Institute of Rare Diseases, West China Hospital of Sichuan University, Sichuan University, Chengdu, 610041, China.
Center for Archaeological Science, Sichuan University, Chengdu, 610000, China.
BMC Biol. 2024 Jan 25;22(1):18. doi: 10.1186/s12915-024-01828-x.
The underrepresentation of Hmong-Mien (HM) people in Asian genomic studies has hindered our comprehensive understanding of the full landscape of their evolutionary history and complex trait architecture. South China is a multi-ethnic region and indigenously settled by ethnolinguistically diverse HM, Austroasiatic (AA), Tai-Kadai (TK), Austronesian (AN), and Sino-Tibetan (ST) people, which is regarded as East Asia's initial cradle of biodiversity. However, previous fragmented genetic studies have only presented a fraction of the landscape of genetic diversity in this region, especially the lack of haplotype-based genomic resources. The deep characterization of demographic history and natural-selection-relevant genetic architecture of HM people was necessary.
We reported one HM-specific genomic resource and comprehensively explored the fine-scale genetic structure and adaptative features inferred from the genome-wide SNP data of 440 HM individuals from 33 ethnolinguistic populations, including previously unreported She. We identified solid genetic differentiation between HM people and Han Chinese at 7.64‒15.86 years ago (kya) and split events between southern Chinese inland (Miao/Yao) and coastal (She) HM people in the middle Bronze Age period and the latter obtained more gene flow from Ancient Northern East Asians. Multiple admixture models further confirmed that extensive gene flow from surrounding ST, TK, and AN people entangled in forming the gene pool of Chinese coastal HM people. Genetic findings of isolated shared unique ancestral components based on the sharing alleles and haplotypes deconstructed that HM people from the Yungui Plateau carried the breadth of previously unknown genomic diversity. We identified a direct and recent genetic connection between Chinese inland and Southeast Asian HM people as they shared the most extended identity-by-descent fragments, supporting the long-distance migration hypothesis. Uniparental phylogenetic topology and network-based phylogenetic relationship reconstruction found ancient uniparental founding lineages in southwestern HM people. Finally, the population-specific biological adaptation study identified the shared and differentiated natural selection signatures among inland and coastal HM people associated with physical features and immune functions. The allele frequency spectrum of cancer susceptibility alleles and pharmacogenomic genes showed significant differences between HM and northern Chinese people.
Our extensive genetic evidence combined with the historical documents supported the view that ancient HM people originated from the Yungui regions associated with ancient "Three-Miao tribes" descended from the ancient Daxi-Qujialing-Shijiahe people. Then, some have recently migrated rapidly to Southeast Asia, and some have migrated eastward and mixed respectively with Southeast Asian indigenes, Liangzhu-related coastal ancient populations, and incoming southward ST people. Generally, complex population migration, admixture, and adaptation history contributed to the complicated patterns of population structure of geographically diverse HM people.
在亚洲基因组研究中，苗瑶语族（HM）人群的代表性不足，这阻碍了我们全面了解他们进化历史和复杂特征结构的全貌。华南是一个多民族地区，自古以来就有苗瑶语族、南亚语系（AA）、台语系（TK）、南岛语系（AN）和汉藏语系（ST）等民族在此定居，被认为是东亚生物多样性的最初摇篮。然而，以前的零散遗传研究仅呈现了该地区遗传多样性的一部分景观，特别是缺乏基于单倍型的基因组资源。因此，有必要深入研究 HM 人群的人口历史和与自然选择相关的遗传结构。
我们报告了一个 HM 人群特有的基因组资源，并综合分析了来自 33 个民族语言群体的 440 名 HM 个体的全基因组 SNP 数据，全面探讨了他们的精细遗传结构和适应特征，包括以前未报道过的畲族。我们发现 HM 人群与汉族在 7.64 到 15.86 年前（kya）之间存在明显的遗传分化，并且在青铜时代中期，中国南方内陆（苗/瑶）和沿海（畲）HM 人群之间发生了分离事件，后者从古代北亚东部获得了更多的基因流。进一步的多混合模型证实，广泛的基因流来自周围的 ST、TK 和 AN 人群，这些人群交织在一起形成了中国沿海 HM 人群的基因库。基于共享等位基因和单倍型的分离共享独特祖先成分的遗传发现表明，来自云贵高原的 HM 人群携带了以前未知的基因组多样性。我们发现，中国内陆和东南亚的 HM 人群之间存在直接的、最近的遗传联系，因为他们共享最多的扩展身份同源片段，支持长途迁移假说。单倍型进化拓扑和基于网络的进化关系重建发现，西南部 HM 人群存在古老的单倍型创始谱系。最后，人群特异性生物适应性研究发现，内陆和沿海 HM 人群之间存在与身体特征和免疫功能相关的共享和分化的自然选择特征。癌症易感性等位基因和药物基因组学基因的等位基因频率谱在 HM 人群和北方汉族人群之间存在显著差异。
我们广泛的遗传证据与历史文献相结合，支持了这样一种观点，即古代 HM 人群起源于与古代“三苗部落”有关的云贵地区，而这些“三苗部落”则是从古代大溪-屈家岭-石家河文化中衍生而来的。然后，其中一些人最近迅速迁移到东南亚，而另一些人则向东迁移，并分别与东南亚原住民、良渚相关的沿海古代人群以及南迁的 ST 人群混合。总的来说，复杂的人口迁移、混合和适应历史导致了地理上多样化的 HM 人群的复杂群体结构模式。
