类乌齐牦牛乳酸脱氢酶基因克隆及组织表达

Cloning and Differential Expression Analysis of Lactate Dehydrogenase Gene in Leiwuqi Yak

旨在克隆西藏类乌齐牦牛乳酸脱氢酶(LDHB)基因并检测其组织表达情况,为给进一步研究LDHB在高海拔地区的极端低氧适应性及能量代谢中的调控作用提供依据。结果表明,类乌齐牦牛LDHB基因CDS区全长1 004bp,编码334个氨基酸,存在2处碱基突变,导致密码子分别由AAG→GAG(赖氨酸→谷氨酸)、ATC→AGC(异亮氨酸→丝氨酸);编码蛋白分子质量为36.72ku,为疏水稳定性蛋白,功能预测在糖酵解及氧化还原等过程中发挥主要功能;系统进化树表明,西藏类乌齐牦牛与九龙牦牛、黄牛的氨基酸序列相似性最高,亲缘关系最近,其次为山羊、宽吻海豚、猪、马、羊驼和野生双峰骆驼,与鸡、乌鸦、非洲爪蟾和鲤鱼较远;定量分析显示,LDHB基因在牦牛肺脏中的表达水平显著高于心脏和肝脏,推测该基因与牦牛抗缺氧性状相关。

As a glycolytic enzyme,lactate dehydrogenase(LDHB)shows distinct tissue specificity in vivo,and plays an important role in physiological functions and developmental processes in mammals.The aim of this study is to clone the CDS sequence of LDHB gene and to determine its expression in various tissues in Leiwuqi yak,this will facilitate the function research on how LDHB gene regulates extreme hypoxia adaptability and energy metabolism at high altitudes area.The results showed that the CDS region of LDHB gene was 1 004 bp length,encoding 334 amino acids.A total of 2 nucleotide mutations were found,including a mutation of A362 to G362 and a mutation of T466 to G466,and resulted in the mutation of lysine to glutamate and fromisoleucine to serine respectively.The predicted molecular mass of LDHB protein was 36.72 ku,and predicted to be a hydrophobic stable protein.Functional prediction analysis found that LDHB may played a major role in glycolysis,redox and other processes,mainly involved in the metabolism of organisms.The phylogenetic tree showed that the amino acid sequences of Tibetan leiwuqi yak,Jiulong yak and Bos taurus shared the highest similarity and closest genetic relationship,followed by capra hircus,bottlenose dolphin,sus scrofa,equus caballus,vicugna pacos,and camelus ferus,far from gallus,xenopus laevis,cyprinus carpio.The RT-qPCR analysis showed that the expression of LDHB gene in yak lung was significantly higher than in other tissues,this indicated a potential role of LDHB in anti-hypoxic traits in yak.In conclusion,the structure and function of LDHB gene in yak were relatively conservative.