Fig. 4: Defective differentiation of ependyma and choroid plexus in trip6^−/− mice.

Schematic illustration of mouse brain ventricles and choroid plexus, with vertical lines indicating the approximate coronal section planes analyzed (a). Scheme (b′) and immunofluorescence microscopy analysis (b) of ependyma (Epn) and choroid plexus (Chp) within the 3rd ventricle (Vent: ventricular lumen) in control brain sections, illustrating ciliation and ependymal cell differentiation [visualized by acetylated tubulin (Ac.TUB) and S100β labeling, correspondingly]. Nuclear DNA is stained by DAPI. Note that S100β is expressed in ependymal (arrows, b–f) but also in non-ependymal cells (arrowheads, b–f). Trip6 deletion (c) results in differentiation defects indicated by reduction in ciliation and S100β expression. Importantly, these defects [which are apparent also in the LV (Vent) (e, f cf. control d)] are observed in mice with (e) or without (f) hydrocephalus, suggesting that differentiation defects precede development of this pathology. For higher magnification images, please see Supplementary Fig. 3. Defective ciliation in trip6^−/− brain is further demonstrated by labeling the ciliary transport protein CLUAP1 (h). Yellow arrows indicate the height of the cilia lawn in control (g) and trip6^−/− (h) specimens. Scale bars: 50 μm (b–f), 10 μm (g, h).