齐口裂腹鱼生长激素基因cDNA克隆与序列分析

Molecular Cloning and Sequence analysis of the cDNA for the Growth Hormone Gene of Schizothorax prenanti

鱼类生长激素是一种单一肽链蛋白激素,主要作用是促进机体的生长。采用RT-PCR方法,首次从齐口裂腹鱼(Schizothorax prenanti)脑垂体总RNA中克隆出生长激素(growth hormone,GH)cDNA的开放阅读框ORF(open reading frame)序列,全长633bp。经DNA Star软件分析,该基因编码210个氨基酸,分子量为23.55kD,等电点为5.46,含有1个疏水区和1个N-糖基化位点。空间结构含有4个α螺旋和4个β折叠,形成2个二硫键。序列比较发现,齐口裂腹鱼GH与草鱼、鲤的GH同源性分别为99.8%、99.4%;与黄鳝、花鲈和大黄鱼的GH同源性分别为57.4%、63.5%和64.2%。

The growth hormone of fish is a kind of proteohormone, the primary function of which is promoting the growth of organism. RT-PCR was used in this experiment to clone the ORF （open reading frame） sequence of cDNA for the growth hormone gene from the pituitarygland of Schizothorax prenanti. The full length of this sequence is 633 bp. Software DNA Star was used for analysis of this gene, results were that the gene was composed of 210 amino acid, the putative molecular weight and isoelectric point of the protein was 23.55 kD and 5.46 respectively, a hydrophobic region and a N-glycosylation site were contained. Spatial structure of this protein contained four α-helix and four β-sheet, two disulfide bond were formed. Through sequence analysis, the homology of GH （growth hormone） between Schizothorax prenanti and Ctenopharyngodon idellus, Cyprinus carpio, Monopterus albus, Lateolabrax japonicus, Pseudosciaena croceawas was 99.8% , 99.4% , 57.4% ,63.5% and 64.2% respectively.