| This project is aimed at: (1) Cloning, sequence analysis and expression of IGF- â… which play vital roles in growth and reproductive regulation. (2) Discussing the significance and possibility of a further study towards the production of their recombinant IGF-â… by recombinant DNA technique, and their application in assisted reproduction. The primary results were as follows.1. By RT-PCR IGF-â… from golden monkey encoding 153 amino acid were isolated, with predicted molecular mass of 16.9kD. All showed high degree of homology with other reported sequences at nucleotide and amino acids levels. cDNA encoding IGF-â… which are highly conserved in evolution and play important role in growth, reproduction and immune regulation were also isolated. The ORF of golden monkey IGF-â… (IGF-â… ) (459bp) encodes a precursor of 153 amino acids comprising of a 48 amino acids signal peptide and a 70 amino acids mature protein..2. The golden monkey IFG-â… gene has a high homology with other mammal IGF-â… genes, and the homology of the sequence coding mature peptide is from 88.6%(rat) to 93.8%(horse), ORF from 88.5%(rat) to 94.4%(human).3. The DNA fragments encoding IGF-â… from golden monkey were subcloned to the pET-DsbA expression vector and highly expressed in E. coli host BL21 with IPTG inductioa The expressed proteins fused by DsbA (DsbA- IGF-â… ) with their molecular mass of 32kD. The production of DsbA-IGF-â… provide a basis for further studies on the biological activity of IGF-â… .4. When cloned IGF-â… from golden monkey were compared with homologous sequences from human, cattle, sheep, pig, rat and mice, they all displayed a fairly high degree of conservation. Among all the species compared, the human exhibits highest degree of amino acid similarity with golden monkey, suggesting that administrating human hormone forgrowth, reproduction and immune regulation of gplden monkey should work better than exogenous hormones from any other species.
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