Fig. 1

Mutations in the chokh locus affect the development of the RPE. Dorsal view of wt (A), chk^w (B) and chk^s (C) larvae at 5 dpf. (B) In chk^w, the RPE is reduced (red arrowhead), the NRs are fused at the midline (white arrowhead) and the lenses are present but misaligned (black arrowhead). Cross-sections through the head of wt (G), chk^s (H) and chk^w (I, J) larvae at 5 dpf. At this stage, the eye is laminated in the wt (inset in panel G). The NRs are fused in both chk alleles (red arrowheads in panels H and I) but undergo lamination and differentiation even in the complete absence of the RPE. (J) The PRCL (red arrowhead) maintains a similar morphology with or without associated RPE. (D–F) Dorsal views of wt, chk^w and chk^s under DIC optics at 12 hpf, 24 hpf and 36 hpf. The evagination of the optic lobes (black arrowheads in panels D–F) and the differentiation of the lens (blue arrowheads in panel E) are always observed in both alleles. In contrast, a pigmented RPE is observed only in wt embryos (red arrowhead in panel F). 1, lens; 2, ganglion cell layer (GCL); 3, inner plexiform layer (IPL); 4, inner nuclear layer (INL); 5, photoreceptor cell layer (PRCL); 6, retinal pigment epithelium (RPE); wt, wild-type; NR, neural retina.