Expression pattern of HIF1a mRNA in brain, heart and liver tissues of Tibet chicken embryos in hypoxia revealed with quantitative real-time PCR

The problem of hypoxia adaptation in high altitudes is an unsolved brainteaser in the field of the life sciences. As one of the best chicken breeds with adaptability to highland environment, the Tibet chicken, is genetically different from lowland chicken breeds. It is well known that hypoxia has significant impact on growth by inducing the expression of the alpha subunit of the heterodimeric transcription factor, hypoxia-inducible factor 1 (HIF1a). In the present study, HIF1a expression in brain, heart and liver tissues of the Tibet and Dwarf Recessive White chicken embryos were investigated at the different development stages of days 10, 17 and 20 by real-time PCR, and the expression pattern of HIF1a in chicken embryos of the two chicken breeds incubated under conditions of hypoxia (13% O2) and normoxia (21% O2) was studied. The incubation mortality of the Tibet chicken was lower than the Dwarf Recessive White chicken during the whole incubation in hypoxia, and the mRNA expression of HIF1a had presented the differences in three tissues. The results implied that the hypoxia adaptability of the Tibet chicken embryo was higher than the Dwarf Recessive White chicken, especially in the early stage (day 10) and at a later time (day 20) during the incubation period, but the mechanism of the oxygen transfer of embryos of mountain species is not completely understood, and hypoxia adaptability of the Tibetan chicken remains to be studied further.