Figure 1.

Sensitivity of microglial recombination induced in Cx3cr1^CreER:R26-tdTomato mice using different tamoxifen administration regimes. (A) A representative flow cytometric gating strategy used to identify microglia in a naïve retina based on CD45 and CD11b expression. (B) Representative deconvolved tdTomato fluorescent fundal images of mice with representative tdTomato histograms (unit area scaling) on gated microglia from various tamoxifen administration regimes. (C) Confocal microscopy from a 3-day topical regime naïve retina shows microglia with a physiological ramified morphology, suggesting no gross perturbations in the microglia as a consequence of the transgenic model. (D) Aggregate data demonstrating the percentage of microglia that were tdTomato^hi (as quantified by flow cytometry) shows that a 3- and 4-day topical, in addition to subcutaneous, regimes result in full microglial tagging (n = 3–6). None, no tamoxifen administered; 1D, 1-day topical tamoxifen regime; 2D, 2-days topical tamoxifen regime; 3D, 3-days topical tamoxifen regime; 4D, 4-days topical tamoxifen regime; Sc, subcutaneous tamoxifen regime. ^****p ≤ 0.0001, ns, not significant. Scale bar = 30 μm.