Gene-pool structure of Tuvinians inferred from Y-chromosome marker data

The gene-pool structure of Tuvinians was examined in terms of the composition and frequency of Y-chromosome haplogroups in five geographically distanct populations. In the Tuvinian gene pool, a total of 22 haplogroups were identified with six of these, which were the most frequent (C3c, C3*, N1b, N1c1, Q1a3, and R1a1a). It was demonstrated that eastern regions of Tuva were most different from the other regions in haplotype frequencies. The evaluation of genetic diversity based on the frequencies of biallelic haplogroups and YSTR haplotypes revealed very high diversity values for all samples. In general, the genetic diversity values identified in Tuvinians were the highest for the indigenous ethnic groups of Siberia. The evaluation of the genetic differentiation of the samples examined using the analysis of molecular variance (AMOVA) showed that the gene pool of Tuvinians was relatively poorly differentiated with respect to haplogroup frequencies. Phylogenetic analysis within haplogroup N1b revealed strong founder effect, i.e., reduced diversity and star-like phylogeny of the median network of haplotypes, which formed a separate subcluster exclusive to Tuvinians. It was demonstrated that, in Tuvinians, haplogroup N1c1 was the most heterogeneous in haplotype profile and consisted of three different haplotype clusters, demonstrating considerable differences of western population from the rest of the Tuva populations. Phylogenetic analysis of haplogroups revealed common components for Tuvinians, Khakasses, Altaians, and Mongols.