Simple and superlattice models. (A) Simple (left) and superlattice (right) models of transverse sections of thick filament bare regions in electron micrographs. (B) Sampling of intensity on myosin layer lines of x-ray diffraction pattern. 10, 11, etc. show positions of reflections on equator. 43.0, 21.5, and 14.3 nm show positions of first, second, and third myosin layer lines. In the simple lattice, note alignment of layer line sampled spots with corresponding equatorial reflections; in the case of the superlattice, the sampling is more complex. Based on Luther et al. (1996) and Harford and Squire (1986), with permission.