Fig. 3

Sox11 morphants lack mature rod photoreceptors.

(A) Representative transverse retinal sections from XOPS-GFP zebrafish injected with control, sox11 MO, or sox11 MO plus zebrafish sox11 mRNA at 3 dpf (from the set of individuals analyzed in (B). Even sox11 morphants with well-laminated retinas and no evidence of coloboma (second panel) displayed greatly reduced numbers of mature rods compared to controls (left panel). Co-injection of wild type zebrafish sox11 mRNA (right panel) rescued the rod deficiency at 3 dpf. (B) Quantification of the number of rod photoreceptors/section. Number of embryos analyzed: control MO, n = 25; sox11 MO without coloboma, n = 25; sox11 MO with coloboma, n = 25; sox11 MO plus zebrafish sox11 mRNA, n = 17 (**p<0.00001; n.s., p>0.05, Student′s t- test). (C) Two-color fluorescent in situ hybridization (FISH) for neuroD, crx, nr2e3, and rhodopsin expression in control and sox11 morphants with and without coloboma at 3 dpf. Expression of the rod lineage genes neuroD (top), crx (middle), and nr2e3 (bottom) was qualitatively normal in sox11 morphants with or without coloboma. However, rhodopsin expression (green) was greatly reduced compared to control morphants (left column). Number of embryos analyzed: n = 14 per group, 3 independent biological replicates. (D) Quantitative RT-PCR (qPCR) performed on mRNA from control and sox11 morphant heads at 3 dpf revealed a significant decrease in rhodopsin expression in sox11 morphants compared to controls. However, nr2e3 transcript levels were not significantly different between control and sox11 morphants. Relative transcript abundance was normalized to atp5h levels and is presented as the mean fold-change in expression relative to controls (n = 30 embryos per group, 3 independent biological replicates). *p<0.003; n.s, p>0.05, Student′s t-test. D, dorsal; V, ventral; L, lens; dpf, days post fertilization; MO, morpholino; GCL, ganglion cell layer; INL, inner nuclear layer; ONL, outer nuclear layer; ON, optic nerve.