Prolonged il1b expression and apoptosis are induced by macrophage loss during fin fold regeneration.
(A) ISH analysis of il1b expression in spi1b, csf3r, and irf8 morphants. The spi1b and irf8 morphants displayed prolonged il1b expression at 6 hpa. Scale bar, 50 μm. (B) Quantification of il1b expression detected using ISH analysis in (A). The level of il1b expression was evaluated as in Figure 1D. Data are the sum of two experiments (total n > 16 for each MO). (C) TUNEL analysis of the amputated fin fold at 12 hpa after il1b knockdown or Dex treatment in larvae in which macrophages were depleted using the spi1b or irf8 MO. Scale bar, 100 μm. Apoptosis caused by spi1b and irf8 MOs was rescued by il1b MO administration or Dex treatment. (D) Quantification of TUNEL staining in the spi1b morphants (C; bracketed areas). (E) Quantification of TUNEL staining in the irf8 morphants in (C). In (D) and (E), data are presented as means ± SEM. Student’s t test, ***p<0.001.