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https://www.frontiersin.org/articles...67309/abstract
full version but with editions https://sci-hub.ren/10.3389/fgene.2020.567309
Intra-population variability of Y chromosome
Our findings display slight differences from previous studies20with regard to main haplogroup distribution, haplogroup frequencyand the occurrence of rare haplogroups. In the 388present study, as expected, the most common haplogroup (hg) was found to be R, with a frequency of 71.02%; this is slightly higher than the 68.6% reported by Kayser et al., (2005).
Regarding its subhaplogroups, the highest frequency was observed for R1a(56.93%) followed by R1b(14.08%);
similarly, Kayser et al., (2005) found haplogroup R1a1* to be the most prevalent (57%). The interpolation maps indicate that R1a is distributed mostly in the center part of Poland 3ith a few regions on the west and east of the country. Interestingly, R1a was also foundto be 5presentin high numbers in eastern regions, including the Podlaskie and Warmian-Mazurian voivodeships, as well as almost all of the Lublin voivodeship; similar results were also obtained from central regions and Western Pomerania, which may have some historical basis.
In contrast, R1b was more widely distributed, reaching further east and west than the others; however, it is observed at relatively low frequencies in regions adjacent to the western and eastern borders of Poland. Such a pattern of distribution of hgR in the Polish population can reflect some historical events such as massive human migrations or the changes in the territorialborders.
A similar situation was observed in the case of hg I, whose distribution also followed geographic lines and possibly,historical events. Haplogroup I1 is found to be represented mostly in western Poland with only one region behind the Vistula river with a frequency higher than 9.68%: cluster number 38 (the border of Lublin and Mazovia voivodeships).
Haplogroup I2 appears in eastern Poland,mostly in the Podlaskie and Lublin voivodeships, but also reaches the eastern parts of Mazovia, the western parts of Warmian-Mazurian and almost all of Subcarpathia, which makes these regions similar to the west in terms of haplogroup frequency. Kayser et al. (2005) also note that hgI was ranked just behind hg R with regard to prevalence; however its prevalence was found to be 17.30% compared to 15.49% observed in the current study.
Kayser et al. (2005) also report similar frequencies for the subsequent haplogroups, N (3.7% 414vs. 4.29%)and E (4.5% vs. 3.84%),with a slight difference in the place of haplogroup in the total pattern. Interestingly, in the case of hg N, the Podlaskie voivodeship is distinct from the remaining voivodeships: the frequency of hg N, which is common among Finns and other inhabitants of north-eastEurope, is 14.55% in this area and brings Podlaskie closer to the northern regions in this regard.
In contrast, hg E displays much greater homogeneity across the map, with fewer marked differences between regions.
Regarding the occurrence and frequency of rare haplogroups, i.e. those with a frequency less than 1%, hgs Q, C, T, Hand Owere identified in the current study, while K, DE and P were reported by Kayser et al. (2005). The greatest difference between the two sets of results concerns hgF, its prevalence being 2.0%in the previous study but absent from the present results. 425The observed differences between the studiescan be accounted for by differences in sample population number and profile. The present study was based on a data set comprising 2705 individuals from all 16 voivodeships and 337 out of the 380 counties, while Kayser et al. 428(2005) was probably based on inhabitants of the main cities in Poland (Wrocław, Warsaw, Lublin, Kraków, Bydgoszcz, Gdańsk, Szczecin and Suwałki). Unfortunately, due to a lack of such studies, it is not possible to perform a detailed comparison of haplogroup frequencies for all voivodeshipsand counties.
Clusters on PCA
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