Figure 3

TCre-KO embryos exhibit defects in cell proliferation and survival. Transverse sections at E11.5 of control (A) and TCre-KO (C) embryos labeled for mitotic cells using an Ab against phospho-Histone 3. TCre-KO embryos display a decrease in cell proliferation in the otic epithelium compared to controls upon quantification (E). Proliferation was reduced in both dorsal and ventral regions of the otic vesicle, but not in the POM. For the dorsal otic vesicle, 11.2 and 21.4 positive cells were observed for mutant and control, respectively, while 14.0 and 22.4 positive cells were observed observed for the ventral otic vesicle. TCre-KO embryos exhibit an increase in apoptosis at E11.5, identified by an Ab to active Caspase 3 (B, D). Arrow and bracketed area in (d) mark apoptotic cells. Quantification of apoptotic cells in control and mutant otic epithelium is shown (F). Asterisks indicate significant difference (* = p < 0.05, ** = p < 0.01, one-tailed, unpaired Student's t-test). Error bars represent 95% confidence interval. Boxed areas are magnified in a-d. Scale bar indicates 200 μm in (A), and 50 μm in (a).