Fig. 1
The cochlear morphology and hearing function were not affected by Sox2 overexpression. A The cross-section of the cochlear sensory epithelium. The IHCs and OHCs are located on the top layer, and most supporting cells (including BC, IphC, IPC, OPC, DC, and HeC) are located on the under layer. Some HCs can be observed in the top layer. IPC inner pillar cell, OPC outer pillar cell, DC Deiters’ cell, IPhC inner phalangeal cell, BC inner border cell, HeC Hensen’s cell, IS inner sulcus, CC Claudius cell. B Schematic for creating the transgenic mouse models. The Rosa26-CAG-LSL(loxP-stop-loxP)-Sox2 transgenic mice, referred to as the Sox2OE mice, were designed using the CRISPR/Cas9 method. C Images of Sox2 immunofluorescence (whole mount, HC layer) showed that there was no detectable Sox2 expression in the cochlear HCs of the control group, while in the PrestinCreER+/–/Sox2OE+/– group Sox2 expression was clearly observed in OHCs. D Experimental protocol for E–F. Tamoxifen was injected once daily during P21–P22, and the cochlear morphology and hearing function were assessed by immunofluorescence and ABR at P30. E Representative Myosin7a immunofluorescence showed no difference in HC morphology between the PrestinCreER+/–/Sox2OE+/– and control groups. F Quantification of IHCs and OHCs in the PrestinCreER+/–/Sox2OE+/– and control groups. G The ABR thresholds of adult PrestinCreER+/–/Sox2OE+/– and control mice. Data are presented as the mean ± SEM. n = 5 for each group. Scale bar = 20 µm