Genomics Study Of The Ancient Population From The Shirenzigou Site In Xinjiang

Xinjiang,geographically located in northwestern of China,has been one of the most well-known link between the East and the West for a long time.The Silk Road through Xinjiang has been the important bridge between the world and China since the Han dynasty(207 BCE–220 BCE).The population of Xinjiang has a complex genetic history.Genetic studies based on modern Xinjiang population show that there are genetic links between Xinjiang population and populations of eastern and western Eurasia.The origin,migration and integration history of the early populations in Xinjiang is of great interest.This study aims to sequence the whole genomes of the ancient Iron Age samples from the Shirenzigou site in the eastern part of the Tianshan region,and explore the origin and admixture history of this population.We successfully obtained the whole-genome data of 10 ancient individuals from 12 samples.The genomic coverage is ranged from ~ 0.04 x to 0.75 x.Five samples were Carbon dated to the Iron Age(~200-100 BCE).Through the sex determination,four samples were found to be females and the others were males.We retrieved mitochondrial and Y-chromosomal genomes and further assigned the haplogroups of each individual.The dominant mtDNA lineages of the Shirenzigou samples are U4,U5,H,A,D4 and G3.Y haplogroups of the Shirenzigou samples are R1b and Q1a.Both paternal and maternal lineages of the Shirenzigou ancient population are admixed from the eastern and western lineages of Eurasia.The genetic analysis of autosomal genome data of Shirenzigou population also shows admixed ancestry from the eastern and western Eurasia.On the PCA plots,ancient Shirenzigou samples and present-day populations from Central Asia and northwestern China form a genetic cline from East to West in the first PCA.ADMIXTURE and f3-statistics reveal that the majority of the East Eurasian ancestry in the Shirenzigou individuals are related to northeastern Asian populations,while the West Eurasian ancestry is best presented by Yamnaya-like ancestry.Combining both the genetic and archaeological evidences,our study supports the “Steppe hypothesis” for the peopling of the Xinjiang region and furthermore reveals that the extinct of Tocharian languages are related to Yamnaya populations.