鲮胰岛素样生长因子Ⅰ(IGF-Ⅰ)cDNA的分子克隆和序列分析

Molecular cloning and sequence analysis of insulin-like growth factor I(IGF-I)cDNA from Cirrhinus molitorella

采用逆转录 聚合酶链式反应 (RT PCR)方法 ,从鲮肝脏总RNA中扩增出胰岛素样生长因子 I(IGF I)基因 ,克隆至质粒pUCm -T。测定该基因序列 ,推导其编码的蛋白质序列。克隆的鲮IGF IcDNA编码序列包括信号肽、B、C、A、D和E 6个区域 ,共 16 1个氨基酸残基。与鲤IGF I比较 ,信号肽由 4 4个氨基酸残基组成比鲤少 17个 ,成熟肽核苷酸序列和氨基酸序列的同源性分别为 95 .2 %和 10 0 %。E区域分析结果表明 ,克隆的鲮IGF I序列属于IGF IEa

Total RNA was isolated from Cirrhinus molitorella liver tissue. The cDNA encoding insulin like growth factor I (IGF I) was amplified by reverse transcription polymerase chain reaction (RT PCR) strategy using isolated total RNA as template.The amplified cDNA fragment was inserted to vector pUCm T. The cloned cDNA was sequenced and the amino acid sequence of Cirrhinus molitorella IGF I was predicted .The nucleotide sequence and deduced amino acid sequence shared 95.2% and 100% homology with that of Cyprinus carpio mature IGF I peptide. Analysis of E domain indicated that cloned Cirrhinus molitorella belonged to IGF I Ea 2 subtype.