Ren Yue, Xi Qiming, He Zhaohua, Sun Hongxian, Li Shaobin
Institute of Livestock Research, Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa 850000, China.
Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lhasa 850000, China.
Animals (Basel). 2024 Feb 6;14(4):535. doi: 10.3390/ani14040535.
After a long period of adaptive evolution, Tibetan sheep have adapted to the plateau environment in terms of genetics, physiology and biochemistry, but the mechanism of hypoxia adaptation has not been fully elucidated, and the functional genes and molecular mechanisms regulating the hypoxia adaptation of Tibetan sheep need to be further studied. In this study, Tibetan sheep were selected as the research object, and the mRNA expression levels of the hypoxa-related gene in heart, lung, kidney, liver, spleen and longissimus dorsi muscle of Hu sheep (100 m) and Tibetan sheep at different altitudes (2500 m, 3500 m, 4500 m) were assessed by RT-qPCR. The SNPs loci were detected by sequencing and Kompetitive Allele-Specific PCR (KASP) technology, then the correlation between genetic polymorphism and blood gas was analyzed. The results show that the expression of the gene was the highest in the kidney, indicating that the expression of gene had tissue differences. The expression levels of the gene in the heart, lung and liver of Tibetan sheep at a 4500 m altitude were significantly higher than those in Hu sheep ( < 0.05), and the levels in the hearts of Tibetan sheep increased with the increase in altitude. Three mutations were identified in the EPO gene, the SNPs (g.855 A > C) in exon 1 and the SNPs (g.1985 T > G and g.2115 G > C) in exon 4, which were named EPO-SNP1, EPO-SNP2 and EPO-SNP3, respectively, and all three SNPs showed three genotypes. Correlation analysis showed that g.2115 G > C sites were significantly correlated with O ( < 0.05), and haplotype combinations were significantly correlated with O ( < 0.05). Thesee results suggest that the expression of the gene is altitude-differentiated and organ-differentiated, and the gene variants have significant effects on O, which may be beneficial to the adaptation of Tibetan sheep to hypoxia stress.
经过长期的适应性进化，藏羊在遗传、生理和生化方面已适应高原环境，但低氧适应机制尚未完全阐明，调控藏羊低氧适应的功能基因和分子机制有待进一步研究。本研究以藏羊为研究对象，采用RT-qPCR技术检测了湖羊（100 m）和不同海拔（2500 m、3500 m、4500 m）藏羊心脏、肺、肾、肝、脾和背最长肌中低氧相关基因的mRNA表达水平。通过测序和竞争性等位基因特异性PCR（KASP）技术检测SNP位点，进而分析基因多态性与血气的相关性。结果表明，该基因在肾脏中的表达最高，表明该基因的表达具有组织差异。4500 m海拔藏羊心脏、肺和肝脏中该基因的表达水平显著高于湖羊（P<0.05），且藏羊心脏中的表达水平随海拔升高而增加。在EPO基因中鉴定出3个突变，分别为外显子1中的SNP（g.855 A>C）和外显子4中的SNP（g.1985 T>G和g.2115 G>C），分别命名为EPO-SNP1、EPO-SNP2和EPO-SNP3，这3个SNP均表现出3种基因型。相关性分析表明，g.2115 G>C位点与O2显著相关（P<0.05），单倍型组合与O2显著相关（P<0.05）。这些结果表明，该基因的表达具有海拔差异和器官差异，该基因变异对O2有显著影响，可能有利于藏羊适应低氧应激。
