[Differential gene expression of hypoxia inducible factor-1alpha and hypoxic adaptation in chicken]

Hypoxia inducible factor-1 (HIF-1) is a transcriptional factor first discovered in cancer cells under hypoxic conditions, and was demonstrated to play a key role in the organism's adaptation to changing oxygen tensions. The Tibetan chicken, a breed indigenous to the Tibetan plateau is particularly adaptable to the low oxygen tension and low temperature conditions in the high altitude environment. By comparison, the White Leghorn and ShouGuang chicken are low-altitude chicken breeds. The eggs of these three chicken breeds were incubated in a fitted hatcher that simulated hypoxic condition. The results demonstrated that the hatching rate for Tibetan chicken was significantly higher than the two low altitude breeds, and Tibetan chicken displayed higher endurance in the hypoxia environment. To a certain degree, the hypoxic condition proved fatal to hatching for the low-altitude chickens. Gene expression of HIF-1alpha was detected in brain and skeletal muscle tissues for three chicken varieties using the TaqMan probe FQRT-PCR method. The results showed that HIF-1alpha mRNA displayed tissue specific differential expression, with the highest in the brain. In addition, the expression of HIF-1alpha mRNA in the brain of Tibetan chicken embryos was similar to that of the low-altitude chickens when they were hatched under normal oxygen tensions.