Fig. 4

GPRC5C is localized at the ciliary gate. Confocal images of coronal sections (A) and en face preparation (B) adult mouse OE, immunolabelled for GPRC5C (green) and γ-tubulin (red) show punctate localization of GPRC5C along the membrane of the dendritic knob in a ring-like manner surrounding a γ-tubulin cluster that is localized in the lumen of the dendritic knob. Arrow indicates an individual dendritic knob. C Airyscan image with deconvolution processing of immunolabelling for GPRC5C (green), γ-tubulin (red) and acetylated-tubulin (white). GPRC5C is localized in the region between the basal body and the cilia. Arrow indicates an individual dendritic knob. D Immunogold labelling of freeze-fracture replica of the OE with GPRC5C antibody. Clusters of immunogold particles localized to the base of the cilia (black arrows). Higher magnification images show a distinct localization of GPRC5C at the ciliary necklace region, characterized by rows of ciliary proteins (arrow). E Quantitative analysis of anti-GPRC5C immunogold labellings of freeze-fractured plasma membranes of proximal and distal cilia. Proximal dendrite, n = 50 ROIs; distal dendrite, n = 40 ROIs. F, G Confocal images of FBF1 (green) and γ-tubulin (red), H, I MKS3 (green) and γ-tubulin (red). The localization pattern of FBF1 and MKS3 in the dendritic knob is similar to that of GPRC5C, all showing punctate staining along the membrane of the knob surrounding the γ-tubulin staining in the core. K Quantification of MKS3 staining intensity. Significance obtained upon performing Student’s t test (n = 3, individual data values Additional file 2, error bars represent SEM, *p < 0.05). L, M Confocal images of WT and Gprc5c^−/− OE immunolabelled MKS3 showing increased staining intensity and altered pattern of staining in Gprc5c^{− −}dendritic knobs. Scale bars A, B, G, I, M 2 µm; C 1 µm; D 200 nm (right), 100 nm (left), F, H 10 µm; L 5 µm