Fig. 6. The division plane forms between the MT band and nucleus.

a Time-lapse images of wild-type (WT) zygote expressing MT (green)/nuclear (magenta) markers. Enlarged images from Fig. 1a are shown. PPB (yellow rectangle) forms below the MT band (white rectangle) and above the nucleus (cyan arrowhead). Cell division plane (yellow arrowhead) forms between the PPB and nucleus as shown by the dashed lines. b Boxplot showing center positions of the indicated structures. MT band and PPB are shown with the nucleus at the same time points. Significant differences for each structure relative to the cell division plane, and for the MT band and nucleus relative to PPB, were determined by Wilcoxon’s signed rank test (n = 13). n.s., not significant; *P < 0.05 and **P < 0.01. “Division plane” samples correspond to “none” in Fig. 2m. c Time-lapse images of Sgr2 zygote. Upper and lower panels show MIP and midplane images, respectively. A spherical vacuole (Vac) occupying the zygote tip prevents the nucleus from reaching the tip. Cell division plane forms at the nuclear position (Supplementary Movie 11). d Boxplot showing the ratio of apical to basal cell length. Significant difference was detected by two-sided Student’s t-test (**P = 0.00166; n = 14 and 18 for WT and sgr2, respectively). WT zygotes correspond to “none” in Fig. 2m. e, f Time-lapse images of WT (e) and trm678 (f) zygotes, expressing MT(SG)/nucleus markers. WT shows dynamics similar to (a). trm678 lacks a PPB, and cell division plane forms at the nuclear position (Supplementary Movie 12). Images are representative of 18, 21, and 24 samples for sgr2, WT, and trm678, respectively. g Boxplot showing the ratio of apical to basal cell length. Significant difference was detected by a two-sided Brunner-Munzel test (**P = 2.21 × 10⁻⁹; n = 21 and 24 for WT and trm678, respectively). For all boxplots, the center line, median, box limits, upper and lower quartiles, whiskers, maximum and minimum points within 1.5 × the interquartile range from the box limits. Individual data points are also shown. Scale bars: 10 μm. Source data are provided as a Source Data file.