In situ hybridization on 12μm transverse sections through the otocyst of E10.5 mouse embryos using probes for Axin2 (A, D), Brn4 (B, E), Tbx1 (C, F), and Sox10 (G-G’’, HH’’). Abbreviations: oe, otic epithelium; otc, otocyst; nt, neural tube; drg, dorsal root ganglion; d, dorsal; m, medial. White dashed line indicates anterior (G, H) or posterior (G’’, H’’) edge of otocyst. Scale bar in A, 100μm (applies to A-C, G-G’’); scale bar in D, 50μm (applies to D-F, HH’’).