Development of single-vector Tet-on inducible systems with high sensitivity to doxycycline

Mol Biotechnol. 2012 Jul;51(3):240-6. doi: 10.1007/s12033-011-9461-z.


Single-vector Tet-on systems were developed to enable the tight regulation of transgenes in mammalian cells with a low dosage of doxycycline. Both the regulatory and the responsive units were integrated in a single vector and separated by a short DNA segment (214 bp). In the developed single-vector Tet-on systems, a high level of expression of the transgene can be induced by doxycycline at a concentration of as low as 1 ng/ml, which is 500-1,000 times lower than that usually utilized in other Tet-on systems. The single-vector Tet-on system developed here exhibited 3.5-10.8 times greater inducibility of the transgene in response to doxycycline than did a dual-vector system from a commercial source. Further studies indicate that the basal activity of Tet-on systems depends greatly on the strength of the promoter that controls the transactivator. The basal activity of Tet-on systems was high when the transactivator that was directed by the human cytomegalovirus promoter, and it was almost undetectable when the transactivator was placed under the control of a moderate strength mouse mammary tumor virus promoter. Moreover, the introduction of selectable markers allows the developed single-vector Tet-on systems to facilitate the generation of conditional transgenic cells and animals with high inducibility, low basal activity and detrimental effects of the long-term administration of doxycycline.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Cell Line, Tumor
  • Cytomegalovirus / genetics
  • Doxycycline / pharmacology*
  • Genetic Vectors / genetics*
  • HEK293 Cells
  • Humans
  • Mammary Tumor Virus, Mouse / genetics
  • Promoter Regions, Genetic / drug effects
  • Response Elements / drug effects
  • Tetracycline / pharmacology*
  • Trans-Activators / genetics
  • Transfection
  • Transgenes*


  • Anti-Bacterial Agents
  • Trans-Activators
  • Tetracycline
  • Doxycycline