Myonecrosis due to infection of Penaeus vannamei with purified virions.

(a) Coagulative necrosis of skeletal muscle accompanied by haemocytic infiltration and fibrosis. As a reference, normal skeletal muscle can be observed in the upper right corner. H&E stain; bar, 50 μm.

(b) Perinuclear pale basophilic to dark basophilic inclusion bodies are evident in this group of muscle cells (arrows point at some examples). H&E stain; bar, 20 μm.

(c) In situ hybridisation of skeletal muscle tissue using a digoxigenin-labelled infectious myonecrosis virus probe. A black precipitate is present in areas where the probe has hybridised with target virus. Bismarck brown counterstain; bar, 50 μm.
Source: DV Lightner