Supplementary Figure 4: Nuclear H2B displacements influenced by stress directionality.
A different cell from that in Fig. 4. From left to right: bright-field images of the cell, GFP-Histone 2B fluorescence images, and displacement map images of the same murine melanoma B16 cell. Nucleus is outlined with a dashed line. The thick white arrows point to the bead; the red arrows indicate direction of the bead displacement; the color bar indicates the displacement magnitude. (a) No applied stress (non-magnetized); (b) Magnetizing in Z axis and apply a 15 Pa torque (0.1Hz) in Y axis bright-field images; (c) Magnetizing in Z axis and apply a 15 Pa torque (0.1 Hz) in X axis bright-field images; (d) Magnetizing along Z axis and apply a 9 Pa along X axis and 12 Pa along Y axis (the resultant stress is 15 Pa and stress angle is 36.9°). (e) Magnetizing along Z axis and apply a 10.6 Pa along X axis and 10.6 Pa along Y axis (the resultant stress is 15 Pa and stress angle is 45°). (f) Magnetizing along Z axis and apply a 12 Pa along X axis and 9 Pa along Y axis (the resultant stress is 15 Pa and stress angle is 53.1°). The white square in each displacement map is enlarged and presented on the right (the 4th image in each row) to show the differences of the displacements between each loading direction (a-f) at the same loading magnitude. It is apparent that stress angles (loading directions) are important in resulting major differences in GFP-H2B displacements. The thin white arrow (150 nm) provides a scale for the magnitudes of the red arrows. Image acquisition time is 1 second per image. Scale bars, 7.5 μm. (g) Computed cell stiffnesses (complex moduli) for this cell at different forcing directions.at different forcing directions.
