Chromosome Haplogroups Research Articles

Live birth sex ratios and father's geographic origins in Jerusalem, 1964-1976.

To examine whether ancestry influenced sex ratios of offspring in a birth cohort before parental antenatal sex selection influenced offspring sex. We measured the sex ratio as the percent of males according to countries of birth of paternal and maternal grandfathers in 91,459 live births from 1964 to 1976 in the Jerusalem Perinatal Study. Confidence limits (CI) were computed based on an expected sex ratio of 1.05, which is 51.4% male. Of all live births recorded, 51.4% were male. Relative to Jewish ancestry (51.4% males), significantly more males (1,761) were born to Muslim ancestry (54.5, 95% CI = 52.1-56.8, P = 0.01). Among the former, sex ratios were not significantly associated with paternal or maternal age, education, or offspring's birth order. Consistent with a preference for male offspring, the sex ratio decreased despite increasing numbers of births over the 13-year period. Sex ratios were not affected by maternal or paternal origins in North Africa or Europe. However, the offspring whose paternal grandfathers were born in Western Asia included fewer males than expected (50.7, 50.1-51.3, P = 0.02), whether the father was born abroad (50.7) or in Israel (50.8). This was observed for descendents of paternal grandfathers born in Lebanon (47.6), Turkey (49.9), Yemen & Aden (50.2), Iraq (50.5), Afghanistan (50.5), Syria (50.6), and Cyprus (50.7); but not for those from India (51.5) or Iran (51.9). The West Asian group showed the strongest decline in sex ratios with increasing paternal family size. A decreased sex ratio associated with ancestry in Western Asia is consistent with reduced ability to bear sons by a subset of Jewish men in the Jerusalem cohort. Lower sex ratios may be because of pregnancy stress, which may be higher in this subgroup. Alternatively, a degrading Y chromosome haplogroup or other genetic or epigenetic differences on male germ lines could affect birth ratios, such as differential exposure to an environmental agent, dietary differences, or stress. Differential stopping behaviors that favor additional pregnancies following the birth of a daughter might exacerbate these lower sex ratios.

Y chromosome haplogroups based genome-wide association study pinpoints revelation for interactions on non-obstructive azoospermia.

The Y chromosome has high genetic variability with low rates of parallel and back mutations, which make up the most informative haplotyping system. To examine whether Y chromosome haplogroups (Y-hgs) could modify the effects of autosomal variants on non-obstructive azoospermia (NOA), based on our previous genome-wide association study (GWAS), we conducted a genetic interaction analysis in GWAS subjects. Logistic regression analysis demonstrated a protective effect of Y-hg O3e* on NOA. Then, we explored the potential interaction between Y-hg O3e* and autosomal variants. Our results demonstrated that there was a suggestively significant interaction between Y-hg O3e* and rs11135484 on NOA (Pinter = 9.89 × 10−5). Bioinformatic analysis revealed that genes annotated by significant single nucleotide polymorphisms (SNPs) were mainly enriched in immunological pathways. This is the first study of interactions between Y-hgs and autosomal variants on a genome-wide scale, which addresses the missing heritability in spermatogenic impairment and sheds new light on the pathogenesis of male infertility.

Evaluation of Y chromosomal SNP haplogrouping in the HID-Ion AmpliSeq™ Identity Panel.

The Y chromosomal haplogroup determined from single nucleotide polymorphism (SNP) combinations is a valuable genetic marker to study ancestral male lineage and ethical distribution. Next-generation sequencing has been developed for widely diverse genetics fields. For this study, we demonstrate 34 Y-SNP typing employing the Ion PGM™ system to perform haplogrouping. DNA libraries were constructed using the HID-Ion AmpliSeq™ Identity Panel. Emulsion PCR was performed, then DNA sequences were analyzed on the Ion 314 and 316 Chip Kit v2. Some difficulties became apparent during the analytic processes. No-call was reported at rs2032599 and M479 in six samples, in which the least coverage was observed at M479. A minor misreading occurred at rs2032631 and M479. A real time PCR experiment using other pairs of oligonucleotide primers showed that these events might result from the flanking sequence. Finally, Y haplogroup was determined completely for 81 unrelated males including Japanese (n=59) and Malay (n=22) subjects. The allelic divergence differed between the two populations. In comparison with the conventional Sanger method, next-generation sequencing provides a comprehensive SNP analysis with convenient procedures, but further system improvement is necessary.

Human Y Chromosome Haplogroup N: A Non-trivial Time-Resolved Phylogeography that Cuts across Language Families

The paternal haplogroup (hg) N is distributed from southeast Asia to eastern Europe. The demographic processes that have shaped the vast extent of this major Y chromosome lineage across numerous linguistically and autosomally divergent populations have previously been unresolved. On the basis of 94 high-coverage re-sequenced Y chromosomes, we establish and date a detailed hg N phylogeny. We evaluate geographic structure by using 16 distinguishing binary markers in 1,631 hg N Y chromosomes from a collection of 6,521 samples from 56 populations. The more southerly distributed sub-clade N4 emerged before N2a1 and N3, found mostly in the north, but the latter two display more elaborate branching patterns, indicative of regional contrasts in recent expansions. In particular, a number of prominent and well-defined clades with common N3a3'6 ancestry occur in regionally dissimilar northern Eurasian populations, indicating almost simultaneous regional diversification and expansion within the last 5,000 years. This patrilineal genetic affinity is decoupled from the associated higher degree of language diversity.

Genetic heritage of Croatians in the Southeastern European gene pool-Y chromosome analysis of the Croatian continental and Island population.

The research objective of this study is to enlarge and deepen the Y chromosome research on the Croatian population and enable additional insights into the population diversity and historic events that shaped the current genetic landscape of Croatia and Southeastern Europe (SEE). A high-resolution phylogenetic and phylogeographic analysis of 66 biallelic (SNPs) and 17 microsatellite (STRs) markers of the Y chromosome was performed using 720 Croatian samples. The obtained results were placed in a wider European context by comparison with ∼4450 samples from a number of other European populations. A high diversity of haplogroups was observed in the overall Croatian sample, and all typical European Y chromosome haplogroups with corresponding clinal patterns were observed. Three distinct genetic signals were identifiable in the Croatian paternal gene pool - I2a1b-M423, R1a1a1b1a*-M558, and E1b1b1a1b1a-V13 haplogroups. The analyses of the dominant and autochthonous I2a1b-M423 lineage (>30%) suggest that SEE had a significant role in the Upper Paleolithic, the R1a1a1b1a*-M558 lineage (19%) represents a signal from present day Slavic populations of Central Europe in the Croatian population, and the phylogeography of the E1b1b1a1b1a-V13 clade (around 9%) implies cultural diffusion of agriculture into Europe via the Balkan Peninsula. Am. J. Hum. Biol., 2016. © 2016 Wiley Periodicals, Inc. Am. J. Hum. Biol. 28:837-845, 2016. © 2016Wiley Periodicals, Inc.

New native South American Y chromosome lineages.

Many single-nucleotide polymorphisms (SNPs) in the non-recombining region of the human Y chromosome have been described in the last decade. High-coverage sequencing has helped to characterize new SNPs, which has in turn increased the level of detail in paternal phylogenies. However, these paternal lineages still provide insufficient information on population history and demography, especially for Native Americans. The present study aimed to identify informative paternal sublineages derived from the main founder lineage of the Americas-haplogroup Q-L54-in a sample of 1841 native South Americans. For this purpose, we used a Y-chromosomal genotyping multiplex platform and conventional genotyping methods to validate 34 new SNPs that were identified in the present study by sequencing, together with many Y-SNPs previously described in the literature. We updated the haplogroup Q phylogeny and identified two new Q-M3 and three new Q-L54*(xM3) sublineages defined by five informative SNPs, designated SA04, SA05, SA02, SA03 and SA29. Within the Q-M3, sublineage Q-SA04 was mostly found in individuals from ethnic groups belonging to the Tukanoan linguistic family in the northwest Amazon, whereas sublineage Q-SA05 was found in Peruvian and Bolivian Amazon ethnic groups. Within Q-L54*, the derived sublineages Q-SA03 and Q-SA02 were exclusively found among Coyaima individuals (Cariban linguistic family) from Colombia, while Q-SA29 was found only in Maxacali individuals (Jean linguistic family) from southeast Brazil. Furthermore, we validated the usefulness of several published SNPs among indigenous South Americans. This new Y chromosome haplogroup Q phylogeny offers an informative paternal genealogy to investigate the pre-Columbian history of South America.Journal of Human Genetics advance online publication, 31 March 2016; doi:10.1038/jhg.2016.26.

スーパーサイエンスハイスクール（SSH）コンソーシアムによる日本人のY染色体とミトコンドリアDNAハプログループ地域分布調査

スーパーサイエンスハイスクール（SSH）コンソーシアムによる日本人のY染色体とミトコンドリアDNAハプログループ地域分布調査

Genetic Evidence for Modifying Oceanic Boundaries Relative to Fiji.

We present the most comprehensive genetic characterization to date of five Fijian island populations: Viti Levu, Vanua Levu, Kadavu, the Lau Islands, and Rotuma, including nonrecombinant Y (NRY) chromosome and mitochondrial DNA (mtDNA) haplotypes and haplogroups. As a whole, Fijians are genetically intermediate between Melanesians and Polynesians, but the individual Fijian island populations exhibit significant genetic structure reflecting different settlement experiences in which the Rotumans and the Lau Islanders were more influenced by Polynesians, and the other Fijian island populations were more influenced by Melanesians. In particular, Rotuman and Lau Islander NRY chromosomal and mtDNA haplogroup frequencies and Rotuman mtDNA hypervariable segment 1 region haplotypes more closely resemble those of Polynesians, while genetic markers of the other populations more closely resemble those of the Near Oceanic Melanesians. Our findings provide genetic evidence supportive of modifying regional boundaries relative to Fiji, as has been suggested by others based on a variety of nongenetic evidence. Specifically, for the traditional Melanesia/Polynesia/Micronesia scheme, our findings support moving the Melanesia-Polynesia boundary to include Rotuma and the Lau Islands in Polynesia. For the newer Near/Remote Oceania scheme, our findings support keeping Rotuma and the Lau Islands in Remote Oceania and locating the other Fijian island populations in an intermediate or "Central Oceania" region to better reflect the great diversity of Oceania.

Populations of Transcarpathia and Bukovina on the genetic landscape of surrounding regions

The territory of present-day Ukraine is subdivided into some regions with specific demographic and politic history. Nevertheless, the corresponding subdivision in genetic structure is not revealed in previous investigations: populations of Ukrainians under study were genetically homogeneous on SNP markers of Y chromosome. In the current investigation we studied the Y-chromosomal genetic structure of Transcarpathia and Bukovina populations. Several factors exist to expect the genetic specificity of these populations. Both ones are placed in the Carpathian foothills, at the south-western border of the Ukrainian area. During the last millennium these territories were the parts of different states and were open for ethnically diverse migrations. It was revealed that the major Y chromosomal haplogroups in Transcarpathia population were R1a1a1*(М198), I2a (Р37.2), R1a1a1g (М458), E1b1b1a1 (M78). The major haplogroups in Bukovina population were I2a (Р37.2), R1a1a1*(М198), R1a1a1g (М458), R1b1b2 (М269), E1b1b1a1 (M78), I1 (М253). The Bukovina population differs from the typical Ukrainian population by higher frequency of I2a (Р37.2) and lower frequency of R1a1a1*(М198). Moreover, this is the only population among ones studied in Ukraine where the most frequent haplogroup is I2a (Р37.2) but not R1a1a1*(М198). Such a deviation can be caused by possible mixing with neighbouring southern groups, and Carpathian mountains were not a border for exchange in this case. Interestingly, the haplogroup N1c (M178) is not revealed in Transcarpathia at all, obviously due to the mountain barrier. It was revealed by principal component analysis that Ukrainians from Transcarpathia and Bukovina despite some specific peculiarities are more similar to other Ukrainian populations than to the surrounding ethnic groups such as Poles, Slovaks, Hungarians, Romanians, Moldavians and Gagauzes. Ukrainians of Transcarpathia and Bukovina form the entire genetic continuum with the whole Ukraine on maps of gene distances, confirming the homogeneity of Ukrainian parental gene pool and it’s differentiation from other groups. After performing the analysis of Y-haplogroup spatial distribution, it is supposed that the northern ridges ofCarpathian mountainsare the East-European barrier decreasing the gene flow. It decreases the spreading of haplogroups N1c (М178) and R1a (М198) southward and movement of E1b (М78), R1b (М269), J (М304) and G (М201) northward.

Phylogeographic Refinement and Large Scale Genotyping of Human Y Chromosome Haplogroup E Provide New Insights into the Dispersal of Early Pastoralists in the African Continent

Haplogroup E, defined by mutation M40, is the most common human Y chromosome clade within Africa. To increase the level of resolution of haplogroup E, we disclosed the phylogenetic relationships among 729 mutations found in 33 haplogroup DE Y-chromosomes sequenced at high coverage in previous studies. Additionally, we dissected the E-M35 subclade by genotyping 62 informative markers in 5,222 samples from 118 worldwide populations. The phylogeny of haplogroup E showed novel features compared with the previous topology, including a new basal dichotomy. Within haplogroup E-M35, we resolved all the previously known polytomies and assigned all the E-M35* chromosomes to five new different clades, all belonging to a newly identified subhaplogroup (E-V1515), which accounts for almost half of the E-M35 chromosomes from the Horn of Africa. Moreover, using a Bayesian phylogeographic analysis and a single nucleotide polymorphism-based approach we localized and dated the origin of this new lineage in the northern part of the Horn, about 12 ka. Time frames, phylogenetic structuring, and sociogeographic distribution of E-V1515 and its subclades are consistent with a multistep demic spread of pastoralism within north-eastern Africa and its subsequent diffusion to subequatorial areas. In addition, our results increase the discriminative power of the E-M35 haplogroup for use in forensic genetics through the identification of new ancestry-informative markers.

Y chromosome haplogroup D2a1 is significantly associated with high levels of luteinizing hormone in Japanese men

The association between the Y chromosome haplogroup D2 and risk of azoospermia and low sperm motility has been previously studied, and it was indicated that haplogroups DE (YAP lineage) are associated with prostate cancer risk in Japanese males. Our assumption had been that Y chromosome haplogroups may be associated with sex hormone levels, because sex hormones have been deemed responsible for spermatogenesis and carcinogenesis. In this study, we assessed the association between Y chromosome haplogroups and sex hormone levels, including those of testosterone, sex hormone-binding globulin (SHBG), follicle-stimulating hormone (FSH), luteinizing hormone (LH), inhibin-B, and calculated free testosterone (cFT), in 901 young men from the general Japanese population (cohort 1) and 786 Japanese men of proven fertility (cohort 2). We found that the haplogroup D2a1 was significantly associated with high LH levels in a combined analysis involving two cohorts (β = 0.068, SE = 0.025, p = 0.0075), following correction for multiple testing. To date, this result is the first evidence that implicates Y chromosome haplogroups in an association with sex hormone levels.

A late Neolithic expansion of Y chromosomal haplogroup O2a1‐M95 from east to west

AbstractThe origin and dispersal of Y‐Chromosomal haplogroup O2a1‐M95, distributed across the Austro Asiatic speaking belt of East and South Asia, are yet to be fully understood. Various studies have suggested either an East Indian or Southeast Asian origin of O2a1‐M95. We addressed the issue of antiquity and dispersal of O2a1‐M95 by sampling 8748 men from India, Laos, and China and compared them to 3307 samples from other intervening regions taken from the literature. Analyses of haplogroup frequency and Y‐STR data on a total 2413 O2a1‐M95 chromosomes revealed that the Laos samples possessed the highest frequencies of O2a1‐M95 (74% with >0.5) and its ancestral haplogroups (O2*‐P31, O*‐M175) as well as a higher proportion of samples with 14STR‐median haplotype (17 samples in 14 populations), deep coalescence time (5.7 ± 0.3 Kya) and consorted O2a1‐M95 expansion evidenced from STR evolution. All these suggested Laos to carry a deep antiquity of O2a1‐M95 among the study regions. A serial decrease in expansion time from east to west: 5.7 ± 0.3 Kya in Laos, 5.2 ± 0.6 in Northeast India, and 4.3 ± 0.2 in East India, suggested a late Neolithic east to west spread of the lineage O2a1‐M95 from Laos.

Polymorphisms at 17 Y-STR loci in Botswana populations

Seventeen Y-chromosomal short tandem repeats (YSTRs)-DYS19, DYS389I, DYS389II, DYS385a/b, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, and Y-GATA-H4-were analyzed in 252 unrelated male individuals from Botswana. A total of 238 unique haplotypes were identified. The discrimination capacity (DC) was 0.9444 whereas the haplotype diversity (HD) was 0.9990. A database search of the 238 unique haplotypes in the Y chromosome haplogroup database (YHRD) yielded three African American, six Sub-Saharan African, and two admixed South American matches. Five additional African–American matches were detected in the Applied Biosystems Y-STR database. RST, multi-dimensional scaling (MDS) and AMOVA were used to investigate population differentiation in Sub-Saharan Africa and in Botswana. The populations in Sub-Saharan Africa were found to be heterogeneous, with Botswana showing significant differences from its neighbors. No geographic regional or ethnic differentiation was observed within Botswana. Regional and ethnic variation can be useful in forensic working hypotheses.

Traces of forgotten historical events in mountain communities in Central Italy: A genetic insight.

Analysis of human genetic variation in mountain communities can shed light on the peopling of mountainous regions, perhaps revealing whether the remote geographic location spared them from outside invasion and preserved their gene pool from admixture. In this study, we created a model to assess genetic traces of historical events by reconstructing the paternal and maternal genetic history of seven small mountain villages in inland valleys of Central Italy. The communities were selected for their geographic isolation, attested biodemographic stability, and documented history prior to the Roman conquest. We studied the genetic structure by analyzing two hypervariable segments (HVS-I and HVS-II) of the mtDNA D-loop and several informative single nucleotide polymorphisms (SNPs) of the mtDNA coding region in 346 individuals, in addition to 17 short tandem repeats (STRs) and Y-chromosome SNPs in 237 male individuals. For both uniparental markers, most of the haplogroups originated in Western Europe while some Near Eastern haplogroups were identified at low frequencies. However, there was an evident genetic similarity between the Central Italian samples and Near Eastern populations mainly in the male genetic pool. The samples highlight an overall European genetic pattern both for mtDNA and Y chromosome. Notwithstanding this scenario, Y chromosome haplogroup Q, a common paternal lineage in Central/Western Asia but almost Europe-wide absent, was found, suggesting that Central Italy could have hosted a settlement from Anatolia that might be supported by cultural, topographic and genetic evidence.

From Arabia to Iberia: A Y chromosome perspective

At different times during recent human evolution, northern Africa has served as a conduit for migrations from the Arabian Peninsula. Although previous researchers have investigated the possibility of the Strait of Gibraltar as a pathway of migration from North Africa to Iberia, we now revisit this issue and theorize that although the Strait of Gibraltar, at the west end of this corridor, has acted as a barrier for human dispersal into Southwest Europe, it has not provided an absolute seal to gene flow. To test this hypothesis, here we use the spatial frequency distributions, STR diversity and expansion time estimates of Y chromosome haplogroups J1-P58 and E-M81 to investigate the genetic imprints left by the Arabian and Berber expansions into the Iberian Peninsula, respectively. The data generated indicate that Arabian and Berber genetic markers are detected in Iberia. We present evidence that suggest that Iberia has received gene flow from Northwest Africa during and prior to the Islamic colonization of 711A.D. It is interesting that the highest frequencies of Arabia and Berber markers are not found in southern Spain, where Islam remained the longest and was culturally most influential, but in Northwest Iberia, specifically Galicia. We propose that Moriscos' relocations to the north during the Reconquista, the migration of cryptic Muslims seeking refuge in a more lenient society and/or more geographic extensive pre-Islamic incursions may explain the higher frequencies and older time estimates of mutations in the north of the Peninsula. These scenarios are congruent with the higher diversities of some diagnostic makers observed in Northwest Iberia.

Admixed origin of the Kayah (Red Karen) in Northern Thailand revealed by biparental and paternal markers.

This study analyzes the autosomal short tandem repeats (STRs) variation and the presence of Y chromosomal haplogroups from 44 individuals of the Kayah or Red Karen (KA) in Northern Thailand. The results based on autosomal STRs indicated that the KA exhibited closer genetic relatedness to populations from adjacent regions in Southeast Asia (SEA) than populations from Northeast Asia (NEA) and Tibet. Moreover, an admixed origin of the KA forming three population groups was observed: NEA, Southern China, and Northern Thailand. The NEA populations made a minor genetic contribution to the KA, while the rest came from populations speaking Sino-Tibetan (ST) languages from Southern China and Tai-Kadai (TK) speaking groups from Northern Thailand. The presence of six paternal haplogroups, composed of dual haplogroups prevalent in NEA (NO, N, and D1) and SEA (O2 and O3) as well as the intermediate genetic position of the KA between the SEA and NEA also indicated an admixed origin of male KA lineages. Our genetic results thus agree with findings in linguistics that Karenic languages are ST languages that became heavily influenced by TK during their southward spread. A result of the Mongol invasions during the 13th century A.D. is one possible explanation for genetic contribution of NEA to the KA.

Ancient DNA reveals a migration of the ancient Di-qiang populations into Xinjiang as early as the early Bronze Age.

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.

New clustering methods for population comparison on paternal lineages.

The goal of this study is to show two new clustering and visualising techniques developed to find the most typical clusters of 18-dimensional Y chromosomal haplogroup frequency distributions of 90 Western Eurasian populations. The first technique called "self-organizing cloud (SOC)" is a vector-based self-learning method derived from the Self Organising Map and non-metric Multidimensional Scaling algorithms. The second technique is a new probabilistic method called the "maximal relation probability" (MRP) algorithm, based on a probability function having its local maximal values just in the condensation centres of the input data. This function is calculated immediately from the distance matrix of the data and can be interpreted as the probability that a given element of the database has a real genetic relation with at least one of the remaining elements. We tested these two new methods by comparing their results to both each other and the k-medoids algorithm. By means of these new algorithms, we determined 10 clusters of populations based on the similarity of haplogroup composition. The results obtained represented a genetically, geographically and historically well-interpretable picture of 10 genetic clusters of populations mirroring the early spread of populations from the Fertile Crescent to the Caucasus, Central Asia, Arabia and Southeast Europe. The results show that a parallel clustering of populations using SOC and MRP methods can be an efficient tool for studying the demographic history of populations sharing common genetic footprints.

Phylogenetic analysis of two haploid markers of 500-years-old human remains found in a central region of Korea

To understand the genetic history of maternal/paternal lineages of Koreans, we analyzed two haploid markers, mitochondrial DNA (mtDNA), and Y-chromosomal variations, in 25 human remains (dated at about 400–600 years old) excavated from a central region of Korea (Yangchon cemetery of Gimpo-si, Gyeonggi-do). MtDNA control region (HVS-I/II) sequences of 19 ancient human samples from a total of 25 remains were successfully determined by sequencing after PCR-cloning and direct sequencing techniques. Among the 25 remains, 12 individuals were found to be males determined by the amelogenin locus using PCR amplification. We found that the vicinal burial of the remains seemed to be related matrilineally or patrilineally. The most common mtDNA haplogroups were found to be D4a (5/19), followed by D4 (3/19), F1bde (3/19), D4c (2/19), D4g2a (1/19), B5b (1/19), F (1/19), F1a1 (1/19), G4 (1/19), and N9a (1/19), which are prevalent in the Northeast and Southeast Asians, including modern Koreans. On the paternal side, there are three dominant Y chromosome haplogroups C (41.7 %), O3 (25 %), and Y* (33.3 %) in total male samples. The phylogenetic analysis of the mtDNA HVS-I sequence variation revealed both the overall similarity to other northeastern populations, and also a larger genetic contribution from southeastern populations. Thus, these results are consistent with previous reports that the peopling of Korea is likely to have involved multiple sources. Larger sample sizes and additional genetic markers will be necessary to fully understand the population structure and the genetic history of the Koreans.

Ancient DNA evidence reveals that the Y chromosome haplogroup Q1a1 admixed into the Han Chinese 3,000 years ago.

Y chromosome haplogroup Q1a1 is found almost only in Han Chinese populations. However, it has not been found in ancient Han Chinese samples until now. Thus, the origin of haplogroup Q1a1 in Han Chinese is still obscure. This study attempts to provide answer to this question, and to uncover the origin and paternal genetic structure of the ancestors of the Han Chinese. Eighty-nine ancient human remains that were excavated from the presumed geographic source of the Han Chinese and dated to approximately 3,000 years ago were treated by the amelogenin gene polymerase chain reaction test, to determine their sex. Then, Y chromosome single nucleotide polymorphisms were subsequently analyzed from the samples detected as male. Samples from 27 individuals were successfully amplified. Their haplotypes could be attributed to haplogroups N, O*, O2a, O3a, and Q1a1. Analyses showed that the assigned haplogroup of each sample is correlated to the suspected social status and observed burial custom associated with the sample. The origins of the observed haplotypes and their distribution in present day Han Chinese and in the samples suggest that haplogroup Q1a1 was probably introduced into the Han Chinese population approximately 3,000 years ago.