The upper panel shows schematic diagram of doxycycline-inducible Krt14-rtTA/TetO-Cre/R26-mTmG model. Krt14-rtTA mice were crossed with TetO-Cre mice and R26R-tdTomato reporter mice to generate doxycycline inducible reporter mouse model for lineage tracing Krt14 + cell. The lower panel shows schematic strategy for lineage tracing studies of Krt14 + cells from puberty stage for experiments in b - d . Krt14-rtTA/TetO-Cre/R26-mTmG mice were administered with 0.1 mg or 2 mg doxycycline intraperitoneally only once at postnatal 5-week-old (P5w). The mammary glands were harvested for GFP labeling analysis 1 year after pulsing.
