Assessment of mtDNA variability and phylogenetic relationships of Siberian local horse breeds

Abstract

Local horse breeds of Siberia have universal economic characteristics and good adaptive qualities. The most valuable gene pool of these breeds has been formed over the centuries, and is of considerable interest for study at the molecular genetic level. The aim of our research was to study the sequence of the hypervariable region of the D-loop of mtDNA in 88 horses of the Buraytskaya, Zabaikalskaya, Tuvinckaya, and Yakutskaya breeds. Analysis of the sequenced D-loop sequence of 530 bp was performed using the Neighbor-Joining method in combination with bootstrap analysis in the MEGA7 program. When studying the polymorphism of the hypervariable region of the D-loop of mtDNA in local horses of Siberia, we identified 16 haplogroups: A, B, C, D, E, G, I, L, M, N, O, P, Q, and R, according to the modern classification. Three additional mtDNA haplogroups with a high level of bootstrap support (100%) were found in Buryatskaya horses. Sequenced fragments of the D-loop from 15471 to 16000 nucleotide positions included up to 113 polymorphic sites, mainly represented by transitions. The studied horse breeds differed among themselves in the structure of the mitochondrial genome and demonstrated a high level of diversity of haplotypes and haplogroups typical of the Mongolian population and other horses of Eurasia.