Complete mitochondrial DNA analysis of eastern Eurasian haplogroups rarely found in populations of northern Asia and eastern Europe

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.     

Trading genes along the silk road: mtDNA sequences and the origin of central Asian populations.

Central Asia is a vast region at the crossroads of different habitats, cultures, and trade routes. Little is known about the genetics and the history of the population of this region. We present the analysis of mtDNA control-region sequences in samples of the Kazakh, the Uighurs, the lowland Kirghiz, and the highland Kirghiz, which we have used to address both the population history of the region and the possible selective pressures that high altitude has on mtDNA genes. Central Asian mtDNA sequences present features intermediate between European and eastern Asian sequences, in several parameters-such as the frequencies of certain nucleotides, the levels of nucleotide diversity, mean pairwise differences, and genetic distances. Several hypotheses could explain the intermediate position of central Asia between Europe and eastern Asia, but the most plausible would involve extensive levels of admixture between Europeans and eastern Asians in central Asia, possibly enhanced during the Silk Road trade and clearly after the eastern and western Eurasian human groups had diverged. Lowland and highland Kirghiz mtDNA sequences are very similar, and the analysis of molecular variance has revealed that the fraction of mitochondrial genetic variance due to altitude is not significantly different from zero. Thus, it seems unlikely that altitude has exerted a major selective pressure on mitochondrial genes in central Asian populations.     

Mitochondrial diversity and phylogeographic structure of Chinese domestic goats

China has numerous native domestic goat breeds, but so far there has been no extensive study on genetic diversity, population demographic history, and origin of Chinese goats. Here, we examined the genetic diversity and phylogeographic structure of Chinese domestic goats by determining a 481-bp fragment of the first hypervariable region of mitochondrial DNA (mtDNA) control region from 368 individuals representing 18 indigenous breeds. Phylogenetic analyses revealed that there were four mtDNA lineages (A-D) identified in Chinese goats, in which lineage A was predominant, lineage B was moderate, and lineages C and D were at low frequency. These results further support the multiple maternal origins of domestic goats. The pattern of genetic variation in goat mtDNA sequences indicated that the two larger lineages A and B had undergone population expansion events. In a combined analysis of previously reported sequences and our sequences belonging to lineage B, we detected two subclades, in which one was unique to eastern Asia and another was shared between eastern and southern Asia. A larger genetic variation in eastern Asia than southern Asia and the pattern of phylogeographic variation in lineage B suggest that at least one subclade of lineage B originated from eastern Asia. There was no significant geographical structuring in Chinese goat populations, which suggested that there existed strong gene flow among goat populations caused by extensive transportation of goats in history.     

Geographic variation in human mitochondrial DNA control region sequence: the population history of Turkey and its relationship to the European populations

The hypervariable segment I of the control region of the mtDNA (positions 16024-16383) was amplified from hair roots by PCR and sequenced in 45 unrelated individuals from Anatolia (Asian Turkey). Forty different sequences were found, defined by 56 variable positions, of which only one involves a transversion. The neighbor-joining tree of Kimura's distance matrix for all sequences shows four main clusters. Cluster D was found to be the most statistically robust of the four, and all the sequences in it shared a mutation that is present only in European and West Asian populations. The variability in cluster D could have originated between 37,000 and 107,000 years ago. No branch is unexpectedly long, denoting the absence of sequences that diverged much before the others. The pairwise difference distribution is bell-shaped, in accordance with a population expansion occurring roughly 35,000 to 100,000 years ago. When compared to other Caucasoid populations through the pairwise difference distribution, there is a pattern from the Middle East (older expansion) to the various European populations, with Turkey in an intermediate position; when Turkish sequences are compared through a neighbor-joining tree on a genetic distance matrix of populations, this position is again evidenced. Although there is a very low level of genetic divergence among Caucasoid populations as shown by mtDNA control region sequences, a geographic pattern of genetic variation emerges, denoting a stepping-stone position of Turkey between the Middle East and Europe, which is in agreement with the hypothesis of a replacement of Neanderthals by modern humans, which could be related to the Upper Paleolithic cultural expansion.      

Genetic evidence for the proto-Austronesian homeland in Asia: mtDNA and nuclear DNA variation in Taiwanese aboriginal tribes.

Previous studies of mtDNA variation in indigenous Taiwanese populations have suggested that they held an ancestral position in the spread of mtDNAs throughout Southeast Asia and Oceania (Melton et al. 1995; Sykes et al. 1995), but the question of an absolute proto-Austronesian homeland remains. To search for Asian roots for indigenous Taiwanese populations, 28 mtDNAs representative of variation in four tribal groups (Ami, Atayal, Bunun, and Paiwan) were sequenced and were compared with each other and with mtDNAs from 25 other populations from Asia and Oceania. In addition, eight polymorphic Alu insertion loci were analyzed, to determine if the pattern of mtDNA variation is concordant with nuclear DNA variation. Tribal groups shared considerable mtDNA sequence identity (P>.90), where gene flow is believed to have been low, arguing for a common source or sources for the tribes. mtDNAs with a 9-bp deletion have considerable mainland-Asian diversity and have spread to Southeast Asia and Oceania through a Taiwanese bottleneck. Only four Taiwanese mtDNA haplotypes without the 9-bp deletion were shared with any other populations, but these shared types were widely dispersed geographically throughout mainland Asia. Phylogenetic and principal-component analyses of Alu loci were concordant with conclusions from the mtDNA analyses; overall, the results suggest that the Taiwanese have temporally deep roots, probably in central or south China, and have been isolated from other Asian populations in recent history.     

Mitochondrial DNA diversity in Southeast Asian populations

In a previous study of Southeast Asian genetic variation, we characterized mitochondrial DNAs (mtDNAs) from six populations through high-resolution restriction fragment length polymorphism (RFLP) analysis. Our analysis revealed that these Southeast Asian populations were genetically similar to each other, suggesting they had a common origin. However, other patterns of population associations also emerged. Haplotypes from a major founding haplogroup in Papua New Guinea were present in Malaysia; the Vietnamese and Malaysian aborigines (Orang Asli) had high frequencies of haplogroup F, which was also seen in most other Southeast Asian populations; and haplogroup B, defined by the Region V 9-base-pair deletion, was present throughout the region. In addition, the Malaysian and Sabah (Borneo) aborigine populations exhibited a number of unique mtDNA clusters that were not observed in other populations. Unfortunately, it has been difficult to compare these patterns of genetic diversity with those shown in subsequent studies of mtDNA variation in Southeast Asian populations because the latter have typically sequenced the first hypervariable segment (HVS-I) of the control region (CR) sequencing rather than used RFLP haplotyping to characterize the mtDNAs present in them. For this reason, we sequenced the HVS-I of Southeast Asian mtDNAs that had previously been subjected to RFLP analysis, and compared the resulting data with published information from other Southeast Asian and Oceanic groups. Our findings reveal broad patterns of mtDNA haplogroup distribution in Southeast Asia that may reflect different population expansion events in this region over the past 50,000-5,000 years.     

The Peopling of Korea Revealed by Analyses of Mitochondrial DNA and Y-Chromosomal Markers

Background

The Koreans are generally considered a northeast Asian group because of their geographical location. However, recent findings from Y chromosome studies showed that the Korean population contains lineages from both southern and northern parts of East Asia. To understand the genetic history and relationships of Korea more fully, additional data and analyses are necessary.

Methodology and Results

We analyzed mitochondrial DNA (mtDNA) sequence variation in the hypervariable segments I and II (HVS-I and HVS-II) and haplogroup-specific mutations in coding regions in 445 individuals from seven east Asian populations (Korean, Korean-Chinese, Mongolian, Manchurian, Han (Beijing), Vietnamese and Thais). In addition, published mtDNA haplogroup data (N = 3307), mtDNA HVS-I sequences (N = 2313), Y chromosome haplogroup data (N = 1697) and Y chromosome STR data (N = 2713) were analyzed to elucidate the genetic structure of East Asian populations. All the mtDNA profiles studied here were classified into subsets of haplogroups common in East Asia, with just two exceptions. In general, the Korean mtDNA profiles revealed similarities to other northeastern Asian populations through analysis of individual haplogroup distributions, genetic distances between populations or an analysis of molecular variance, although a minor southern contribution was also suggested. Reanalysis of Y-chromosomal data confirmed both the overall similarity to other northeastern populations, and also a larger paternal contribution from southeastern populations.

Conclusion

The present work provides evidence that peopling of Korea can be seen as a complex process, interpreted as an early northern Asian settlement with at least one subsequent male-biased southern-to-northern migration, possibly associated with the spread of rice agriculture.     

Mitochondrial and nuclear genetic relationships among Pacific Island and Asian populations.

Mitochondrial and autosomal short tandem-repeat (STR) genetic distances among 28 Pacific Island and Asian populations are significantly correlated (r=.25, P<.01) but describe distinct patterns of relationships. Maternally inherited-mtDNA data suggest that Remote Oceanic Islanders originated in island Southeast Asia. In contrast, biparental STR data reveal substantial genetic affinities between Remote Oceanic Islanders and Near Oceanic populations from highland Papua New Guinea and Australia. The low correlation between maternal and biparental genetic markers from the same individuals may reflect differences in genome-effective population sizes or in sex-biased gene flow. To explore these possibilities, we have examined genetic diversity, gene flow, and correlations among genetic, linguistic, and geographic distances within four sets of populations representing potential geographic and cultural spheres of interaction. GST estimates (a measure of genetic differentiation inversely proportional to gene flow) from mtDNA sequences vary between 0.13 and 0.39 and are typically five times greater than GST estimates from STR loci (0.05-0.08). Significant correlations (r>.5, P<.05) between maternal genetic and linguistic distances are coincident with high mtDNA GST estimates (>0.38). Thus, genetic and linguistic distances may coevolve, and their correspondence may be preserved under conditions of genetic isolation. A significant correlation (r=.65, P<.01) between biparental genetic and geographic distances is coincident with a low STR GST estimate (0.05), indicating that isolation by distance is observed under conditions of high nuclear-gene flow. These results are consistent with an initial settlement of Remote Oceania from island Southeast Asia and with extensive postcolonization male-biased gene flow with Near Oceania.     

Mitochondrial diversity in European and Chinese pigs is consistent with population expansions that occurred prior to domestication

Mitochondrial DNA (mtDNA) diversity in European and Asian pigs was assessed using 1536 samples representing 45 European and 21 Chinese breeds. Diagnostic nucleotide differences in the cytochrome b (Cytb) gene between the European and Asian mtDNA variants were determined by pyrosequencing as a rapid screening method. Subsequently, 637bp of the hypervariable control region was sequenced to further characterize mtDNA diversity. All sequences belonged to the D1 and D2 clusters of pig mtDNA originating from ancestral wild boar populations in Europe and Asia, respectively. The average frequency of Asian mtDNA haplotypes was 29% across European breeds, but varied from 0 to 100% within individual breeds. A neighbour-joining (NJ) tree of control region sequences showed that European and Asian haplotypes form distinct clusters consistent with the independent domestication of pigs in Asia and Europe. The Asian haplotypes found in the European pigs were identical or closely related to those found in domestic pigs from Southeast China. The star-like pattern detected by network analysis for both the European and Asian haplotypes was consistent with a previous demographic expansion. Mismatch analysis supported this notion and suggested that the expansion was initiated before domestication.     

Phylogeography of the Korean pine (Pinus koraiensis) in northeast Asia: inferences from organelle gene sequences

Range-wide genetic variation of Korean pine (Pinus koraiensis) was assessed using maternally inherited mtDNA and paternally inherited cpDNA for 16 natural populations throughout northeast Asia in order to study its phylogeographical history during the Quaternary. The cpDNA variation indicated that there was no difference between populations on the Asian continent and those in the Japanese archipelago. In contrast, the mtDNA variation indicated that there was significant difference between the populations from the two regions, with each region having a different lineage. The continental populations exhibited no diversity in the mtDNA examined despite the species’ current extensive range and large populations. Conversely, while the Korean pine is rare in Japan, the Japanese populations exhibited greater levels of mtDNA diversity (H _T?=?0.502). The higher mtDNA diversity and evidence from numerous Korean pine macrofossil remains dated to the Pleistocene and recovered various sites in Japan suggest that the Japanese archipelago once served as a refugium to a much larger Korean pine population with a more extensive range than is the case today. The presence of the single mtDNA haplotype across the Asian continent suggests that the present widespread populations could have expanded from a single refugium population after the last glacial periods.     

The emerging limbs and twigs of the East Asian mtDNA tree

We determine the phylogenetic backbone of the East Asian mtDNA tree by using published complete mtDNA sequences and assessing both coding and control region variation in 69 Han individuals from southern China. This approach assists in the interpretation of published mtDNA data on East Asians based on either control region sequencing or restriction fragment length polymorphism (RFLP) typing. Our results confirm that the East Asian mtDNA pool is locally region-specific and completely covered by the two superhaplogroups M and N. The phylogenetic partitioning based on complete mtDNA sequences corroborates existing RFLP-based classification of Asian mtDNA types and supports the distinction between northern and southern populations. We describe new haplogroups M7, M8, M9, N9, and R9 and demonstrate by way of example that hierarchically subdividing the major branches of the mtDNA tree aids in recognizing the settlement processes of any particular region in appropriate time scale. This is illustrated by the characteristically southern distribution of haplogroup M7 in East Asia, whereas its daughter-groups, M7a and M7b2, specific for Japanese and Korean populations, testify to a presumably (pre-)Jomon contribution to the modern mtDNA pool of Japan.     

Mitochondrial DNA variation in Indo-Pacific populations of the giant tiger prawn,Penaeus monodon

Surveys of mitochondrial DNA (mtDNA) variation in the giant tiger prawn, Penaeus monodon, using restriction fragment length polymorphisms have provided the first clear evidence that the Indo-West Pacific region is a site of accumulation of genetic diversity rather than a site of origin of genetic diversity. No haplotyes were found in common between a group of five southeast African populations and a group of five Australian (including Western Australia) and three southeast Asian populations. The dominant haplotype was different in the Australian and southeast Asian population groups. Genetic diversity (pi) was greatest in Indonesia (pi averaged 0.05), less in the Philippines and Australia (pi averaged 0.01), and markedly less in the southeast African and the West Australian populations (pi averaged 0.003). The high diversity of the southeast Asian populations resulted from the occurrence in those populations of a set of haplotypes found only in southeast Asia but derived from the southeast African haplotypes. These genetic variants therefore evolved in the Indian Ocean and later migrated into the Indo-West Pacific region. Low genetic variation in the geographically marginal populations in southeast Africa and Western Australia is considered to be the result of bottlenecks, but mismatch distributions suggest that large population sizes have been maintained in Indonesian populations for long periods.     

Evolutionary history of the COII/tRNALys intergenic 9 base pair deletion in human mitochondrial DNAs from the Pacific

Length changes in human mitochondrial DNA (mtDNA) are potentially useful markers for inferring the evolutionary history of populations. One such length change is a nine base pair (9-bp) deletion that is located in the intergenic region between the COII gene and the Lysine tRNA gene (COII/tRNALys intergenic region). This deletion has been used as a genetic marker to trace descent from peoples of East Asian origin. A geographic cline of the deletion frequency across modern Pacific Islander populations suggests that the deletion may be useful for tracing prehistoric Polynesian origins and affinities. Mitochondrial DNA sequence variation within two variable segments of the control region (CR) permits a number of inferences regarding the evolutionary history of the 9-bp deletion that cannot be determined from frequency data alone. We obtained CR sequences from 74 mtDNAs with the 9-bp deletion from Indonesia, coastal Papua New Guinea (PNG), and American Samoa. Phylogenetic and pairwise distribution analysis of these CR sequences pooled with previously published CR sequences reveals that the deletion arose independently in Africa and Asia and suggests possible multiple origins of the deletion in Asia. A clinal increase of the frequency of the 9-bp deletion across the three Pacific populations is associated with a decrease in CR sequence diversity, consistent with founder events. Furthermore, analysis of pairwise difference distributions indicates an expansion time of proto-Polynesians that began 5,500 yr ago from Southeast Asia. These results are consistent with the express train model of Polynesian origins.      

Peopling of Sahul: mtDNA variation in aboriginal Australian and Papua New Guinean populations.

We examined genetic affinities of Aboriginal Australian and New Guinean populations by using nucleotide variation in the two hypervariable segments of the mtDNA control region (CR). A total of 318 individuals from highland Papua New Guinea (PNG), coastal PNG, and Aboriginal Australian populations were typed with a panel of 29 sequence-specific oligonucleotide (SSO) probes. The SSO-probe panel included five new probes that were used to type an additional 1,037 individuals from several Asian populations. The SSO-type data guided the selection of 78 individuals from Australia and east Indonesia for CR sequencing. A gene tree of these CR sequences, combined with published sequences from worldwide populations, contains two previously identified highland PNG clusters that do not include any Aboriginal Australians; the highland PNG clusters have coalescent time estimates of approximately 80,000 and 122,000 years ago, suggesting ancient isolation and genetic drift. SSO-type data indicate that 84% of the sample of PNG highlander mtDNA belong to these two clusters. In contrast, the Aboriginal Australian sequences are intermingled throughout the tree and cluster with sequences from multiple populations. Phylogenetic and multidimensional-scaling analyses of CR sequences and SSO types split PNG highland and Aboriginal Australian populations and link Aboriginal Australian populations with populations from the subcontinent of India. These mtDNA results do not support a close relationship between Aboriginal Australian and PNG populations but instead suggest multiple migrations in the peopling of Sahul.     

mtDNA lineage analyses: origins and migrations of Micronesians and Polynesians

The islands of Micronesia and Polynesia collectively comprise the last major region of the globe to be settled by humans. Both of these groups of islands were colonized within the last 4,000 years by Austronesian-speaking agriculturists. Based on biogeographic and linguistic patterns, central-eastern Micronesia and Polynesia are included by many in a single category called Remote Oceania. Similarities of biologic, linguistic, and cultural traits within Remote Oceania highlight a question central to Oceanic studies: Are similarities among islands due to a common origin of isolated communities, to ongoing interactions among islands, or both? Analyses of mitochondrial DNA (mtDNA) sequences reveal that most remote Oceanic populations are polyphyletic. These polyphyletic populations violate the assumptions of many genetic distance and population demography models and so are problematic to interpret. The majority of mtDNA sequences from Micronesian and Polynesian populations are derived from Asia, whereas others are inferred to have originated in New Guinea. These data support an Island Southeast Asian origin and a colonization route along the north coast of New Guinea. The Marianas and Yap proper (main island) appear to have been independently settled directly from Island Southeast Asia, and both have received migrants from Central-Eastern Micronesia since then. Palau clearly demonstrates a complex prehistory including a significant influx of lineages from New Guinea. Thus genetic similarities among Micronesian and Polynesian populations result, in some cases, from a common origin, and in others, from extensive gene flow.     

Genetic studies of human diversity in East Asia

East Asia is one of the most important regions for studying evolution and genetic diversity of human populations. Recognizing the relevance of characterizing the genetic diversity and structure of East Asian populations for understanding their genetic history and designing and interpreting genetic studies of human diseases, in recent years researchers in China have made substantial efforts to collect samples and generate data especially for markers on Y chromosomes and mtDNA. The hallmark of these efforts is the discovery and confirmation of consistent distinction between northern and southern East Asian populations at genetic markers across the genome. With the confirmation of an African origin for East Asian populations and the observation of a dominating impact of the gene flow entering East Asia from the south in early human settlement, interpretation of the north-south division in this context poses the challenge to the field. Other areas of interest that have been studied include the gene flow between East Asia and its neighbouring regions (i.e. Central Asia, the Sub-continent, America and the Pacific Islands), the origin of Sino-Tibetan populations and expansion of the Chinese.     

Phylogeography of northern Dolly Varden Salvelinus malma (Salmoniformes: Salmonidae) from Asia and North America: An analysis based on the mitochondrial DNA genealogy

Spawning in habitats affected by Pleistocene glacial advances over most of its natural range, northern Dolly Varden Salvelinus malma malma typifies Arctic fauna distributed in northeastern Asia and northwestern North America. We reconstructed a genealogy of mtDNA haplotypes from 27 Alaskan and Asian populations to study the influence of historical events on the phylogeography and contemporary population genetic structure. Analysis of molecular variance partitioned most of the mtDNA variability to the intrapopulation component (72.5%) with much reduced differences between populations (21.1%) and regions (6.4%). Similar patterns of variation apparent from hierarchical diversity and nested clade phylogeographical analysis (NCPA) of mtDNA haplotypes identify weak spatial differentiation and low levels of divergence. These findings suggest (1) that demographic history has been influenced by historical range expansions and recent isolation by distance, (2) that present populations from Asia and North America were colonized from one main Beringian Refugium, and (3) that this taxon’s ancestral population probably experienced a bottleneck in the Beringian Refugium during the late Pleistocene (Wisconsin) glacial period. The genealogical and NCPA analyses, and mismatch distribution of S. m. malma mtDNA haplotypes do not confirm the assumptions about presence of the two refugia on the territories of the Beringian Land, in which allopatric S. m. malma ancestral populations evolved, and independent origin of the Sea of Okhotsk populations.     

Genetic affinities of the Andaman Islanders,a vanishing human population

BACKGROUND: The Andaman Islands in the Bay of Bengal are inhabited by hunter-gatherers of unknown origin, now on the verge of extinction. The Andamanese and other Asian small-statured peoples, traditionally known as "Negritos," resemble African pygmies. However, it is generally believed that they descend from the early Australo-Melanesian settlers of Southeast Asia and that their resemblance to some Africans is due to adaptation to a similar environment, rather than shared origins.RESULTS: We analyzed mitochondrial DNA (mtDNA) sequences and RFLP polymorphisms, and Y chromosome biallelic markers and microsatellites, in present-day Andamanese of the Onge, Jarawa, and Great Andamanese tribes, and of inhabitants of the neighboring Nicobar Islands. We also analyzed mtDNA sequences from Andamanese hair samples collected by an ethnographer during 1906-1908. Living Andamanese exhibit low genetic variability that is consistent with their small population size and reproductive isolation.CONCLUSIONS: Our data indicate that the Andamanese have closer affinities to Asian than to African populations and suggest that they are the descendants of the early Palaeolithic colonizers of Southeast Asia. In contrast, the Nicobarese have genetic affinities to groups widely distributed throughout Asia today, presumably descended from Neolithic agriculturalists.     

Y-chromosome and mitochondrial DNA studies on the population structure of the Christmas Island community

Christmas Island is a remote Australian territory located close to the main Indonesian island of Java. Y-chromosome and mitochondrial DNA (mtDNA) markers were used to investigate the genetic structure of the population, which comprises communities of mixed ethnic origin. Analysis of 12 Y-chromosome biallelic polymorphisms revealed a high level of gene diversity and haplotype frequencies that were consistent with source populations in southern China and Southeast Asia. mtDNA hypervariable segment I (HVS-I) sequences displayed high levels of haplotype diversity and nucleotide diversity that were comparable to various Asian populations. Genetic distances revealed extremely low mtDNA differentiation among Christmas Islanders and Asian populations. This was supported by the relatively high proportion of sequence types shared among these populations. The most common mtDNA haplogroups were M* and B, followed by D and F, which are prevalent in East/Southeast Asia. Christmas Islanders of European descent were characterized by the Eurasian haplogroup R*, and a limited degree of admixture was observed. In general, analysis of the genetic data indicated population affinities to southern Chinese (in particular from the Yunnan Province) and Southeast Asia (Thailand, Malaysia, and Cambodia), which was consistent with historical records of settlement. The combined use of these different marker systems provides a useful and appropriate model for the study of contemporary populations derived from different ethnic origins.     

Origin and post-glacial dispersal of mitochondrial DNA haplogroups C and D in northern Asia

More than a half of the northern Asian pool of human mitochondrial DNA (mtDNA) is fragmented into a number of subclades of haplogroups C and D, two of the most frequent haplogroups throughout northern, eastern, central Asia and America. While there has been considerable recent progress in studying mitochondrial variation in eastern Asia and America at the complete genome resolution, little comparable data is available for regions such as southern Siberia--the area where most of northern Asian haplogroups, including C and D, likely diversified. This gap in our knowledge causes a serious barrier for progress in understanding the demographic pre-history of northern Eurasia in general. Here we describe the phylogeography of haplogroups C and D in the populations of northern and eastern Asia. We have analyzed 770 samples from haplogroups C and D (174 and 596, respectively) at high resolution, including 182 novel complete mtDNA sequences representing haplogroups C and D (83 and 99, respectively). The present-day variation of haplogroups C and D suggests that these mtDNA clades expanded before the Last Glacial Maximum (LGM), with their oldest lineages being present in the eastern Asia. Unlike in eastern Asia, most of the northern Asian variants of haplogroups C and D began the expansion after the LGM, thus pointing to post-glacial re-colonization of northern Asia. Our results show that both haplogroups were involved in migrations, from eastern Asia and southern Siberia to eastern and northeastern Europe, likely during the middle Holocene.