High genetic diversity of ancient horses from the Ukok Plateau.

Natalia V. Polosmak,Mariya A. Kusliy,David Caramelli,Alexey I. Makunin,Nadezhda V. Vorobieva,Vladimir A. Trifonov,Kseniya O. Popova,Michael V. Shunkov,Alexander S. Graphodatsky,Anna S. Druzhkova,Sergei K. Vasiliev,Vyacheslav I. Molodin

doi:10.1371/journal.pone.0241997

Abstract

A growing number of researchers studying horse domestication come to a conclusion that this process happened in multiple locations and involved multiple wild maternal lines. The most promising approach to address this problem involves mitochondrial haplotype comparison of wild and domestic horses from various locations coupled with studies of possible migration routes of the ancient shepherds. Here, we sequenced complete mitochondrial genomes of six horses from burials of the Ukok plateau (Russia, Altai Mountains) dated from 2.7 to 1.4 thousand years before present and a single late Pleistocene wild horse from the neighboring region (Denisova cave). Sequencing data indicates that the wild horse belongs to an extinct pre-domestication lineage. Integration of the domestic horse data with known Eurasian haplotypes of a similar age revealed two distinct groups: the first one widely distributed in Europe and presumably imported to Altai, and the second one specific for Altai Mountains and surrounding area.

Highlights

The horse domestication process started about 5 thousand years ago and involved severe population bottlenecks, similar to other animals [1]
Ancient DNA from seven samples (Table 1) was isolated according to the previously published protocol [18] with some modifications: ammonium EDTA salt was used during the bone powder dissolution stage [19], which allowed to reduce the dissolution time from 18–24 h down to 1.5–3 h under the same conditions (500 mg bone powder in 10 ml of buffer at 55 ̊C)
Our data indicate that from five discovered equine haplotypes from the Ukok Plateau, some control region haplotypes (I, F, and D2) were shared between concurrent and earlier populations of horses from Europe, while haplotypes K and K2 are absent from European populations and may represent specific Eastern haplotypes

Summary

Introduction

The horse domestication process started about 5 thousand years ago and involved severe population bottlenecks, similar to other animals [1]. Mares were supposedly consistently restocked from the surrounding wild populations, which manifested in unprecedented retention of the vast part of mitochondrial variation in the domestic breeds [1, 2, 3,4,5,6,7,8,9,10,11]. It is clear that in order to get insights into the details of early domestication one should compare haplotypes of both wild and domestic animals from different locations and to investigate the transportation routes between these sites in ancient times.

Methods

Results

Conclusion