Establishment of transgenic mouse model harboring hepatitis B virus x gene

Objective: To establish a mouse model harboring hepatitis B virus x gene (adr subtype) for studying the function of hepatitis X protein. Methods: Expression vector pcDNA3-HBx, containing CMV promoter and hepatitis B x gene open reading frame (ORF) , was constructed by recombination DNA technique. After restriction enzyme digestion, the coding elements were microinjected into male pronuclei of mouse zygotes. The new born pups were evaluated by multiplex poly-merase chain reaction (PCR). Expression of x gene in transgenic mouse founders were confirmed by immunohistochemistry. Results: Expression vector pcDNA3-HBx was constructed. It was identified by restriction endonucleases digestion and confirmed by DNA sequencing. The sequence of HBx gene was coincident with the reported. Following microinjection the emby-ros were transferred to oviducts of pseudopregnant females. Eleven pups were born and survived, 5 of them were verified to integrate the HBx gene in their genomic DNA. With immunohistochemistry, X protein was detected mainly in hepatocytes cytoplasm of C57-TgN (HBx)SMMU transgenic mice. Then the transgenic mice were mated with normal mice to establish transgenic mice strains. Now one of them had F4 offsprings. Conclusion: HBx (adr subtype) transgenic mice C57-TgN (HBx)SMMU, harboring hepatitis B virus x gene are generated and X protein is expressed. It is a valuable animal system to study the roles of HBx gene in the course of HBV infection and in development of hepatocellular carcinoma in vivo.