Fig. 7

The rx3 paralogs, rx1 and rx2, are not involved in the development of the RPE. (A–F) Cross-sections, dorsal upwards, through the eyes of wt embryos injected with rx1-MOs (A, D), rx2-MOs (B, E) or injection buffer only (C, F). When compared to the controls (C, F), the morphant phenotypes do not affect the proportion of the NR surrounded by RPE or the pigmentation in the RPE cells. However, other specific phenotypes are observed. At 48 hpf, the NRs of the morpholino-injected embryos are not laminated (A, B), and the eyes of rx1-morphants (A) are smaller than those of control embryos (C). At 72 hpf, the eyes of rx1 morphants (D) are still smaller than the control embryos (F), but an incipient PRCL and GCL are visible (arrow and arrowhead in D, respectively). Conversely, the only evident phenotype at 72 hpf in rx2 morphants is a subtle delay in the maturation of the lenses, also present in rx1 morphants (asterisk in panels D and E). (G, H) Lateral images of 9 dpf double-mutant embryos for rx3 and rx1, obtained by injecting rx1ATG-MO into the chk^w background. The lenses and the small patches of NR-associated RPE observed in chk^w (blue and red arrowheads, respectively in panel G) are absent in the double mutants. Splicing defects in the mRNA of rx2 (arrow in line 3) and rx1 (arrow in line 4) are observed upon rx2GT-MO or rx1GT-MO injections as scored by RT-PCR (I). 1, 1 kbp DNA markers; 2, low molecular weight DNA markers; 5–6, controls without reverse transcriptase for rx2 and rx1, respectively. Scale bars: 20 μm. Refer to Fig. 1 for abbreviations.