Northernmost autochthonous Yakutian horses: A radically adapted genome for a uniquely sustainable production system

Highlights

• Northernmost Yakutian horse is unique in terms of adaptation and production system.

• The review summarizes information on their history and adaptation to Arctic extremes.

• Selection signature studies in their genome show adaptive parallels to Yakut cattle.

Abstract

Yakutia is one of the coldest inhabited regions on Earth, with extreme annual temperature fluctuations ranging from 30 °C in summer to −70 °C in winter. In this environment, autochthonous Yakutian horses exhibit remarkable physiological, reproductive, metabolic and behavioral adaptations that allow year-round free-range grazing, even under deep snow cover and severe cold conditions. This breed underpins a traditional livestock system central to Yakut culture, where horse meat forms a major dietary component. It also supports food security, providing meat rich in polyunsaturated fatty acids (PUFAs) with an optimal omega n-6/n-3 ratio. Yakutian mares produce nutrient-rich milk with a biochemical profile similar to that of human milk, allowing foals to achieve exceptional growth rates, up to 1.5 kg/day. This breed is an example of rapid adaptation (∼100 generations; 600–800 years) to Arctic extremes through such mechanisms as changes in coat, fat metabolism, thermogenesis, and energy efficiency, as supported by genes within the positive selection signatures in its genome. This narrative review integrates a comprehensive evidence base on the origin, adaptation, year-round free-grazing management and sustainable production system of Yakutian horses. We also provide an overview of the more advanced functional genomics of Yakut cattle to propose a roadmap for future genomic studies of the Yakutian horse. We hypothesize that recent migration followed by rapid natural selection-driven adaptation explains the survival, productivity and cultural importance of Yakutian horses in one of the harshest environments in the world.