团头鲂促性腺激素β亚基cDNA的克隆和序列分析  

MOLECULAR CLONING AND SEQUENCE ANALYSIS OF THE TWO GONADOTROPIN β-SUBUNIT cDNAs OF BLUNT SNOUT BREAM(MEGALOBRAMA AMBLYCEPHALA)

作　　者：曲宪成[1] 刘颖[1] 杨艳红[1] 崔严慧[1] 周正峰[1] 

机构地区：[1]上海水产大学生命科学与技术学院,上海200090

出　　处：《水生生物学报》2007年第3期377-385,共9页Acta Hydrobiologica Sinica

基　　金：回国留学人员科研启动基金(科01-113);上海市重点学科建设项目资助(Y1101);上海水产大学博士启动基金(科00-119)资助

摘　　要：本研究利用RT-PCR和RACE克隆了团头鲂(Megalobrama amblycephala)脑下垂体中两种促性腺激素β亚基(GtHIβ和GtHIIβ)cDNA序列,并对其进行了结构和系统进化分析。团头鲂GtHIβ亚基cDNA全长567碱基对(bp),5’端非翻译区26bp;3’端非翻译区148bp;开放阅读框(ORF)393bp,其编码含有130个氨基酸的蛋白质,包括由108个氨基酸组成的成熟肽以及22个氨基酸组成的信号肽。GtHII亚基cDNA全长564bp,5’端非翻译区43bp;3’端非翻译区95bp;ORF426bp,其编码含有141个氨基酸的蛋白质,包括由117个氨基酸组成的成熟肽以及24个氨基酸组成的信号肽。团头鲂GtHIβ亚基氨基酸序列与青鱼(Mylopharyngodon piceus)等15种鱼类相比较,相似性为90%—31%,与湖蛙(RanaRidibunda)等5种四足类的相似性为38%—21%;GtHII亚基与青鱼等15种鱼类相比较,其相似性为95%—41%,与湖蛙等5种四足类的相似性为49%—36%,团头鲂GtHIβ和GtHII亚基与鲤科鱼类的相似性最高,显示出较为亲近的进化关系。另外,团头鲂GtHIβ和GtHIIβ亚基含有12个保守的半胱氨酸残基和1个N糖基化位点。The cDNAs encoding β-subunits of gonadotropin hormone Ⅰ（GtH Ⅰβ） and gonadotropin hormone Ⅱ（GtH Ⅱβ） have been cloned from pituitary of blunt snout bream （ Megalobrama amblycephala ） using reverse transcription-polymerase chain reaction （RT-PCR） and rapid amplification of cDNA end （RACE） methods. Then, amino acid sequence and phylogenetic relations were analysed. The GtH I/3 subunit cDNA is 567 base pair（bp） that comprises of a 5＇ -UTR of 26bp, a 3＇ -UTR of 148bp and an open reading frame （ORF） of 393bp which encodes a 130 amino acid protein with a signal peptide of 22 amino acids and a mature peptide of 108 amino acids. On the other hand, GtH Ⅱβ subunit cDNA is 564bp that comprises of a 5＇-UTR of 43bp, a 3＇- UTR of 95bp and an ORF of 426bp which encodes a 141 amino acid protein with a signal peptide of 24 amino acids and a mature peptide of 117 amino acids. The amino acid sequence identities of Megalobrama amblycephala GtH Ⅰβ and GtH Ⅱβ subunits in comparison with other 15 fishes including Mylopharyngodon piceus are 90%--31% and 95%--41% , respectively; while in comparison with 5 tetrapods including Rana Ridibunda are 38 %--21% and 49%--36%, respectively. Both GtH Ⅰβand GtH Ⅱβ subunits of Megalobrama amblycephala resemble most to those of Cyprinidae, implying their eloser phylogenetie relationship. In addition, both Megalobrama amblycephala GtH Ⅰβ and GtH Ⅱβ subunits have 12 conserved eysteine residues and 1 N-linked glycosylation site.

关 键 词：RT-PCR RACE 克隆 团头鲂 促性腺激素β亚基cDNA 

分 类 号：Q343[生物学—遗传学]