Objective:To construct the recombinant plasmid pBI-Eg95 of E.granulosus

and to study its expression efficiency in the Agrobacterium tumefaciens(At) LBA4404 strain.Methods:Total RNA was extracted from hydatid cyst protoscoleces shattered by supersound.The Eg95 coding gene was amplified by RT-PCR

and then was cloned into the plant expression vector pBI121 to construct the recombinant plasmid pBI-Eg95.The recombinant plasmid was electroporated into At(LBA4404) strain.The recombinant At(rAt) was induced by IPTG for 0

1

3

5

7

9

11or13 hour

respectively.The expression product was identified by SDS-PAGE and Western blot assay.Results:The 471bp Eg95 coding gene was successfully amplified

and the recombinant pBI-Eg95 plasmid was successfully constructed

which was confirmed by restriction endonuclease digestion and PCR.The recombinant plasmid pBI-Eg95 was expressed successfully in the rAt

and the expression product with an approximately Mr of 16.5 kD could be detected by sera from mice infected by E.granulosus

and the expression efficiency was about 20 percent of the total bacterial protein.Conclusion:The recombinant plasmid could provide the basis for further research of the transgenic plant vaccine of E.granulosus.