Expression of Human Growth Hormone in Bombyx mori Using Bac-to-Bac Baculovirus Expression System

Human growth hormone(hGH) secreted by adenohypophysis plays an important role in human growth,development and metabolism,showing extensive physiological functions.Using Bac-to-Bac expression system of Bombyx mori nuclepolyhedrovirus(BmNPV),a hgh gene was cloned into a baculovirus transfer vector pFastBacHTb which was used to transform BmDH10Bac to prepare recombinant shuttle vector Bacmid-hgh through bacterial transposition.The recombinant plasmid Bacmid-hgh was used to transfect BmN cells to obtain the recombinant baculovirus containing human growth gene hgh.The recombinant baculovirus was used to infect BmN cells and the recombinant virus was collected and used to inoculate newly exuviated Bombyx mori larvae of the 5th instar.After 3 d,the larvae showed symptom of infection by baculovirus.SDS-PAGE and Western blotting detected target protein with molecular weight of approximately 20 kD in hemolymph of the larvae,indicating that human growth hormone had been successfully expressed in Bombyx mori larvae through Bac-to-Bac system.