蓝点马鲛mstn克隆及表达分析  

Cloning and expression analysis of mstn in Scomberomorus niphonius

作　　者：史钧信 薛良义[1] 黄红丽[1] 郑春静 

机构地区：[1]宁波大学海洋学院,宁波315211 [2]宁波市海洋与渔业研究院,宁波315000

出　　处：《生物学杂志》2015年第6期12-16,共5页Journal of Biology

基　　金：宁波市科技局项目(编号2012C10035)

摘　　要：利用同源克隆和cDNA末端快速扩增(RACE)技术克隆了蓝点马鲛肌肉生长抑制素基因(mstn),并分析了mstn的结构特征和亲缘关系。克隆的蓝点马鲛mstn共3870 bp,包括3个外显子1131 bp和2个内含子1201 bp。外显子Ⅰ379 bp,内含子Ⅰ374 bp,外显子Ⅱ371 bp,内含子Ⅱ827 bp,外显子Ⅲ381 bp,5'UTR 108 bp,3'UTR 1430 bp。3'UTR含有加尾信号AATAAA。mstn共编码376个氨基酸包括信号肽(1 aa^22 aa)、TGF-β前肽区域(37 aa^257 aa)和TGF-β功能域(282 aa^376 aa)。在内含子Ⅱ和3'UTR发现微卫星序列,分别为(CA)_5和(CA)_(10)TG(CA)_6CT(CA)_(10)。蓝点马鲛MSTN具有脊椎动物MSTN的共同特征,含一个蛋白酶水解位点RARR和9个保守的半胱氨酸残基。脊椎动物MSTN氨基酸序列的亲缘关系分析发现,蓝点马鲛与鳜鱼亲缘关系最近与其他鲈形总目鱼类聚为一簇。以β-actin为内参基因,qPCR分析表明,蓝点马鲛mstn在二龄鱼不同组织表达情况不同,在鳃、肝和肾中表达较高,而在肌肉、肠、胃、脾和性腺中表达量较低。这些结果可为蓝点马鲛肌肉生长和发育的分子机制研究提供信息。Scomberomorus niphonius is widely distributed in China＇s coastal area. It is a kind of migratory species and has been a very important part in China＇s fishery catches till now. mstn has attracted the attention of large numbers of researchers since its important effect on muscle growth. Homology cloning and rapid amplification of cDNA ends （ RACE） were employed to clone mstn of S. nipho-nius, and its structural characteristics and phylogenetic relationship were also analyzed in this paper. The length of cloned mstn was 3870 bp, including 1131 bp of 3 exons and 1201 bp of 2 introns. ExonⅠ, intronⅠ, exonⅡ, intronⅡand exonⅢwere 379 bp, 374 bp, 371 bp, 827 bp, and 381 bp, respectively. 5＇UTR and 3＇UTR were 108 bp and 1430 bp, respectively. A polyA signal AATAAA was found in 3＇UTR. The whole sequences encoded 376 amino acids, containing a putative signal peptide （1aa-22aa）, a TGF-βpropeptide domain （37aa-257aa） and a TGF-β functional domain （282aa-376aa）. Two microsatellites were found, （CA）5 in in-tronⅡ and （CA）10TG（CA）6CT（CA）10 in 3＇UTR. The similar microsatellites were also found in other fishes, which suggested that these regions might have some special functions. The common domains of vertebrate MSTNs were found in S. niphonius MSTN, inclu-ding a conservative hydrolytic site （ RARR） and 9 cysteine residues. The phylogeny analysis showed that the relationship between S. niphonius and S. chuatsi was the closest, and S. niphonius grouped into the same branch with other Percomorpha fishes. mstn expres-sions in different tissues were examined by qPCR, and β-actin was employed as housekeeping gene. qPCR results showed that mstn transcriptional level varied among different tissues in two years old S. niphonius, with a high expression in gill, liver and kidney, and a low expression in muscle, intestine, stomach, spleen and gonad. These results provide useful information for the study of the molecu-lar mechanism of S. niphonius muscle growth and development.

关 键 词：蓝点马鲛 肌肉生长抑制素基因 克隆 RACE 组织表达 

分 类 号：S917.4[农业科学—水产科学]