| description |
Organisms living at high altitudes are presented with physiologically and metabolically challenging conditions due to the reduction in barometric pressure and oxygen availability. Hypoxia can be detrimental to survival, and a powerful homeostasis system has evolved in animals to cope with fluctuations in oxygen concentration. Along with the plastic physiological response displayed by many organisms, there is strong evidence for genetic adaptation to altitude in humans and other vertebrates. We studied the genomic basis of adaptation to high elevation in the house mouse, Mus musculus domesticus, a species that has been recently introduced to high altitude. We collected mice from five populations along an altitudinal transect in Ecuador, from 0 to 3000 meters elevation. We sequenced 50 complete exomes representing 10 unrelated individuals from each of five localities. Associations between genotype and environmental variables were identified using a variety of approaches that attempt to control for the correlated histories of populations. Using these approaches, we identified a set of candidate genes in gene ontologies consistent with other studies targeting altitude adaptation in vertebrates, including genes in the hypoxia-induced transcription factor (HIF) as well as angiogenesis and energy metabolism. In addition, we found a lack of non-synonymous SNPs in our candidate genes, suggesting that most mutations related to adaptation to altitude in our house mouse transect are regulatory. |