Tg(Scgb1a1-rtTA,-tTS,tetO-CHI3L1)1Eli

Three constructs were co-injected to create this transgene. Two constructs used the rat Scgb1a1 (CC10) promoter to drive either reverse tetracycline transactivator (rtTA) or a tetracycline-controlled transcriptional silencer (tTS). In this system, the CC10 promoter constitutively drives the expression of rtTA and tTS in a lung-specific fashion. In the absence of doxycycline, tTS binds to and actively suppresses the expression of the tet-O-regulated human CHI3L1 transgene. In the presence of dox, tTS is released allowing the activating, dox binding rtTA to bind to the tet-O and activate transgene expression. Expression of human CHI3L1 was detected in bronchio-alveolar fluid 24 hours after doxycycline administration. (J:148490)