Fig. 4

Overexpression of Mak restores photoreceptor survival and visual function of pday mutants. (A,Aʹ) Labeling of wild-type and pday mutant retinas with zpr1 (red, A,Aʹ) and anti-eGFP (green, A) antibodies carrying the transgene Tg[crx:eGFP] or Tg[crx:eGFP-MAK]. Nuclei were counterstained with Hoechst 33342 (blue). zpr1 signals were markedly decreased in the dorso-central region of pday mutant retinas carrying Tg[crx:eGFP] (white dotted lines), but maintained in pday mutant retinas carrying Tg[crx:eGFP-MAK]. Scale bars: 20 µm. (B) The fraction of zpr1-positive area in the total retinal area in wild-type and pday mutants with Tg[crx:eGFP] or Tg[crx:eGFP-MAK]. The fraction was markedly reduced in pday mutants with Tg[crx:eGFP] (red bar), but recovered in pday mutants with Tg[crx:eGFP-MAK] (purple bar), equivalent to that in wild-type with Tg[crx:eGFP] (blue bar) or Tg[crx:eGFP-MAK] (green bar). Bars and lines indicate mean±s.d. Statistical significance was evaluated with ordinary one-way ANOVA and Tukey's multiple comparison tests. ns, not significant; *P<0.0332; ****P<0.0002. (C) The fraction of optokinetic response (OKR)+ (blue) and OKR− (red) embryos relative to total progeny produced by crosses of pday+/− parent fish, pday+/− parent fish carrying Tg[crx:eGFP] and pday+/− parent fish carrying Tg[crx:eGFP-MAK]. 57 of 244 (23.3%) embryos produced by three independent crosses of pday+/− parent fish were negative for OKR. However, 100% of total 257 embryos produced by three independent crosses of pday+/− parent fish carrying Tg[crx:eGFP-MAK] were positive for OKR. 68 of 266 (25.5%) embryos produced by three independent crosses of pday+/− parent fish carrying Tg[crx:eGFP] were negative for OKR. Bars and lines indicate mean±s.d. Statistical significance was evaluated with two-way ANOVA and Tukey's multiple comparison tests. ns, not significant; ***P<0.0002.