Structure and diversity of the mitochondrial gene pool in indigenous populations of Tuva and Buryatia based on restriction polymorphism data

The populations of Tuvinians (N = 36) and Buryats (N = 105) were characteri zed by using the data on mitochondrial DNA (mtDNA) polymorphism. The gene p ools of both ethnic groups possessed the mtDNA types belonging to the four main haplogroups, A, B, C, and D, found only in the indigenous populations of Asia and America. The total frequencies of the A, B, C, and D haplogroup s in Tuvinians and Buryats were 72.3% and 52.4%, respectively. These values , along with the frequency for Altai populations (57.2%), were highest in t he Asian populations studied, indicating that the populations from southern and eastern Siberia can be considered as ancestral relatives to the ethnic groups of the New World. Analysis of the mtDNA region V polymorphism showe d the presence of 9-bp deletion and 4-bp insertion in both populations with frequencies respectively of 13.9 and 5.56% in Tuvinians and 4.8 and 1.9% i n Buryats. The frequency of the +AvaII/8249 variant was 11.1% in Tuvinians and 3.81% in Buryats. Analysis of the association between the region V dele tion-insertion polymorphism and certain restriction haplogroups pointed to repeated and independent emergence of the 4-bp insertion in Siberia.