Population History of the Dniester-Carpathians: evidence from Alu insertion and Y-chromosome polymorphisms

The Dniester-Carpathian region has attracted much attention from historians, linguists, and anthropologists, but remains insufficiently studied genetically. We have analyzed a set of autosomal polymorphic loci and Y-chromosome markers in six autochthonous Dniester-Carpathian population groups: 2 Moldavian, 1 Romanian, 1 Ukrainian and 2 Gagauz populations. To gain insight into the population history of the region, the data obtained in this study were compared with corresponding data for other populations of Western Eurasia. The analysis of 12 Alu human-specific polymorphisms in 513 individuals from the Dniester-Carpathian region showed a high degree of homogeneity among Dniester-Carpathian as well as southeastern European populations. The observed homogeneity suggests either a common ancestry of all southeastern European populations or a strong gene flow between them. Nevertheless, tree reconstruction and principle component analyses allow the distinction between Balkan-Carpathian (Macedonians, Romanians, Moldavians, Ukrainians and Gagauzes) and Eastern Mediterranean (Turks, Greeks and Albanians) population groups. These results are consistent with those from classical and other DNA markers and are compatible with archaeological and paleoanthropological data. Haplotypes constructed from Y-chromosome markers were used to trace the paternal origin of the Dniester-Carpathian populations. A set of 32 binary and 7 STR Y-chromosome polymorphisms was genotyped in 322 Dniester-Carpathian Y-chromosomes. On this basis, 21 stable haplogroups and 171 combination binary marker/STR haplotypes were identified. The haplogroups E3b1, G, J1, J2, I1b, R1a1, and R1b3, most common in the Dniester-Carpathian region, are also common in European and Near Eastern populations. Ukrainians and southeastern Moldavians show a high proportion of eastern European lineages, while Romanians and northern Moldavians demonstrate a high proportion of western Balkan lineages. The Gagauzes harbor a conspicuous proportion of lineages of Near Eastern origin, comparable to that in Balkan populations. In general, the Dniester-Carpathian populations demonstrate the closest affinities to the neighboring southeastern and eastern European populations. The expansion times were estimated for 4 haplogroups (E3b1, I1b, R1a1, and R1b3) from associated STR diversity. The presence in the studied area of genetic components of different age indicates successive waves of migration from diverse source areas of Western Eurasia. Neither of the genetic systems used in this study revealed any correspondence between genetic and linguistic patterns in the Dniester-Carpathian region or in Southeastern Europe, a fact which suggests either that the ethnic differentiation in these regions was indeed very recent or that the linguistic and other social barriers were not strong enough to prevent genetic flow between populations. In particular, Gagauzes, a Turkic speaking population, show closer affinities not to other Turkic peoples, but to their geographical neighbors