Tet-off
Tetracycline-Controlled Transcriptional Activation is a method of inducible gene expression where transcription is reversibly turned on or off in the presence of the antibiotic tetracycline or one of its derivatives (e.g. doxycycline). In nature, the Ptet promoter expresses TetR, the repressor, and TetA, the protein that pumps tetracycline antibiotic out of the cell.
The difference between Tet-On and Tet-Off is not whether the transactivator turns a gene on or off, as the name might suggest; rather, both proteins activate expression. The difference relates to their respective response to doxycycline (Dox, a more stable tetracycline analogue); Tet-Off activates expression in the absence of Dox, whereas Tet-On activates in the presence of Dox.
Read more about Tet-off: Tet-Off and Tet-On, Tet-On Advanced and Tet-On 3G, Tetracycline Response Element (TRE), Advantages and Disadvantages, External Links