Fig. 6.

Sensory patch and cranial neurogenic development is affected in Cwe/Cwe mice. (A–D) RNA in situ hybridisation for Bmp4 on E14.5 sections. (A) Bmp4 marks the developing cristae in control mice. (B) No Bmp4 expression is detected in Cwe/Cwe vestibular system. (C) In the wildtype cochlea, Bmp4 is expressed adjacent to the developing organ of Corti. (D) No Bmp4 expression was detected in Cwe/Cwe cochlea. (E–H) Immunolabelling for Sox2 on E14.5 sections. (E) In wildtype embryos Sox2 marks the all sensory patches including the cristae shown here and the vestibular ganglion (not shown). (F) Cwe/Cwe animals have normal Sox2 expression in the vestibular ganglion, but lack Sox2 in the vestibular epithelia. (G) In wildtype embryos Sox2 marks the developing organ of Corti and the acoustic ganglion. (H) No Sox2 positive cells were found in the severely truncated Cwe/Cwe cochlea. (I–L) Whole mount RNA in situ hybridisation for Jag1 and Bmp4 at E10.5. (I) In wildtype embryos, Jag1 was detected in an anterior and posterior expression domain in the otocyst (arrowheads). (J) Cwe/Cwe embryos lack Jag1 expression in the anterior and posterior patches of the otocyst. In contrast, a ventral expression was detected. (K) Bmp4 expression marks anterior and posterior patches in the wildtype otocyst (arrowheads). (L) In Cwe/Cwe embryos Bmp4 expression is absent in the otocyst. (M–P) Whole mount RNA in situ hybridisation for NeuroD at E10.5. (M, O) NeuroD expression marks all cranial neurogenic placodes including the olfactory placode (delineated), epibranchial and the vestibulo-acoustic placode (⁎). (N, P) Stage-matched Cwe/Cwe embryos have significant smaller NeuroD-expressing olfactory (delineated), epibranchial and vestibulo-acoustic (⁎) domains. Scale bar = 200 μm. ac, anterior crista; ba, branchial arch; bt, basal turn of cochlea; co, cochlea; ep, epibranchial; he, heart; lc, lateral cristal; ma, malleus; ot, otocyst; ta, tail; tg, trigeminal ganglion; ve, vestibule; vg, vestibular ganglion.