Population and Genetic Structure of the Siberian Population According to Data on the Frequencies of Polymorphic Variants of Vitamin D Transport and Reception Genes

The gene pools of Siberian peoples are a potential source of data on the compositions of haplotypes of polymorphic gene variants formed during the evolution of populations under the influence of a specific set of natural and climatic factors, in conditions of relative geographical and cultural isolation, as well as traditional subsistence practices. In order to study genetic adaptation to insufficient supply of vitamin D (low level of insolation and availability of nutrients containing cholecalciferol and ergocalciferol) in samples of indigenous Turkic-speaking (Teleuts, Tomsk Tatars, Shors) and foreign East Slavic (Russians) population of Siberia, a study of the frequencies of polymorphic variants (14 SNPs) of genes responsible for transport of vitamin D – GC (Group-Specific Component), the structure of its main receptor – gene VDR (vitamin D receptor) and the RXR receptor (retinoid X receptor) in form of genes RXRA and RXRG was conducted. The total sample size was 411 people. The analysis of polymorphic variant frequencies demonstrated specific features of the gene pools of Siberian indigenous populations compared to the Russian population, global frequencies and frequencies characteristic of populations of Europe and East Asia. In pairwise comparison with the sample of Russians, statistically significant differences were found in terms of frequencies rs7041 (Shors), rs3847987 (Tomsk Tatars, Teleuts, Shors), rs9409929 (Tomsk Tatars, Teleuts), rs877954 (Tomsk Tatars), rs283696 (Teleuts). According to data of average genetic distances (d), the minimum distances were noted between Teleuts and Tomsk Tatars. The sample of Russians in general turned out to be the most distant in the genetic space of the studied peoples of Siberia. The study of haplotype frequencies of polymorphic variants of vitamin D transport and receptor genes demonstrated the accumulation of SNP in the indigenous gene pool associated, according to the literature, with a higher levels of serum vitamin D. According to the GC and VDR genes, the haplotypic profile of polymorphic variants was characterized by pronounced specificity and differed in composition from that of the Russian population. The study allows us to conclude that structure of gene pools of indigenous peoples of Siberia retains a distinctiveness that reflects the history of their composition and demonstrates the features of the genetic adaptation of indigenous populations to environmental conditions.