Evidence for positive selection on α and β globin genes in pikas and zokor from the Qinghai-Tibetan Plateau

Hemoglobin plays an important role in oxygen transfer from respiratory surfaces to metabolizing tissues. Evidence from other vertebrate taxa suggests that the specific amino acid changes in key positions of hemoglobin or structural changes in the hemoglobin proteins play important roles in controlling Hb-O 2 affinity, as well as helping high-attitude animals to adapt to high altitude hypoxia. Pikas and zokor are keystone species in the Tibetan plateau ecosystem and are considered to be genetically adapted to extremely hypoxic environment. In the present study, the α and β globin gene sequences from four species of pikas and one species of zokor were obtained and then conducted molecular evolutionary analysis. Our study provides evidence of positive selection on pikas and zokor α and β globins and demonstrates adaptive evolution of pikas and zokor α and β globins that could affect the ability of hemoglobin to bind to oxygen. These findings increase the knowledge contributes to the understanding of adaptive evolutionary of pikas and zokor to high altitude hypoxic conditions of the Qinghai-Tibetan Plateau. Nevertheless, further functional experiments will be required to test the findings in this study.