In Aspergillus, controlled gene expression is often achieved using the reverse tetracycline-
controlled transactivator (rtTA) dependent Tet-on system, whereby transcription is activated
in a titratable manner by addition of the tetracycline derivative doxycycline. The
complementary Tet-off system utilises the tetracycline-controlled transactivator (tTA)
component to quantitatively reduce gene expression. In this study, we utilised a synthetic
biological approach to engineer highly optimised Tet-off conditional expression systems in …