Adaptation to Altitude

Adaptation by dogs to altitude depends on numerous factors, including the body`s response to ambient oxygen levels. This response to oxygen levels can be affected by the genetic profile.

Definition

Adaptability to high altitudes depends on different factors that have been extensively studied. Among the factors involved, increased oxygen uptake and supply have been identified as important. A significant correlation has been established between adaptation to altitude and a genetic variant present in the EPAS1 gene, related to hypoxia (reduction of oxygen supply to a tissue). This variant, identified in dogs adapted to high altitudes, promotes adaptation to hypoxia through a physiological decrease in oxygen demand. This adjustment is commonly achieved by increasing ATP-producing pathways and reducing the activity of ATP-requiring pathways.

Genetic basis

The presence of one or two copies of the variant has been associated with a higher probability of adaptation to high altitudes. Also, carriers of a single copy of the variant have a 50% chance of transmitting it to their offspring.

Other relevant information

As with dogs, different genetic variants found in the EPAS1 gene have also been identified in humans. For example, genetic differences have been observed between the general population and Tibetan mountaineers. This finding suggests the possibility of parallel evolution in humans and dogs in terms of adaptation to hypoxia at high altitudes, as part of an adaptive process.

Bibliography

Gou X, Wang Z, Li N, et al. Whole-genome sequencing of six dog breeds from continuous altitudes reveals adaptation to high-altitude hypoxia. Genome Res. 2014 Aug;24(8):1308-15.

vonHoldt B, Fan Z, Ortega-Del Vecchyo D, et al. EPAS1 variants in high altitude Tibetan wolves were selectively introgressed into highland dogs. PeerJ. 2017 Jul 12;5:e3522.