达氏鲟2种胰岛素样生长因子的克隆及其对饥饿胁迫的响应.

【Objective】Insulin-like growth factor system(IGFs) are a group of regulating factors that play an important part in the proliferation and differentiation of cells, immunity and development of the skeletal muscle. Therefore, the analysis of IGF expression is conducive to revealing its functions in the process of fish growth and nutritional regulation.【Method】In this study, we obtained the full length cDNA of IGF-1 and IGF-2 from the unigene database by transcriptome sequencing of Acipenser dabryanus. The tissue distribution and expression level during starvation stress were also analyzed. 【Result】The full length of IGF-1 was 2262 bp which contained 292 bp 5′ untranslated region(UTR), 1841 bp 3′ UTR and 489 bp open reading frame(ORF). The ORF of IGF-1 encoded 163-residue peptide. The full length of IGF-2 was 1821 bp which contained 109 bp 5′UTR, 1052 bp 3′ UTR and 660 bp ORF. The ORF of IGF-2 encoded 220-residue peptide. Phylogenetic analysis showed that the IGF-1 and IGF-2 clustered with other species in genus Acipenser. Tissue expression analysis showed that IGF-1 and IGF-2 were widely expressed in different tissues, and IGF-1 was highly expressed in eye while IGF-2 was mostly detected in liver and gonad. During starvation, the expression level of IGF-1 was increased firstly and then decreased significantly in liver, gut and muscle.【Conclusion】The expression level of IGF-1 was decreased significantly during fasting for 14 days compared to the initial value in all the examed tissues(P<0.05), indicating a positive correlation between nutritional status and IGF-1 mRNA level. Whereas, the expression level of IGF-2 was decreased slightly with no significant change detected(P>0.05) during fasting for 14 days compared to the initial value, inferring a diverse function of IGF-1 and IGF-2 in A. dabryanus. [ABSTRACT FROM AUTHOR]