Y-chromosomal STR haplotypes in a Romanian population sample

A glance of genetic relations in the Balkan populations utilizing network analysis based on in silico assigned Y-DNA haplogroups

The aim of this study is to provide an insight into Balkan populations’ genetic relations utilizing in silico analysis of Y-STR haplotypes and performing haplogroup predictions together with network analysis of the same haplotypes for visualization of the relations between chosen haplotypes and Balkan populations in general. The population dataset used in this study was obtained using 23, 17, 12, 9 and 7 Y-STR loci for 13 populations. The 13 populations include: Bosnia and Herzegovina (B&H), Croatia, Macedonia, Slovenia, Greece, Romany (Hungary), Hungary, Serbia, Montenegro, Albania, Kosovo, Romania and Bulgaria. The overall dataset contains a total of 2179 samples with 1878 different haplotypes. I2a was detected as the major haplogroup in four out of thirteen analysed Balkan populations. The four populations (B&H, Croatia, Montenegro and Serbia) which had I2a as the most prevalent haplogroup were all from the former Yugoslavian republic. The remaining two major populations from former Yugoslavia, Macedonia and Slovenia, had E1b1b and R1a haplogroups as the most prevalent, respectively. The populations with E1b1b haplogroup as the most prevalent one are Macedonian, Romanian, as well as Albanian populations from Kosovo and Albania. The I2a haplogroup cluster is more compact when compared to E1b1b and R1b haplogroup clusters, indicating a larger degree of homogeneity within the haplotypes that belong to the I2a haplogroup. Our study demonstrates that a combination of haplogroup prediction and network analysis represents an effective approach to utilize publicly available Y-STR datasets for population genetics.

Croatian national reference Y-STR haplotype database

A reference Y-chromosome short tandem repeat (STR) haplotype database is needed for Y-STR match interpretation as well as for national and regional characterization of populations. The aim of this study was to create a comprehensive Y-STR haplotype database of the Croatian contemporary population and to analyze substructure between the five Croatian regions. We carried out a statistical analysis of the data from previously performed genetic analyses collected during routine forensic work by the Forensic Science Centre "Ivan Vučetić". A total of 1,100 unrelated men from eastern, western, northern, southern and central Croatia were selected for the purpose of this study. Y-STRs were typed using the AmpFISTR Yfiler PCR amplification kit. Analysis of molecular variance calculated with the Y chromosome haplotype reference database online analysis tool included 16 population samples with 20,247 haplotypes. A total of 947 haplotypes were recorded, 848 of which were unique (89.5%). Haplotype diversity was 0.998, with the most frequent haplotype found in 9 of 1,100 men (0.82%). Locus diversity varied from 0.266 for DYS392 to 0.868 for DYS385. Discrimination capacity was 86.1%. Our results suggested high level of similarity among regional subpopulations within Croatia, except for mildly different southern Croatia. Relative resemblance was found with Bosnia and Herzegovina and Serbia. Whit Atheys' Haplogroup Predictor was used to estimate the frequencies of Y-chromosome haplogroups. I2a, R1a, E1b1b and R1b haplogroups were most frequent in all Croatian regions. These results are important in forensics and contribute to the population genetics and genetic background of the contemporary Croatian population.

Population genetic analysis of haplotypes based on 17 short tandem repeat loci on Y chromosome in population sample from eastern Croatia

AIM

To investigate the population genetics of 17 short tandem repeat (STR) loci on the Y chromosome in the population of eastern Croatia.

METHODS

We carried out a statistical analysis of the data from previously performed genetic analysis collected during routine forensic work by the Forensic Science Centre "Ivan Vucetić". A total of 220 unrelated healthy men from eastern Croatia were selected for the purpose of this study. Genomic DNA was extracted by Chelex from FTA cards. Y-chromosomal STRs were determined using the AmpFISTR Yfiler PCR amplification kit. The haplotype frequencies were determined by direct counting and analyzed using Arlequin 3.1 and analysis of molecular variance calculated with the Y-chromosome haplotype reference database online analysis tool.

RESULTS

A total of 207 haplotypes were recorded, 197 of which were unique (90%). Haplotype diversity was 0.9993, with the most frequent haplotype found in 4 of 220 men (1.8%). Average locus diversity was 0.600, and it ranged from 0.256 for DYS392 to 0.780 for DYS458. Our results were compared with the pattern of Y-chromosome variability in publicly available population samples based on a minimal European haplotype set of 9 STRs and the greatest resemblance was found with samples from the Croatian capital of Zagreb, from Bosnia and Herzegovina, and from Serbia.

CONCLUSION

This is the first description of Y chromosome haplotyping of the population of eastern Croatia, which may serve as a basis for genetic epidemiology and forensic studies. Further studies are needed for characterization of the genetic structure of the Y-chromosome in the modern Croatian population.

Searching for the origin of Gagauzes: inferences from Y-chromosome analysis

The Gagauzes are a small Turkish-speaking ethnic group living mostly in southern Moldova and northeastern Bulgaria. The origin of the Gagauzes is obscure. They may be descendants of the Turkic nomadic tribes from the Eurasian steppes, as suggested by the "Steppe" hypothesis, or have a complex Anatolian-steppe origin, as postulated by the "Seljuk" or "Anatolian" hypothesis. To distinguish these hypotheses, a sample of 89 Y-chromosomes representing two Gagauz populations from the Republic of Moldova was analyzed for 28 binary and seven STR polymorphisms. In the gene pool of the Gagauzes a total of 15 Y-haplogroups were identified, the most common being I-P37 (20.2%), R-M17 (19.1%), G-M201 (13.5%), R-M269 (12.4%), and E-M78 (11.1%). The present Gagauz populations were compared with other Balkan, Anatolian, and Central Asian populations by means of genetic distances, nonmetric multidimentional scaling and analyses of molecular variance. The analyses showed that Gagauzes belong to the Balkan populations, suggesting that the Gagauz language represents a case of language replacement in southeastern Europe. Interestingly, the detailed study of microsatellite haplotypes revealed some sharing between the Gagauz and Turkish lineages, providing some support of the hypothesis of the "Seljuk origin" of the Gagauzes. The faster evolving microsatellite loci showed that the two Gagauz samples investigated do not represent a homogeneous group. This finding matches the cultural and linguistic heterogeneity of the Gagauzes well, suggesting a crucial role of social factors in shaping the Gagauz Y-chromosome pool and possibly also of effects of genetic drift.

Y-STR haplotypes in populations from the Eastern Mediterranean region of Turkey

We present the frequency distributions of Y-haplotypes determined by ten Y-chromosomal STR polymorphisms (i.e., DXYS156-Y, DYS19, DYS385, DYS389 I and II, DYS390, DYS391, DYS392, DYS393) in unrelated males from the Eastern Mediterranean region of Turkey (104 Turkish and Arabian-speaking Eti Turks from Adana area, 111 Roma and 110 Turks, Kahramanmara degrees area). The haplotype diversity was 0.974 in the Eti Turks, 0.979 in the Roma, and 0.989 in the Turks. Two variant alleles were characterized by sequencing, i.e., allele 9.2 at DXYS156 and 12.2 at DYS385. Some of the haplotypes are particular to one of the three populations; some are shared by all three populations. A search against the Y-Haplotype Reference Database revealed several matches to samples not only from Turkey and neighboring regions (e.g., Syria, Iraq) but also from all over Europe.

Paternal and maternal lineages in the Balkans show a homogeneous landscape over linguistic barriers, except for the isolated Aromuns

The Balkan Peninsula is a complex cultural mosaic comprising populations speaking languages from several branches of the Indo-European family and Altaic, as well as culturally-defined minorities such as the Aromuns who speak a Romance language. The current cultural and linguistic landscape is a palimpsest in which different peoples have contributed their cultures in a historical succession. We have sought to find any evidence of genetic stratification related to those cultural layers by typing both mtDNA and Y chromosomes, in Albanians, Romanians, Macedonians, Greeks, and five Aromun populations. We have paid special attention to the Aromuns, and sought to test genetically various hypotheses on their origins. MtDNA and Y-chromosome haplogroup frequencies in the Balkans were found to be similar to those elsewhere in Europe. MtDNA sequences and Y-chromosome STR haplotypes revealed decreased variation in some Aromun populations. Variation within Aromun populations was the primary source of genetic differentiation. Y-chromosome haplotypes tended to be shared across Aromuns, but not across non-Aromun populations. These results point to a possible common origin of the Aromuns, with drift acting to differentiate the separate Aromun communities. The homogeneity of Balkan populations prevented testing for the origin of the Aromuns, although a significant Roman contribution can be ruled out.

Population genetic study in two Transylvanian populations using forensically informative autosomal and Y-chromosomal STR markers

Our study provides population genetic data on two population samples collected in a Hungarian speaking region of Transylvania, Romania. Allele frequency and profile databases were generated on 17 autosomal STR loci (D2S1338, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D19S433, D21S11, VWA, FGA, TH01, TPOX, CSF1PO, Penta E and Penta D) as well as at the 12 European Y-STR extended haplotype loci (DYS19, DYS389-I/II, DYS390, DYS391, DYS392, DYS393, DYS385 loci, DYS437, DYS438 and DYS439). Data were compared to a Central Hungarian (Budapest region) population sample [B. Egyed, S. Füredi, M. Angyal, L. Boutrand, A. Vandenberghe, J. Woller, Z. Padar, Analysis of eight STR loci in two Hungarian populations, Forensic Sci. Int. 113 (2000) 25-27] that was used as a reference group of the Hungarian population. Calculating the F(ST) indices and with the pairwise comparisons of interpopulation molecular variance (AMOVA) the two populations from Transylvania could be fit into the Hungarian population data showing less substructuring effects as compared to the previous findings in Hungary [B. Egyed, S. Füredi, M. Angyal, L. Boutrand, A. Vandenberghe, J. Woller, Z. Padar, Analysis of eight STR loci in two Hungarian populations, Forensic Sci. Int. 113 (2000) 25-27; B. Egyed, S. Füredi, M. Angyal, I. Balogh, L. Kalmar, Z. Padar, Analysis of the population heterogeneity in Hungary using fifteen forensically informative STR markers, Forensic Sci. Int. 158 (2005) 244-249].

Mutations or exclusion: an unusual case in paternity testing

In an immigration case with the scope of family reunification, the DNA extracted from the saliva samples of the male child, the alleged mother and the putative father was typed with 22 autosomal short tandem repeat (STR) systems. In seven STR systems, the alleged mother could be excluded from maternity, and the case then had to be regarded as a deficiency case. Taking this fact into consideration, only two exclusions were found for the putative father, and the question arose whether there was an exclusion of the putative father or the existence of two mutations. Autosomal STR typing could not clarify the case, but the application of eight Y-chromosomal markers showed that the alleged father could be excluded from paternity.

Population study of Y-chromosome STR haplotypes in Japanese from the Tokushima

The Y-chromosome short tandem repeat (STR) systems including DYS19, DYS389I/II, DYS390, DYS391, DYS392, DYS393, DYS385 and YCAII were investigated in 121 Japanese males (Tokushima area). Analysis of the nine loci permitted classification of the samples into 107 haplotypes, and the haplotype diversity was estimated to be 0.989. DYS385 showed the highest gene diversity (GD) value (GD=0.946), while DYS391 showed the lowest GD value (GD=0.27). Furthermore, in DYS392, we found a new mutant allele that added a T within the repeat region (a mutation in the repetitive region), and the allele was designated 13.1 according to the sequence structure. We also detected allele 20 in DYS392 as a new allele. In DYS385, a new allele 26 that has not been previously reported was observed.

Y-chromosome STR haplotype in Szekely population

Eight Y-chromosome STR markers (DYS19, DYS389/I, DYS389/II, DYS390, DYS391, DYS392, DYS393, DYS385) were examined in an isolated Szekely (known as old Hungarian) population living in Corund, Romania. Ninety different haplotypes were obtained from 99 unrelated Szekely males.