半滑舌鳎促滤泡激素基因全长cDNA的克隆与组织表达分析

从半滑舌鳎Cynoglossus semilaevis Günther脑垂体中提取总RNA，利用RT-PCR和RACE技术首次克隆得到半滑舌鳎促滤泡激素（FSH）基因全长cDNA序列。半滑舌鳎FSHcDNA全长为541bp，开放阅读框为393bp，编码130个氨基酸（GenBank序列登录号：JQ277933）。发现一个N-糖基化位点：24～27NTT。与其他脊椎动物的FSH成熟肽氨基酸序列同源性比较表明，半滑舌鳎FSH与鲽形目和鲈形目鱼类FSH同源性为42％～49％，与鲤形目和高等脊椎动物FSH同源性为27％～319/5。用MEGA4．0软件构建了NJ树，获得的进化树表明，半滑舌鳎FSH与其他鱼类FSH聚类，亲缘关系较近。实时荧光定量组织表达分析表明，FSHmRNA除在垂体中大量表达外，其他组织也有表达，尤以脑、性腺表达量较高。半滑舌鳎FSHmRNA在垂体以外组织中的广泛表达，暗示FSH可能具有广泛的生理功能。

Full length cDNA cloning and tissue expression analysis of follicle-stimulating hormone （FSH） from half-smooth tongue sole Cynoglossus semilaevis Günther

Total RNA was extracted from the pituitary gland of half-smooth tongue sole Cynoglossus semilaevis Gtinther, and the follicle-stimulating hormone （FSH） was cloned usingRT-PCR and RACE technology for the first time. The obtained FSH cDNA is 541bp, and the open reading frame is 393bp encoding a peptide of 130 amino acids. This cDNA sequence was submitted to GenBank with accession No. JQ277933. One N-glycosylation site was found in the deduced amino acid sequence（NTT, 24-27）. Multiple amino acid sequence alignment wes per formed with other vertebrates. It showed that FSH peptide of half-smooth tongue sole was more similar to their orthologs of Pleuronectiformes and Perciformes wifh 42 %-49 % identity, as to Cypriniformes and Mammalia with 27%-31%identity. The pairwise distances were com puted and phylogenetic tree was constructed using NJ method based on the codon sequences of the chosen species by MEGA 4.0 software. The result indicated that the FSH of half-smooth tongue sole was clustered with other fish FSH, and the half-smooth tongue sole gene shared the high homology with teleost. Real-time PCR analysis showed that FSH mRNA was expressed at the highest level in pituitary, and also strong amplification signals were detected in all other tis sues, especially in brain and gonad. Wide expression of FSH mRNA of half-smooth tongue sole in non-pituitary tissues may suggest that it has more physiological functions.