Study On RNAi Technology Inhibited Bombyx Mori Baculovirus Multiplication

RNA interference (RNAi) was the process by which a gene was suppressed using double-stranded RNA (dsRNA). The phenomenon has been observed as gene expression mediated mechanism in protozoan, elegans, fungi, insect, and mammal etc., which was very old and highly conserved in evlution.In this reseach, IE-1 gene was inserted into plasmid pBluescripâ…¡SK(+)(pSK-IE) in a series-opposing form that could transcript into hairpin dsRNA drivered by IE-1 promoter. The IE dsRNA expression element was cloned into piggyBacA3 plasmid, and achieved the transgene RNAi plasmid pigA3-IE-Neo. Both transfecting cell and injecting silkworm pupa using pSK-IE showed inhibiting BmNPV effection. The results indicated it feasible to construct RNAi DNA vector using IE-1 promoter, and RNAi detectability was determined by transfection efficiency. Selected by G418 for 4 months, cells induced pigA3-IE-Neo, whose positive rate reach out of 80%, were obtained. Transgene cells showed stronger inhibiting BmNPV effection than ordinary cells after infection. In addition, alk-exo gene of BmNPV was cloned and Phylogenetic tree of alk-exo gene was constructed. And fused expression of S and M gene of SARS-CoV was fulfilled in prokaryotic expression system and insect expression system.