藏羚羊肌红蛋白(MGB)基因编码区的克隆与分析  

Cloning and Sequencing of Myoglobin Coding cDNA from Tibetan Antelope

作　　者：马兰[1] 白振忠[1] 杨应忠[1] 靳国恩[1] 韵海霞[1] 格日力[1] 

机构地区：[1]青海大学医学院高原医学研究中心,西宁810001

出　　处：《动物学杂志》2007年第5期70-75,共6页Chinese Journal of Zoology

基　　金：国家自然科学基金项目(No.30660052);青海省重点科技攻关项目(No.2003-N-120)

摘　　要：为了探讨藏羚羊低氧适应的分子生物学机制,从藏羚羊(Pantholops hodgsonii)骨骼肌组织中提取总RNA,通过逆转录聚合酶联反应(RT-PCR)技术扩增出MGB基因编码区cDNA片段,并与pGEM-T Easy载体连接构建重组质粒,转化DH5α菌。扩增培养后鉴定阳性质粒并进行序列测定,结果与NCBI数据库进行比较。结果显示,MGB基因编码区由465bp组成,编码154个氨基酸。其序列与绵羊、牛、猪、人、小鼠、大鼠的同源性分别是98%、97%、90%、86%、82%、81%。推测出的氨基酸序列与绵羊、牛有98%同源性,而与猪、人、小鼠及大鼠分别有89%、85%、80%、79%的同源性。与NCBI数据库登录的绵羊的MGB cDNA序列比较发现,藏羚羊MGB基因的21位和78位密码子分别发生了突变(GGT→GAT和GAA→AAG),其对应的氨基酸分别由甘氨酸变为天冬氨酸及谷氨酸变为赖氨酸。至此,成功克隆出藏羚羊MGB基因编码区,为进一步揭示藏羚羊低氧适应的分子机制打下基础。In order to explore the molecular mechanism of Tibetan Antelope （Pantholops hodgsonii ） adaptation to chronic hypoxia, total RNA was isolated from Tibetan Antelope skelecton muscle, and the coding region of MGB gene was amplified by RT-PCR technique using a general PCR primer based on previously reported cDNA sequence in sheep, cattle, pig, human, mouse and rat. The product of PCR was directly inserted into the pGEM-T Easy vector and sequenced. DNA sequences were compared with Genbank data by Blast. The results showed that MGB gene coding region is composed of 465 bp and codes 154 amino acids. DNA sequencing proved that Tibetan Antelope MGB sequence was highly homologous with that of sheep （98%）, cattle （97%）, pig （90%）, human （ 86% ）, mouse （82%） and rat （81% ） .The deduced amino acid sequence showed 98% ,98% ,89% ,85% ,80% and 79% identity when compared with that of the sheep, cattle, pig, human, mouse and rat. When comparing the MGB sequence of P. hodgsonii with that of sheep, two variations could be observed at the codon of 21 （GGT→ GAT） and 78 （GAA→AAG）, which leads to two variations on the corresponding amino acid： Gly→ Asp and Glu→Lys, respectively. In summary, wesuccessfully cloned the MGB gene coding region from Tibetan Antelope, which is important for understanding the molecular mechanism of Tibetan Antelope Adaptation to chronic hypoxia.

关 键 词：藏羚羊 肌红蛋白 基因克隆 低氧适应 

分 类 号：Q78[生物学—分子生物学]