Analysis of cell division of the primordia. (a) Plot of the orientation and the localization of cell division in control and N RNAi and CycE RNAi. Each white line indicates one dividing cell. Direction of white line shows the orientation of cell division at that point. Yellow circles show the area of high intensity of Hoechst fluorescence. (b) The area of measured cell division. Five regions were determined by using a pair of characteristic crescent shape furrows as landmarks. This furrow stably formed as the first furrow in all of the analyzed primordia (Supplementary Figure S10). (c) Plot of the percentage of the orientation of cell division in five areas of the primordia. Significant change of cell division orientation was not detected (n = 5, for negative control). The results for RNAi are shown in Supplementary Figure S9. (d) Quantification of frequency of cell division in five areas of the primordia. In control and N RNAi, the frequency of mitosis in the right and left parts were twice as high as in the other parts. N RNAi decreased the number of cell divisions in all areas of the primordia. CycE RNAi decreased cell division only in both of the side areas of the primordia. Single asterisk (*) indicates significant (P < 0.05) difference between the primordia areas in each RNAi treatment. Double asterisk (**) indicates the statistical significance comparing the same area of primordia between N or CycE RNAi and negative controls (n = 5, 4, 5 for negative control, N RNAi, CycE RNAi, respectively). Scale bar indicates 1 mm for (a).