Mode locking the cell cycle.

A characteristic property of nonlinear oscillatory systems is their ability to mode lock to a periodic, external, driving signal. In an n:m mode-locked state, the driven system executes n oscillations to every m oscillations of the driving signal, with a constant phase relationship between the two oscillations. We investigate mode locking for a mathematical model of the cell cycle in budding yeast. We determine which variables are most effective in coupling an external stimulus to the cell cycle oscillator, and speculate about whether experiments are feasible and informative for this model organism.