Unusual characteristics of the Wdr1-deficient neutrophil nucleus. (A) Hoechst staining of Tg(lyz:DsRed) embryos reveals that unlike WT, mutant neutrophils display a multiglobular nucleus. (B) Time-lapse imaging of Lyz:H2b-mCherry in Tg(mpx:GFP) mutant embryos documents a striking, continuous unraveling of the chromatin of neutrophils over the course of 9 h, after which chromatin rapidly condenses in several clumps and the cell erupts; see also Videos 4, 5, and 6. (C) TUNEL staining of mutant versus WT GFP⁺ neutrophils by 54 hpf. The second row shows a mutant neutrophil with an already deformed nucleus, but no TUNEL staining, nor GFP depletion from the nucleus (n = 6). 25% of mutant neutrophils are TUNEL⁺ by then; the third and fourth rows show an example (two confocal planes of the same neutrophil); in this case, the nucleus appears multiglobular. Each globule is TUNEL⁺ and also displays enhanced Hoechst staining due to DNA condensation and GFP depletion relative to the cytoplasm (arrow; n = 24). Scale bars, 10 µm.