Conditional Transgenics: Introduction TET On/Off System
A more flexible strategy allows the reversible regulation of transgene
expression. The transgene is under the control of a responsive element (RE), which in turn is under the control of a transcription
activator (TA).
The tetracycline regulated system (tet-system) is one of the most popular systems. In this system, transgenic
expression of the GOI is under the control of a minimal promoter containing the tetracycline responsive element, tet operator, TetO.
Two models of tet regulation exist depending on TA used. 1) tet-off: addition of tetracycline leads to downregulation of gene expression.
2) tet-on: addition of tetracycline leads to induction of gene expression.