Tet responsive and adenovirus based constructs for regulated in vivo expression of Lefty.

Regulated expression of Lefty/Ebaf during embryogenesis is required for development of body asymmetry. A tight regulation of Lefty also contributes to the menstrual tissue shedding in humans. In order to replicate this regulated expression, we have developed a tet-on system and an adenovirus driven model. To drive the expression of Lefty, we have placed Lefty under control of a tetracycline-responsive promoter which responds to a sequence variant of the reversed tet transcriptional activator (rtTA), rtTA2S-M2. In this model, Lefty is regulated by the dose of doxycycline. In the adenovirus driven system, Lefty is regulated by the number of adenoviral particles These model systems would be suitable for understanding the dose-dependent biologic role of Lefty in vivo.