Figure 1:
Age-Associated Changes in Cardiac Nuclear Morphology and Mechanics. (A) Schematic of ventral Drosophila body plan with the heart tube in the abdomen highlighted in blue. Expanded view of the heart tube shows a coronal (XY) confocal section through the heart tube (center) as well as a transverse (XZ) confocal section and schematic to highlight nuclear position in the luminal space (right). Asterisks indicate cardiomyocyte nuclei. Scale bar is 20 μm. (B) Images of w1118 fly nuclei (left) and plot of their corresponding 2D projection data (right). Scale bar is 5 μm. n = 96, 116, and 141 nuclei for 1- , 3-, and 5-week adults, respectively. The brightness of the LaminB staining was autoscaled to highlight nuclear edge and not to represent local protein concentration. (C) 3D renderings of cardiac nuclei (left) and their corresponding for volume and surface area. n = 27, 37, and 34 nuclei for 1- , 3-, and 5-week adult w1118 flies respectively. (D) Atomic force microscopy (AFM) nuclear indentation schematic (top) and plot of stiffness values, i.e., Young’s modulus, for nuclei of w1118 flies (bottom). n = 35 and 28 nuclei for 1- and 5-week adults, respectively. **p<10−2 and ****p<10−4 by one-way ANOVA with Tukey multiple comparisons test in (B-C) and two-sided unpaired t-test with Welch’s correction in (D). Error bars in (B-C) refer to mean +/− SD, and in (D) show min to max, with median and 25th and 75th interquartile range.