ODE, RDE and SDE models of cell cycle dynamics and clustering in yeast

Area of Science:

• Cell Biology
• Biophysics
• Mathematical Biology

Background:

• Periodic oxygen consumption oscillations are observed in yeast populations under specific conditions.
• Previous explanations for these autonomous oscillations, often with periods near integer divisors of the doubling time, have been unsatisfactory.
• These oscillations suggest an underlying synchronization mechanism within the yeast cell cycle.

Purpose of the Study:

• To investigate cell cycle synchronization, termed 'clustering', as a cause for periodic oxygen consumption oscillations in yeast.
• To develop and analyze mathematical models demonstrating the feasibility of clustering.
• To provide a robust explanation for observed autonomous oscillations in yeast populations.

Main Methods:

• Development of novel ordinary differential equation models for the yeast cell cycle.
• Analysis of models using rigorous mathematical proofs and computational simulations.
• Inclusion of random and stochastic perturbations to assess model robustness.

Main Results:

• Demonstrated that both positive and negative growth rate feedback within the cell cycle can induce population clustering.
• Showed that clustering occurs across a variety of models and a broad range of parameter values, indicating robustness.
• Confirmed that clustering leads to periodic-like behavior with periods that are nearly integer divisors of the cell cycle period.

Conclusions:

• Cell cycle clustering is a robust phenomenon capable of generating the observed periodic oxygen consumption oscillations in yeast.
• The integer nature of clusters naturally explains the observed periodicity relative to the cell cycle.
• Experimental evidence supports the occurrence of cell cycle clustering in oscillating yeast cultures.