Figure 3.
Cre activity after tracheal RU486 in K5CrePR1Rosa26 mice. (A) K5CrePR1.Rosa26 mice were treated with 100μg tracheal RU486 and β-gal activity assessed 7d later. No β-gal staining was observed in Cre negative monogenic littermates while RU486-inducible Cre activity was seen in K5CrePR1.Rosa26 animals. Representative images are shown; 3-4 mice/group were analyzed for β-gal expression. The dashed line delineates the epithelial basement membrane; the scale bar represents 100μm. Untreated K5CrePR1.Rosa26 mice had 5.3 ± 1.0 (mean ± SEM) recombinant cells/100μm tracheal epithelium while RU486-treated mice had 14.5 ± 4.2 recombinant cells/100μm tracheal epithelium (p=0.05). (B) Co-localization of β-gal staining with K5, p63, and CCSP expression in K5CrePR1.Rosa26 mice treated with tracheal RU486. Arrows indicate co-localization of β-gal and immunohistochemical staining in basal cells (K5+ and p63+) and Clara cells (CCSP+).