engleski

Mitochondrial DNA Analysis of the Southeast European Genetic Variation Reveals a New, Local Subbranching in Hg X2

High mtDNA variation in Southeastern Europe is a reflection of the turbulent and complex demographic history of this area, influenced by gene flow from various parts of Eurasia and a long history of intermixing. Our results of 1035 samples from four SEE populations (Croatians, Slovenians, Bosnians, Herzegovinians) show that their maternal genetic diversity fits within a wider European maternal genetic landscape, but in spite of the geographical proximity of sampled populations, certain differences can be observed in mtDNA haplogroup composition and variation. Also, we observed five new samples in the Bosnian population and one new Herzegovinian sample designated as X2* individuals, that could not be asigned to any of its sublineages (X2a’k) according to the existing X2 phylogeny. Subhaplogroup X2 is highly diversificated and spread over a wide geographic area, but usually at low frequencies (<5%). A detailed picture of X2 migrations across Europe, Asia and North America is still unrevealed and therefore intriguing. In attempt to clarify the phylogeny of our X2 samples, their mitochondrial DNA has been completely sequenced and no matching sequences have been found among over 18 000 mtDNAs in the updated mtDNA phylogenetic tree. We suppose that these lineages present SEE variants of the X2 clade and that they are signs of one or several local micro-differentiation processes that occured in a relatively recent demographic past. Additional sequencing of X2* individuals in this area is in progress and we expect our new insights will contribute to further resolution of the X2 phylogeny.

mitochondrial DNA; Southeastern Europe; haplogroup X2; phylogeny

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