Energy metabolism plays an important role in life survival for species living in high altitude hypoxia condition.Air-breathing organisms require oxygen to create energy.Tibetans are the well-adapted highlanders in Qinghai-Tibetan Plateau.It was thought that different metabolic approaches could lead to different adaptation traits to high altitude hypoxia.Recently identified hypoxia inducible factors pathway regulators,endothelial PAS domain protein1(EPAS1)/HIF-2α and PPARA,were involved in decreasing hemoglobin concentrations in Tibetans.Because EPAS1 and PPARA also modulated the energy metabolism during hypoxia,we hypothesized that positive selected EPAS1 and PPARA genes were also involved in unique energy metabolisms in Tibetans.In this brief review,we take a look into genetic determinations to energy metabolisms for hypoxia adaptations traits in Tibetans and mal-adaptive conditions such as high altitude diseases.
Neuroglobin(Ngb) is a respiratory protein that is preferentially expressed in brain of mouse and man.In this article,Tibetan antelope,living at altitude of 3 000～5 000 m for millions of years,was selected as the model of hypoxia-tolerant adaptation species.Using reverse transcription polymerase chain reaction(RT-PCR) and Western blot techniques,expression of Ngb gene was amplified and analyzed in antelope brain tissue.Our results showed that Ngb homology protein in Tibetan antelope was identified with more sequence similarity with cattle(96%),sheep(95%),and human(95%).We detected that there were some mutations occurred in the Open Reading Frame of Ngb in Tibetan antelope compared with sheep.Phylogenetic analysis of Ngb chain showed that it was closer to cattle than the others.This study suggests possible roles of central nervous system enriched Ngb in adaptation of Tibetan antelope to extremely high altitude.
Zhen-zhong BAIYing-zhong YANGGuo-en JINLan MARi-li Ge
