Molecular cloning of prepro-thyrotropin-releasing hormone cDNAs from the common carp Cyprinus carpio and goldfish Carassius auratus
Molecular cloning of prepro-thyrotropin-releasing hormone cDNAs from the common carp Cyprinus carpio and goldfish Carassius auratus
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DOI：
10.1016/j.ygcen.2004.11.011
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发表时间：
2005-03-01
影响因子：
2.7
通讯作者：
Yanagisawa, T
中科院分区：
文献类型：
--
作者：
Aoki, Y;Takahashi, M;Yanagisawa, T
为了扩大我们对前促甲状腺激素释放激素原（ppTRH）从鱼类进化到四足动物的认识，我们测定了两种鲤科鱼类（普通鲤鱼Cyprinus carpio和金鱼Carassius auratus）的ppTRH cDNA序列。根据从斑马鱼EST数据库中鉴定的斑马鱼ppTRH序列和红鲑ppTRH序列之间的保守区域设计简并引物，并进行PCR扩增。从通过cDNA末端的5 '-和3'-快速扩增获得的ppTRH cDNA确认全长ppTRH。鲤鱼ppTRH cDNA编码187个氨基酸，包括6个拷贝的TRH前体序列（Lys/Arg-Arg-Gln-His-Pro-Gly-Lys/Arg-Arg），而金鱼ppTRH cDNA编码231个氨基酸，包括8个拷贝的TRH前体序列。ppTRH序列的分子系统发育分析反映了物种分类的预测模式。鲤鱼、金鱼和斑马鱼的ppTRH具有一些独特的特征。鲤鱼和斑马鱼的ppTRH小于金鱼的ppTRH，这主要是由于分别缺少29和17个连续氨基酸。缺失区包括一个或两个TRH前体序列，两侧是一些谷氨酸残基，类似于人ppTRH的富含谷氨酸的区域。亲水性曲线表明，在C-末端亲水区域中存在TRH祖序列是硬骨鱼和人ppTRH的特征。这些观察结果可能为更好地理解ppTRH的分子进化提供线索。(C)2004年爱思唯尔公司All rights reserved.
To expand our knowledge on the evolution of prepro-thyrotropin-releasing hormone (ppTRH) from fish to tetrapods, sequences of ppTRH cDNAs from two cyprinid telcosts, the common carp Cyprinus carpio and goldfish Carassius auratus, were determined. Degenerate primers were designed based on the conserved regions between the zebrafish ppTRH sequence identified from the zebrafish EST database and the sockeye salmon ppTRH sequence, and PCR amplification was performed. Full-length ppTRHs were confirmed from ppTRH cDNAs obtained by 5'- and 3'-rapid amplification of cDNA ends. The common carp ppTRH cDNA encodes 187 amino acids including 6 copies of the TRH progenitor sequence (Lys/Arg-Arg-Gln-His-Pro-Gly-Lys/Arg-Arg), whereas the goldfish ppTRH cDNA encodes 231 amino acids including 8 copies of the TRH progenitor sequence. The molecular phylogenetic analysis of the ppTRH sequences reflected the predicted pattern of species classification. The common carp, goldfish, and zebrafish ppTRHs have some unique characteristics. The common carp and zebrafish ppTRHs are smaller than that of the goldfish mainly due to the absence of 29 and 17 consecutive amino acids, respectively. The deleted region includes one or two TRH progenitor sequences flanked by some glutamate residues, similar to the glutamate-rich regions of human ppTRH. Hydropathy profiles showed that the presence of a TRH progenitor sequence in the C-terminal hydrophilic region is a characteristic of teleosts and human ppTRHs. These observations may provide clues to a better understanding of the molecular evolution of ppTRH. (C) 2004 Elsevier Inc. All rights reserved.