Fig. 2. ISH of RH2 opsin probes to transverse sections of zebrafish eyes. (A–C) Serial eye sections at 16 dpf hybridized with the RH2-1 3'-UTR (A), RH2-2 3'-UTR (B) and RH2-4 CDR (C) probes. Double arrows in (A) and (B) indicate the areas where the expression of RH2-1 and RH2-2 are disappearing, respectively. Arrows in (C) indicate the scarce hybridization signals detected for RH2-3/RH2-4. (D–F) Serial eye sections at 1 month pf hybridized with RH2-1 3'-UTR (D), RH2-2 3'-UTR (E) and RH2-4 CDR (F) probes. The single stars, double stars, and triple stars are position markers showing their corresponding locations between sections. (G–H) Serial sections at 2 years pf hybridized with the RH2-1 3'-UTR (G), RH2-2 3'-UTR (H) and RH2-4 3'-UTR (I) probes. Arrowheads in (H) and (I) point to the same location between the sections. An arrow in (I) indicates the hybridization signal of RH2-4 at ciliary marginal zone. In all panels, the dorsal side is to the top and ventral is to the bottom. Scale bars, 50 µm (A–F) or 200 µm (G–I).