三角鲂形态特征和胰岛素样生长因子-Ⅰ基因的序列分析

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ICE-Ⅰ cDNA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-Ⅰ cDNA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。

Morphologic characters and sequence analysis of insulin-like growth factor-Ⅰ gene in triangular bream Megalobrama terminalis

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.