Figure 2. Apical to Basolateral Ependymal EGFR Localization.

(A) IHC images in x-z views of LV whole mounts from FOXJ1-GFP⁺ animals, with antibodies to EGFR, GFP, and DAPI. Scale bar: 10 µm.

(B) Quantification of the apical/basolateral EGFR expression ratio in FOXJ1-GFP⁺ pRGPs. *p < 0.0001, one-way ANOVA, n = 10 cells for each group, mean ± SEM.

(C) STED super-resolution images from the P1 and P7 LV surface labeled with EGFR and GFP antibodies. Single apical and lateral optical sections are shown. Scale bar: 5 µm.

(D) 3D rendering of STED super-resolution images from (C), with EGFR in red and GFP in white for clarity. Scale bars: 2 µm.

(E) Quantifications of apical EGFR particles as the fraction of the volume measured. *p < 0.001, Student’s t test, n = 10, mean ± SEM.

(F) IHC images from P14 LV whole mounts injected P1 with either WT-EGFR-HA or P667A-EGFR-HA lentivirus and labeled with anti-Foxj1/HA antibodies and DAPI. The asterisk indicates the cell body of HA⁺ cells quantified; note apically expressed P667A-EGFR-HA (arrow, left panels) from the deeper section of the same cell in right panels (*). Scale bars: 10 µm.

(G) Quantifications of Foxj1⁺ cells per total HA⁺ cells for each construct. *p < 0.0286, Wilcoxon two-sample test, n = 4 animals, mean ± SEM.

(H) Quantifications of multicilia⁺ cells per total HA⁺ cells for each construct. *p < 0.0286, Wilcoxon two-sample test, n = 4 animals, mean ± SEM.

See also Figures S2 and S3.