title: Generation of the regulatory protein rtTA transgenic mice.
abstract: OBJECTIVE
  To translate Tet-on system into a conditional mouse model, in which hepatitis B or C virus (HBV or HCV) gene could be spatiotemporally expressed to overcome "immune tolerance" formed during the embryonic development and "immune escape" against hepatitis virus antigen(s), an effector mouse, carrying the reverse tetracycline-responsive transcriptional activator (rtTA) gene under the tight control of liver-specific human apoE promoter, is required to be generated.
  
  
  METHODS
  To address this end, rtTA fragment amplified by PCR was effectively inserted into the vector of pLiv.7 containing apoE promoter to create the rtTA expressing vector, i.e., pApoE-rtTA. ApoE-rtTA transgenic fragment (-6.9 kb) released from pApoE-rtTA was transferred into mice by pronucleus injection, followed by obtaining one transgene (+) founder animal from microinjection through PCR and Southern blot analysis.
  
  
  RESULTS
  rtTA transgene which could be transmitted to subsequent generation (F1) derived from founder was expressed in a liver-specific fashion.
  
  
  CONCLUSIONS
  Taken together, these findings demonstrate that rtTA transgenic mice, in which rtTA expression is appropriately targeted to the murine liver, are successfully produced, which lays a solid foundation to 'off-on-off' regulate expression of target gene (s) (e.g., HBV and/or HCV) in transgenic mice mediated by Tet-on system.
authors.affiliation: Center of Experimental Animals, Sun Yat-Sen (Zhongshan) University, No. 74, Zhongshan Road 2, Guangzhou 510080, Guangdong Province, China.
authors.forename: Kang
authors.initials: K
authors.lastname: Xu
authors.forename: Xin-Yan
authors.initials: XY
authors.lastname: Deng
authors.forename: Ying
authors.initials: Y
authors.lastname: Yue
authors.forename: Zhong-Min
authors.initials: ZM
authors.lastname: Guo
authors.forename: Bing
authors.initials: B
authors.lastname: Huang
authors.forename: Xun
authors.initials: X
authors.lastname: Hong
authors.forename: Dong
authors.initials: D
authors.lastname: Xiao
authors.forename: Xi-Gu
authors.initials: XG
authors.lastname: Chen
mesh_terms: D000818:Animals; D001057:Apolipoproteins E / Q000235:genetics; D006526:Hepatitis C / Q000235:genetics* / Q000276:immunology; D018936:Hepatitis C Antigens / Q000235:genetics* / Q000276:immunology; D007108:Immune Tolerance; D008099:Liver; D051379:Mice; D008822:Mice, Transgenic / Q000235:genetics*; D011401:Promoter Regions, Genetic; D013752:Tetracycline; D015534:Trans-Activators / Q000235:genetics* / Q000276:immunology; D019076:Transgenes / Q000235:genetics* / Q000276:immunology
chemical_list: D001057:Apolipoproteins E; D018936:Hepatitis C Antigens; D015534:Trans-Activators; D013752:Tetracycline