Mitogenomic diversity in Russians and Poles

•Complete mitogenomes were sequenced in populations of Russians and Poles.•High diversity but low differentiation was observed among six Russian populations.•Bayesian skyline analysis demonstrates the Bronze Age expansion ∼4.3 kya.

Complete mtDNA genome sequencing improves molecular resolution for distinguishing variation between individuals and populations, but there is still deficiency of mitogenomic population data. To overcome this limitation, we used Sanger-based protocol to generate complete mtDNA sequences of 376 Russian individuals from six populations of European part of Russia and 100 Polish individuals from northern Poland. Nearly complete resolution of mtDNA haplotypes was achieved - about 97% of haplotypes were unique both in Russians and Poles, and no haplotypes overlapped between them when indels were considered. While European populations showed a low, but statistically significant level of between-population differentiation (Fst = 0.66%, p = 0), Russians demonstrate lack of between-population differences (Fst = 0.22%, p = 0.15). Results of the Bayesian skyline analysis of Russian mitogenomes demonstrate not only post-Last Glacial Maximum expansion, but also rapid population growth starting from about 4.3 kya (95% CI: 2.9-5.8 kya), i.e. in the Bronze Age. This expansion strongly correlates with the Kurgan model established by archaeologists and confirmed by paleogeneticists.