Protocols for inducible and reversible reporter gene expression in TPH2-tTA/Ptet-nLacZ mice.

Dox was administered with 5 µg/ml from initiation of matings until birth. At P0, Dox concentration was changed to 50 µg/ml. Suppression of Ptet-controlled gene expression in adult mice was also done with 50 µg/ml Dox. In protocol 1, mice were maintained under chronic Dox administration throughout life until sacrifice at P90. In protocol 2, transgenic mice were maintained in the absence of Dox until P60 when Dox administration was initiated until sacrifice at P90. In protocol 3, Dox was given from conception until P60 when Dox was withdrawn until sacrifice at P90. Protocol 4 is based on protocol 3. Here, Ptet-controlled βgal expression was re-suppressed from P90 until sacrifice at P120. Protocol 5 is based on protocol 4, but removal of Dox at P120 until sacrifice at P150 reactivated Ptet-controlled βgal expression. +Dox, administration of Doxycycline; θDox, no administration of Dox.