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

Abstract

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 as other Thai groups; 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.

Reconstructing the human genetic history of mainland Southeast Asia: insights from genome-wide data from Thailand and Laos

“…Shared genetic ancestry between Lisu and Lahu is evident in the haplotype sharing and admixture graph results (Figure 4 and 5F; Supplementary Figure 15), although there are differences: Lisu have mixed ancestries probably due to Sinicization in southern China before movement to Thailand (Schliesinger, 2000) or interactions with northern Thai lowlanders after settlement in Thailand (Penth and Forbes, 2004), while the Lahu are more isolated, e.g. the ADMIXTURE result for K = 7 (Supplementary Figure 5) and the IBD sharing results ( Supplementary Figure 7), in agreement with a previous study of uniparental markers (Kutanan et al, 2020). There is strong ancestry sharing between the Thai Lahu and Chinese Lahu (Figures 3-4), and the Chinese Lahu are moreover genetically similar to Vietnamese Lahu (Liu et al, 2020), indicating a close relationship among Lahu from MSEA and China.…”

“…By contrast, the Karen in Thailand are refugees who claim to be the first settlers in Myanmar before the arrival of Mon and Burmese people, and moved from Myanmar beginning around 1750 A.D. due to the growing influence of the Burmese (Kuroiwa and Verkuyten, 2008;Gravers, 2012). The Lawa share ancestry with the Karen_ST (Figure 4; Supplementary Figure 5), in agreement with previous findings of shared MSY haplotypes (Kutanan et al, 2020). Genetic relatedness between Karen and Lawa groups was also reported in a previous genome wide study (Xu et al, 2010).…”

“…Most of the hill tribes are isolated from the lowlanders and from each other, which enhances genetic drift and inbreeding, as found in previous studies of autosomal STR (Kampuansai et al, 2017) and mtDNA and MSY variation (Kutanan et al, 2020). We therefore expected similar indications of isolation in our study, which included eight of the official hill tribes (all but the Akha).…”

“…Living in a remote and isolated region of Thailand, the hill tribes are of interest for their cultural variation in residence pattern after marriage, i.e. patrilocality vs. matrilocality (Oota et al, 2001;Kutanan et al, 2019Kutanan et al, , 2020.…”

“…This population structure and history remains largely unexplored by genetic studies, which have almost exclusively analyzed autosomal short tandem repeat (STR) loci, and mitochondrial DNA (mtDNA) and male specific Y chromosome (MSY) sequences. These studies revealed the relative genetic heterogeneity of the AA groups and homogeneity of TK groups (Kampuansai et al, 2017(Kampuansai et al, , 2020Kutanan et al, 2014Kutanan et al, , 2017Kutanan et al, , 2019Srithawong et al, 2015Srithawong et al, , 2020 and contrasting male and female genetic histories in the region, especially for the matrilocal vs. patrilocal hill tribes (Oota et al, 2001;Kutanan et al, 2018aKutanan et al, , 2019Kutanan et al, , 2020. While genome-wide data provide much richer insights into population structure and genetic history, previous genome-wide studies of Thai/Lao populations are either primarily from northern populations (HUGO Pan-Asian SNP Consortium, 2009;Xu et al, 2010;Lipson et al, 2018) or do not provide any information on ethnolinguistic background (Wangkumhang et al, 2013;Lazaridis et al, 2014).…”