Fig. 2: Sarcomere structures of C2−/− (red / triangles) and NTG fibers (black / squares).
a A representative image of an X-ray diffraction pattern, with reflections of interest labeled. The area around the equatorial axis was scaled differently to make reflections easier to view. b A cross-section of a myofibril in the thick (gray) and thin (red) filament overlap zone. Example myosin thick-thin filament crossbridges drawn (dotted lines). Overlayed are the geometric lattice planes d1,0 and d1,1, which lead to the 1,0 and 1,0 equatorial intensities, respectively. c d10 spacing quantifies lattice spacing. d σD quantifies lattice spacing heterogeneity. e I1,1/I1,0 is a measure of mass distribution (i.e., myosin heads) between thick and thin filaments. f SM3 is the periodicity between myosin heads along the thick filament and indicates myosin head orientation. g SM6 is from a periodicity along the thick filament and quantifies the average thick filament length. h √IM3 is proportional to the electron density creating the reflection and can be interpreted as quantifying the orderness of myosin heads along the thick filament. i A cartoon representation of the thin filament, with periodicities of interest labeled. j ST3 is the (third-order) axial periodicity of troponin. k SA6 is the axial periodicity of the left-handed helix of actin and indicates thin filament twisting and elongation. Statistical results are presented as a connecting letters report, where different letters are statistically different (P < 0.05). Data reported as mean ± s.e.m., contain n = 7–14, and were evaluated with a mixed-model ANOVA followed by a Tukey’s HSD post hoc test on significant main effects. Full statistical details are provided in Table 2. Structural data presented as normalized to 2.4 µm SL is shown in Supplemental Fig. 2.
