Lower mitochondrial DNA content relates to high-altitude adaptation in Tibetans

Abstract

Mitochondrial DNA (mtDNA) is crucial to mitochondria in energy production and other physiological functions. When lowlanders arrive at high altitude, the mitochondrial content tends to decrease. However, the mtDNA content of native highlanders share the same feature as lowlanders remains unknown. It is also interesting to dissect the other changes in blood plasma that might accompany the change of mtDNA content. To address these issues, we recruited 241 Tibetan subjects in Tibet and 220 Han subjects in Shaanxi province. Relative mtDNA copy number and blood biochemical indexes were measured. Results show that relative mtDNA copy number in Tibetans is significantly lower as compared to Han subjects; sex, age, blood glucose, triglyceride and total cholesterol show no influence on mtDNA content, but carbon dioxide combining power is negatively correlated with mtDNA content. These results indicate that an increase in CO₂ combining power along with lower mtDNA content may provide adaptive potential.

• Adaptation
• carbon dioxide combining power
• copy number
• high altitude
• mitochondrial DNA

Acknowledgements

We thank Dr. He Y-H for helpful suggestions.

Declaration of interest

This work was supported by non-profit grants from National Basic Research Program of China (2012CB518205), Yunnan Province (2011FA024), Natural Science Foundation of China (31123005, 31322029), and the Chinese Academy of Sciences. The authors declare no conflicts of interest. The authors alone are responsible for the content and writing of this article.