Pylev Vladimir Yur'evich

Introduction. Trehalose or mushroom sugar has been increasingly used in the food industry in the past decades. To be absorbed in the human intestine, trehalose needs to be broken down by an enzyme known as trehalase. Today, it is known that the G→A substitution in the rs2276064 locus of the TREH gene results in the reduced activity of this enzyme.

The aim of this study was to analyze the frequency of TREH (rs2276064) alleles and genotypes in the populations of South Siberia, Kazakhstan, Central Asia and Mongolia that differ in the contribution of the ancestral East Eurasian (Mongoloid) component to their gene pools.

Methods. We genotyped 987 DNA samples collected from the representatives of 17 indigenous populations from Siberia, Kazakhstan and Mongolia. The samples of 311 ethnic Russians comprised a reference dataset. In addition to estimating the frequencies of TREH alleles and genotypes, we analyzed the contribution of the ancestral East Eurasian (Mongoloid) and West Eurasian (European) ADMIXTURE components for the studied populations using an Illumina 750k microarray of SNP markers.

Results. The frequency of the A*TREH allele associated with trehalase deficiency increases from west to east (r_sp =0.500, p <0.05). TREH is correlated more strongly with the contribution of the ancestral East Eurasian (Mongolian) component than with the geography of the studied populations: r_sp =0.613 (p =0.007); with AA*TREH frequency r_sp =0.688 (p =0.002).

Conclusions. The rs2276064-А TREH allele is more frequent than previously estimated from clinical data. The more substantial is the contribution of the ancestral East Eurasian (Mongoloid) component, the higher is the frequency of the risk A*TREH allele, which rises dramatically to 29-30% in the Kyrgyz, Khakass, Tuvinian and 39% in Khalkha Mongol populations. Together, carriers of the AG and AA*TREH genotypes make up 35% to 65% of the populations of Oriental origin. We hypothesize that the high frequency of genetic trehalase deficiency determinants in the populations of Siberia, Kazakhstan, Central Asia, and Mongolia is associated with their anthropological characteristics and is not purely dependent on geographic factors.

© 2023. This work is licensed under a CC BY 4.0 license

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. © 2024. This work is licensed under a CC BY 4.0 license