Fig. 1. Histological sections of 4 dpf wild-type, IFT57 and IFT88 mutant and morphant retinas. (A) Wild-type retinas at 4 dpf are fully laminated, and the outer nuclear layer (ONL), inner nuclear layer (INL) and retinal ganglion cells (RGC) are present. The outer plexiform layer (OPL) and the inner plexiform layer (IPL) are easily observable. (B,C) Lamination and cellular differentiation are unaffected in both IFT57 and IFT88 mutants; however, acellular holes (arrows) in the ONL are observed. (D) High-magnification images of wild-type retinas showing photoreceptor outer segments (arrowheads). Outer segments are not observed in IFT88 mutants (C); however, short outer segments are observed in IFT57 mutants (arrowhead). (G) Western blot analysis of IFT57 mutants at 4 dpf. No IFT57 protein is observed in IFT57 mutants (upper blot, lane 2). Blots probed with anti-acetylated tubulin serve as a loading control (lower blot). (H,I) Histological analysis of IFT57 and IFT88 morphants phenocopy the IFT57 and IFT88 mutations, respectively. Arrowheads in D,E,H indicate outer segments and arrows in E,H,I indicate acellular holes or pyknotic nuclei. Scale bar: 100 µm in A-C; 20 µm in D-F,H,I.