Reconstructions Of The Fine-scale Population Genetic Structure And Evolutionary History Of Guizhou Mongolian,manchu And Maonan Populations Based On The Genome-wide Variations

Objective:To exploring the fine-scale genetic structure and complex evolutionary history of Altaic-speaking Mongolian,Manchu and Tai-Kadai-speaking Maonan populations in Guizhou province based on genome-wide high-density genetic variation information analysis,providing reference data for the study of regional origin and phenotypic inference of major ethnic groups in Guizhou.Methods:We collected 28 samples of Manchu unrelated individuals in Jinsha County,27samples of Manchu unrelated individuals in Bijie County,26 unrelated samples of Mongolian unrelated individuals in Bijie County,and 41 samples of unrelated Maonan individuals in Pingtang County from Guizhou Province in southwestern China.We used a commercial kit to extract DNA and used Nanodrop nucleic acid concentration analyzer,gel electrophoresis and other DNA quality inspection,quantitative to measure the DNA concentration.We generated genome-wide SNP data including nearly 700,000 single-nucleotide polymorphisms（SNPs）by using the Infinium Global Screening Array.We merged our new data with the Human Origin dataset and the 1240K dataset and performed principal component analysis and ADMIXTURE analysis to explore the overall genetic structure and genetic component composition of the studied populations.Tree Mix was aslo used to explore the phylogenetic relationship between the studied populations and other East Asian populations.Outgroup-f₃-statistics was used to explore the general patterns of relatedness between research populations and published populations.The genetic affinity of the studied populations with reference populations and potential ancestral sources of studied populations were conducted by admixture-f₃-statistics and f₄-statistics.We used qpWave and qpAdm to explore the minimum ancestral source numbers and estimate ancestry proportion of the studied populations,and ALDER software was estimated to date admixture events.We finally performed qpGraph analysis to constructct the evolutional history of studied populations.Assigning haplotype,counting number and calculating frequency of haplogroups to infer the uniparental admixture history of our studied populations.Results:Results from principal component analysis based on high-density SNPs data showedthefourfollowinggeneticclusters:Altaic,Austronesian/Austroasiatic/Tai-Kadai,Hmong-Mien and Sino-Tibetan speaking population clusters.Our studied Tungusic and Mongolic-speaking populations from Guizhou province formed a unique genetic cluster,which was located at an intermediate position between the western Tibetan Plateau cluster and Hmong-Mien cluster and partially overlapped with previously published Sinitic and Hmong-Mien speaking populations.Results from ADMIXTURE and f-statistics further showed that the studied Guizhou Mongolians and Manchus had a strong genetic affinity with southern East Asians,especially for inland southern East Asians.The qpAdm-based ancestries admixture models demonstrated that Guizhou Mongolians and Manchus people could be modeled as the admixture of one northern ancestry related to Tungusic/Mongolic speakers or Yellow River farmers and one southern ancestry associated with Austronesian,Tai-Kadai,and Austroasiatic speakers.The qpGraph-based phylogeny further confirmed that Guizhou Manchus and Mongolians derived approximately half of the ancestry from their northern ancestors and the other half from southern indigenous East Asians,with mixing event daing to～600-1000year ago,which was coinciding with historically documented the great Mongolia Empire expansion.Focused on the Tai-Kadai-speaking populations,we found a genetic affinity among geographically different Tai-Kadai-speaking populations,especially for Guizhou Maonan people and reference Maonan from Guangxi.Furthermore,formal tests based on the f₃/f₄-statistics further identified an adjacent connection between Maonan and geographically adjacent Hmong-Mien and Sino-Tibetan populations.Fitted qpAdm-based two-way admixture models with ancestral sources from northern and southern East Asians demonstrated that Guizhou Maonan derived majority of ancestry from historical ancients of Guangxi and minor ancestry from Northeast Asians related populations,which further provide evidence supporting southern China origin in linguistic.We obtained genotype data of 700,000 SNPs from Mongolian,Manchu and Maonan in Guizhou via the genome-wide microarray typing technology,which provided reference data for further mining the unique genetic marker loci of each ethnic group,and also used for further inference of regional origin and phenotype of Guizhou ethnic groups.It provides guiding clues for confirming the origin of unknown samples in actual prosecution cases and solving cases in judicial practice.Conclusions:1.We identified one unique genetic cline among East Asian populations formed by our studied Mongolians and Manchus samples,which was close to the southern Hmong-Mien cline and Austronesian/Austroasiatic cline but distinct with northern Mongolic and Tungusic cline.Guizhou Mongolic and Manchus people harbored both northern East Asians ancestry and also additional gene fluxes from the south,and the estimated mixing time is about 600～1000 years ago.2.The Maonan in Guizhou has a close genetic relationship with the adjacent Hmong-Mien population and Sino-Tibetan population and is a mixed population related to ancient people in the historical period affected by the southward migration of a small number of people from North-East Asia.3.The study of the fine genetic structure of Mongolian,Manchu and Maonan in Guizhou is expected to provide forensic data for the regional origin and phenotypic inference of Guizhou populations.