三角鲂形态特征和胰岛素样生长因子-Ⅰ基因的序列分析

摘要

对三角鲂(Megalobrama terminalis)形态学特征进行研究,用RT-PCR的方法从三角鲂肝脏克隆了三角鲂胰岛素样生长因子-Ⅰ(IGF-Ⅰ)基因的cDNA序列.三角鲂传统的形态学数据与团头鲂相似.序列分析表明,三角鲂IGF-ⅠcDNA由486个核苷酸构成,编码161个氨基酸,包含整个信号肽、B、C、A、D和E区,与鲂属团头鲂比较,三角鲂与团头鲂IGF-ⅠcDNA序列同源性为99.8%,氨基酸序列同源性为99.4%.由此可见三角鲂的遗传学特征与团头鲂非常相似.%The morphologic characters were studied and the IGF-ⅠcDNA and gene of triangular bream Megalobrama terminalis from its liver were cloned by RT-PCR for the first time. The traditional appearance data in triangular bream is similar to the data in bluntnose bream. Sequence analysis indicated that the IGF-ⅠcDNA of triangular bream consisted of 486 nucleotides encoding 161 amino acids which spanned the complete signal peptide and domains B, C, A, D and E. Compared with bluntnose bream (Megalobrama amblycephala), another member of Megalobrama, triangular bream IGF-Ⅰshared 99.8% and 99.4% identity in cDNA sequence and predicted amino acid sequence, respectively. Thus, it can be concluded that triangular bream and bluntnose bream are very similar.