The doxycycline-dependent transcriptional repressor, tTA, was placed under control of the bovine keratin 5 (K5, KRT5) promoter. When tested on a tetO-LacZ transgenic background, doxycycline suppressed expression of beta-galactosidase in a tissue-specific manner. Reduced beta-galactosidase activity was detected in skin (basal layer of the epidermis and hair follicles), tongue, forestomach, and trachea. No reduction was seen in tissues that do not express endogenous keratin 5 (liver, spleen, muscle, heart, intestine).
Diamond I, Owolabi T, Marco M, Lam C, Glick A. Conditional gene expression in the epidermis of transgenic mice using the tetracyclin-regulated transactivators tTA and rTA linked to the keratin 5 promoter. J Invest Dermatol 115, 788-794, 2000. PMID: 11069615