Gene expression of gold fish growth hormone Il in baculovirus

Using a transfer vector plasmid pSXIVVI +X3 without an initiation codon, the occluded recombinant Trichoplusia ni nuclear polyhedrosis virus as an expressing vector carrying the cDNA encoding gold fish growth hormone Ⅱ(gf GHⅡ) under the control of the SynXIV promoter has been constructed. Immunoblot analysis revealed that the virus mediated gfGH Ⅱ can be detected as early as 24 hr pi and the expression level reached to the highest in 96 hr pi in the Sf cells and culture medium or larvae and haemolymph, the molecular weight of the expressed protein is 22.5 kDa, which is equivalent to the value calculated from the predicted amino acid sequence. The expression level in vivo and in vitro was quantified using RIA. Average 10 5 Sf9 cells may secret gfGH Ⅱ into medium reaching level of 86.74 ng. The expression level of gfGHⅡ in larvae may reach to 214g per gram of dry larvae.