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1.
To resolve the phylogeny of the autochthonous mitochondrial DNA (mtDNA) haplogroups of India and determine the relationship between the Indian and western Eurasian mtDNA pools more precisely, a diverse subset of 75 macrohaplogroup N lineages was chosen for complete sequencing from a collection of >800 control-region sequences sampled across India. We identified five new autochthonous haplogroups (R7, R8, R30, R31, and N5) and fully characterized the autochthonous haplogroups (R5, R6, N1d, U2a, U2b, and U2c) that were previously described only by first hypervariable segment (HVS-I) sequencing and coding-region restriction-fragment-length polymorphism analysis. Our findings demonstrate that the Indian mtDNA pool, even when restricted to macrohaplogroup N, harbors at least as many deepest-branching lineages as the western Eurasian mtDNA pool. Moreover, the distribution of the earliest branches within haplogroups M, N, and R across Eurasia and Oceania provides additional evidence for a three-founder-mtDNA scenario and a single migration route out of Africa.  相似文献   

2.
To elucidate the human colonization process of northern Asia and human dispersals to the Americas, a diverse subset of 71 mitochondrial DNA (mtDNA) lineages was chosen for complete genome sequencing from the collection of 1,432 control-region sequences sampled from 18 autochthonous populations of northern, central, eastern, and southwestern Asia. On the basis of complete mtDNA sequencing, we have revised the classification of haplogroups A, D2, G1, M7, and I; identified six new subhaplogroups (I4, N1e, G1c, M7d, M7e, and J1b2a); and fully characterized haplogroups N1a and G1b, which were previously described only by the first hypervariable segment (HVS1) sequencing and coding-region restriction-fragment-length polymorphism analysis. Our findings indicate that the southern Siberian mtDNA pool harbors several lineages associated with the Late Upper Paleolithic and/or early Neolithic dispersals from both eastern Asia and southwestern Asia/southern Caucasus. Moreover, the phylogeography of the D2 lineages suggests that southern Siberia is likely to be a geographical source for the last postglacial maximum spread of this subhaplogroup to northern Siberia and that the expansion of the D2b branch occurred in Beringia ~7,000 years ago. In general, a detailed analysis of mtDNA gene pools of northern Asians provides the additional evidence to rule out the existence of a northern Asian route for the initial human colonization of Asia.  相似文献   

3.
MtDNA and Y-chromosome lineages in the Yakut population   总被引:1,自引:0,他引:1  
The structure of female (mtDNA) and male (Y-chromosome haplotypes) lineages in the Yakut population was examined. To determine mtDNA haplotypes, sequencing of hypervariable segment I and typing of haplotype-specific point substitutions in the other parts of the mtDNA molecule were performed. Y haplogroups were identified through typing of biallelic polymorphisms in the nonrecombining part of the chromosome. Haplotypes within haplogroups were analyzed with seven microsatellite loci. Mitochondrial gene pool of Yakuts is mainly represented by the lineages of eastern Eurasian origin (haplogroups A, B, C, D, G, and F). In Yakuts haplogroups C and D showing the total frequency of almost 80% and consisting of 12 and 10 different haplopypes, respectively, were the most frequent and diverse. The total part of the lineages of western Eurasian origin ("Caucasoid") was about 6% (4 haplotypes, haplogroups H, J, and U). Most of Y chromosomes in the Yakut population (87%) belonged to haplogroup N3 (HG16), delineated by the T-C substitution at the Tat locus. Chromosomes of haplogroup N3 displayed the presence of 19 microsatellite haplotypes, the most frequent of which encompassed 54% chromosomes of this haplogroup. Median network of haplogroup N3 in Yakuts demonstrated distinct "starlike phylogeny". Male lineages of Yakuts were shown to be closest to those of Eastern Evenks.  相似文献   

4.
The mtDNA polymorphism in representatives of various archaeological cultures of the Developed Bronze Age, Early Scythian, and Hunnish-Sarmatian periods was analyzed (N = 34). It detected the dominance of Western-Eurasian haplotypes (70.6%) in mtDNA samples from the representatives of the ancient population of the Early Bronze Age–Iron Age on the territory of Altai Mountains. Since the 8th to the 7th centuries BC, a sharp increase was revealed in the Eastern Eurasian haplogroups A, D, C, and Z (43.75%) as compared to previous cultures (16.7%). The presence of haplotype 223-242-290-319 of haplogroup A8 in Dolgans, Itelmens, Evens, Koryaks, and Yakuts indicates the possible long-term presence of its carriers in areas inhabited by these populations. The prevalence of western Eurasian haplotypes is observed not only in the Altai Mountains but also in Central Asia (Kazakhstan) and the south of the Krasnoyarsk Krai. All of the three studied samples from the Western Eurasian haplogroups were revealed to contain U, H, T, and HV. The ubiquitous presence of haplotypes of haplogroup H and some haplogroups of cluster U (U5a1, U4, U2e, and K) in the vast territory from the Yenisei River basin to the Atlantic Ocean may indicate the direction of human settlement, which most likely occurred in the Paleolithic Period from Central Asia.  相似文献   

5.
Polymorphism of mtDNA was examined in five ethnic populations that belong to the Turkic language group and inhabit the territory of the Altai-Sayan upland (N = 1007). Most of the haplogroups identified in the examined populations belonged to East Eurasian lineages. In all five populations, only three haplogroups, C, D, and F, were prevailing. The frequencies of the other six haplogroups (A, B, G, M, Y, and Z) varied in the range from 1.1 to 6.5%. Among West Eurasian haplogrous, the most common were haplogroups H, J, T, and U. An analysis of Y-chromosome haplogroups in 407 individuals showed that only two haplogroups, N* and R1a1, were present in all five populations examined. Moreover, in different ethnic groups, the highest frequencies were observed for C-M130, N-P43, and N-Tat haplogroups. The differences in the distribution patterns of ancient West Eurasian and East Eurasian haplotypes from Gorny Altai in the present-day populations from the northern part of Eurasia revealed can be explained in terms of the multistage expansion of humans across these territories. The ubiquity of haplotypes from haplogroup H and cluster U across the wide territory from the Yenisei River basin to the Atlantic Ocean can indicate directional human expansion, which most likely occurred out of Central Asia as early as in the Paleolithic era, and took place in several waves with the glacier retreat.  相似文献   

6.
Phylogenetic relationships between the sequences of the mitochondrial DNA (mtDNA) hypervariable segment 1, belonging to subhaplogroup U4, were examined in the populations of Eastern Europe, Ural, and Northwest Siberia. It was shown that the frequency of subhaplogroup U4, as well as its proportion in the U-component of the gene pools, increased eastwards, reaching maximum values in the populations of Northwest Siberia. Phylogenetic analysis it was showed that the appearance of specific U4-lineage (16113C–16356–16362) in the ancestors of Mansi was most likely caused by its divergence from the East European cluster 16356–16362 in the Late Upper Paleolithic (18566 ± 12915 years before present). Other U4 mtDNA lineages (16189–16356 and 16311–16356), typical mostly of the indigenous populations of Northwest Siberia (Mansi, Nganasans, and Kets) may have formed during the Neolithic–early Bronze Age (6055 ± 3599 years before present, on average). It seems likely that the isolation of ancient populations inhabiting the region between the Ob' and Yenisei rivers was the key factor, providing the appearance of the unique Caucasoid mtDNA lineages in their gene pools. These results were consistent with the traditional point of view on the mixed origin of the Finno-Ugric populations of the Volga–Ural region and West Siberia, resulted from the genetic relationships between the populations of Europe and Asia.  相似文献   

7.
The mtDNA polymorphism was analyzed in eight ethnic groups (N = 979) of the Volga–Ural region. Most mtDNA variants belonged to haplogroups H, U, T, J, W, I, R, and N1 characteristic of West Eurasian populations. The most frequent were haplogroups H (12–42%) and U (18–44%). East Eurasian mtDNA types (A, B, Y, F, M, N9) were also observed. Genetic diversity was higher in Turkic than in Finno-Ugric populations. The frequency of mtDNA types characteristic of Siberian and Central Asian populations substantially increased in the ethnic groups living closer to the Urals, a boundary between Europe and Asia. Geographic distances, rather than linguistic barriers, were assumed to play the major role in distribution of mtDNA types in the Volga–Ural region. Thus, as concerns the maternal lineage, the Finno-Ugric populations of the region proved to be more similar to their Turkic neighbors rather than to linguistically related Balto-Finnish ethnic groups.  相似文献   

8.
Studies of human mitochondrial (mt) DNA genomes demonstrate that the root of the human phylogenetic tree occurs in Africa. Although 2 mtDNA lineages with an African origin (haplogroups M and N) were the progenitors of all non-African haplogroups, macrohaplogroup L (including haplogroups L0-L6) is limited to sub-Saharan Africa. Several L haplogroup lineages occur most frequently in eastern Africa (e.g., L0a, L0f, L5, and L3g), but some are specific to certain ethnic groups, such as haplogroup lineages L0d and L0k that previously have been found nearly exclusively among southern African "click" speakers. Few studies have included multiple mtDNA genome samples belonging to haplogroups that occur in eastern and southern Africa but are rare or absent elsewhere. This lack of sampling in eastern Africa makes it difficult to infer relationships among mtDNA haplogroups or to examine events that occurred early in human history. We sequenced 62 complete mtDNA genomes of ethnically diverse Tanzanians, southern African Khoisan speakers, and Bakola Pygmies and compared them with a global pool of 226 mtDNA genomes. From these, we infer phylogenetic relationships amongst mtDNA haplogroups and estimate the time to most recent common ancestor (TMRCA) for haplogroup lineages. These data suggest that Tanzanians have high genetic diversity and possess ancient mtDNA haplogroups, some of which are either rare (L0d and L5) or absent (L0f) in other regions of Africa. We propose that a large and diverse human population has persisted in eastern Africa and that eastern Africa may have been an ancient source of dispersion of modern humans both within and outside of Africa.  相似文献   

9.
Maliarchuk BA 《Genetika》2004,40(11):1549-1556
Phylogenetic relationships between the sequences of the mitochondrial DNA (mtDNA) hypervariable segment 1, belonging to subhaplogroup U4, were examined in the populations of Eastern Europe, Ural, and Northwest Siberia. It was shown that the frequency of subhaplogroup U4, as well as its proportion in the U-component of the gene pools, increased eastwards, reaching maximum values in the populations of Northwest Siberia. Phylogenetic analysis it was showed that the appearance of specific U4-lineage (16113C-16356-16362) in the ancestors of Mansi was most likely caused by its divergence from the East European cluster 16356-16362 in the Late Upper Paleolithic (18566 +/- 12915 years before present). Other U4 mtDNA lineages (16189-16356 and 16311-16356), typical mostly of the indigenous populations of Northwest Siberia (Mansi, Nganasans, and Kets) may have formed during the Neolithic-early Bronze Age (6055 +/- 3599 years before present, on average). It seems likely that the isolation of ancient populations inhabiting the region between the Ob' and Yenisei rivers was the key factor, providing the appearance of the unique Caucasoid mtDNA lineages in their gene pools. These results were consistent with the traditional point of view on the mixed origin of the Finno-Ugric populations of the Volga-Ural region and West Siberia, resulted from the genetic relationships between the populations of Europe and Asia.  相似文献   

10.
Xinjiang is at the crossroads between East and West Eurasia, and it harbors a relatively complex genetic history. In order to better understand the population movements and interactions in this region, mitochondrial and Y chromosome analyses on 40 ancient human remains from the Tianshanbeilu site in eastern Xinjiang were performed. Twenty‐nine samples were successfully assigned to specific mtDNA haplogroups, including the west Eurasian maternal lineages of U and W and the east Eurasian maternal lineages of A, C, D, F, G, Z, M7, and M10. In the male samples, two Y chromosome haplogroups, C* and N1 (xN1a, N1c), were successfully assigned. Our mitochondrial and Y‐chromosomal DNA analyses combined with the archaeological studies revealed that the Di‐qiang populations from the Hexi Corridor had migrated to eastern Xinjiang and admixed with the Eurasian steppe populations in the early Bronze Age. Am J Phys Anthropol 157:71–80, 2015. © 2014 Wiley Periodicals, Inc.  相似文献   

11.
The genetic composition of the Russian population was investigated by analyzing both mitochondrial DNA (mtDNA) and Y-chromosome loci polymorphisms that allow for the different components of a population gene pool to be studied, depending on the mode of DNA marker inheritance. mtDNA sequence variation was examined by using hypervariable segment I (HVSI) sequencing and restriction analysis of the haplogroup-specific sites in 325 individuals representing 5 Russian populations from the European part of Russia. The Y-chromosome variation was investigated in 338 individuals from 8 Russian populations (including 5 populations analyzed for mtDNA variation) using 12 binary markers. For both uniparental systems most of the observed haplogroups fell into major West Eurasian haplogroups (97.9% and 99.7% for mtDNA and Y-chromosome haplogroups, respectively). Multidimensional scaling analysis based on pairwise F(ST) values between mtDNA HVSI sequences in Russians compared to other European populations revealed a considerable heterogeneity of Russian populations; populations from the southern and western parts of Russia are separated from eastern and northern populations. Meanwhile, the multidimensional scaling analysis based on Y-chromosome haplogroup F(ST) values demonstrates that the Russian gene pool is close to central-eastern European populations, with a much higher similarity to the Baltic and Finno-Ugric male pools from northern European Russia. This discrepancy in the depth of penetration of mtDNA and Y-chromosome lineages characteristic for the most southwestern Russian populations into the east and north of eastern Europe appears to indicate that Russian colonization of the northeastern territories might have been accomplished mainly by males rather than by females.  相似文献   

12.
MtDNA and Y-Chromosome Lineages in the Yakut Population   总被引:1,自引:0,他引:1  
The structure of female (mtDNA) and male (Y-chromosome haplotypes) lineages in the Yakut population was examined. To determine mtDNA haplotypes, sequencing of hypervariable segment I and typing of haplotype-specific point substitutions in the other parts of the mtDNA molecule were performed. Y haplogroups were identified through typing of biallelic polymorphisms in the nonrecombining part of the chromosome. Haplotypes within haplogroups were analyzed with seven microsatellite loci. Mitochondrial gene pool of Yakuts is mainly represented by the lineages of eastern Eurasian origin (haplogroups A, B, C, D, G, and F). In Yakuts haplogroups C and D showing the total frequency of almost 80% and consisting of 12 and 10 different haplopypes, respectively, were the most frequent and diverse. The total part of the lineages of western Eurasian origin (Caucasoid) was about 6% (4 haplotypes, haplogroups H, J, and U). Most of Y chromosomes in the Yakut population (87%) belonged to haplogroup N3 (HG16), delineated by the T–C substitution at the Tat locus. Chromosomes of haplogroup N3 displayed the presence of 19 microsatellite haplotypes, the most frequent of which encompassed 54% chromosomes of this haplogroup. Median network of haplogroup N3 in Yakuts demonstrated distinct starlike phylogeny. Male lineages of Yakuts were shown to be closest to those of Eastern Evenks.  相似文献   

13.
North Africa is considered a distinct geographic and ethnic entity within Africa. Although modern humans originated in this Continent, studies of mitochondrial DNA (mtDNA) and Y-chromosome genealogical markers provide evidence that the North African gene pool has been shaped by the back-migration of several Eurasian lineages in Paleolithic and Neolithic times. More recent influences from sub-Saharan Africa and Mediterranean Europe are also evident. The presence of East-West and North-South haplogroup frequency gradients strongly reinforces the genetic complexity of this region. However, this genetic scenario is beset with a notable gap, which is the lack of consistent information for Algeria, the largest country in the Maghreb. To fill this gap, we analyzed a sample of 240 unrelated subjects from a northwest Algeria cosmopolitan population using mtDNA sequences and Y-chromosome biallelic polymorphisms, focusing on the fine dissection of haplogroups E and R, which are the most prevalent in North Africa and Europe respectively. The Eurasian component in Algeria reached 80% for mtDNA and 90% for Y-chromosome. However, within them, the North African genetic component for mtDNA (U6 and M1; 20%) is significantly smaller than the paternal (E-M81 and E-V65; 70%). The unexpected presence of the European-derived Y-chromosome lineages R-M412, R-S116, R-U152 and R-M529 in Algeria and the rest of the Maghreb could be the counterparts of the mtDNA H1, H3 and V subgroups, pointing to direct maritime contacts between the European and North African sides of the western Mediterranean. Female influx of sub-Saharan Africans into Algeria (20%) is also significantly greater than the male (10%). In spite of these sexual asymmetries, the Algerian uniparental profiles faithfully correlate between each other and with the geography.  相似文献   

14.
Analysis of mtDNA markers in a population of the Nogays (n = 206), the people inhabiting the North Caucasus and speaking a Turkic language of the Altaic linguistic family, has revealed a high level of genetic diversity (H = 0.99). The identified haplotypes include all major West Eurasian haplogroups, with the prevalence of H and U clusters (22 and 21%, respectively), but the percentage of lineages specific for East Eurasian populations is the highest (40%). Some other mtDNA variants in the Nogay population belong to the M1 haplogroups typical of northeastern Africa and U2 characteristic of Indian populations. Thus, components of different origin have contributed to the gene pool of Nogays. An erratum to this article is available at .  相似文献   

15.
The analysis of mtDNA polymorphism was carried out in the population of Siberian Tatars from the Barabinsk forest steppe living on the territory of Novosibirsk oblast (N = 199). As a result of the analysis of HVS I and HVS II nucleotide sequence, 101 haplotypes that refer to 22 mtDNA haplogroups were detected. The population of Baraba Tatars is represented by both East Eurasian (38.7%) and West Eurasian mtDNA lines (61.3%). H, T, U5, and J haplogroups prevail among West Eurasian haplogroups; C, D, G, M, and A haplogroups prevail among East Eurasian ones. According to the index of genetic diversity, Tatars from the Barabinsk forest steppe (0.9141) are the closest to Kazakhs (0.9108), Bashkirs (0.9165), and Tobol-Irtysh Tatars (0.9104). The greatest statistically significant interpopulation differences (FST) were detected between all studied samples; the smallest interpopulation differences were detected between all Tatar samples, as well as between Tatars and Komi, Mansi, Udmurts, Kazakhs, Chuvashes, and Bashkirs. The haplogroup H is the most common in populations that we studied. In the present study, was registered the haplotype 16126–16294 with the frequency of 4% (T cluster) previously found only in Caucasians. High frequency of haplogroups U4, U5, and H in the gene pool of Baraba Tatars brings them together not only with Samoyeds but also with Finno-Ugric populations. The highest intrapopulation genetic diversity was detected in Tatars from the Barabinsk forest steppe, Tobol-Irtysh Tatars, Kazakhs, and Bashkirs. The presence of the haplogroup B in the mitochondrial DNA genetic pool of Siberian Tatars brings them together with Turks that came from regions of Altai and Central Kazakhstan and inhabited the Western Siberian forest steppe in the 6th–9th centuries. The haplogroup U7, which is typical of populations of Jordan, Kuwait, Iran, and Saudi Arabia, could also have entered the territory of residence of Siberian Tatars in the middle of second millennium BC, when Iranian-speaking tribes entered Siberia.  相似文献   

16.
With the aim of uncovering all of the most basal variation in the northern Asian mitochondrial DNA (mtDNA) haplogroups, we have analyzed mtDNA control region and coding region sequence variation in 98 Altaian Kazakhs from southern Siberia and 149 Barghuts from Inner Mongolia, China. Both populations exhibit the prevalence of eastern Eurasian lineages accounting for 91.9% in Barghuts and 60.2% in Altaian Kazakhs. The strong affinity of Altaian Kazakhs and populations of northern and central Asia has been revealed, reflecting both influences of central Asian inhabitants and essential genetic interaction with the Altai region indigenous populations. Statistical analyses data demonstrate a close positioning of all Mongolic-speaking populations (Mongolians, Buryats, Khamnigans, Kalmyks as well as Barghuts studied here) and Turkic-speaking Sojots, thus suggesting their origin from a common maternal ancestral gene pool. In order to achieve a thorough coverage of DNA lineages revealed in the northern Asian matrilineal gene pool, we have completely sequenced the mtDNA of 55 samples representing haplogroups R11b, B4, B5, F2, M9, M10, M11, M13, N9a and R9c1, which were pinpointed from a massive collection (over 5000 individuals) of northern and eastern Asian, as well as European control region mtDNA sequences. Applying the newly updated mtDNA tree to the previously reported northern Asian and eastern Asian mtDNA data sets has resolved the status of the poorly classified mtDNA types and allowed us to obtain the coalescence age estimates of the nodes of interest using different calibrated rates. Our findings confirm our previous conclusion that northern Asian maternal gene pool consists of predominantly post-LGM components of eastern Asian ancestry, though some genetic lineages may have a pre-LGM/LGM origin.  相似文献   

17.
Polymorphisms in mitochondrial (mt) DNA and Y-chromosomes of seven socially and linguistically diverse castes and tribes of Eastern India were examined to determine their genetic relationships, their origin, and the influence of demographic factors on population structure. Samples from the Orissa Brahmin, Karan, Khandayat, Gope, Juang, Saora, and Paroja were analyzed for mtDNA hypervariable sequence (HVS) I and II, eight Y-chromosome short tandem repeats (Y-STRs), and lineage-defining mutations diagnostic for Indian- and Eurasian-specific haplogroups. Our results reveal that haplotype diversity and mean pairwise differences (MPD) was higher in caste groups of the region (>0.998, for both systems) compared to tribes (0.917-0.996 for Y-STRs, and 0.958-0.988 for mtDNA haplotypes). The majority of paternal lineages belong to the R1a1, O2a, and H haplogroups (62.7%), while 73.2% of maternal lineages comprise the Indian-specific M*, M5, M30, and R* mtDNA haplogroups, with a sporadic occurrence of West Eurasian lineages. Our study reveals that Orissa Brahmins (a higher caste population) have a genetic affinity with Indo-European speakers of Eastern Europe, although the Y-chromosome data show that the genetic distances of populations are not correlated to their position in the caste hierarchy. The high frequency of the O2a haplogroup and absence of East Asian-specific mtDNA lineages in the Juang and Saora suggest that a migration of Austro-Asiatic tribes to mainland India was exclusively male-mediated which occurred during the demographic expansion of Neolithic farmers in southern China. The phylogeographic analysis of mtDNA and Y-chromosomes revealed varied ancestral sources for the diverse genetic components of the populations of Eastern India.  相似文献   

18.
Phylogeography can help to determine LGM refugia and postglacial migration routes. However, the locations of LGM refugial areas in eastern Europe are not clear. Moose (Alces alces) is presently a common species in central and north-eastern Europe, but there are no studies showing its phylogenetic pattern and genetic diversity across its whole continuous range. Moose never became extinct in the eastern part of its range, and the eastern mtDNA lineage has the largest effective population size. The present study shows the phylogeographic pattern and genetic diversity of European moose and compares the results of mtDNA analyses with the archaeological record of the species to identify its LGM refugia and postglacial migration routes. I combined the mtDNA control region sequences obtained in all studies of moose in Europe and western Asia. The genetic data were then compared with the archaeological records of the species dated to the LGM. I found that the European moose lineage inhabits Europe and western Asia. It is composed of two clades: the eastern and the central-western, consisting of a total of six discrete haplogroups. The most complex, the eastern clade, has the largest range. Some of the haplogroups have narrow or scattered distributions and two are common in almost the whole range. Genetic diversity hotspots were detected in contact zones of different mtDNA haplogroups rather than in the LGM refugial areas of moose. Archaeological records dated to the LGM were found in several localities in central, southern and eastern Europe as well as in western Asia. The range of the moose during the LGM was much larger than previously thought. The eastern clade survived the LGM in western Siberia, the Ural Mountains and Russian plain. LGM refugia of moose were also located in the Caucasus, Carpathians, Balkans and northern Italy.  相似文献   

19.
To resolve the phylogeny of certain mitochondrial DNA (mtDNA) haplogroups in eastern Europe and estimate their evolutionary age, a total of 73 samples representing mitochondrial haplogroups U4, HV*, and R1 were selected for complete mitochondrial genome sequencing from a collection of about 2,000 control region sequences sampled in eastern (Russians, Belorussians, and Ukrainians) and western (Poles, Czechs, and Slovaks) Slavs. On the basis of whole-genome resolution, we fully characterized a number of haplogroups (HV3, HV4, U4a1, U4a2, U4a3, U4b, U4c, U4d, and R1a) that were previously described only partially. Our findings demonstrate that haplogroups HV3, HV4, and U4a1 could be traced back to the pre-Neolithic times ( approximately 12,000-19,000 years before present [YBP]) in eastern Europe. In addition, an ancient connection between the Caucasus/Europe and India has been revealed by analysis of haplogroup R1 diversity, with a split between the Indian and Caucasus/European R1a lineages occurring about 16,500 years ago. Meanwhile, some mtDNA subgroups detected in Slavs (such as U4a2a, U4a2*, HV3a, and R1a1) are definitely younger being dated between 6,400 and 8,200 YBP. However, robust age estimations appear to be problematic due to the high ratios of nonsynonymous to synonymous substitutions found in young mtDNA subclusters.  相似文献   

20.
Previous studies have shown that there were extensive genetic admixtures in the Silk Road region. In the present study, we analyzed 252 mtDNAs of five ethnic groups (Uygur, Uzbek, Kazak, Mongolian, and Hui) from Xinjiang Province, China (through which the Silk Road once ran) together with some reported data from the adjacent regions in Central Asia. In a simple way, we classified the mtDNAs into different haplogroups (monophyletic clades in the rooted mtDNA tree) according to the available phylogenetic information and compared their frequencies to show the differences among the matrilineal genetic structures of these populations with different demographic histories. With the exception of eight unassigned M*, N*, and R* mtDNAs, all the mtDNA types identified here belonged to defined subhaplogroups of haplogroups M and N (including R) and consisted of subsets of both the eastern and western Eurasian pools, thus providing direct evidence supporting the suggestion that Central Asia is the location of genetic admixture of the East and the West. Although our samples were from the same geographic location, a decreasing tendency of the western Eurasian-specific haplogroup frequency was observed, with the highest frequency present in Uygur (42.6%) and Uzbek (41.4%) samples, followed by Kazak (30.2%), Mongolian (14.3%), and Hui (6.7%). No western Eurasian type was found in Han Chinese samples from the same place. The frequencies of the eastern Eurasian-specific haplogroups also varied in these samples. Combined with the historical records, ethno-origin, migratory history, and marriage customs might play different roles in shaping the matrilineal genetic structure of different ethnic populations residing in this region.  相似文献   

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