Abstract
Purpose: :
To characterize the spatial and temporal distribution of photoreceptor precursors in the ciliary epithelium of rd1 mice.
Methods: :
Cilio-retinal flat-mounts and histological sections from rd1 mice ranging in age from post-natal day 6 (P6) to P60 were analyzed. BrdU (50 or 150mg/kg) was injected intraperitoneally to label proliferating cells. We used antibodies for BrdU, Ki67, rhodopsin, recoverin, Pax6, and synaptophysin, DAPI, and PNA to characterize cells in the ciliary epithelium.
Results: :
The neuroblast layer composed of proliferating retinal progenitor cells were identified in the pars plana as well as the peripheral retina in rd1 mice at P6. Within the neuroblast layer in the ciliary epithelium, there were many rod and cone photoreceptor precursors. Cone photoreceptor precursors were much more frequently identified compared to rod photoreceptor precursors in the ciliary epithelium (61% vs 28% of recoverin-positive cells, respectively). Unlike the pars plana of wild-type mice in which photoreceptor precursors rapidly decrease and are rarely seen after retinal histogenesis (P12), many photoreceptor precursors persisted in the ciliary epithelium for a prolong period in rd1 mice even after P30.
Conclusions: :
Rod and cone photoreceptor precursors are present in the adult pars plana of mice with inherited retinal degeneration.
Keywords: retinal degenerations: cell biology • ciliary body • retinal development