Histological analysis of 96 hpf larvae from DU-exposed adult fish compared to controls.

(A-A’) Toluidine-blue staining of the larva at the level of the trunk. Vacuole-like structures (appearing as white dots) are abundant in DU-treated larvae compared to controls. (B-C) Mitochondrial morphology in skeletal muscles observed by transmission electronic microscopy of control larvae. The inner mitochondrial membranes are dense and well visible (black arrow head). (B’-C’) Alteration of mitochondrial morphology and absence or decreases density of inner mitochondrial membranes (*) in larvae from DU-exposed fish. (D-E) High-resolution transmission electronic microscopy of skeletal muscles in controls and (D’-E’) in the 96 hpf larvae obtained from DU-exposed fish. Disruption of myofibres (red asterisks) and swelling of Z-bands are visible in DU larvae. Z- and A-bands are indicated. Triads constituted of t-tubes and the two flanking cisterna of the sarcoplasmic reticulum are visible in the controls (black arrows) but are absent or deformed in larvae from DU-treated fish (red arrows).