Fig. 1

Figure 1. Macrophages are necessary for ? cell loss in the setting of overnutrition (A) Schematic of the feeding regimen. Each day, fish were cultured for 8 h in nutrient-rich medium (5% chicken egg yolk) and for 16 h in nutrient-free medium, as indicated by the green and white rectangles, respectively. The 8-h culture in nutrient-rich medium is referred to as an overnutrition session. Time 0 starts at the onset of the first overnutrition 6 days post fertilization. (B) Detailed ?-cell number dynamics during the 16 h of nutrient-free medium culture from 56?72 h (n > 15/time point). Data are mean ± SEM. Multiple t tests were performed within the fed and unfed groups. ?p < 0.05, ??p < 0.01, ???p < 0.001. (C) Macrophages in irf8?/? fish (bottom) and control (top). Scale bars, 200 ?m. (D) Effect of genetic deficiency of macrophages (irf8?/?) on ? cell number. Data are mean ± SEM. n > 15/group, two-way ANOVA followed by Tukey?s multiple comparisons test; ns, not significant; ???p < 0.001. (E) Effect of clodronate liposomes (bottom) and empty liposomes (top) on macrophages. A green signal from Tg(mpeg1:EGFP) marks macrophages. A red signal from Tg(ins:H2B-mcherry) labels ? cells. Liposomes were injected at 32 hpt, and fish were imaged at 64 hpt. Scale bars, 300 ?m; scale bars within panels, 50 ?m. See also Figure S1D. (F) Effect of clodronate liposomes on ? cell loss in zMIR fish. Data are mean ± SEM. n > 20/group, two-way ANOVA followed by Tukey?s multiple comparisons test; ???p < 0.001. (G) Effect of metronidazole (MTZ) and DMSO on macrophages in zMIR fish with Tg(mpeg1:NTR-mcherry). Scale bars, 300 ?m; scale bars within panels, 50 ?m. See also Figure S1F. (H) Effect of macrophage ablation by MTZ on ? cell loss. Data are mean ± SEM. n > 15/group, two-way ANOVA followed by Tukey?s multiple comparisons test; ??p < 0.01, ???p < 0.001.