| 摘要 |
NEW MATERIAL:The fish growth hormone polypeptide having the peptide sequence of formula. USE:Growth-promoting agent for pisciculture. PREPARATION:For example, the frozen pituitary gland of chum salmon is solubilized by disintegrating in a solution containing guanidium thiocyanate, mixed with a solution containing cesium chloride, and subjected to the ultracentrifugation to recover the RNA as the precipitate. The RNA is passed through a column of oligo(dT)cellulose. The mRNA separated by the above process is mixed with a vector primer prepared by incising a plasmid with a restriction enzyme, and treated with a reverse transcriptase to synthesize a DNA complementary to the mRNA. The DNA is cyclized to a recombinant DNA by reacting with a linker DNA. Escherichia coli is transformed with the recombinant plasmid to the E.coli containing the DNA coding said polypeptide, and the transformed strain is cultured in a medium to produce the compound of formula. |
