Genetic Variability of Roma Population in Serbia: The Perspective From Uniparentally Inherited Markers

The Roma represent a widespread ethnic minority in Europe that has a unique genetic ancestry shaped by a string of population bottlenecks, differential gene flow from/to the general population, and founder effects during their migrations. This study aimed to further characterize the diversity of the Roma population in Serbia and assess the substructuring within the population from the perspective of the mtDNA and Y chromosome. The control region of the mtDNA of 269 samples was sequenced, and 27 Y-STRs and 22 Y-SNPs were analyzed in 165 male samples. We classified samples in concordance with the previously published study on Serbian Roma, based on the geographical region of origin and religious affiliation, and evaluated their genetic relationships with Roma and general populations from the countries throughout their migrational route. Despite the dominance of the ancestral lineages in the paternal genetic pool, a higher diversity was noted in the mtDNA pool. Signals of bidirectional local male gene flow were shown by the presence of the haplogroup H-M2972 among the Serbian population and the high frequency of the I-L621 lineage among Roma. Our results highlight intrapopulation substructuring reflected in different proportions of South Asian and heterogeneity of West Eurasian lineages in both markers across different geographical and religious Roma groups. Asymmetrical gene flow was observed within all Roma subpopulations, while the male-biased gene flow was observed only within the predominantly Orthodox group from the central region of Serbia. Our data reveal the diversity of both uniparental pools of Serbian Roma and emphasize the role of religious affiliation in patterns of admixture with the general population.