Fig. 3.

Fgf8^mcm genetic labeling occurs shortly after hair cell terminal mitosis. (A) Tamoxifen induction at E11.5 induces tdTomato expression in hair cells throughout the central region of the utricle in which the striolar region lies at E18.5. (B) Higher magnification image from the framed region in A shows tdTomato colocalization with oncomodulin-positive hair cells (examples marked by arrows). (C) Newly divided hair cells labeled by EdU incorporation at E12.5 are genetically labeled by the tdTomato reporter with concurrent tamoxifen induction (examples marked by arrowheads). Dashed line indicates the boundary of the utricular sensory epithelium. (D) Higher magnification 3D-reconstruction of EdU-labeled hair cells. Arrowheads correspond to the two tdTomato-positive cells indicated in C. (E,E′) Higher magnification image corresponding to the framed region in C similarly reveals vestibular hair cells containing EdU and labeled by tdTomato (E) and DAPI (E′). Scale bars: 50 µm in A,C; 5 µm in B,D; 10 µm in E,E′.