Figure 3. Different CDH23 protein isoforms localize to distinct cell layers of the retina. A, E, I, and M are differential interference contrast (DIC) images of longitudinal cryosections (B-D, F-H, J-L and N-P, respectively) through adult mouse retina showing photoreceptors cell layers. Indirect immunofluorescence labeling of CDH23 with the cytoplasmic domain antibody TF7 (B) revealed CDH23 in the ciliary region of photoreceptor cells, the ONL, and in the OPL. Double labeling with antibodies TF7 and centrin, a ciliary marker (C), revealed colocalization of CDH23 and centrin in the ciliary apparatus of the photoreceptor cells (D). F-H: Double labeling with antisera TF7 (F) and the synaptic protein PSD-95 with antisera PSD95 (G) revealed CDH23 colocalization with PSD-95 in the synaptic terminals in the OPL of photoreceptors cells (H). Double labeling with CDH23_V3 specific antibodies TF648 and TF649 (J, N) and PSD95 (K, O) revealed that CDH23_V3 was detected only in the OPL where it colocalized with PSD-95 (L, P). Scale bars represent 10 µm. Abbreviations: retinal pigment epithelium (RPE), outer segment (OS), inner segment (IS), outer nuclear layer (ONL), outer plexiform layer (OPL), and inner nuclear layer (INL).