||Fig. 1. The retina is essentially regenerated 30 days after resection.
(A–D) The progress of regeneration was analyzed by hematoxylin and eosin staining. (A) The retina after resection of the nasal-dorsal quarter on day 1. The site of resection is evidenced by the disruption of the retinal lamination and RPE (red asterisks). (B) On post-resection day 3 the RPE has re-assembled around the site of resection (red arrow) and cells have begun to fill in the wound. (C) On post-resection day 13 the RPE has closed around the wound (red arrow) and RPCs have repopulated the wound. (D) On post-resection day 30 the lamination of the retina is completely restored and the resection site is no longer evident.
(E–J) Analysis of regeneration progress using markers of differentiated neural cell types. Immunolabeling for Islet-1 (E–G) and Rhodopsin (H–J) in control retinas (E, H) and regenerating retinas at 15 days (F, I) and 30 days post-resection (G, J). Control retinas shown in panels E and H are from sibling embryos to those shown in panels G and J, respectively. At 15 days post-resection, the putative RPCs are still present at the site of resection (F, I; red bracket). The putative RPCs are not immunoreactive to Islet 1 (F; red bracket) or Rhodopsin (I; red bracket) antibodies. At 30 days post-resection, the putative RPCs are absent from the nasal-dorsal quarter of the retina and complete retinal lamination is observed by immunoreactivity to Islet-1 (G) and Rhodopsin (J). Uninjured retinas lack putative RPCs in the nasal-dorsal quarter and show Islet-1 and Rhodopsin immunoreactivities (E, H). L — lens; G — ganglion cell layer, I — inner nuclear layer; and P — photoreceptor layer. Scale bar = 50 μm.