Tg(KRT5-tTA)1216Glk

This transgene contains the tetracycline-regulated transactivator gene tTA under control of the bovine keratin 5 promoter. The tTA coding sequence lies downstream of approximately 5.2 kilobases of DNA from the 5' flanking region of the keratin gene followed by a beta-globin intron and upstream of an SV40 polyadenylation signal. In the absence of doxycycline, mice doubly transgenic for this transgene and a tetO-lacZ reporter gene exhibit levels of beta-galactosidase(b-gal) activity in skin 500-fold, and in tongue and forestomach 200-300-fold, those of tetO-lacZ singly transgenic mice. Immunohistochemical staining for b-gal detects expression in skin and hair follicles, specifically in the basal layer of the interfollicular epidermis and in the outer root sheath of the hair follicle, and in tongue, forestomach and trachea. No significant b-gal activity is detected in tissues that do not express endogenous keratin 5 or in the presence of doxycycline. (J:65791)