Fig. 4.

Divergence of apoptotic susceptibility. (A) The difference in time of apoptosis between cells from different generations. As the number of generations between cells increases, the curve flattens. (B) Analysis of the difference in DEVDase activation between cells from different generations and between unrelated cells (blue circles). Cells are fit to an exponential recovery curve (solid red line). Exponential fit is: y=42.5+43.2(1–e^{–(g–1)/1.94}) with y minutes, and g in generational difference between cells; R²=0.988 for the shown data points. Red dotted line is the asymptote of exponential recovery fit. Pink overlay is the error of the asymptote. (C) Difference in DEVDase activation between related cells (sister cells, green; cousin cells, red) as a function of time since cells shared a common ancestor. Recovering exponential fit (blue line), confidence interval of fit (yellow line) are plotted as well as individual time points from a 500 minute binning (black squares). Exponential fit is: y=5.8+68.5(1–e^–t/1256) with y and t in minutes; R²=0.122. (D) Difference in DEVDase activation between newly divided sister cells for different treatments with cycloheximide (see text). Relative to untreated cells, the difference is smaller for cells in CHX for 9 hours (P=0.0039). Error bars represent 95% confidence intervals.