Adaptation in GAL1-MAD2.

<b>A)</b> Left panel: Cumulative distribution of length of mitotic arrest in wild-type or Mad2-overepressing cells. Cells growing in YPRG are arrested in G1 and released in nocodazole, indefinitely. Cells carry Mad2-GFP to record checkpoint activation status, and Clb2-mCherry to record both mitotic entry (Clb2 rise time) and mitotic exit (Clb2 degradation time). Mitotic arrest is defined as the difference between mitotic exit and mitotic entry. Central panel: barplots with the percentages of the different classes of Clb2 behavior in wild-type or <i>GAL1-Mad2</i> cells arrested indefinitely in nocodazole. For the definition of the cell classes see <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1012879#pcbi.1012879.s002" target="_blank">S2A Fig</a>. Right panel: cumulative distribution of APC/C activation time for the simulated data. Adaptation is defined as APC/C crossing the activation threshold with at least one unattached kinetochore. Reactions in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1012879#pcbi.1012879.t003" target="_blank">Table 3</a>, parameters in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1012879#pcbi.1012879.t002" target="_blank">Table 2</a>, initial conditions in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1012879#pcbi.1012879.t001" target="_blank">Table 1</a> (checkpoint ON). <b>B)</b> Bifurcation diagrams of wild type cells (same as in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1012879#pcbi.1012879.g001" target="_blank">Fig 1C</a>) and <i>GAL1-MAD2</i> mutant. Expression level of Mad2 is increased to 125% compare to WT. In <i>GAL1-MAD2</i>, the saddle node bifurcation is located at 0.4 unattached kinetochores. Equations in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1012879#pcbi.1012879.s010" target="_blank">S1 Text</a>, and parameters in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1012879#pcbi.1012879.t002" target="_blank">Table 2</a>. <b>C</b>) Example of an arrested cell taken from a movie of cells growing in YPRG, arrested in G1 and released in nocodazole for 180 minutes, when nocodazole is removed from the media. Cells carry the tetR-GFP/tetO construct to keep track of chrV segregation, and Htb2-mCherry to score nuclear division time. Definition of nuclear division time is presented in the Image analysis section of the Materials and Methods. <b>D</b>) Example of a cell correctly segregating chrV. In the lowest row, yellow and orange traces are cells segmentations, while red crosses mark the position of chrV. In the second column is the frame when nuclear division is registered. Definitions of correct or wrong segregation are presented in the Image analysis section of the Materials and Methods. <b>E)</b> Example of a cell missegregating chrV. Details in panel <b>(C)</b>. <b>F</b>) Percentage of cells that divide nuclei. Cells growing in YPRG are arrested in G1 and released in nocodazole for 180 minutes, when nocodazole is removed from the media. Cells carry the tetR-GFP/tetO construct to keep track of chrV segregation, and Htb2-mCherry to score nuclear division time. <b>G)</b> Percentage of cells that missegregate chromosome V. Here, 100% means the cells that divide nuclei as shown in panel <b>F</b>. Data for wild-type and <i>GAL1-MAD2</i> cells are presented also in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1012879#pcbi.1012879.g005" target="_blank">Fig 5E</a>. For statistical comparisons we used an exact Fisher test, where the contingency table has wild-type or mutant cells versus correct or wrong segregation of chrV (p-values: 5 10^-3 for APC-A, 1.3 10^-4 for GAL-MAD2). <b>H)</b> Scatter plot of missegregation rate (from panel G) and adaptation rate (<a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1012879#pcbi.1012879.g003" target="_blank">Fig 3A</a> for WT and <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1012879#pcbi.1012879.g004" target="_blank">Fig 4B</a> for APC-A). The red curve represents the probability P of having at least one missegregation event. It is computed as 1-(1-p)¹⁶, where p is the probability of missegregating one chromosome, under the assumption that all chromosomes share the same probability of missegregation. (PDF)