Fig. 4.
PGAL1-WHI5 cells retain size control during the G1 phase, in addition to weak size control in the budded portion of the cell cycle. (A–C) Cell-cycle correlations for daughter cells. See Fig. 3 for details on plotting features for A–C. Data are compiled from three experiments for each cell type with a total of 347 PGAL1-WHI5 daughters, 800 PGAL1-WHI5 mothers, 853 PWHI5-WHI5 daughters and 1,581 PWHI5-WHI5 mothers. (A) Plot of time spent in G1 phase (determined by nuclear localization of Whi5) vs. cell volume at birth (Vb) for PGAL1-WHI5 and PWHI5-WHI5 cells. (B) Plot of time spent in the budded phases (the sum of S-phase, G2, and mitosis, determined by nuclear exclusion of Whi5) vs. cell volume at Start (Vs) for PGAL1-WHI5 and PWHI5-WHI5 cells. (C) Plot of Vb vs. volume at division (Vd). (D–F) PCCs measured for the datasets plotted in A–C. Error bars show 95% confidence intervals inferred by bootstrapping analysis. Black lines correspond to statistically significant differences with P values less than 0.05 quoted, calculated using a Fisher’s z-transformation on both datasets. (D) PCC values for G1 duration vs. Vb for daughter cells show a statistically significant difference between cell types (P = 0.02). This difference is consistent with stronger size control occurring during the G1 phase for PGAL1-WHI5 cells, not weaker as would be predicted by the inhibitor dilution model. (E) PCC values for budded duration measured at birth vs. Vb for daughter cells shows a statistically significant difference between the two cell types with P = 0.001. This difference corresponds to the presence of weak size control during the budded portion of the cell cycle. (F) PCC values for Vb vs. Vd for daughter cells show no statistically significant difference between the two cell types.