Figure 5.

Stochastic simulation of the budding yeast cell cycle. (A) Time courses of some key regulatory proteins. (B) Cell-cycle trajectories (blue line) superimposed on the bifurcation diagram (Figure 2). Arrows show the direction of progress through the cell cycle and the abrupt jump from right to left indicates a cell-division event. A cell-cycle trajectory is the locus of [ClbM](t) (the blue line in panel A) versus V(t), plotted parametrically in time from cell birth to cell division. A newborn cell starts at the left end of a jump, and follows the blue trajectory until it reaches cell division, at the right end of the next jump. At each division, the newborn daughter cell receives 40% of the size of the dividing mother cell.