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Fig. 8 Retinal sections from adult Tg(nrd:egfp)/albino zebrafish over a time course of light treatment and immunolabeled with EGFP (green) to visualize the nrd:egfp transgene and co-labeled with either PCNA (A, C, D, I, J, J′, K, L, L′, M, N) or Glutamine Synthetase (B, G, H).
(A) At 48 hours after light onset, almost all rod photoreceptors have been ablated and proliferating cells can be seen in the in the INL. Nuclei are labeled in blue with TO-PRO-3 (TP3). (B) At this time point, Müller glial cells express Glutamine Synthetase (G.S., red, arrow), and do not co-label with EGFP (arrowhead). (C) At 72 hours after light onset, clusters of proliferating progenitors begin to migrate towards the ONL (arrowheads). (D) At 96 hours post light onset, PCNA-positive progenitors (arrowheads) are present in both in INL and ONL, with occasional aberrant migration to the GCL. (E–F) At 72 and 96 hours after light onset, respectively, clusters of progenitors weakly express EGFP (arrowheads). (F) At 96 hours after light onset, EGFP is observed in a newly-formed and disorganized ONL. (G–H) At 72 and 96 hours after light onset, respectively, weakly-EGFP-positive clusters in the INL (arrowheads) down-regulated Glutamine Synthetase. Müller glial cells that did not re-enter the cell cycle strongly express G.S. (arrows), but are EGFP-negative. (I–J′) At 72 hours after light onset, weakly-EGFP-positive cells in both the INL and ONL co-label with PCNA. The box in I represents the PCNA and EGFP labeling shown in J and J2, respectively. (K–L′) At 96 hours after light onset, weakly-EGFP-positive cells in both the INL (arrowheads) and ONL continue to co-label with PCNA. The box in K represents the PCNA and EGFP labeling shown in L and L2, respectively. (M) At 7 days after light onset, a subset of PCNA-positive progenitors in the ONL co-label with EGFP (N) At 11 days after light onset, only a few PCNA-positive progenitors remain in the ONL. EGFP can be visualized in rod photoreceptors and newly-formed rod inner segments (arrowhead).