Mitochondrial diversity in mountain horse population from the South-Eastern Europe.

This study examined the genetic diversity of various mountain horse breeds in Southeastern Europe in areas such as the Balkan Mountain, the Rhodopes, and the Rila-Pirin massif. It found that these populations possessed a high degree of genetic diversity, suggesting they have been well-preserved despite geographic isolation, and revealed a significant genetic mixture in one particular population.

Methodology and Findings

• The research genotyped a total of 121 horses from three different mountainous regions in Bulgaria, focusing on the mitochondrial D-loop region.
• Analyses revealed a rich array of genetic diversity in these populations, presenting all known haplogroups with the exception of C, F and R.
• The West Eurasian haplogroups B, D, M, and L had the highest frequencies, followed by haplogroups A, J, I, O’P, and Q, though these latter groups were not equally distributed among the three populations.
• The study revealed a preserved genetic profile in horse breeds from the Balkan and the Rhodopes mountain ranges.

Unexpected findings

• The horse population in the Rila-Pirin region showed an unexpected mixture of genetic profiles. Despite the geographic and historical isolation, there was significant genetic introgression with Asiatic-type haplogroups detected.
• Similarly, the Carpathian mountain pony possessed a mixed Euro-Asiatic haplotype profile, despite being geographically and historically separate from the other populations.

Research Significance

• The genetic heterogeneity found in these breeds suggests that these horse populations have been well preserved despite their isolation.
• The surprising genetic mixture found in the Rila-Pirin breed indicates more complex breeding and genetic exchange histories in these horse populations than was previously believed.
• The research strongly suggests that these diverse gene pools should be maintained, indicating future needs for conservation efforts in these horse breeds.