Efficient macrophage ablation in the mfrp retina. (A–D) mpeg1:NTR-eYFP expression in WT and mfrp–/– retina flat-mount preparations with and without MTZ treatment. (A'-D') Immune staining for 4C4 antibody marking macrophages. (A''–D'') Merged and colorized images of A–D', with blue representing 4C4 and yellow representing YFP. (A'''–D''') Higher magnification images of (A'') to (D''). (E, F) Cell counts of mpeg1:NTR-eYFP+ cells (E) or 4C4+ cells (F) in WT and mfrp–/– retina flat-mount preparations with and without MTZ treatment. Two-way ANOVA was used for statistical analysis. Sidak's multiple comparisons were used for post hoc analysis. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001. For WT untreated, n = 5; for WT MTZ treated, n = 2; for mfrp–/– untreated, n = 5; for mfrp–/– MTZ treated, n = 6.