The structure of the gene pool of the southern tribal groups of tuvans

Introduction. The Y-gene pool of the southern Tuvan tribal groups – Soyan and Choodu – was first studied and their comparative analysis with representatives of Kyrgys (south-east of Tuva) and Oorzhak (west of Tuva) tribal groups was carried out. Purpose of the study: to determine the genetic status of the Soyan and Choodu tribal groups within the genetic landscape of the population of Southern Siberia. Materials and methods. The sample (total N=150) included samples from representatives of Oorzhak (N=42), Soyan (N=29), Kyrgys (N=46) and Choodu (N=33) tribal groups. The genotyping panel included 60 SNP-markers of Y-chromosome, characteristic of the populations of Northern Eurasia. Results. In the gene pools of studied tribal groups, 27 branches of 7 large haplogroups (C2, J2, N1, O, R1a, R1b) of Y-chromosome were identified. The main part of Choodu, Oorzhak, Soyan gene pools is represented by “North Eurasian” haplogroups (N1, Q) and Kyrgys gene pool is dominated by “East Eurasian” haplogroups C2 and O. The “West-Eurasian” haplogroups, mainly represented by subhaplogroup R1a1a-Z93, account for less than a quarter of the gene pool of all four studied groups, without revealing a clear geographical trend. In the genetic space of the population of Southern Siberia the Soyan, Choodu and Kyrgys, together with other of Tuvan tribal groups, formed the Tuvan-Tofalar claster. Tuvan-Tofalar, Altai and Khakass clusters indicate three sources of gene pool of the indigenous population of Southern Siberia. Maps of genetic distances showed greater similarity of the Soyan and Choodu with the rest of Tuvan tribal groups than with other populations of Southern Siberia. But the map of genetic distances from Kyrgyz reveals a different pattern: areal of genetically similar populations is more extensive, covering southern and southeastern Tuva, Mongolia and western Buryatia. Conclusion. The prevalence of “North-Eurasian” haplogroups in the gene pools of the studied Tuvan tribal groups and data of historians, ethnographers, linguists and geneticists suggest that their gene pool was formed at the Samoyed-Ket layer (VI-III centuries BC), and the accumulation of Central Asian component in the gene pool of Kyrgys occurred at a later stage of Kyrgys gene pool formation, presumably from the XII-XVIII centuries. Analysis of the gene pool of Tuvans through their tribal groups structure makes a significant contribution to the reconstruction of the ethnogenesis of Tuvan tribal groups, along with the data of anthropologists, historians, ethnographers and linguists.