通过Y染色体谱系探寻汉藏语系人群分化的早期历史

The Sino-Tibetan language family includes Chinese, Tibetan, Burmese etc., whose mother language speakers comprise >90% of all Chinese population. The phylogeny of Sino-Tibetan-speaking populations has long been unclear, with several competing hypothesis. It is known that the phylogeny of male-specific Y chromosome is highly correlated with language classification, which makes it a tool for tracing the formation history of Sino-Tibetan-speaking populations. Our research group has accumulated >4000 blood samples from >30 populations in 9 language clades of Sino-Tibetan languages, and found that the only prevalent and frequent haplogroup among all these language clades is O-M117. Using high-throughput sequencing of Y chromosome, we discovered an intensive star-like expansion inside O-M117 at ~6000 years ago, which matches the expansion time of Sino-Tibetan language family according to linguistic calculations, indicating that this haplogroup is characteristic for Sino-Tibetan languages. ..In this project, we will do sequence capturing of all the 10 Mbp non-repetitive and non-recombining region of Y chromosome of 120 male samples of each Sino-Tibetan language clades, and do high-throughput sequencing, in order to discover new polymorphism, reconstruct a detailed phylogenetic tree, calculate the divergence and expansion age of the clades, and understand the divergence order and time among the populations. We will also explore the non-Sino-Tibetan components in each contemporary Sino-Tibetan populations, and the composition, proportion and date of mixing, in order to understand a more comprehensive history of early formation of the Sino-Tibetan populations.

汉藏语系包括汉语、藏语、缅语等，其母语人口占中国90%以上。长期以来，汉藏语系的人群谱系并不明确，存在多种假说。已知男性特有的Y染色体的谱系与语言分类高度相关，能以此追踪汉藏语系人群的形成历史。本课题组已积累了汉藏语系9个语支30余个人群的4000余份血液样本，发现各语支共享唯一普遍高频的单倍群O-M117。通过Y染色体高通量测序，我们发现该单倍群在约6000年前发生过一次强烈的星状扩张，接近语言学计算的汉藏语系的扩张时间，表明这是汉藏语系的特征支系。..本研究将对汉藏语系各语支120份男性样本的Y染色体非重组区全部约10 Mbp非重复区进行序列捕获及高通量测序，发现其中新的多态位点，构建详细的谱系树，并计算各支系分化和扩张年代，理清各语支人群之间的分化顺序及时间。我们也将探索现代汉藏语系各族群形成过程中融入的非汉藏语人群的组成、比例及融合年代，以全面认识这些族群的早期形成史。

汉藏语系包括汉语、藏语、缅语等400多种语言，其母语人口占中国90%以上。长期以来，汉藏语系的人群谱系并不明确，存在多种假说。已知男性特有的Y染色体的谱系与语言分类高度相关。我們发现汉藏语系各语支人群共享唯一普遍高频的单倍群O-M117支系，认为通过该单倍群的树形可以揭示汉藏语系人群的早期发展历史。..本项目中，我们通过对分布在多个族群的上百个属O-M117支系的男性Y染色体的>10 Mbp区域的高通量测序，构建了该支系的详细树形，并重新计算了扩张年代。结果重现了之前在O-M117支系下发现的Oα-F5星状扩张（扩张时间在约7700年前），发现该扩张下游的主要分支及其上游的分支均基本分布在汉族中，而藏缅语族的O-M117仅集中在下游的Oα1c1-CTS1462中（内部扩张时间约为6300年前之后）。这说明汉藏语系的早期扩张的大部分后代均进入了汉族中，而藏缅语族由其中分出的一支发展而来。这与以往语言学界对汉藏语系早期发展的几种假说均完全不同，但和考古学的发现可以对应，即汉族和整体汉藏语系对应早期农业产生的老官台及仰韶文化，而藏缅语族群由从仰韶文化分支出来的马家窑文化发展而来。..本项目得到的发现为汉藏语系和汉族的起源和演化提供了全新的假说，为解开中国人群的史前和历史时期形成之谜提供了重要材料。