Abstract: Hypoxia inducible factor 1 (HIF-1),which is a transcription factor composed of HIF-1α and arylhydocarbon nuclear receptor translocator (ARNT),plays an important role in the signal transduction of cell response to hypoxia.Plateau pikas (Ochotona curzoniae),which are a kind of high anoxia-tolerance and cold adaptation species lived only above 3000 m on Qinhai-Tibet Plateau,have unusual high RMR and NST,acting mainly via increasing NST to adapt to extreme cold of the Qinghai-Tibet Plateau;and high ratio of oxygen utilizing to cope with plateau hypoxia environment.In this study,the plateau pikas were taken to Beijing and adapted under normal oxygen and room temperature for 7 days.One fragment of the plateau pika HIF-1α cDNA was obtained by RT-PCR technique and labeled with 32P as specific probe.Northern blot analysis showed that HIF-1α mRNA was expressed in many kinds of tissues and displayed a tissue specific expression:the highest in brain,next in kidney,and much less in heart,liver,and spleen.