Cultural variation impacts paternal and maternal genetic lineages of the Hmong-Mien and Sino-Tibetan groups from Thailand. Human mtDNA and Y-chromosome data from Hmong-Mien and Sino-Tibetan speaking 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.

在泰国，使用苗瑶语族（Hmong-Mien, HM）与汉藏语系（Sino-Tibetan, ST）的族群被统称为山地民族；此类族群曾是首批研究证实父居制与母居制对线粒体DNA（mtDNA）与Y染色体男性特异性区域（MSY）变异模式存在影响的研究对象。然而，此前针对苗瑶语族与汉藏语系族群的研究尚不够深入；本研究报道并分析了来自14个群体的234条Y染色体男性特异性区域（MSY）部分序列（约2.3百万碱基对）与416条完整线粒体DNA序列，结合本团队既往已发表的数据后，本数据集将成为迄今为止针对泰国山地民族的最大规模研究数据集。研究团队发现苗族（Hmong）与勉族（IuMien，使用勉语）群体间存在显著遗传差异：苗族在遗传层面既区别于勉族，也区别于泰国其他所有族群；而勉族在遗传上与其他语族群体的相似性更高，与苗族的相似性则相对较低。总体而言，相较于既往研究，本研究观测到父居制与母居制对线粒体DNA与Y染色体男性特异性区域变异模式的影响程度相对较弱。但在苗瑶语族与汉藏语系族群中，源自东北亚（NEA）与东南亚（SEA）的Y染色体男性特异性区域与线粒体DNA谱系的频率分布却存在显著差异：苗瑶语族群体的Y染色体男性特异性区域谱系中，东北亚起源的谱系占比极高，而线粒体DNA谱系中东北亚起源的占比则较低；汉藏语系族群则呈现出完全相反的模式。一种潜在的解释为：泰国苗瑶语族族群的祖先实行父居制，而泰国汉藏语系族群的祖先实行母居制。综上，本研究结果证实了文化习俗对线粒体DNA与Y染色体男性特异性区域变异模式的影响。