Fig. 3: F-actin alignment parallel to the division plane correlates with furrow curvature.
a Snapshots showing the z-projection of confocal z-stacks below the furrow surface of post-deformed liposomes with the low (left), moderate (center), and high (right) furrow curvature. Furrow curvature\(\,{\kappa }_{{{{\rm{f}}}}}\) was calculated from midplane images. b Schematic showing the definition of the orientation order parameter parallel to the division plane. The local order parameter \({S}_{{||}}(x,y)\) is calculated from the neighboring four orientation directors, which takes 1 for parallel and -1 for perpendicular to the division plane. Mean order parameter \(\langle {S}_{{||}}\rangle\) was calculated by averaging \({S}_{{||}}(x,y)\) for all points within the image. c Snapshots showing the actin fluorescence image within the furrow (top) and corresponding \({S}_{{||}}(x,y)\) (bottom). d Snapshots showing the z-projection of confocal z-stacks below the furrow surface of post-deformed liposomes with cofilin (left) or Arp2/3 with His-VCA (right). The actin organization at the furrow and \({S}_{{||}}(x,y)\) are shown below. e Boxplot showing furrow curvature (n = 43 liposomes and N = 16 independent experiments in control; n = 28 and N = 5 in cofilin; n = 16 and N = 6 in Arp2/3). f Boxplot showing the mean order parameter (n = 43 liposomes and N = 16 independent experiments in control; n = 28 and N = 5 in cofilin; n = 16 and N = 6 in Arp2/3). g Scatter plot of furrow radius vs. mean order parameter (n = 43 liposomes and N = 16 independent experiments in control; n = 28 and N = 5 in cofilin; n = 16 and N = 6 in Arp2/3). The dashed lines are linear fitting to individual data. Cofilin, Arp2/3, and His-VCA were used at 0.15 µM, 18 nM, and 1.5 µM, respectively. Data are presented as boxplots where the interquartile range (IQR) is between Q1 (25th percentile) and Q3 (75th percentile), the center line indicates the median, whiskers are extended to Q3 + 1.5 × IQR and Q1 − 1.5 × IQR (e, f); *p < 0.05; **p < 0.01; ***p < 0.001 in a two-sided Wilcoxon rank sum test (e, f) or a two-sided Pearson’s linear correlation coefficient (g). n.s., not significant. Scale bars, 10 μm. Source data are provided as a Source Data file.
