Four single-nucleotide polymorphisms (SNP) of the Phosphoglyceric Kinase (PGK) gene were discov- ered based on comparison of the sequences from an altiplano chicken breed (Tibetan chicken) and two lowland breeds (White Leghorn and Shouguang chicken). Gel-shift results indicate that one of these SNPs, an A→G mutation at position 59 in exon10, is able to bind hypoxia-induced factor-l (HIF-1), functioning as a hypoxia response element (HRE). The mutant gene results in M→T mutation at position 379 amino acid. The combined activity of this HRE and HIF-1 could increase correspondingly under a hypoxic stimulus. Hypoxia leads to increased death rates of chicken embryos; while the M→T mutation described herein is prevalent in healthy embryos grown under hypoxic conditions, thus it may repre- sent an adaptation to hypoxia. Fluorescence quantitative reverse transcription PCR results revealed that HIF-1 upregulates the transcript level of the glycolytic enzyme PGK in the brain and skeletal mus- cle of animals subjected to hypoxia. Thus, a large amount of ATP is produced by increased glycolysis, allowing the organism to meet energy metabolism demands. As such, we believe this SNP to be an adaptation to the external anoxic environment.
WANG CunFang1,3, YUAN CunZhong2, ZHANG Lao1, WU ChangXin1 & LI Ning2 1 College of Animal Science and Technology, China Agricultural University, Beijing 100094, China
