Wdr1 deficiency leads to the accumulation of F-actin in the carmin mutant. (A) F-Actin (green) and neutrophils (red) in the tail of Wdr1^carmin versus Wdr⁺ sibling embryos (dorsal up and rostral to the right); arrows point at cortical/subcortical F-actin aggregates in epidermal cells of the caudal fin in mutant embryos. (B) F-Actin in neutrophils. In WT neutrophils, F-actin is observed diffuse in the cytoplasm and delineating the cell cortex, whereas in the mutant it accumulates as intracytoplasmic clumps. (C) Time-lapse confocal imaging of Tg(mpx:GFP) carmin and WT sibling embryos injected with a mpx:Lifeact-ruby plasmid also reveal intense and only slowly remodeling F-actin clumps in the mutant neutrophils; time is indicated in h:min:s (see also Video 2). Scale bars, 100 µm (A) and 10 µm (B and C).