June 28, 2005

Y chromosomes and mtDNA of Russians

A very interesting article for the genetic composition of Russians as evidence by uniparentally inherited markers. From the Introduction:
The origin of Eastern Slavs (Russians, Ukrainians, and Belorussians) is a complex issue that has been debated by linguists, anthropologists, archeologists, and [End Page 877]historians for more than 300 years. The Slavonic colonization of eastern Europe [which was most intensive in the 6th–7th centuries A.D. according to archeological data (Sedov 1995)] has entailed changes in the anthropological composition of Slavs because of their interpopulation contacts with Baltic tribes in the northwest, Finno-Ugric tribes in the north and east, and Iranian (or Iranic-speaking) tribes in the south of eastern Europe (Alekseeva and Alekseev 1989). Notwithstanding the vast factual material concerning ancient and modern Eastern Slavonic populations, accumulated by archeologists, anthropologists, and historians, many problems still remain unsolved, including the character of interactions between Slavs and autochthonous populations of eastern Europe.

Previous genetic studies of classical genetic markers (Rychkov et al. 1999) and anthropological data (Alekseeva 1973; Rychkov and Balanovska 1988) have shown geographic differences between Russian populations and have allowed researchers to recognize at least two groups of Russians. It has been suggested that the most western Russian populations appear to be descendants of the Slavs, whereas northern, eastern, and southern Russian populations are the result of admixture between Slavonic tribes and pre-Slavonic populations of eastern Europe (Rychkov and Balanovska 1988). In addition, principal components analyses performed on the basis of anthropological data revealed that modern Russians are represented by two regional groups of populations, southeastern and northwestern (Alekseeva 1999). Using computer cartography of anthropological and genetic data, Balanovsky and Balanovska (2002) recently identified a latitudinal (north–south) trend as the main geographic pattern of the Russian gene pool variation.

Some information about Y-chromosome haplogroup N3, which is found at an frequency ranging from 4.5-35%, and is indicative of Finno-Ugric admixture:
It is noteworthy that among the Russian populations studied, the Pskov population shows the highest frequency (35%) of haplogroup N3, which is characteristic of all Uralic- and Baltic-speaking populations north and east of the Baltic Sea (Rosser et al. 2000; Zerjal et al. 2001). This haplogroup is considered a signature of Uralic Finno-Ugric-speaking tribes migrating to northern Europe about 5,000 years ago (Passarino et al. 2002). The presence of haplogroup N3 in Russians suggests that some admixture between Slavonic and Finno-Ugric and/or Baltic tribes occurred during the colonization of the East European plain by Slavs in the early Middle Ages and later. In addition, the distribution pattern of haplogroup N3 in other Slavonic-speaking populations suggests that proto-Slavs probably did not carry this lineage at a substantial frequency (Barac et al. 2003).

Finally, the conclusions of the study:
Y-chromosome variation data obtained in the present study demonstrate that the Russian gene pool appears to be close to central-eastern European populations. The data show a high frequency of haplogroups R1a and N3. The high incidence of R1a haplotypes in Eastern Slavs and in Baltic and some Finno-Ugric populations of eastern Europe is a well-established fact (Rosser et al. 2000; Wells et al. 2001; Zerjal et al. 2001), but little is known about the spread of haplogroup N3 in different Russian populations. Our data indicate that this haplogroup is unevenly distributed in Russian populations, with frequencies ranging from 4.8% to 35%. It is noteworthy that in most of the populations studied (with the exception of the Pskov sample) the frequency of haplogroup N3 does not exceed 20%. An important feature distinguishing Russians from their eastern European neighbors is almost complete absence of paragroup N*, which is ancestral to haplogroup N3. In Europe the highest frequencies of paragroup N* (up to 42.5%) were detected in Volga Finno-Ugric populations: Udmurts and Mari (Rosser et al. 2000; Khusnutdinova et al. 2002). Therefore Y-chromosome data suggest that the Russian male gene pool is characterized by its own structural features, although genetic influences on Russians from Uralic- or Baltic-speaking populations are also highlighted. The latter is clearly defined in the most northern Russian populations, such as Pskov Russians and Pomors. A possible explanation for this phenomenon includes replacement of an earlier Uralic or Baltic language in populations of the north of eastern Europe by the present Russian language, occurring with a low input of Slavonic mtDNA and Y-chromosome haplotypes. The high frequency of haplogroup N3 in Pskov and Pomor Russians (and probably in other northern Russian populations) is striking and should be investigated further using Y-chromosome STR analysis and a comparison with published N3-associated Y-chromosome STR haplotype data in Finno-Ugric and Baltic populations. These data should be studied with respect to the hypothesis that the genetic history of N3 Y chromosomes in Baltic-speaking populations is distinct from that of the Uralic speakers and "that there were two distinct early migrations of haplogroup 16 into Europe" (Zerjal et al. 2001). To test this and other hypotheses concerning the recent historical interactions between eastern European populations, more populations need to be studied for more genetic markers.

The present study demonstrates that Russian populations contain relatively high levels of mtDNA sequence diversity (in the means of pairwise nucleotide [End Page 896] differences), but the level of FST-based between-population differentiation is low. However, the results of the multidimensional scaling analysis performed on the basis of pairwise FST values for mtDNA HVSI sequences suggest that the Russian populations can be differentiated into subregions. The multidimensional scaling analysis revealed that Russian populations analyzed in combination with other central and eastern European populations do not cluster together and that populations from the southern and western parts of Russia (such as Stavropol, Rostov, Kursk, Orel, Kaluga, and Saratov) are separated from eastern and northern populations (Vladimir, Tula, Yaroslavl, Kostroma, and Pskov). Interestingly, southwestern Russian populations demonstrate genetic similarities with a set of central and northern European populations of different linguistic affiliation [Slavonic, Baltic, Germanic, and even Finno-Ugric (Estonians)], whereas northeastern Russian populations cluster together with eastern and northern European populations speaking not only Finno-Ugric languages but also Turkic (Tatars) and North Caucasus (Adygei) ones.

The multidimensional scaling analysis performed on the basis of pairwise FST values for Y-chromosome haplogroup data shows a somewhat different picture (for mtDNA sequences) of population differentiation in Russia. The most important subdivision was found only between northern populations of Pskov and Pomor Russians and the rest of the Russian populations studied. Historically, this observed discrepancy in the depth of penetration of mtDNA and Y-chromosome lineages characteristic for the most southwestern Russian populations into the east and north of eastern Europe may indicate [in accordance with anthropological data (Rychkov and Balanovska 1988)] that only the most western Russian populations appear to be descendants of the Slavs, whereas northern and eastern Russian populations seem to be the result of an admixture between Slavonic tribes and pre-Slavonic populations of eastern Europe. In addition, the data allow one to assume the possibility that Slavonic male lineages penetrated the original eastern European populations further than mtDNA lineages. One should note, however, that this scenario should be tested with additional mtDNA and Y-chromosome data in multiple Russian-, Finno-Ugric-, and Turkic-speaking populations of eastern Europe, which are poorly characterized genetically.

In addition, to estimate the degree of population replacement in eastern Europe associated with the Slavonic colonization starting in the early Middle Ages [6th–7th centuries A.D. according to archeological data (Sedov 1995)], it would be important to perform analyses of multiple samples from small urban areas, because such an approach seems to be informative in genetic history studies (Capelli et al. 2003).

Hum Biol. 2004 Dec;76(6):877-900

Differentiation of mitochondrial DNA and Y chromosomes in Russian populations

Malyarchuk B et al.

The genetic composition of the Russian population was investigated by analyzing both mitochondrial DNA (mtDNA) and Y-chromosome loci polymorphisms that allow for the different components of a population gene pool to be studied, depending on the mode of DNA marker inheritance. mtDNA sequence variation was examined by using hypervariable segment I (HVSI) sequencing and restriction analysis of the haplogroup-specific sites in 325 individuals representing 5 Russian populations from the European part of Russia. The Y-chromosome variation was investigated in 338 individuals from 8 Russian populations (including 5 populations analyzed for mtDNA variation) using 12 binary markers. For both uniparental systems most of the observed haplogroups fell into major West Eurasian haplogroups (97.9% and 99.7% for mtDNA and Y-chromosome haplogroups, respectively). Multidimensional scaling analysis based on pairwise F(ST) values between mtDNA HVSI sequences in Russians compared to other European populations revealed a considerable heterogeneity of Russian populations; populations from the southern and western parts of Russia are separated from eastern and northern populations. Meanwhile, the multidimensional scaling analysis based on Y-chromosome haplogroup F(ST) values demonstrates that the Russian gene pool is close to central-eastern European populations, with a much higher similarity to the Baltic and Finno-Ugric male pools from northern European Russia. This discrepancy in the depth of penetration of mtDNA and Y-chromosome lineages characteristic for the most southwestern Russian populations into the east and north of eastern Europe appears to indicate that Russian colonization of the northeastern territories might have been accomplished mainly by males rather than by females.


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