Sox2 induces neuronal phenotypes in cochlear nonsensory cells. A, B, Low- (A) and high-magnification (B) images of Sox2.nucEGFP transfected cells (green) located in KO of cochlear explants labeled with anti-TuJ1 (red in A, B) or anti-Map2 (red in C). A subset of transfected cells are labeled with anti-TuJ1 and have developed a neuronal phenotype. Asterisk in A indicates a Sox2.nucEGFP transfected cell that is TuJ1-positive and has extended a single neurite (enlarged in inset). In contrast with Neurog1.EGFP or NeuroD1.EGFP, the Sox2.nucEGFP construct carries a nuclear localization signal sequence and is therefore restricted to the nucleus. Scale bars: A, 20 μm; B (for B, C), 10 μm.