Molecular cloning of Insulin-like Growth Factor-I from triangular bream (Megalobrama terminalis)

摘要

Triangular bream (Megalobrama terminalis) IGF-I DNA and gene were cloned from triangular bream liver for the first time by RT-PCR. Sequence analysis indicated that the IGF-I cDNA consisted of 486 nucleotides encoding 117 amino acids which spanned the complete signal peptide, B, C, A, D and E domains. Analysis of the E domain indicated that triangular bream IGF-I belongs to the IGF-I Ea-2 subtype. Compared to bluntnose bream (Megalobrama amblycephala), another member of the same Megalobrama genus, triangular bream IGF-I shared 99.8% identity in cDNA sequence and 99.4% in predicted amino acid sequence. However, considerable differences were found in comparison to with common carp ( Cyprinus carpio) and grass carp ( Ctenopharyngodon idellus), which are members of the same family but of a different genus.