Fig. 3: Endothelial progenitors located in the central retinal vein within the optic nerve slowly supply endothelial cells under normal conditions.

a Schematic diagram of the strategy for tamoxifen administration and lineage tracing for Procr[CD201];CreERT2-tdTomato mice at indicated time points. b Flat-mount confocal microscopic analysis of retina and optic nerve for td-Tomato combined with CD31 and DAPI staining. The time course was examined for homeostatic condition at 2, 7, 14, 28 days post-tamoxifen injection (dpi) and 2 months post-injection (Mpi) in optic nerve, central retina and mid-peripheral retina of 8-week-old mice. Bar indicates 50 µm. c Quantification of tdTomato⁺CD31⁺ ECs in optic nerve, artery or vein and in the central and mid-peripheral retina at 2 (n = 5), 7 (n = 4), 14 (n = 4) and 28 (n = 4) days and 2 months (n = 6) post-tamoxifen injection. Data were from at least four mice for each tracing time point and lines are presented as median. Each image are from representative of at least two independent experiments. Significance was determined using a one-way ANOVA with Tukey’s multiple comparisons test. d Schematic illustration of the proposed tdTomato labeled cells migration from optic nerve.