in areas surrounding the Baltic and White seas. Significant correlations with ground surface temperature were revealed. However, compared with our previous results, these correlations diminished, indicating that the influence of climate on Delta32 distribution was, if anything at all, indirect. The proposed scenario includes: i) arise and initial spread of the mutation among Uralic-speaking populations; ii) a frequency increase in northeastern Europe as a result of selection and/or genetic drift; iii) secondary spread (with selection continued) due to gene flow and the migrations of northern Europeans across the globe.


Assuntos
Demografia , Meio Ambiente , Predisposição Genética para Doença , Genética Populacional , Infecções por HIV/genética , HIV-1 , Receptores CCR5/genética , Ásia , Bases de Dados Genéticas , Emigração e Imigração , Europa (Continente) , Frequência do Gene , Humanos , Mutação/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA