Genetic History of Xinjiang’s Uyghurs Suggests Bronze Age Multiple-Way Contacts in Eurasia

Abstract

The Uyghur people residing in Xinjiang, a territory located in the far west of China and crossed by the Silk Road, are a key ethnic group for understanding the history of human dispersion in Eurasia. Here we assessed the genetic structure and ancestry of 951 Xinjiang's Uyghurs (XJU) representing 14 geographical subpopulations. We observed a southwest and northeast differentiation within XJU, which was likely shaped jointly by the Tianshan Mountains, which traverses from east to west as a natural barrier, and gene flow from both east and west directions. In XJU, we identified four major ancestral components that were potentially derived from two earlier admixed groups: one from the West, harboring European (25-37%) and South Asian ancestries (12-20%), and the other from the East, with Siberian (15-17%) and East Asian (29-47%) ancestries. By using a newly developed method, MultiWaver, the complex admixture history of XJU was modeled as a two-wave admixture. An ancient wave was dated back to ∼3,750 years ago (ya), which is much earlier than that estimated by previous studies, but fits within the range of dating of mummies that exhibited European features that were discovered in the Tarim basin, which is situated in southern Xinjiang (4,000-2,000 ya); a more recent wave occurred around 750 ya, which is in agreement with the estimate from a recent study using other methods. We unveiled a more complex scenario of ancestral origins and admixture history in XJU than previously reported, which further suggests Bronze Age massive migrations in Eurasia and East-West contacts across the Silk Road.

Germline variation in BRCA1/2 is highly ethnic‐specific: Evidence from over 30,000 Chinese hereditary breast and ovarian cancer patients

“…We tested this possibility by using Uygur group as a model. Uygur group is the largest minority group in Xinjiang, northwestern China, with its unique genetic features . A series of BRCA studies have been carried out in Uygur group, with the identification of 70 BRCA variants.…”

“…It is of interest to know whether BRCA ethnic-specificity exists within the Chinese population, given the fact that it has 56 ethnic groups with divergent genetic backgrounds. 41 We tested this possibility by using Uygur group as a model. Uygur group is the largest minority group in Xinjiang, northwestern China, with its unique genetic features.…”

“…Uygur group is the largest minority group in Xinjiang, northwestern China, with its unique genetic features. 41 A series of BRCA studies have been carried out in Uygur group, with the identification of 70 BRCA variants. Of these, 20 BRCA1 variants and 6 BRCA2 variant were present only in the Uygur group.…”

MultiWaver 2.0: modeling discrete and continuous gene flow to reconstruct complex population admixtures

“…Therefore, many methods have been developed based on this type of information [7-11, 13, 14]. The history of several classical admixed populations (African Americans, Mexicans, and Uyghur) have been well studied using these methods [15][16][17][18][19][20][21]. However, there are two shortcomings involved in these methods.…”

“…Second, the prior admixture model was often an overly simplified scenario, such as a hybrid-isolation (HI), gradual admixture (GA), or continuous gene flow (CGF) models. Knowledge of admixture history is often lacking when real data are analyzed, especially for complex admixed populations [2,15,[22][23][24]. Therefore, results can be unreliable in cases where the selected prior model deviates from the real admixture history.…”