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Fig. 7 Microglial ablation after brain injury attenuates pro-regenerative signaling. (a) qRT-PCR showing relative mRNA levels of different inflammatory cytokines or regenerative signaling molecules. Two pooled hemi-telencephala (injured side) per condition (clodronate-treated vs. control lesioned) were used, and the Y axis is log fold change. (b–e) Post-injury qRT-PCR timecourse analysis of gene expression for stat3 (b), ascl1a (C) c-myc (d) or gata3 (e) in injured hemi-telencephala from fish receiving control or clodronate liposomes, or in irf8+/− (control), irf8−/− and csf1rDM mutant brains. (f) GFP labeling of telencephala from a pStat3 signaling reporter line at 2 dpl after control or clodronate liposome injections. The boxed areas in the left panels are shown at higher magnification at right. (g) Quantification of corrected GFP fluorescence intensity of right (injured) telencephala from tg(gfap:GFP), tg(stat3-GFP), tg(ascl1a:GFP), and tg(tcf7miniP:dGFP) reporter fish at 2 dpl after clodronate injury compared to controls. (h) EdU labeling of control and clodronate injected brains at 2 dpl with or without heat shock (HS) to induce stat3 and ß-catenin transgene expression. (i) Quantification of EdU+ cells at 2 dpl after ectopic activation of stat3, ascl1a, ß-catenin, and stat3 + ß-catenin with or without HS treatment in control and clodronate injured fish. The schematic above shows the experimental design. (j) Quantification of cells double-labeled for Gfap/EdU or Sox2/EdU in brains from the double transgenic stat3 and constitutively active-beta-catenin (ca-bcatenin) overexpression fish with control and clodronate injury, and with and without heat shock (HS). NS, not significant; ***p < .0001; **p < .001; *p < .01 by ANOVA with Tukey's post-hoc test in (c, g, i, and j). Scale bars = 100 μm for image panels, and error bars indicate SD.