Utevska O. The gene pool of Ukrainians revealed by different systems of genetic markers: the origin and statement in Europe

The gene pool of Ukrainians and its position on European genetic landscape were characterized using three systems of neutral genetic markers: NRY, mtDNA and wide-genome autosomal loci. Altogether 1,197 DNA samples of indigenous Ukrainians from 13 regional populations were collected and studied. Molecular genetic analysis included: genotyping on SNP and STR markers of Y chromosome, SNP analysis of non-coding mtDNA region, sequencing of HVS1; genotyping of genomic autosomal loci and Y-chromosome sequencing. Genetic-statistical analysis included: the evaluation of the genetic similarity of populations, genetic diversity, genetic differentiation; the analysis of the genome ancestral components and IBD analysis, phylogenetic and cartographic analysis. It was shown that the Y-chromosome gene pool of Ukrainians is characterized by high genetic diversity, low differentiation, integrity and relative apartness from the neighboring populations. It was shown that Ukrainians from different regional populations are characterized by a higher genetic similarity between themselves than with neighboring ethnic groups even in contact zones. The internal differentiation of Ukrainian gene pool on Y chromosome markers is insignificant and is most pronounced between the populations of Polissya, Western and Eastern forest-steppe. The areas of genetic similarity were determined and maps of genetic distances for Ukrainians were constructed using microsatellite markers of the Y chromosome and mtDNA haplotypes. The clusters of co-propagating mtDNA haplotypes were revealed. The groups of populations with the resembling patterns of Y chromosome similarity were identified using maps of genetic distances. The components of the autosomal gene pool of Ukrainians, its position in the European gene pool, the impact of ancient Europeans were estimated. The ratio of West European and West Asian haplotypes among Ukrainians - carriers of the Y chromosome haplogroup R-M269 - was determined, as well as the ratio of the Baltic and Finno-Ugric haplotypes among Ukrainians - carriers of N-M178. The geographically specific clusters of the haplotypes were identified for the haplogroup I-P37.2, its recent secondary expansion from Ukrainian territory was supposed. The migration routes of R-M458 carriers in Eastern Europe were revealed. The territory of Ukraine was considered as a contact zone and genetic barrier within Europe. According to IBD analysis, two major pre-Slavic genetic substrates were confirmed - "Central East-European" for Western and Eastern Slavs and "South East-European" for Southern Slavs. The results of research are important for the reconstruction of Ukrainian ethnic history, as well as the demographic history of the Northern Black Sea region and Europe on the whole. The data obtained on DNA polymorphism are deposited in world databases and are open for research purposes. The collection of Ukrainian DNA samples is a part of the North-Eurasian BioBank created for human genetics and genomics studies.