Fig. 3

Infiltrating cells are recruited from the retinal vasculature. To determine whether leukocytes were primarily infiltrating through the retinal vasculature or the choroidal vasculature, IP injections of EdU were performed at light onset to label dividing cells. a IHC of a section through the optic nerve head of WT and Arr1^−/− retinas at 24 h showed EdU staining (red) predominantly of infiltrating cells at the vitreoretinal surface of Arr1^−/− mice. Scale bar 100 μm. Similar results were observed in 2–3 sections from 2 to 4 mice of both genotypes. b Flow cytometry was used to quantify CD11b⁺ EdU⁺ cells (red box) from retina, choroid, and blood of Arr1^−/− mice. Black box indicates the number of CD11b⁺ not labeled with EdU. c CD11b⁺ EdU⁺ labeled cells were abundant in the retina at 24 and 48 h. In contrast, CD11b⁺ EdU⁺ cells in the choroid did not significantly increase until 48 h and even then were far more rare than in blood and retina. Blood samples were used to verify EdU incorporation and, as expected, showed a significant increase at 24 and 48 h. *p < 0.05, **p < 0.01, ***p < 0.001; error bars are SEM from 3 mice (blood) or 6 retina/choroid per time point