FIGURE 3.

Predicted force-SL relation of WT and NEB KO TC fibers. We assumed a thick filament length of 1.6 μm and a bare zone width of 0.15 μm. WT fibers had a thin filament length of 1.2 μm (measured from the mid-Z-disk to edge of H-zone). For NEB KO, we constructed eight predicted F-SL relations with thin filaments that were 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, or 1.2 μm (covering the full range that we measured (11)), and from these eight relations we determined the average relation (see thick curve labeled KO). (Notice that averaging the eight relations assumes that thin filament length is uniformly distributed from 0.5 to 1.2 μm, which is consistent with our previous measurements (11).) The WT and average NEB KO curves intersect at the SL used in this study (2.0 μm).