Gal3 expressed by subretinal microglia is central in restricting disease progression in acute, genetic, and aging mouse models of retinal degeneration. (A) Images of phalloidin staining in WT and Lgals3−/− RPE tissues in LD. (B) Quantifications of dysmorphic RPE cells (n = 6, 7, and 3, respectively). (C) TUNEL (green) and DAPI (blue) staining in WT and Lgals3−/− retinal cross-sections in LD. INL, inner nuclear layer. (D) Quantifications of TUNEL+ photoreceptors in ONL (n = 5, 5, and 3, respectively). (E) Rhodopsin (red) and Iba1 (green) staining in WT and Lgals3−/− retinal cross-sections in LD. Images from single planes of confocal scans were shown. (F) Quantifications of rhodopsin+ subretinal microglia (n = 4 per group). (G) Images of phalloidin staining in WT and Lgals3−/− RPE tissues at 2 years (2y) of age. (H) Quantifications of RPE cell size. Dots represent individual images with n = 5 mice per group. (I) ERG data showing scotopic a- and b-waves in 2-year-old WT (n = 5) and Lgals3−/− (n = 5) mice. (J) Scotopic a- and b-waves of ERG data among Lgals3+/+ (n = 12), Lgals3+/− (n = 6), and Lgals3−/− (n = 10) in P23H mice. (K) Quantifications of ONL thickness among Lgals3+/+ (n = 7), Lgals3+/− (n = 7), and Lgals3−/− (n = 8) in P23H mice. (L) Representative images of dysmorphic RPE cells in Gal3 cKO in LD. Iba1, green; phalloidin, red; Gal3, magenta. (M) Quantifications of dysmorphic RPE cells in Gal3 cKO mice (n = 9) compared with genotype control (Cx3cr1CreER/+Lgals3fl/fl mice, n = 9) and tamoxifen control (Cx3cr1CreER/+ mice treated with tamoxifen, n = 8). Scale bars: 100 μm. Data were collected from two to three independent experiments. *: P < 0.05; **: P < 0.01; ***: P < 0.001; ****: P < 0.0001. One-way ANOVA with Tukey’s post hoc test (B, D, and M); unpaired Student’s t test (F and H); two-way ANOVA with Tukey’s post hoc test (I, J, and K).