Loss of F10 results in late-onset hemorrhage at multiple sites. (A) Grossly visible hemorrhaging occurred in f10^−/− mutant fish as early as 27 dpf, but not in wild-type or heterozygous siblings. Massive hemorrhages were observed in the brain, muscle, gill filaments, and abdomen as shown in viable f10^−/− mutants. (B) Hematoxylin and eosin stained histologic sections of f10^−/− mutants confirmed substantial intracranial, abdominal, and intramuscular hemorrhage at 27 dpf. Arrows indicate sites of hemorrhage. Locations of magnified insets (×4) are indicated by the smaller boxes in the same panel. Anterior is toward the left, and dorsal is toward the top. Scale bar, 100 µm. ad, abdomen; fb, forebrain; gf, gill filament; hb, hindbrain; mb, midbrain.