| Tibetan antelope(Pantholops hodgsonni)belongs to the Bovidae family ofArtiodactyla order and Pantholops genus. It mainly distributed in Qinghai-Tibetanplateau and Xinjiang Autonomous Region in China, as well as in India at elevation from3500-5500meters,espically in4500-5500meters. It has been listed as an Appendix Ispecies by the Convention on International Trade in Endangered Species (CITES) andas Category I by the Key Protected Wildlife List of China. As we all know,TibetanAntelope can run at a top speed of70km to100km/h). it is a typically hypoxia and lowtemperature tolerant mammal.Heme oxygenase-1(HO-1) is heat shock protein32(HSP32) and also called theinduced HO-1, which is a kind of antioxidant enzymes to antagonist oxidatie stress. Themolecular weight of it is32kD, widely distributed at the tissues all over the body,especially in microsomes of mononuclear cells and macrophages system in the body andthe activity at the heart, lungs, kidneys, liver, spleen, bone marrow and meshyendodermis cell is the highest. Human HO-1has288amino acids and HO-1genelocated at chromosome22q12, contains four introns, five exens. HO-1can be induce byall kinds of causes under oxidative stress by damage factors, including hemoglobin,high oxygen, hypoxia, heat shock, endotoxin, hydrogen peroxide, cytokines, uv, heavymetal, nitric oxide (NO) and so on. The common features of these inducers are that theycan cause oxidative stress. In Recent studies, HO-1plays more important role inendogenous antioxidant enzymes, essence the stress protein, which appear adaptabilityexpression in all kinds of oxidative stress state and has many protection effects such asanti-free radical and so on. The oxidation resistance of HO-1comes from degeneratefree hemoglobin that can cause oxidation and generate bilirubin that is a powerfulantioxidant product. This product can remove non-specific variety of free radicals. TheTibetan antelope live in high altitude and low oxygen alpine region and can run70-100kilometers as the speed of60kilometers per hour continually, which showed high levelof protection and adaptation mechanism at genetic and molecular level. Heme oxygenase-1(HO-1) have widely cell protection and antioxidant effect. In order toreveal the effect of Tibetan antelope heme oxygenase-1(HO-1) on the cell protectionand antioxidant and biological mechanism of low oxygen adaptation, the hemeoxygenase-1(HO-1) gene was cloned from the Tibetan antelope liver tissue, and thesequence was analyzed.And compared with Capra hircus heme oxygenase-1the coding sequence, andmany variations can be observed at the codon of123(GCCâ†'ACT) and230(TGGâ†'TGG)，284(GCCâ†'GGC),287(AATâ†'CAT)，which lead to many variations on thecorresponding amino acid:123Alaâ†'Thr and,230Serâ†'Leu,284Leuâ†'Phe,287Metâ†'Cys.The further research on the relationship between mutation site and plateaulow oxygen adaption are required. Evolutionary tree analysis shows that the Tibetanantelope’s heme oxygenase-1and other animals’ integrated a bouquet, and originatedfrom common ancestry but in different evoluation branch. The heme oxygenase-1of theTibetan antelope and Capra hircus are in common branch, and the second is cattle. Themutations and its cells protection function needs to be further study. To further illustrateadaption in plateau low oxygen of the Tibetan antelope heme oxygenase-1(HO-1) playsthe important role. As a native mammal that has been living for many thousands ofgeneration at high altitude and successfully adapted to chronic hypoxia. However, themechanism of adaptation to high altitude in these animals has not been investigated. |
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