Silkworm Bio-reactor

There are two main types of silkworm bio-reactor: transgenic silkworm and baculovirus expression vector system (BEVS). The transgenic vector PigA3GFP[IE-GMCSF] was generated by cloning hGM-CSF gene under the control of IE-1 promote from BmNPV into PigA3GFP, the transgenic vector and the helper helper-pigA3 were transferred into silkworm through pressure penetration and sperm mediation to obtain silkworm with green fluorescent emission. PCR identified hGM-CSF from genomic DNA of transgenic silkworm. ELISA measurement performed that concentration of hGM-CSF in lyophilized powder directly made of the third transgenic silkworm was about 95ng/100mg. Otherwise, M gene of SARS Coronavirus were inserted into expression vector pET28a(+) and expressed in E.coli BL21, the result indicated that M gene (28Kda) was expressed in E.coli BL21, but another unexpected protein(18kDa) appeared, of what we presumed that it might be due to the codon bias of E.coli or digestion after expression; M gene of SARS Coronavirus was also coloned into transfer vector pBacPAK-His and was expressed by BEVS. SDS-PAGE,Western Blotting showed that the protein (30kDa) expressed in silkworm whose molecular weight was bigger than that of theoretic protein (25.96KDa) and that might arise from protein post-modification such as glycosylation.