Stable stochastic dynamics in yeast cell cycle

TL;DR

This paper presents a stochastic model of the yeast cell cycle demonstrating how the cell maintains stable oscillations despite intense molecular noise, highlighting the role of fixed points in stability.

Contribution

The paper introduces a novel stochastic model that explains the stability of the yeast cell cycle amidst molecular noise, emphasizing fixed points as key to this robustness.

Findings

Protein and mRNA noise levels are intense but do not disrupt cell cycle oscillations.

Simulated noise levels match observed statistical tendencies in cell populations.

Fixed points in the model underpin the stability of the cell cycle despite perturbations.

Abstract

Chemical reactions in cell are subject to intense stochastic fluctuations. An important question is how the fundamental physiological behavior of cell is kept stable against those noisy perturbations. In this paper a stochastic model of cell cycle of budding yeast is constructed to analyze the effects of noise on the cell cycle oscillation. The model predicts intense noise in levels of mRNAs and proteins, and the simulated protein levels explain the observed statistical tendency of noise in populations of synchronous and asynchronous cells. In spite of intense noise in levels of proteins and mRNAs, cell cycle is stable enough to bring the largely perturbed cells back to the physiological cyclic oscillation. The model shows that consecutively appearing fixed points are the origin of this stability of cell cycle.