Biology subjects

Srikummool, M.

Publications and source records attributed to Srikummool, M..

5 recordsLinked to original sources

bioRxiv2024

Under the name of "Lua": Revisiting Genetic Heterogeneity and Population Ancestry of Austroasiatic speakers in Northern Thailand Through Genomic Analysis

Austroasiatic (AA)-speaking populations in northern Thailand are of significant interest due to their status as indigenous descendants and their location at the crossroads of AA prehistoric distribution across Southern China, the Indian Subcontinent, and Mainland Southeast Asia. However, the complexity of ethnic identification can result in inaccuracies regarding the origin and migration history of these populations. To address this, we conducted a genome-wide SNP analysis on 89 individuals from two Lavue- and three Lwa-endonym populations and combined them with previously published data to elucidate the genetic diversity and clustering of AA groups in northern Thailand. Our findings align with linguistic classifications, revealing distinct genetic structure among the three branches of the Mon-Khmer subfamily within the AA family: Monic, Khmuic, and Palaungic. Although the term "Lua" ethnicity is used confusingly to identify ethnic groups belonging to both Khmuic and Palaungic branches, our genomic data clarifies that the Khmuic-speaking Lua living on the eastern side of the region show genetic differentiation from the Palaungic-speaking Lavue and Lwa populations living on the western side. Within the Palaungic branch, the Dara-ang population stands out as genetically distinct, reflecting remnants of ancient ancestry. The Lavue populations, mainly inhabiting mountainous areas, exhibit a genetic makeup unique to the AA family, with a close genetic relationship to the Karenic subgroup of the ST family. Conversely, the Lwa and Blang populations, residing in lowland river valleys, display genetic signatures resulting from admixture with Tai-Kadai-speaking ethnic groups. Author summaryIn the past, many Austroasiatic speakers in northern Thailand concealed their identity due to perceptions of inferiority compared to the majority Tai-Kadai-speaking group in the region. However, attitudes have shifted in the modern era, with a greater appreciation for ethnic diversity and the unique aspects of different valuable cultures. This scenario provides an opportunity for us to use genetic insights to untangle the complexities of ethnic identification among these indigenous inhabitants of Mainland Southeast Asia. Through our genetic analysis, we aimed to shed light on the ancestry and diversity of the Austroasiatic people in northern Thailand, often collectively referred to as "Lua" or "Lawa", which is an exonym (a name of the ethnic group created by another group of people) commonly used in prior scientific reports. Our findings clearly indicate genetic distinctions among the Lua, Lavue, and Lwa ethnic groups. The intricate interplay of genetics, cultural heritage, and historical influences has shaped these ethnic communities. Our study underscores the importance of accurate ethnic classifications, emphasizing the use of self-identified endonyms, names created and used by the ethnic group themselves. This approach respects the Austroasiatic communities in northern Thailand and acknowledges their significant contributions to advancing our understanding of genetic anthropology.

evolutionary biology↗

bioRxiv2020

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 analysed 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.

genomics↗

bioRxiv2020

Cultural variation impacts paternal and maternal genetic lineages of the 1 Hmong-Mien and Sino-Tibetan groups from Thailand

The Hmong-Mien (HM) and Sino-Tibetan (ST) speaking groups are known as hill tribes in Thailand; they were the subject of the first studies to show an impact of patrilocality vs. matrilocality on patterns of mitochondrial (mt) DNA vs. male-specific portion of the Y chromosome (MSY) variation. However, HM and ST groups have not been studied in as much detail; here we report and analyze 234 partial MSY sequences ([~]2.3 mB) and 416 complete mtDNA sequences from 14 populations that, when combined with our previous published data, provides the largest dataset yet for the hill tribes. We find a striking difference between Hmong and IuMien (Mien-speaking) groups: the Hmong are genetically different from both the IuMien and all other Thai groups, whereas the IuMien are genetically more similar to other linguistic groups than to the Hmong. In general, we find less of an impact of patrilocality vs. matrilocality on patterns of mtDNA vs. MSY variation than previous studies. However, there is a dramatic difference in the frequency of MSY and mtDNA lineages of Northeast Asian (NEA) origin vs. Southeast Asian (SEA) origin in HM vs. ST groups: HM groups have high frequencies of NEA MSY lineages but lower frequencies of NEA mtDNA lineages, while ST groups show the opposite. A potential explanation is that the ancestors of Thai HM groups were patrilocal, while the ancestors of Thai ST groups were matrilocal. Overall, these results attest to the impact of cultural practices on patterns of mtDNA vs. MSY variation.

genetics↗

bioRxiv2019

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 MSEA families: Austroasiatic (AA), Tai-Kadai (TK) and Sino-Tibetan (ST). 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 analyse complete mtDNA 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 post-marital residence pattern on genetic diversity in patrilocal vs. matrilocal groups. Additionally, both male and female demographic expansions were observed during the early Mesolithic ([~]10 kya), with two later major male-specific expansions during the Neolithic period ([~]4-5 kya) and the Bronze/Iron Age ([~]2.0-2.5 kya). These two later expansions are characteristic of the modern AA and TK 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 mtDNA simulations, supporting contrasting male and female genetic histories.

genetics↗

bioRxiv2017

New insights from Thailand into the maternal genetic history of Mainland Southeast Asia

Tai-Kadai (TK) is one of the major language families in Mainland Southeast Asia (MSEA), with a concentration in the area of Thailand and Laos. Our previous study of 1,234 mtDNA genome sequences supported a demic diffusion scenario in the spread of TK languages from southern China to Laos as well as northern and northeastern Thailand. Here we add an additional 560 mtDNA sequences from 22 groups, with a focus on the TK-speaking central Thai people and the Sino-Tibetan speaking Karen. We find extensive diversity, including 62 haplogroups not reported previously from this region. Demic diffusion is still a preferable scenario for central Thais, emphasizing the extension and expansion of TK people through MSEA, although there is also some support for an admixture model. We also tested competing models concerning the genetic relationships of groups from the major MSEA languages, and found support for an ancestral relationship of TK and Austronesian-speaking groups.

genetics↗