Genomic structure, polymorphism and expression analysis of the growth hormone (GH) gene in female and male Half-smooth tongue sole (Cynoglossus semilaevis)
Genomic structure, polymorphism and expression analysis of the growth hormone (GH) gene in female and male Half-smooth tongue sole (Cynoglossus semilaevis)
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DOI：
10.1016/j.gene.2011.11.015
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发表时间：
2012-02-01
期刊：
影响因子：
3.5
通讯作者：
Tang, QiSheng
中科院分区：
文献类型：
--
作者：
Ma, Qian;Liu, ShuFang;Tang, QiSheng
生长激素（growth hormone，GH）是硬骨鱼类发育和体细胞生长的重要调节因子，可能与半滑舌鳎（Cynoglossus semilaevis）性生长二型性的形成机制有关。本研究采用同源克隆和cDNA末端快速扩增-聚合酶链反应（RACE-PCR）技术，从半滑舌鳎中克隆了生长激素基因的全长cDNA。该基因全长826 bp，开放阅读框（ORF）为603 bp，编码200个氨基酸（M）。生长激素的前体由17个氨基酸的信号肽和183个氨基酸的成熟多肽组成。雌、雄成虫GH基因序列分别为3428 bp和3371 bp，均包含6个外显子和5个内含子，其大小差异主要是由微卫星引起的。对雌性、正常雄性和超大型雄性成体的14个组织进行性别特异性组织表达分析，发现GH mRNA主要表达于垂体，雌性的表达量是正常雄性的3.6倍，而超大型雄性的mRNA表达量是正常雄性的1.7倍。利用半滑舌鳎全同胞家系研究了生长激素mRNA表达的性别差异，在10 ~ 380日龄的12个时间点均检测到生长激素mRNA的表达。生长激素mRNA的显着增加，检测开始在80日龄的鱼，然后下降到非常低的水平开始在230日龄的鱼。差异表达分析表明，除10日龄外，其余各日龄雌鼠GH表达水平均显著高于雄鼠（P< 0.01）。在GH基因第二内含子中发现了两个微卫星位点。利用这两个多态性标记对224只个体进行基因分型，结果表明，渤海、黄海和孵化场样本中雌、雄个体间差异不显著。(C)2011 Elsevier B. V.保留所有权利。
Growth hormone (GH) is a polypeptide which is an important regulator of development and somatic growth in teleosts, and may be associated with the mechanisms which drive sexual growth dimorphism in the Half-smooth tongue sole (Cynoglossus semilaevis). In this study, the full length gh cDNA was cloned from C semilaevis by homology cloning and the rapid amplification of cDNA ends polymerase chain reaction (RACE-PCR). The full-length gh cDNA is 826 bp and contains an open reading frame (ORF) of 603 bp encoding a protein of 200 amino acids (M). The precursor of gh consists of a 17 amino-add signal peptide followed by a 183 amino-acid mature polypeptide. GH gene sequences obtained from female and male adults consist of 3428 bp and 3371 bp, respectively, each of which includes six exons and five introns, and the difference in the GH gene size was mainly caused by the microsatellites. When 14 tissues from females, normal males and extra-large male adults were analyzed for sex-specific tissue expression, the gh mRNA was found to be predominantly expressed in the pituitary, and the expression levels in females were 3.6 times as much as those in normal males, while the mRNA expression in extra-large males was 1.7 times as much as those in normal males. Sex differences in gh mRNA expression during development were also examined by using a full-sib family of C semilaevis, and the gh mRNA was detected at all of the 12 time points sampled from 10 to 380 days-old. A significant increase in gh mRNA was detected starting in 80 day old fish and was then followed by a drop to very low levels starting at 230 day old fish. Differential expression indicated that the gh expression level in females was significantly higher than males (P< 0.01) at all of the stages except for 10 days-old. Two microsatellite loci were identified in the second intron of the GH gene. Using these two polymorphic markers to genotype 224 individuals, there was no significant difference between the females and males in the Bohai Sea, the Yellow Sea and the hatchery samples. (C) 2011 Elsevier B.V. All rights reserved.