Rer1p is highly expressed in ciliated organs and affects ciliogenesis in zebrafish. (a) WISH (i–iii) and immunostaining (iv–vi) show that rer1 is highly expressed in ciliated organs: KV (delineated with a dashed box in i), lateral views of the otic vesicle (OV; different hybridization probe in inset; ii), ALL and PLL neuromasts (ii–v), and pronephros (delineated with dashed lines in vi). (b) Rer1p knockdown results in a “curly tail down” phenotype after 24 hpf. (c) Ciliary defects in SMO ALL neuromast cells at 48 hpf (confocal) and 72 hpf (scanning EM; zoomed area of boxes in right images). Rer1p staining is absent in SMO. (d) Pronephric cilia are shortened in Rer1p morphants (SMO, ATGMO, and UTRMO) compared with control (uninjected and p53MO) and rescued upon reexpression of Rer1p (n > 9; three experiments). (e) Ciliary defects of olfactory pits in SMO at 48 hpf (confocal; scanning EM). Boxed areas are enlarged in the bottom images. (f) Short cilia in the inner ear sensory patches of SMO at 24 hpf (indicated with arrows) and 48 hpf. (g) Reduced cilia length in the KV (10-somite stage [ss]) of SMO/ATGMO (n = 10). (h, left) Impaired photoreceptor outer segments (OS) in 4-dpf SMO. OPL, outer plexiform layer; PR, photoreceptor; RPE, retinal pigment epithelium. (right) EM of OS of 4-dpf larvae. Decreased number and mean size of the outer segments in SMO (n = 4 embryos). uninj., uninjected. In all panels except h, cilia are visualized using anti–acetylated tubulin (ac.tub) staining. Means ± SD (h) or SEM (d and g); ***, P < 0.001, Wilcoxon rank sum test (h) or Student’s t test (d and g). Bars: (a) 100 µm; (b) 500 µm.