Association Study Between COX17, EPOR, VEGF-A Gene Polymorphisms And High-Altitude Adaption Among Tibetan Sheep

To analyse the molecular mechanism of Tibetan sheep’s adaptation to high altitudehypoxia. The study used different altitudes sheep as preliminary research sample. UsingCOX17, EPOR, VEGF-A be associated with oxygen, energy metabolism as a candidategene, COX17, EPOR, VEGF-A was analysed by DNA mixing tank, direct sequencingand high resolution melting curve to analysis gene polymorphism in different groups ofsheep, then analysis the correlation of COX17, EPOR, VEGF-Apolymorphism withTibetan sheep’s high altitude hypoxia adaptation. In order for the possession of sheepgenetic resources protection, development and breeding of new varieties provide ascientific basis.1. Correlation between COX17polymorphism and Tibetan sheep high altitudehypoxia adaptationTwo SNP sites were found in COX17gene intron: SNP1(g.402T/C), SNP2(g.408T/C). COX17gene SNP1(g.402T/C), SNP2(g.408T/C) genotype and allelefrequencies in low-elevation populations were statistically difference (P<0.05) with highaltitude and the elevation group, while differences between high-altitude populationsand the elevation group were not significant (P>0.05). SNP1(g.402T/C), SNP2(g.408T/C) in intermediate altitude and high altitude TT in the advantage genotype. CCis the advantage genotype at low altitude sheep population. SNP1, SNP2in closelinkage disequilibrium in three groups (D’>0.75r2>0.33), Tibetan sheep populationsSNP1, SNP2advantage alleles are T allele, TT is the advantage genotype, TT isadvantages haplotypes.2. Association between EPOR gene polymorphism and Tibetan sheep high altitudehypoxia adaptationThree SNP loci-SNP1(g.237A/G), SNP3(g.4657G/A), SNP4(g.4857G/A) werefound in different altitudes sheep EPOR intron. SNP2mutation (g.2922C/G) be capableof alanine to threonine was found in the coding region of SNP2mutation but did notlead to changes in senior structures. EPOR gene SNP1(g.237A/G), SNP2(g.2922C/G)genotype and allele frequencies in low-elevation population groups were statistically difference (P <0.01) compared with high altitude, were significant difference(P<0.05)compared with intermediate altitude, high altitude and the intermediate altitude betweensheep populations was not significant (P>0.05). SNP2(g.2922C/G) in intermediatealtitude and high altitude GG is the advantage genotype, CC is the advantage genotypeat low altitude, SNP1, SNP2, SNP3and SNP4was close linkage disequilibrium in threegroups (D ’>0.75r2>0.33). G is the advantage allele in Tibetan sheep populations, GG isthe advantage genotype, GCGG is the advantage haplotypes.3. Correlation between VEGF-A gene polymorphism and Tibetan sheep highaltitude hypoxia adaptation.Three SNPs were found in coding region of VEGF-A in different altitudes sheep:SNP1(g.15005T/A), SNP2(g.15020T/A), SNP3(g.15028T/A). SNP2(g.15020T/A)mutation was capable of cysteine to serine, but did not cause changes in proteinsecondary and senior structures. VEGF-A gene SNP2(g.15020T/A), SNP3(g.15028T/A)genotype and allele frequencies with significant differences (P<0.05) in high altitudeand low altitude populations, while SNP1(g.15005T/A) genotype and allele frequencieswas not significant (P>0.05) in high altitude and low altitude sheep populations, SNP2(g.15020T/A), SNP3(g.15028T/A)in high altitude sheep populations TT is theadvantange genotype, AA is the advantage genotype in low altitude sheep populations.SNP2and SNP3were in close linkage disequilibrium (D ’>0.75r2>0.33). SNP1doesnot exist inkage disequilibrium (D’<0.75r2<0.33) with SNP2and SNP3. SNP1, SNP2,SNP3advantages genes are T allele in Tibetan sheep populations, TT is the advantagegenotype, TTT haplotype is the advantage haplotypes.