鳡肌肉生长抑制素(MSTN)基因的克隆及其组织特异性表达分析

Cloning and expression analysis of the myostatin gene in Elopichthys bambusa

  • 摘要: 以鳡肌肉总RNA为模板,采用RT-PCR和RACE的方法,获得了鳡肌肉生长抑制素(myostatin,MSTN)基因的3个重叠片段,测序后拼接得到2 177 bp全长cDNA序列,其包含了5′端非翻译区的89个核苷酸和3′端非翻译区1 052个核苷酸以及1 125个核苷酸的开放性阅读框,翻译编码375个氨基酸,其中前22个氨基酸为鳡MSTN的信号肽。鳡MSTN具有MSTN的共同特征,有蛋白酶水解位点RIRR和在C端生物活性区含9个保守的半胱氨酸残基。核苷酸和氨基酸同源性分析发现鳡MSTN与厚颌鲂、草鱼和鲤等鲤形目鱼类的同源性较高,与鲈形目的同源性较低,与哺乳动物和鸟类的同源性最低;系统发育分析表明鳡MSTN与厚颌鲂亲缘关系最近。 半定量RT-PCR分析表明,该基因在肌肉和脑中表达量最高,在心肌中也有较高表达,在肝脏、肠、鳃和肾等组织中未见明显表达,此结果表明鳡MSTN基因除对肌肉生长发育有调控作用以外,可能还有其他功能。

     

    Abstract: In order to clone full-length myostatin gene and characterize its tissue expression profile in E. bambusa,RT-PCR and rapid-amplification of cDNA ends(RACE)were used to acquire full-length cDNA.A full-length of 2 177 bp myostatin cDNA sequence in E. bambusa was cloned,which included a 1 125 bp complete ORF encoding a 375 amino acids peptide,a 89 bp long 5′-untranslated region,and a 1 052 bp long 3′-untranslated region.The 375 amino acids long putative peptide contains a 22 amino acids long signal peptide,a conserved RIRR proteolytic processing site,and 9 conserved cysteine residues in the C terminal of the protein.The E. bambusa MSTN had high similarity to the Megalobrama pellegrini,Ctenopharyngodon idella,Cyprinus carpio myostatin while had low similarity to the M. perciformfishes myostatin and lower similarity to the mammalian and bird myostatin.The phylogenetic analyses showed that the E. bambusa myostatin had closest relationship with the M. pellegrini myostatin.Furthermore,myostatin mRNA tissue expression profile was assessed by semi-quantitative RT-PCR.In the seven examined tissues,the myostatin gene was expressed strongly in muscle and brain,weakly in heart but not expressed in kidney,intestine,gill,heart and liver.These results suggested that the fish myostatin gene might not only play roles in muscle development but also contribute to other biological functions.

     

/

返回文章
返回