Genetic data from Y chromosome STR and SNP loci in Ukrainian population

Phylogeographic review of Y chromosome haplogroups in Europe

The Y chromosome has been widely explored for the study of human migrations. Due to its paternal inheritance, the Y chromosome polymorphisms are helpful tools for understanding the geographical distribution of populations all over the world and for inferring their origin, which is really useful in forensics. The remarkable historical context of Europe, with numerous migrations and invasions, has turned this continent into a melting pot. For this reason, it is interesting to study the Y chromosome variability and how it has contributed to improving our knowledge of the distribution and development of European male genetic pool as it is today. The analysis of Y lineages in Europe shows the predominance of four haplogroups, R1b-M269, I1-M253, I2-M438 and R1a-M420. However, other haplogroups have been identified which, although less frequent, provide significant evidence about the paternal origin of the populations. In addition, the study of the Y chromosome in Europe is a valuable tool for revealing the genetic trace of the different European colonizations, mainly in several American countries, where the European ancestry is mostly detected by the presence of the R1b-M269 haplogroup. Therefore, the objective of this review is to compile the studies of the Y chromosome haplogroups in current European populations, in order to provide an outline of these haplogroups which facilitate their use in forensic studies.

Y-Chromosome Genetic Analysis of Modern Polish Population

The study presents a full analysis of the Y-chromosome variability of the modern male Polish population. It is the first study of the Polish population to be conducted with such a large set of data (2,705 individuals), which includes genetic information from inhabitants of all voivodeships, i.e., the first administrative level, in the country and the vast majority of its counties, i.e., the second level. In addition, the available data were divided into clusters corresponding to more natural geographic regions. Genetic analysis included the estimation of F_ST distances, the visualization with the use of multidimensional scaling plots and analysis of molecular variance. Y-chromosome binary haplogroups were classified and visualized with the use of interpolation maps. Results showed that the level of differentiation within Polish population is quite low, but some differences were indicated. It was confirmed that the Polish population is characterized by a high degree of homogeneity, with only slight genetic differences being observed at the regional level. The use of regional clustering as an alternative to counties and voivodeships provided a more detailed view of the genetic structure of the population. Those regional differences identified in the present study highlighted the need for additional division of the population by cultural and ethnic criteria in such studies rather than just by geographical or administrative regionalization.

A study of the Bodrogköz population in north-eastern Hungary by Y chromosomal haplotypes and haplogroups

We have determined the distribution of Y chromosomal haplotypes and haplogroups in population samples from one of the most important areas in north-eastern Hungary from many villages in the Bodrogköz. The Bodrogköz region was chosen due to its isolated nature, because this area was a moorland encircled by the Tisza, Bodrog, and Latorca Rivers and inhabitants of this part of Hungary escaped from both Tatar and Ottoman invasions, which decimated the post-Hungarian Conquest populations in many parts of the country. Furthermore, in the first half of the tenth century, this region served as the Palatial Centre and burial grounds of the Hungarian tribes. It has thus been assumed that the present population in this area is likely to be more similar to the population that lived in the Conquest period. We analysed male-specific markers, 23 Y-STRs and more than 30 Y-SNPs, that reflect the past and recent genetic history. We found that the general haplogroup distribution of the samples showed high genetic similarity to non-Bodrogköz Hungarians and neighbouring populations, despite its sheltered location and historical record. We were able to classify the Y-chromosomal haplogroups into four large groups based on STR mutation events: pre-Roman/Roman ancient lineage, Finno-Ugric speakers arriving into the Carpathian Basin, Migration period admixture, and post-Hungarian Conquest admixture. It is clear that a significantly larger database with deep haplogroup resolution, including ancient DNA data, is required to strengthen this research.

Y-Chromosomal Lineages of Latvians in the Context of the Genetic Variation of the Eastern-Baltic Region

Variations of the nonrecombining Y-chromosomal region were investigated in 159 unrelated Baltic-speaking ethnic Latvians from four different geographic regions, using 28 biallelic markers and 12 short tandem repeats. Eleven different haplogroups (hgs) were detected in a regionally homogeneous Latvian population, among which N1c, R1a, and I1 cover more than 85% of its paternal lineages. When compared its closest geographic neighbors, the composition of the Latvian Y-chromosomal gene pool was found to be very similar to those of Lithuanians and Estonians. Despite the comparable frequency distribution of hg N1c in Latvians and Lithuanians with the Finno-Ugric-speaking populations from the Eastern coast of the Baltic Sea, the observed differences in allelic variances of N1c haplotypes between these two groups are in concordance with the previously stated hypothesis of different dispersal ways of this lineage in the region. More than a third of Latvian paternal lineages belong specifically to a recently defined R1a-M558 hg, indicating an influence from a common source within Eastern Slavic populations on the formation of the present-day Latvian Y-chromosome gene pool.

Genetic structure of the Kuwaiti population revealed by paternal lineages

OBJECTIVE

We analyzed the Y-chromosome haplogroup diversity in the Kuwaiti population to gain a more complete overview of its genetic landscape.

METHOD

A sample of 117 males from the Kuwaiti population was studied through the analysis of 22 Y-SNPs. The results were then interpreted in conjunction with those of other populations from the Middle East, South Asia, North and East Africa, and East Europe.

RESULTS

The analyzed markers allowed the discrimination of 19 different haplogroups with a diversity of 0.7713. J-M304 was the most frequent haplogroup in the Kuwaiti population (55.5%) followed by E-M96 (18%). They revealed a genetic homogeneity between the Kuwaiti population and those of the Middle East (FST  = 6.1%, P-value < 0.0001), although a significant correlation between genetic and geographic distances was found (r = 0.41, P-value = 0.009). Moreover, the nonsignificant pairwise FST genetic distances between the Kuwait population on the one hand and the Arabs of Iran and those of Sudan on the other, corroborate the hypothesis of bidirectional gene flow between Arabia and both Iran and Sudan.

CONCLUSION

Overall, we have revealed that the Kuwaiti population has experienced significant gene flow from neighboring populations like Saudi Arabia, Iran, and East Africa. Therefore, we have confirmed that the population of Kuwait is genetically coextensive with those of the Middle East.

Traces of forgotten historical events in mountain communities in Central Italy: A genetic insight

OBJECTIVES

Analysis of human genetic variation in mountain communities can shed light on the peopling of mountainous regions, perhaps revealing whether the remote geographic location spared them from outside invasion and preserved their gene pool from admixture. In this study, we created a model to assess genetic traces of historical events by reconstructing the paternal and maternal genetic history of seven small mountain villages in inland valleys of Central Italy.

METHODS

The communities were selected for their geographic isolation, attested biodemographic stability, and documented history prior to the Roman conquest. We studied the genetic structure by analyzing two hypervariable segments (HVS-I and HVS-II) of the mtDNA D-loop and several informative single nucleotide polymorphisms (SNPs) of the mtDNA coding region in 346 individuals, in addition to 17 short tandem repeats (STRs) and Y-chromosome SNPs in 237 male individuals.

RESULTS

For both uniparental markers, most of the haplogroups originated in Western Europe while some Near Eastern haplogroups were identified at low frequencies. However, there was an evident genetic similarity between the Central Italian samples and Near Eastern populations mainly in the male genetic pool.

CONCLUSIONS

The samples highlight an overall European genetic pattern both for mtDNA and Y chromosome. Notwithstanding this scenario, Y chromosome haplogroup Q, a common paternal lineage in Central/Western Asia but almost Europe-wide absent, was found, suggesting that Central Italy could have hosted a settlement from Anatolia that might be supported by cultural, topographic and genetic evidence.

The place of Slovakian paternal diversity in the clinal European landscape

BACKGROUND

Several demographic events have been postulated to explain the contemporaneous structure of European genetic diversity. First, an initial settlement of the continent by anatomically modern humans; second, the re-settlement of northern latitudes after the Last Glacial Maximum; third, the demic diffusion of Neolithic farmers from the Near East; and, fourth, several historical events such as the Slavic migration.

AIM

The aim of this study was to provide a more integrated picture of male-specific genetic relationships of Slovakia within the broader pan-European genetic landscape.

SUBJECTS AND METHODS

This study analysed a new Y-chromosome data-set (156 individuals) for both SNP and STR polymorphisms in population samples from five different Slovakian localities.

RESULTS

It was found that the male diversity of Slovakia is embedded in the clinal pattern of the major R1a and R1b clades extending over the continent and a similar pattern of population structure is found with Y-specific SNP or STR variation.

CONCLUSION

The highly significant correlation between the results based on fast evolving STRs on one hand and slow evolving SNPs on the other hand suggests a recent timeframe for the settlement of the area.

Northern Slavs from Serbia do not show a founder effect at autosomal and Y-chromosomal STRs and retain their paternal genetic heritage

Studies on Y-chromosomal markers revealed significant genetic differentiation between Southern and Northern (Western and Eastern) Slavic populations. The northern Serbian region of Vojvodina is inhabited by Southern Slavic Serbian majority and, inter alia, Western Slavic (Slovak) and Eastern Slavic (Ruthenian) minorities. In the study, 15 autosomal STR markers were analysed in unrelated Slovaks, Ruthenians and Serbs from northern Serbia and western Slovakia. Additionally, Slovak males from Serbia were genotyped for 17 Y-chromosomal STR loci. The results were compared to data available for other Slavic populations. Genetic distances for autosomal markers revealed homogeneity between Serbs from northern Serbia and Slovaks from western Slovakia and distinctiveness of Serbian Slovaks and Ruthenians. Y-STR variation showed a clear genetic departure of the Slovaks and Ruthenians inhabiting Vojvodina from their Serbian neighbours and genetic similarity to the Northern Slavic populations of Slovakia and Ukraine. Admixture estimates revealed negligible Serbian paternal ancestry in both Northern Slavic minorities of Vojvodina, providing evidence for their genetic isolation from the Serbian majority population. No reduction of genetic diversity at autosomal and Y-chromosomal markers was found, excluding genetic drift as a reason for differences observed at autosomal STRs. Analysis of molecular variance detected significant population stratification of autosomal and Y-chromosomal microsatellites in the three Slavic populations of northern Serbia, indicating necessity for separate databases used for estimations of frequencies of autosomal and Y-chromosomal STR profiles in forensic casework. Our results demonstrate that regarding Y-STR haplotypes, Serbian Slovaks and Ruthenians fit in the Eastern European metapopulation defined in the Y chromosome haplotype reference database.

Uniparental genetic heritage of belarusians: encounter of rare middle eastern matrilineages with a central European mitochondrial DNA pool

Ethnic Belarusians make up more than 80% of the nine and half million people inhabiting the Republic of Belarus. Belarusians together with Ukrainians and Russians represent the East Slavic linguistic group, largest both in numbers and territory, inhabiting East Europe alongside Baltic-, Finno-Permic- and Turkic-speaking people. Till date, only a limited number of low resolution genetic studies have been performed on this population. Therefore, with the phylogeographic analysis of 565 Y-chromosomes and 267 mitochondrial DNAs from six well covered geographic sub-regions of Belarus we strove to complement the existing genetic profile of eastern Europeans. Our results reveal that around 80% of the paternal Belarusian gene pool is composed of R1a, I2a and N1c Y-chromosome haplogroups – a profile which is very similar to the two other eastern European populations – Ukrainians and Russians. The maternal Belarusian gene pool encompasses a full range of West Eurasian haplogroups and agrees well with the genetic structure of central-east European populations. Our data attest that latitudinal gradients characterize the variation of the uniparentally transmitted gene pools of modern Belarusians. In particular, the Y-chromosome reflects movements of people in central-east Europe, starting probably as early as the beginning of the Holocene. Furthermore, the matrilineal legacy of Belarusians retains two rare mitochondrial DNA haplogroups, N1a3 and N3, whose phylogeographies were explored in detail after de novo sequencing of 20 and 13 complete mitogenomes, respectively, from all over Eurasia. Our phylogeographic analyses reveal that two mitochondrial DNA lineages, N3 and N1a3, both of Middle Eastern origin, might mark distinct events of matrilineal gene flow to Europe: during the mid-Holocene period and around the Pleistocene-Holocene transition, respectively.