Molecular cloning, characterization and expression of thyroid-stimulating hormone receptor in channel catfish
Molecular cloning, characterization and expression of thyroid-stimulating hormone receptor in channel catfish
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DOI：
10.1016/j.ygcen.2009.01.009
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发表时间：
2009-05-01
影响因子：
2.7
通讯作者：
Trant, John M.
中科院分区：
文献类型：
--
作者：
Goto-Kazeto, Rie;Kazeto, Yukinori;Trant, John M.
促甲状腺激素受体（TSHRs）主要在脊椎动物的甲状腺中表达，然而最近，在多种鱼类的性腺中发现了大量编码TSHR的转录本。本研究的目的是表征通道鲶鱼TSHR，并检查转录本是否在性腺中被翻译成蛋白质或将转录本储存为母体RNA以供以后使用。编码TSHR的cDNA是从通道鲶鱼的甲状腺中分离出来的，但转录物被确定在许多组织中表达，包括性腺。事实上，卵巢中TSHR的表达在生殖季节变化明显，在卵黄生长期后达到峰值。此外。在鲶鱼的未受精卵中也检测到TSHR转录本，而在受精卵中未检测到。m - pat分析表明，鲶鱼TSHR转录本在甲状腺卵泡、性腺和未受精卵中被完全聚腺苷化，这表明它们被翻译成蛋白质，而不是“储存mRNA”。使用针对鲶鱼TSHR的多克隆抗体进行Western blot分析，通过观察甲状腺、睾丸和卵黄变性后卵巢中大量的免疫反应蛋白证实了这一假设。功能实验表明，重组鲶鱼TSHR能被牛TSH特异性激活，而不能被重组鲶鱼促卵泡激素（FSH）和黄体生成素（LH）特异性激活。和其他物种一样，异源促性腺激素hCG部分激活了受体。这些结果表明，TSHR在配子体发生中起重要作用，而不是在胚胎发生中起重要作用。(C) 2009爱思唯尔公司版权所有。
Thyroid-stimulating hormone receptors (TSHRs) are primarily expressed in the thyroid of vertebrates, however recently, transcripts encoding TSHR have been found abundantly in the gonads in a variety of fish species. The purpose of this study is to characterize the channel catfish TSHR and to examine whether the transcript are translated into protein in the gonad or store the transcript as maternal RNA for later use. The cDNA encoding the TSHR was isolated from the channel catfish thyroid but the transcript was determined to be expressed in a number of tissues, including the gonads. In fact, the ovarian expression of TSHR changed significantly during the reproductive season and peaked after the vitellogenic growth phase. Furthermore. the TSHR transcript was also detected in unfertilized eggs but not in fertilized egg of catfish. LM-PAT analysis demonstrated that catfish TSHR transcripts were fully polyadenylated in thyroidal follicles, gonads and unfertilized eggs suggesting that they were translated into protein opposed to being "stored mRNA". Western blot analysis using polyclonal antibodies against the catfish TSHR verified this assumption by visualizing immunoreactive protein in the thyroid, testis, and the post-vitellogenic ovary in abundance. A functional assay clearly showed that the recombinant catfish TSHR was specifically activated by bovine TSH but not by recombinant catfish follicle-stimulating hormone (FSH) and luteinizing hormone (LH). As in other species, the heterologous gonadotropin, hCG, partially activated the receptor. These results suggested that TSHR plays important roles for gametogenesis rather than embryogenesis. (C) 2009 Elsevier Inc. All rights reserved.