Fig. 3. Troponin T (TnT) expression in a representative rainbow trout. Red muscle TnT isoforms can be identified based on size using a silver-stained PAGE gel (Top). Lanes 1 and 9 contain purified TnT. Lanes 2 to 8 contain purified myofibrils from 25, 35, 45, 55, 65, 75 and 85% of total length from the snout. TnT isoforms can be identified in these samples based on band position relative to standards (Std.). The relative expression levels (as indicated by staining intensity) for the lower band (TnT S2) decrease from anterior to posterior of the fish. A sample densitometry profile is shown at the bottom with two peaks that correspond to the two TnT isoforms.