Hypoxia-inducible factor 1α cDNA cloning and its mRNA and protein tissue specific expression in domestic yak (Bos grunniens) from Qinghai-Tibetan plateau

Adaptation to hypoxia is regulated by hypoxia-inducible factor 1 (HIF-1), a heterodimeric transcription factor consisting of an oxygen-regulated α-subunit and a constitutively expressed β-subunit. How animals living on Qinghai-Tibetan plateau adapt to the extreme hypoxia environment is known indistinctly. In this study, the Qinghai yak which has been living at 3000–5000 m altitude for at least two millions of years was selected as the model of high hypoxia-tolerant adaptation species. The HIF-1α ORFs (open reading frames) encoding for two isoforms of HIF-1α have been cloned from the brain of the domestic yak. Its expression of HIF-1α was analyzed at both mRNA and protein levels in various tissues. Both its HIF-1α mRNA and protein are tissue specific expression. Its HIF-1α protein’s high expression in the brain, lung, and kidney showed us that HIF-1α protein may play an important role in the adaptation to hypoxia environment.