Fig. 6. Vestibulocochlear ganglion size and organization is perturbed by Xevl depletion. Dorsal is up and the otic vesicle is to the right in all images. (A) Expression of XNeuroD in the vestibulocochlear ganglion (arrow) and ventromedial sensory epithelium (arrowhead) of control stage 35 embryos. (B) Xevl depletion diminishes the size of the vestibulocochlear ganglion (arrow) and reduces the amount of XNeuroD-positive cells in the sensory epithelium and the vestibulocochlear ganglion. The Xevl-depleted otic vesicle also exhibits a loss of columnar morphology in the thickened sensory epithelium compared with the control otic vesicle (arrowhead, 100% affected; n=9). (C-H) Confocal images of vibrotome-sectioned embryo at stage 42 showing islet-1 (C,F; red in E,H) and laminin (D,G; green in E,H) immunostaining of the vestibulocochlear ganglion. (F,H) Xevl depletion causes a reduction in the number of islet-1-labeled cells and an overall reduction in the size of the vestibulocochlear ganglion (arrow). (G,H) In addition, the laminin-rich matrix surrounding the vestibulocochlear ganglion (arrow) is disrupted in Xevl-depleted embryos. Bar, 20 µm. A longer exposure time was necessary for the Xevl-depleted otic vesicle to show islet-1 in the vestibulocochlear ganglion, making islet-1 levels appear higher in the neural tube and otic vesicle of Xevl-depleted embryos compared with controls.