20 research outputs found
Uurali rahvaste geneetiline ajalugu lÀbi isaliini N ja autosoomse varieeruvuse prisma
VĂ€itekirja elektrooniline versioon ei sisalda publikatsiooneEuroopast LÀÀne-Siberini levinud uurali keelkond postuleeriti enam kui saja aasta eest. Mitme pĂ”lvkonna eri teadusvaldkondade teadlaste töö tulemusena on kogutud aukartustĂ€ratav andmestik selle keelkonna rahvaste kohta, kuid erilise huvi objektiks on jÀÀnud kĂŒsimus nende ĂŒhisest pĂ€ritolust, vĂ”imalikust algkodust ja rĂ€ndeteedest, mille kohta on vĂ€lja pakutud arvukalt huvitavaid hĂŒpoteese.
EelkĂ”ige geograafiast sĂ”ltuvas isalt pojale pĂ€randuvate Y-kromosoomi variantide ehk isaliinide jaotusmustris eristub selgelt haplogrupp N, mis seob nii Euroopa kui Aasia pĂ”hjaaladel elavaid rahvaid ning iseloomustab ka suurt osa uurali keeli kĂ”nelevatest meestest. KĂ€esoleva doktoritöö eesmĂ€rgiks oli esiteks rakendada kaasaegseid DNA jĂ€rjestustehnoloogiaid hindamaks haplogrupi N fĂŒlogeneetilise puu sisestruktuuri ja alamklaadide ekspansiooniaegu ning levikut PĂ”hja-Euraasias. Teiseks testida uusimate statistiliste meetoditega vĂ”imaliku geneetilise ĂŒhisosa olemasolu uurali keelesugulaste vahel, tuginedes ĂŒlegenoomsetele genotĂŒpiseerimisandmetele.
Selgus, et haplogrupp N on tĂ”enĂ€oliselt algselt pĂ€rit PĂ”hja-Hiinast vĂ”i mandrilisest Kagu-Aasiast ning haplogrupi sisemine struktuur koosneb mitmest piiritletud geograafilise levikuga alamklaadist. Ăhel neist, haplogrupi N3 alamklaad N3a3â6, mille levikuaja algus jÀÀb umbes 5000 aasta tagusesse aega, on tĂ€helepanuvÀÀrselt lai geograafiline levik, mis ulatub LÀÀnemere idakaldalt kuni Mongoolia ja Vene Beringiani ning hĂ”lmab mĂ€rkimisvÀÀrse osa kĂ”ikidesse suurematesse PĂ”hja-Euraasia keelkondadesse kuuluvatest meestest.
Ălegenoomsete andmete pĂ”hjal on enamusel uurali keeli kĂ”nelejatest piiratud, kuid tuvastatav hiljutine tĂ”enĂ€oliselt Siberi pĂ€ritolu geneetiline ĂŒhisosa, mis vihjab keelte levikuga kaasas kĂ€inud inimeste rĂ€ndele. Samas on see ĂŒhine geneetiline komponent seotud ulatuslikumate ida poolt lĂ€htunud mĂ”jutustega Kirde-Euroopa kaasaegsete rahvaste geenifondile, mis tĂ”enĂ€oliselt ei piirdunud ainult uurali keeli rÀÀkinud inimeste sisserĂ€ndega.The Uralic linguistic family has been postulated for more than a hundred years with a current distribution area spanning from Europe to West Siberia. The prehistory of Uralic languages and their speakers has been under scrutiny of several generations of scientists from a variety of scientific fields. Numerous hypotheses have been proposed regarding their common origin, dispersal routes and possible homeland, but these questions continue to remain scientifically disputable.
A clear disruptor in the pattern of geography-dependent distribution of Y-chromosomal paternal lineages is haplogroup N that unites populations across entire north Eurasia and describes a fair share of Uralic-speaking males in both northeastern Europe and west Siberia. First aim of this thesis was to apply novel DNA re-sequencing approach to resolve the inner phylogenetic structure of haplogroup N and estimate coalescent ages along with geographic distribution of its inner subclades. Second aim was to test for a common autosomal genetic substrate between Uralic speakers using novel statistical methods.
The results suggest hg N to initially originate from North China or Mainland Southeast Asia and contain several novel subclades with distinct phylogeographic spread. One such subclade, N3a3â6 within subhaplogroup N3, displays an expansion time of 5000 years, but has a remarkably wide geographic distribution ranging from the eastern shores of the Baltic Sea to Mongolia and Pacific Russian Beringia, encompassing a considerate fraction of men from all major linguistic families in north Eurasia.
Whole genome data shows a small, yet significant autosomal genetic component of possible Siberian ancestry shared between most of the Uralic-speaking populations, suggesting a migratory contribution to the dispersal of the languages. This component is part of a broader eastern influence on the genepool of modern northern Europe and was probably not limited to the spread of extant Uralic languages.https://www.ester.ee/record=b526783
Genetic characterization of populations in the Marquesas Archipelago in the context of the Austronesian expansion
Our exploration of the genetic constitution of Nuku Hiva (n = 51), Hiva Oa (n = 28) and Tahuata (n = 8) of the Marquesas Archipelago based on the analyses of genome-wide autosomal markers as well as high-resolution genotyping of paternal and maternal lineages provides us with information on the origins and settlement of these islands at the fringe of the Austronesian expansion. One widespread theme that emerges from this study is the genetic uniformity and relative isolation exhibited by the Marquesas and Society populations. This genetic homogeneity within East Polynesia groups is reflected in their limited average heterozygosity, uniformity of constituents in the Structure analyses, reiteration of complete mtDNA sequences, marked separation from Asian and other Oceanic populations in the PC analyses, limited differentiation in the PCAs and large number of IBD segments in common. Both the f3 and the Outgroup f3 results provide indications of intra-East Polynesian gene flow that may have promoted the observed intra-East Polynesia genetic homogeneity while ALDER analyses indicate that East Polynesia experienced two gene flow episodes, one relatively recent from Europe that coincides roughly with the European incursion into the region and an early one that may represent the original settlement of the islands by Austronesians. Median Network analysis based on high-resolution Y-STR loci under C2a-M208 generates a star-like topology with East Polynesian groups (especially from the Society Archipelago) in central stem positions and individuals from the different populations radiating out one mutational step away while several Samoan and outlier individuals occupy peripheral positions. This arrangement of populations is congruent with dispersals of C2a-M208 Y chromosomes from East Polynesia as a migration hub signaling dispersals in various directions. The equivalent ages of the C2a-M208 lineage of the populations in the Network corroborate an east to west flow of the most abundant Polynesian Y chromosome
Phylogenetic history of patrilineages rare in northern and eastern Europe from large-scale re-sequencing of human Y-chromosomes
The most frequent Y-chromosomal (chrY) haplogroups in northern and eastern Europe (NEE) are well-known and thoroughly characterised. Yet a considerable number of men in every population carry rare paternal lineages with estimated frequencies around 5%. So far, limited sample-sizes and insufficient resolution of genotyping have obstructed a truly comprehensive look into the variety of rare paternal lineages segregating within populations and potential signals of population history that such lineages might convey. Here we harness the power of massive re-sequencing of human Y chromosomes to identify previously unknown population-specific clusters among rare paternal lineages in NEE. We construct dated phylogenies for haplogroups E2-M215, J2-M172, G-M201 and Q-M242 on the basis of 421 (of them 282 novel) high-coverage chrY sequences collected from large-scale databases focusing on populations of NEE. Within these otherwise rare haplogroups we disclose lineages that began to radiate similar to 1-3 thousand years ago in Estonia and Sweden and reveal male phylogenetic patterns testifying of comparatively recent local demographic expansions. Conversely, haplogroup Q lineages bear evidence of ancient Siberian influence lingering in the modern paternal gene pool of northern Europe. We assess the possible direction of influx of ancestral carriers for some of these male lineages. In addition, we demonstrate the congruency of paternal haplogroup composition of our dataset with two independent population-based cohorts from Estonia and Sweden
Genes reveal traces of common recent demographic history for most of the Uralic-speaking populations
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
Genes reveal traces of common recent demographic history for most of the Uralic-speaking populations.
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
Development and implementation of SNaPshot multiplex genotyping for investigating human Y-chromosomal variation in Eastern European populations
Standing at the Gateway to Europe - The Genetic Structure of Western Balkan Populations Based on Autosomal and Haploid Markers
<div><p>Contemporary inhabitants of the Balkan Peninsula belong to several ethnic groups of diverse cultural background. In this study, three ethnic groups from Bosnia and Herzegovina - Bosniacs, Bosnian Croats and Bosnian Serbs - as well as the populations of Serbians, Croatians, Macedonians from the former Yugoslav Republic of Macedonia, Montenegrins and Kosovars have been characterized for the genetic variation of 660 000 genome-wide autosomal single nucleotide polymorphisms and for haploid markers. New autosomal data of the 70 individuals together with previously published data of 20 individuals from the populations of the Western Balkan region in a context of 695 samples of global range have been analysed. Comparison of the variation data of autosomal and haploid lineages of the studied Western Balkan populations reveals a concordance of the data in both sets and the genetic uniformity of the studied populations, especially of Western South-Slavic speakers. The genetic variation of Western Balkan populations reveals the continuity between the Middle East and Europe via the Balkan region and supports the scenario that one of the major routes of ancient gene flows and admixture went through the Balkan Peninsula.</p></div
Map of the Western Balkan region with triangles corresponding to the regions from where blood samples were collected.
<p>The sample of Bosnia and Herzegovina consisted of subsamples of three main ethnic groups: Bosniacs (Sarajevo and Zavidovici), Bosnian Croats (Central Bosnia - Zepce and Maglaj; South Bosnia and Herzegovina - Mostar, Grude, Livno, Capljina), Bosnian Serbs (Doboj and Banjaluka region); Croatia (mainland, Zagreb region), Serbia (Belgrade region), Montenegro (Podgorica), Kosovo (Pristina and Prizren) and Macedonia (Skopje).</p
Network of 29 populations constructed with the Neighbor-net approach from F<sub>ST</sub> distances based on the variation of autosomal SNPs.
<p>Western Balkan populations are indicated with violet color.</p