(A) Distribution of Pom1 in wild type, wee1-50, and cdc25-22 mutant cells. Each strain expressed Pom1-GFP and Blt1-mCherry-Sad1-RFP from their native loci. Each panel has two parts: (left) sum projected confocal images of 15 Z-slices of wild-type cells taken at different phases of the life cycle abbreviated as LG (late G2), GM (G2/M), AP (anaphase), CS (constriction), SP (separation), and NT (new end take off); and (right) time series of plots of the average intensity of Pom1-GFP fluorescence along the length of the cells. Scale bar 3 µm. (Top panel) wee1-50 grown at 36°C and imaged at 22°C. (Second panel) Wild-type cells were grown at 25°C and imaged at 22°C. (Third panel) cdc25-22 mutant cells grown at 25°C and imaged at 22°C. (Bottom panel) cdc25-22 mutant cells grown at 36°C for 4 hr before imaging at 22°C. (B) Distributions of Pom1 and Blt1 in cells at the G2/M transition measured by confocal microscopy of wild-type and four mutant strains. Cells were grown at 25°C and imaged at 22°C: (, n = 9 cells) WT, (, n = 7 cells) wee1-50, (, n = 8 cells) cdc25-22, (, n = 9 cells) rga2Δ and (, n = 9 cells) rga4Δ mutant cells. Lines are fluorescence intensities of Blt1-mCherry-Sad1-RFP (magenta) and Pom1-GFP (green) across the full width of the cells and along the lengths of the cells. (C, D) Relationships between cell length and average Blt1-mCherry intensity on the plasma membrane of broad band with average Pom1-mEGFP intensity on the plasma membrane of broad band in five strains in (B). All measurements for each strain are collected in one bin except for () cdc25-22 cells, which are divided into two length bins: 30–36 µm, n = 12 cells; 36–45 µm, n = 22 cells. The transparent symbols are measurements of individual cells. The solid symbols are the mean numbers of node parameters. The vertical error bars show the SD of the mean numbers and the horizontal error bars the standard deviation (SD) of the lengths. (C) Average Pom1-mEGFP intensity per pixel along the plasma membrane across the broad band of nodes in the middle focal plane of the cells as a function of the lengths of the cells. The inset shows the rectangle three pixels wide and the length of the broad band of nodes used to make the measurements. The slope of the linear regression (black dotted line) is not significantly different from zero (p = 0.07; R2 = 0.03). (D) Graph of the average Pom1-mEGFP intensity per pixel versus the average Blt1-mCherry intensity per pixel along the plasma membrane in the middle focal plane of the cells (as in the inset of panel C). The slope of the linear regression (black dotted line) is not significantly different from zero (p = 0.13; R2 = 0.02).