Study On Specificity Of VEGF Gene In Plateau Zokor (Myospalax Baileyi) Skeletal Muscle Tissue

Plateau zokor (Myospalax bailey) is native to the Qinghai-Tibet plateau, vascular endothelial growth factor (VEGF) can promote capillary proliferation, and the microvessel density (MVD) of animal tissues is related to their adaptility to hypoxia. To study their adaptive mechanisms, the VEGF cDNA of plateau zokor was sequenced and analyzed by bioinformatics, and the expression patterns of VEGF in skeletal muscle tissues were measured through real-time PCR and the MVD of skeletal muscle of plateau zokor in different altitudes were measured by immunohistochemical staining and the correlation relation of MVD with VEGF expression was analyzed by SPSS17.0. Our results indicated that, the open reading frame of the plateau zokor VEGF was 645 bp, the coding sequence of the plateau zokor VEGF cDNA shared 92.1%, 93.6% and 93.8% nucleotide sequence homology to that of the plateau pika, rat and mouse, respectively. The deduced amino acid sequence of the plateau zokor VEGF cDNA was composed of 188 amino acids and the amino acids from 1 to 26 were signal peptide sequence. The plateau zokor VEGF₁₈₈ shared 90.2%,94.9% and 94.4% homologous to that of the plateau pika, rat and mouse, respectively. MVD (1107.47±47.98) in high altitude plateau zokor was significantly higher than that (918.74±54.10) of skeletal muscle in low altitude plateau zokor (P<0.05). VEGF isoforms in plateau zokor skeletal muscle is mainly composed of VEGF₁₈₈, VEGF₁₆₄ and VEGF₁₂₀. The expression of total VEGF, VEGF₁₈₈, VEGF₁₆₄ mRNA (respectively 0.90±0.10, 0.66±0.14, 0.94±0.17) in plateau zokor at low altitude was significantly lower than high altitude platau (1.27±0.24, 1.22±0.13, 1.47±0.24 respectively)(P<0.05), while VEGF₁₂₀ mRNA expression did not change significantly(0.67±0.12 at low altitude, 0.58±0.11 at high altitude). VEGF₁₆₄ was significantly correlated with MVD (P <0.05).In conclusion, VEGF main isoform in plateau zokor skeletal muscle is VEGF₁₆₄, VEGF₁₆₄ is the main form to advance capillary proliferation in VEGF forms.The sensitivities to hypoxia of VEGF₁₈₈, VEGF₁₆₄ and VEGF₁₂₀ were different, and in turn reduced.