Abstract: The structure of bluetongue virus(BTV) was consisted of three layers of capsid proteins, VP2 and VP5 proteins consisted the outer capsid of BTV, VP7 protein consisted the middle capsid of BTV, VP3 consisted the inner capsid of BTV.When BTV infected host cells, VP2, VP5 and VP7 proteins of BTV played important roles in the process of infecting host cells.In order to study the molecular mechanism of interaction between BTV and host cells, we cloned VP 2, VP 5 and VP 7 genes into pGBKT7 vector, three recombinant bait plasmids pGBKT7-VP2, pGBKT7-VP5 and pGBKT7-VP7 were successfully constructed, and then the self-activation and toxicity of the bait plasmids were tested.The results showed that three bait plasmids all had no self-activation and toxicity to yeast cells.This research made a steppingstone for the screening of host-cell protein interacting with VP2, VP5 and VP7 proteins using yeast two-hybrid system, and laid a foundation for investigating the interaction between BTV and its host cells.

Key words: bluetongue virus(BTV); bait plasmid; self-activation; toxicity