Indian genetic heritage in Southeast Asian populations.

The great ethnolinguistic diversity found today in mainland Southeast Asia (MSEA) reflects multiple migration waves of people in the past. Maritime trading between MSEA and India was established at the latest 300 BCE, and the formation of early states in Southeast Asia during the first millennium CE was strongly influenced by Indian culture, a cultural influence that is still prominent today. Several ancient Indian-influenced states were located in present-day Thailand, and various populations in the country are likely to be descendants of people from those states. To systematically explore Indian genetic heritage in MSEA populations, we generated genome-wide SNP data (using the Affymetrix Human Origins array) for 119 present-day individuals belonging to 10 ethnic groups from Thailand and co-analyzed them with published data using PCA, ADMIXTURE, and methods relying on f-statistics and on autosomal haplotypes. We found low levels of South Asian admixture in various MSEA populations for whom there is evidence of historical connections with the ancient Indian-influenced states but failed to find this genetic component in present-day hunter-gatherer groups and relatively isolated groups from the highlands of Northern Thailand. The results suggest that migration of Indian populations to MSEA may have been responsible for the spread of Indian culture in the region. Our results also support close genetic affinity between Kra-Dai-speaking (also known as Tai-Kadai) and Austronesian-speaking populations, which fits a linguistic hypothesis suggesting cladality of the two language families.

Forensic efficiency and genetic polymorphisms of 12 X-chromosomal STR loci in Northeastern Thai populations.

Northeastern Thailand comprises one-third of the country and is home to various populations, with Lao Isan constituting the majority, while others are considered minority groups. Previous studies on forensic short tandem repeats (STRs) in Thailand predominantly focused on autosomal STRs but there was a paucity of X-STRs, exclusively reported from the North and Central regions of the country. In this study, we have newly established a 12 X-STRs from a total of 896 samples from Northeastern Thailand, encompassing Lao Isan as the major group in the region, alongside nine minor populations (Khmer, Mon, Nyahkur, Bru, Kuy, Phutai, Kalueang, Nyaw, and Saek). Across all ten populations, the combined powers of discrimination in both genders were high and the combined mean exclusion chance (MEC) indices calculated for deficiency, normal trio and duo cases were also high (> 0.99999). DXS10148 emerged as the most informative marker, while DXS7423 was identified as the least informative. Genetic comparison based on X-STRs frequency supported genetic distinction of cerain minor groups such as Kuy, Saek and Nyahkur from other northeastern Thai groups as well as genetic differences according to the geographic region of Thai groups (Northeast, North and Central). In sum, the overall results on population genetics are in agreement with earlier reports on other genetic systems, indicating the informativeness of X-STRs for use in anthropological genetics studies. From a forensic perspective, despite the limitations of small sample sizes for minority groups, the present results contribute to filling the gap in the reference X-STRs database of the major group Lao Isan, providing valuable frequency data for forensic applications in Thailand and neighboring countries.

Reconstructing the Human Genetic History of Mainland Southeast Asia: Insights from Genome-Wide Data from Thailand and Laos.

Thailand and Laos, located in the center of Mainland Southeast Asia (MSEA), harbor diverse ethnolinguistic groups encompassing all five language families of MSEA: Tai-Kadai (TK), Austroasiatic (AA), Sino-Tibetan (ST), Hmong-Mien (HM), and Austronesian (AN). Previous genetic studies of Thai/Lao populations have focused almost exclusively on uniparental markers and there is a paucity of genome-wide studies. We therefore generated genome-wide SNP data for 33 ethnolinguistic groups, belonging to the five MSEA language families from Thailand and Laos, and analyzed these together with data from modern Asian populations and SEA ancient samples. Overall, we find genetic structure according to language family, albeit with heterogeneity in the AA-, HM-, and ST-speaking groups, and in the hill tribes, that reflects both population interactions and genetic drift. For the TK speaking groups, we find localized genetic structure that is driven by different levels of interaction with other groups in the same geographic region. Several Thai groups exhibit admixture from South Asia, which we date to ∼600-1000 years ago, corresponding to a time of intensive international trade networks that had a major cultural impact on Thailand. An AN group from Southern Thailand shows both South Asian admixture as well as overall affinities with AA-speaking groups in the region, suggesting an impact of cultural diffusion. Overall, we provide the first detailed insights into the genetic profiles of Thai/Lao ethnolinguistic groups, which should be helpful for reconstructing human genetic history in MSEA and selecting populations for participation in ongoing whole genome sequence and biomedical studies.

Close genetic relationship between central Thai and Mon people in Thailand revealed by autosomal microsatellites.

Central Thailand is home to diverse populations with the central Thai constituting the major group, while the Mon, who migrated from southern Myanmar, are sparsely distributed within the region. A total of 338 individuals of eight central Thai (246 samples) and three Mon populations (92 samples) were newly genotyped. When combined with our previously published Mon data, this provides a total of 139 Mon samples. We found genetic similarity between the central Thai and Mon and weak sub-structuring among Thais from central, northern, and northeastern Thailand. The forensic parameter results show high discrimination values which are appropriate for forensic personal identification and paternity testing in both the central Thai and Mon; the probabilities of excluding paternity are 0.999999112 and 0.999999031, respectively, and the combined discrimination power is 0.9999999999999999999999 in both groups. This regional allelic frequency on forensic microsatellites may serve as a useful reference for further forensic investigations in both Thailand and Myanmar.

Contrasting Paternal and Maternal Genetic Histories of Thai and Lao Populations.

The human demographic history of Mainland Southeast Asia (MSEA) has not been well studied; in particular, there have been very few sequence-based studies of variation in the male-specific portions of the Y chromosome (MSY). Here, we report new MSY sequences of ∼2.3 mB from 914 males and combine these with previous data for a total of 928 MSY sequences belonging to 59 populations from Thailand and Laos who speak languages belonging to three major Mainland Southeast Asia families: Austroasiatic, Tai-Kadai, and Sino-Tibetan. Among the 92 MSY haplogroups, two main MSY lineages (O1b1a1a* [O-M95*] and O2a* [O-M324*]) contribute substantially to the paternal genetic makeup of Thailand and Laos. We also analyze complete mitochondrial DNA genome sequences published previously from the same groups and find contrasting pattern of male and female genetic variation and demographic expansions, especially for the hill tribes, Mon, and some major Thai groups. In particular, we detect an effect of postmarital residence pattern on genetic diversity in patrilocal versus matrilocal groups. Additionally, both male and female demographic expansions were observed during the early Mesolithic (∼10 ka), with two later major male-specific expansions during the Neolithic period (∼4-5 ka) and the Bronze/Iron Age (∼2.0-2.5 ka). These two later expansions are characteristic of the modern Austroasiatic and Tai-Kadai groups, respectively, consistent with recent ancient DNA studies. We simulate MSY data based on three demographic models (continuous migration, demic diffusion, and cultural diffusion) of major Thai groups and find different results from mitochondrial DNA simulations, supporting contrasting male and female genetic histories.

Genetic structure of the ethnic Lao groups from mainland Southeast Asia revealed by forensic microsatellites.

PURPOSE: Laotians and Lao Isan are widely spread Lao groups who live in Laos and northeastern Thailand, respectively. We explored the genetic structure between them and other ethnic groups from Thailand to clarify historical patterns of admixture between Tai-Kadai and Austroasiatic speakers, and to expand the forensic reference database for the region. SUBJECTS AND METHODS: We combined new genetic data for 554 individuals from 12 populations, typed for 15 autosomal short tandem repeats, with available data from 14 populations from Thailand, for a total of 1,153 raw genotypes belonging to 26 populations. We calculated forensic parameters and performed various analyses on genetic diversity, genetic structure, genetic admixture, and genetic relationships among the studied populations. RESULTS: Forensic estimators suggest a good power of discrimination with the combined power of exclusion ranging from 0.993628 to 0.999991 and a combined power of discrimination value greater than 0.99999999. Generally, the two Laotian groups were genetically similar, but the central Laotians from Vientiane have a closer genetic relationship to the Lao Isan than the northern Laotians from Luang Prabang. The Lao genetic ancestry forms the majority of the Lao Isan genetic makeup, while Austroasiatic ancestry is present at ∼10%-50%. CONCLUSIONS: Lao Isan populations show signs of Lao ancestry and admixture with local Austroasiatic ancestry, which reflect historical migrations from Laos to Thailand. Lao speakers are genetically more homogeneous than Austroasiatic speakers, suggesting differential historical processes.

Paternal genetic history of the Yong population in northern Thailand revealed by Y-chromosomal haplotypes and haplogroups.

We have determined the distribution of Y-chromosomal haplotypes and haplogroups in the Yong population, one of the largest and well-known ethnic groups that began migrating southward from China to Thailand centuries ago. Their unique mass migration pattern provided great opportunities for researchers to study the genetic links of the transboundary migration movements among the peoples of China, Myanmar and Thailand. We analysed relevant male-specific markers, such as Y-STRs and Y-SNPs, and the distribution of 23 Y-STRs of 111 Yong individuals and 116 nearby ethnic groups including the Shan, Northern Thai, Lawa, Lua, Skaw, Pwo and Padong groups. We found that the general haplogroup distribution values were similar among different populations; however, the haplogroups O1b-M268 and O2-M112 constituted the vast majority of these values. In contrast with previous maternal lineage studies, the paternal lineage of the Yong did not relate to the Xishuangbanna Dai people, who represent their historically documented ancestors. However, they did display a close genetic affinity to other prehistoric Tai-Kadai speaking groups in China such as the Zhuang and Bouyei. Low degrees of genetic admixture within the populations who belonged to the Austroasiatic and Sino-Tibetan linguistic families were observed in the gene pool of the Yong populations. Resettlement in northern Thailand in the early part of the nineteenth century AD, by way of mass migration trend, was able to preserve the Yong's ancestral genetic background in terms of the way they had previously lived in China and Myanmar. Our study has revealed similar genetic structures among ethnic populations in northern Thailand and southern China, and has identified and emphasized an ancient Tai-Kadai patrilineal ancestry line in the Yong ethnic group.

Allelic frequencies of fifteen autosomal STRs in the northeastern Thai people.

We genotyped 15 autosomal STRs loci in 1780 unrelated northeastern Thai individuals. Allele frequencies were computed and all of the loci reached Hardy-Weinberg equilibrium. The forensic parameter results showed high discrimination values which are suitable for forensic personal identification and paternity testing; the combined discrimination power and probability of excluding paternity were 0.9999999999999999999999 and 0.999998449, respectively. Genetic relatedness of northeastern Thais with comparable Thai and Asian populations using phylogenetic analysis revealed close genetic relationship between Mainland Southeast Asian populations and southern Chinese populations.

Complete mitochondrial genomes of Thai and Lao populations indicate an ancient origin of Austroasiatic groups and demic diffusion in the spread of Tai-Kadai languages.

The Tai-Kadai (TK) language family is thought to have originated in southern China and spread to Thailand and Laos, but it is not clear if TK languages spread by demic diffusion (i.e., a migration of people from southern China) or by cultural diffusion, with native Austroasiatic (AA) speakers switching to TK languages. To address this and other questions, we obtained 1234 complete mtDNA genome sequences from 51 TK and AA groups from Thailand and Laos. We find high genetic heterogeneity across the region, with 212 different haplogroups, and significant genetic differentiation among different samples from the same ethnolinguistic group. TK groups are more genetically homogeneous than AA groups, with the latter exhibiting more ancient/basal mtDNA lineages, and showing more drift effects. Modeling of demic diffusion, cultural diffusion, and admixture scenarios consistently supports the spread of TK languages by demic diffusion.

Effect of migration patterns on maternal genetic structure: a case of Tai-Kadai migration from China to Thailand.

The migration of the Tai-Kadai speaking people from southern China to northern Thailand over the past hundreds of years has revealed numerous patterns that have likely been influenced by routes, purposes and periods of time. To study the effects of different migration patterns on Tai-Kadai maternal genetic structure, mitochondrial DNA hypervariable region I sequences from the Yong and the Lue people having well-documented histories in northern Thailand were analyzed. Although the Yong and Lue people were historically close relatives who shared Xishuangbanna Dai ancestors, significant genetic differences have been observed among them. The Yong people who have been known to practice mass migration have exhibited a closer genetic affinity to their Dai ancestors than have the Lue people. Genetic heterogeneity and a sudden reduced effective population size within the Lue group is likely a direct result of the circumstances of the founder effect.

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.

Genetic and linguistic correlation of the Kra-Dai-speaking groups in Thailand.

The Kra-Dai linguistic family includes Thai and Lao as well as a great number of languages spoken by ethnic minorities in Southeast Asia. In Thailand, a dozen of other Kra-Dai languages are spoken in addition to Thai, the national language. The genetic structure of the Kra-Dai-speaking populations in Thailand has been studied extensively using uniparentally inherited markers. To extend this line of genetic investigation, this study used 15 autosomal microsatellites of 500 individuals from 11 populations, belonging to nine Kra-Dai ethnicities, namely, the Kaleung, Phu Thai, Saek, Nyo, Lao Isan, Yuan, Black Tai, Phuan and Lue. These ethnolinguistic groups are dispersed in three different geographic regions of Thailand, that is, Northern, Northeastern and Central. The results show a very low average of pairwised F(st) (0.0099), as well as no population substructure based on STRUCTURE analysis, indicating genetic homogeneity within the Kra-Dai-speaking group, possibly owing to shared linguistic ancestry. The Mantel test, an analysis of molecular variance, and the approximate Bayesian computation procedure employed to evaluate potential factors for driving genetic diversity revealed that language is the predominant factor affecting genetic variations, whereas geography is not. The result of distance-based clustering analyses and spatial analysis of molecular variance revealed genetic distinctions of some populations, reflecting the effects of genetic drift and gene flow on allele frequency within populations, in concordance with the result of R-matrix regression. The genetic and linguistic affiliations of the contemporary Kra-Dai-speaking groups are consistent with each other despite certain deviation due to various evolutionary factors that may have occurred during their migrations and resettlements.

Forensic STR loci reveal common genetic ancestry of the Thai-Malay Muslims and Thai Buddhists in the deep Southern region of Thailand.

Among the people living in the five deep Southern Thai provinces, Thai-Malay Muslims (MUS) constitute the majority, while the remaining are Thai Buddhists (BUD). Cultural, linguistic and religious differences between these two populations have been previously reported. However, their biological relationship has never been investigated. In this study, we aimed to reveal the genetic structure and genetic affinity between MUS and BUD by analyzing 15 autosomal short tandem repeats. Both distance and model-based clustering methods showed significant genetic homogeneity between these two populations, suggesting a common biological ancestry. After Islamization in this region during the fourteenth century AD, gradual albeit nonstatistically significant genetic changes occurred within these two populations. Cultural barriers possibly influenced these genetic changes. MUS have closer admixture to Malaysian-Malay Muslims than BUD countrywide. Admixture proportions also support certain degree of genetic dissimilarity between the two studied populations, as shown by the unequal genetic contribution from Malaysian-Malay Muslims. Cultural transformation and recent minor genetic admixture are the likely processes that shaped the genetic structure of both MUS and BUD.

Geography has more influence than language on maternal genetic structure of various northeastern Thai ethnicities.

Several literatures have shown the influence of geographic and linguistic factors in shaping genetic variation patterns, but their relative impact, if any, in the very heterogeneous northeastern region of Thailand has not yet been studied. This area, called Isan, is geographically structured in two wide basins, the Sakon Nakorn Basin and the Korat Basin, serving today as home to diverse ethnicities encompassing two different linguistic families, that is, the Austro-Asiatic; Suay (Kui), Mon, Chaobon (Nyahkur), So and Khmer, and the Tai-Kadai; Saek, Nyaw, Phu Tai, Kaleung and Lao Isan. In this study, we evaluated the relative role of geographic distance and barriers as well as linguistic differences as possible causes affecting the maternal genetic distances among northeastern Thai ethnicities. A 596-bp segment of the hypervariable region I mitochondrial DNA was utilized to elucidate the genetic structure and biological affinity from 433 individuals. Different statistical analyses agreed in suggesting that most ethnic groups in the Sakon Nakorn Basin are closely related. Mantel test revealed that genetic distances were highly associated to geographic (r = 0.445, P<0.01) but not to linguistic (r = 0.001, P>0.01) distances. Three evolutionary models were compared by Approximate Bayesian Computation. The posterior probability of the scenario, which assumed an initial population divergence possibly related to reduced gene flow among basins, was equal or higher than 0.87. All analyses exhibited concordant results supporting that geography was the most relevant factor in determining the maternal genetic structure of northeastern Thai populations.

Thai Twin Registry: description of the initial stage.

The present study describes the initial phase of the Thai Twin Registry (TTR) in Khon Kaen University, a pioneer research university located in the Northeast of Thailand. The initial steps of the study included the analysis of dermatoglyphic information in Thai twins for answering the research question: Are monozygotic (MZ) and dizygotic (DZ) twins different in dermatoglyphic variables? Subjects were 212 twin pairs (131 MZ and 81 [corrected] DZ), consisting of 155 males and 269 females. Four types of fingerprint pattern (FP) - that is, arch, radial loop, ulnar loop, and whorl - were classified and analyzed and compared between MZ and DZ twins. The arch radial loop and whorl frequencies differ between MZ and DZ twins. When comparing FP in each finger, only the right little finger shows a statistically different FP, while the FP similarity average from 10 homologous fingers of co-twins was greater in MZ than DZ twins. By using the Area Under the Receiver Operating Characteristic curve analysis, the MZ twins could be differentiated from DZ twins by the FP similarity. Summarizing, this valuable report about TTR was conducted by analysis of FP data, which indicated that the MZ and DZ twins exhibited FP pattern and FP similarity differences. Other dermatoglyphic studies of the existing FP database, such as finger ridge count, finger ridge density, and minutia, will be considered for ongoing research at the TTR.

South Asian maternal and paternal lineages in southern Thailand and the role of sex-biased admixture.

Previous genome-wide studies have reported South Asian (SA) ancestry in several Mainland Southeast Asian (MSEA) populations; however, additional details concerning population history, in particular the role of sex-specific aspects of the SA admixture in MSEA populations can be addressed with uniparental markers. Here, we generated ∼2.3 mB sequences of the male-specific portions of the Y chromosome (MSY) of a Tai-Kadai (TK)-speaking Southern Thai group (SouthernThai_TK), and complete mitochondrial (mtDNA) genomes of the SouthernThai_TK and an Austronesian (AN)-speaking Southern Thai (SouthernThai_AN) group. We identified new mtDNA haplogroups, e.g. Q3, E1a1a1, B4a1a and M7c1c3 that have not previously reported in Thai populations, but are frequent in Island Southeast Asia and Oceania, suggesting interactions between MSEA and these regions. SA prevalent mtDNA haplogroups were observed at frequencies of ~35-45% in the Southern Thai groups; both of them showed more genetic relatedness to Austroasiatic (AA) speaking Mon than to any other group. For MSY, SouthernThai_TK had ~35% SA prevalent haplogroups and exhibited closer genetic affinity to Central Thais. We also analyzed published data from other MSEA populations and observed SA ancestry in some additional MSEA populations that also reflects sex-biased admixture; in general, most AA- and AN-speaking groups in MSEA were closer to SA than to TK groups based on mtDNA, but the opposite pattern was observed for the MSY. Overall, our results of new genetic lineages and sex-biased admixture from SA to MSEA groups attest to the additional value that uniparental markers can add to studies of genome-wide variation.

Women's wellness in the mountains: An exploration of medicinal plants among tibeto-burman groups in Thailand.

Ethnopharmacological relevance: This study offers valuable insight into the traditional healing practices of women's healthcare within four Tibeto-Burman groups. By focusing on women's wellness, the research sheds light on the often-neglected yet significant contributions made by women in the field of traditional medicine. Aims of the study: The study seeks to address the gap of studies on the ethnobotany of women healthcare of the Tibeto-Burman groups in Thailand and to analyst the factors that could affect the diversity of ethnobotanical knowledge. Materials and methods: The study compiled data from 15 group-informants residing in 12 different villages. The information gathering process involved a combination of free-listing, semi-structured interviews, group discussion, and the walk-to-the-wood method. To analyze the data, the researchers used various methods such as use-reports, Relative Frequency of Citation (RFC), Relative Importance Index (RI), and Cluster analysis. Results: This study identified 200 plant species used in traditional women's healthcare practices, with leaves being the most frequently used part. Drinking was the most common method for internal use, while bathing and steam were the most emphasized for external use. Blumea balsamifera and Buddleja asiatica had high RI and RFC. Cluster analysis revealed that group-informants were divided by ethnicity and geographical location. Conclusion: This study contributes to the understanding of traditional healthcare practices among Tibeto-Burman groups in Thailand, with a particular focus on women's wellness. The results provide insight into the ethnobotanical knowledge of these communities and highlight the important role played by women in traditional medicine. The study underscores the need for continued research in this field to preserve and utilize this valuable knowledge.

Genetic diversity and ancestry of the Khmuic-speaking ethnic groups in Thailand: a genome-wide perspective.

The Khmuic-speaking populations are believed to be the descendants of one of the earliest groups to settle in Mainland Southeast Asia. In Thailand, there are two agricultural Khmuic-speaking ethnic groups, the Khamu and Lua (Htin). These peoples primarily reside in scattered locations along the mountainous Thailand-Laos border in Nan province. In this study, we conducted genome-wide SNP analysis on 81 individuals from three Khamu and two Lua villages in northern Thailand. Our findings revealed that both the Khamu and Lua groups possess genetic structures that are distinct from other ethnicities in Southeast Asia, indicating a unique history of migration and settlement. Within the Khmuic group, the Khamu populations living in different locations exhibited similar genetic structures and displayed genetic affinities only with some hill-tribes and Tai-Kadai (Kra-Dai)-speaking groups in Thailand, suggesting potential intermixing or cultural exchange. Furthermore, the Lua people displayed a distinctive population structure, which could be attributed to the founder effect and endogamous marriage practices. Additionally, we discovered a relationship between the Khmuic-speaking populations in Thailand and a Neolithic ancient sample obtained from the Tham Pha Ling archaeological site in Laos. This study provides new insight into genetic substructure within the Khmuic-speaking people and their potential relationship to the indigenous inhabitants of Mainland Southeast Asia.

Genomic portrait and relatedness patterns of the Iron Age Log Coffin culture in northwestern Thailand.

The Iron Age of highland Pang Mapha, northwestern Thailand, is characterised by a mortuary practice known as Log Coffin culture. Dating between 2300 and 1000 years ago, large coffins carved from individual teak trees have been discovered in over 40 caves and rock shelters. While previous studies focussed on the cultural development of the Log Coffin-associated sites, the origins of the practice, connections with other wooden coffin-using groups in Southeast Asia, and social structure within the region remain understudied. Here, we present genome-wide data from 33 individuals from five Log Coffin culture sites to study genetic ancestry profiles and genetic interconnectedness. The Log Coffin-associated genomes can be modelled as an admixture between Hòabìnhian hunter-gatherer-, Yangtze River farmer-, and Yellow River farmer-related ancestry. This indicates different influence spheres from Bronze and Iron Age individuals from northeastern Thailand as reflected by cultural practices. Our analyses also identify close genetic relationships within the sites and more distant connections between sites in the same and different river valleys. In combination with high mitochondrial haplogroup diversity and genome-wide homogeneity, the Log Coffin-associated groups from northwestern Thailand seem to have been a large, well-connected community, where genetic relatedness played a significant role in the mortuary ritual.