史氏鲟两种促性腺激素β亚基cDNA克隆及序列进化分析  

cDNA cloning, phylogenetic analysis of two gonadotropins β subunits sequences of Amur sturgeon

作　　者：胡红霞[1,2] 张勇[1] 刘晓春[1] 贝锦新[1] 朱华[2] 林浩然[1,3] 

机构地区：[1]中山大学有害生物控制与资源利用国家重点实验室,中山大学水生经济动物研究所暨广东省水生经济动物良种繁育重点实验室 [2]国家淡水渔业工程技术研究中心(北京)暨北京市水产科学研究所,北京100068 [3]海南大学海洋学院,海口570228

出　　处：《动物学报》2006年第2期362-375,共14页ACTA ZOOLOGICA SINICA

基　　金：国家科计部十五"863"现代农业技术主题;生物与现代农业技术领域;鲟鱼的选育及规模化育种项目(No.2001AA243061;2004AA243060);北京市科学技术委员会项目(No.954830400)~~

摘　　要：从史氏鲟(Acipenserschrenkii)脑垂体中提取总RNA,利用GeneRacerTM技术,分别克隆得到促性腺激素Ⅰ(GTHⅠ)和Ⅱ(GTHⅡ)的β亚基cDNA全长。史氏鲟GTHⅠ-β亚基cDNA全长为1088bp,开放阅读框为384bp,编码128个氨基酸(Genbank序列登录号为:AY575920);GTHⅡ-β亚基cDNA全长为616bp,开放阅读框为408bp,编码136个氨基酸(Genbank序列登录号为:AY575921)。与其他脊椎动物进行了两种基因的氨基酸序列同源性比较表明:史氏鲟GTHⅠ-β与西伯利亚鲟相似性最高,为99·1%;与硬骨鱼类中鲈形目相似性最低,为34·5%。GTHⅡ-β与西伯利亚鲟相似性为98·3%,与其他硬骨鱼类除鲈形目外都超过60%,与鸟类的相似性最低,为42·8%。两个基因成熟肽构建的MP树显示:GTHⅠ与FSH的β亚基和GTHⅡ与LH的β亚基构成两个明显的聚类。用Mega2软件计算了所比对物种间开放读码框的核苷酸遗传距离并构建了NJ树和MP树,两个基因β亚基的NJ系统树和MP系统树拓扑结构相似,鲟鱼与真骨鱼类分别聚类,共同形成硬骨鱼纲聚类,与传统分类学一致。成熟肽相似性、遗传距离和系统树分支长度显示GTHⅠ-β亚基在真骨鱼类进化速率显著快于其他脊椎动物,而LH-β亚基在羊膜动物中进化比其他脊椎动物快。暗示这两种糖蛋白基因的进化伴随物种进化而显示其功能[动物学报52(2):362-375,2006]。To elucidate the role of gonadotropin （GTH） in cultured amur sturgeon Acipenser schrenkii, we extracted total RNA from the pituitary gland and cloned two gonadotropin β-subunits using GeneRacerTM technology. The cDNA of GTH Ⅰ-β subunits is 1 088 bp, and the open reading frame 384 bp encoding peptides of 128 amino acid. The cDNA of GTHⅡ-β is 616 bp and the open reading frame is 408 bp encoding 136 amino acid. They were submitted to GenBank, with accessions No. AY575920 （GTH Ⅰ-β） and No. AY575921 （GTH Ⅱ-β） respectively. Multiple amino acid sequences alignments were performed among vertebrates including teleostei, chondrostei, amphibian, tetrapod, avian and mammalian. The pairwise distances were computed and phylogenetic trees were constructed using NJ and MP methods based on the codon sequences （cds） of the chosen species by Mega 2 software. MP tree was also deduced from data of two subunits mature peptides. It showed that GTH Ⅰ-β subunit of amur sturgeon has the highest homology with Siberian sturgeon, which was 99.1% similarity, and the lowest identity percent was 34.5 %, with the species of Perciformes. The high degree similarity of amur sturgeon GTHⅡ β-subunit with Siberian sturgeon was 98.3 % ; it was more than 60 % similarity between chondrastei with teleostei except Perciformes, whereas the lowest similarity was with avian （42.8 % ）. The topology of two β subunits phylogenetic trees deduced by NJ and MP methods were similar. The Chondrostei and Teleostei were at two distinct clades and formed the Osteichthyes which was in agree with traditional classification. The similarity, heredity distances and the branches length of each lineage showed that GTH Ⅰ -β subunit had faster evolution rate in teleostei while LH β was in the same as in Amniota. It was concluded that the evolution of these two glycoprotein β-subunits were concomitant with the species evolution.

关 键 词：史氏鲟 促性腺激素(GTH) CDNA克隆 进化分析 

分 类 号：S917.4[农业科学—水产科学]