Figure 1—figure supplement 2.

(A) Expression patterns of strip1 mRNA during embryonic development. In situ hybridization using a strip1 antisense probe is shown at different developmental stages: 4 cell, blastula, 75% epiboly, 1, 2, and 3 dpf. In situ hybridization using the sense probe at 1 dpf is shown as a negative control. strip1 mRNA is ubiquitously expressed until gastrula stage. At 1–2 dpf, expression becomes restricted in the heart, optic tectum, and eyes. Ventral view of 2-dpf retina shows a stronger signal in GCL (left panels). OT, optic tectum; GCL, ganglion cell layer. Scale bar, 100 μm.(B) Frontal cryosections of 2-dpf heads following in situ hybridization show that strip1 mRNA is predominantly expressed in the inner retina and the optic tectum. (C) Retinal cryosections show higher expression in RGCs and ACs. Right panels show higher magnification of outlined areas. RGCs, retinal ganglion cells; ACs, amacrine cells; HCs, horizontal cells; PRs, photoreceptors. (D) Live confocal snapshots of the same wild-type and strip1^rw147 mutant retinas at different developmental stages; 40, 52, 62, and 76 hpf stained with Bodipy TR. A primitive IPL is first observed in wild-type retinas as early as 52 hpf. However, it is not as prominent in strip1^rw147 mutant retinas. By 62 hpf, strip1^rw147 mutants display severe defects in IPL formation. Arrowheads indicate rudimentary IPL. Asterisks show IPL defects in strip1^rw147 mutants. Scale bar, 50 μm.