Photoreceptor Differentiation following Transplantation of Allogeneic Retinal Progenitor Cells to the Dystrophic Rhodopsin Pro347Leu Transgenic Pig
Figure 5
Photoreceptor marker expression within a rosette of donor origin. Recipient was 6 weeks of age at time of transplantation and experiment terminated 5 weeks later. (a) Immunohistochemical labeling of the same RPC graft was shown in previous figure. Endogenous GFP fluorescence (green) was present in many cells of the graft, but less so within the rosettes. The largest, most well formed of the rosettes was selected for more detailed evaluation of individual marker expression patterns. (b) GFP labeling was most notable around the periphery of the rosette; however, GFP+ profiles were also integrated into this structure, with small peripheral soma and straight process oriented towards the core of the rosette (arrow 1). An adjacent region (arrow 2) shows a similar cell with a less clearly defined process. A third cell (arrow 3), does not express GFP. (c) Rhodopsin labeling (red) is strongest in the central core of the rosette. In addition, multiple profiles exhibiting rod photoreceptor morphology can be seen to contribute to the rim of the rosette, and these have cell bodies located around the periphery and processes directed inward where they merge with the central core. The arrows point to the same profiles as before, in this case showing strong rhodopsin labeling (arrow 1), no rhodopsin (arrow 2), and moderate rhodopsin (arrow 3). (d) Recoverin (blue) labeling was dense in areas populated by rhodopsin-positive cells and revealed a dense ring of recoverin-positive cells central to the rhodopsin-positive somata, although this labeling did not extend into the core of the rosette despite some marginal overlap at the interface. (e) The merged image reveals that much of the rhodopsin colabels recoverin-positive cells, whereas many recoverin-positive cells do not appear to colabel with rhodopsin. The core is exclusively positive for rhodopsin, as previously noted.
