Predicted structural change in erythropoietin of plateau zokors--adaptation to high altitude

Erythropoietin (EPO) is a glycoprotein hormone, expressed mainly in fetus liver and adult kidneys. EPO plays an important role in enhancing red blood cell formation in bone marrow under hypoxia. Plateau zokor (Myospalax baileyi), an subterranean burrowing endemic rodent inhabiting areas of 2 800-4 200 m above sea level on Qinghai-Tibet Plateau, is a typical high hypoxia tolerant mammal with high ratio of oxygen utilization in adaptation to the harsh plateau environment. To investigate the possible mechanisms of adaptation of plateau zokor EPO to high altitude, the complete cDNA and amino acid sequences of plateau zokor EPO have been described. Phylogenetic tree of Epo showed the convergence of the Spalax and Myospalax, indicating that, the convergent evolution was driven by similar hypoxic ecological niches. Our results showed that some common sites under positive selection in zokor (116M and 144A) and Spalax (102R, 116M, 144A and 152P) are the important sites for Epo biological activity. This study thus reports a gene level observation which may be involved in adaptation to underground life at high altitude.