Testing of a potential mechanism for E. coli temporal cycle imprecision with a structural model.

Area of Science:

• Microbiology
• Cell Biology
• Computational Biology

Background:

• Cell cycle temporal imprecision is a known phenomenon in microbial populations.
• Understanding the sources of variation is crucial for predicting population dynamics.
• Previous models have not fully explained the observed variability in cell cycle duration.

Purpose of the Study:

• To test a novel mechanism for cell cycle temporal imprecision in E. coli B/r-A.
• To investigate the role of septation enzyme activity variations in cell cycle variability.
• To determine if D period fluctuations are the primary driver of cell cycle variations.

Main Methods:

• Development and utilization of a structured mathematical model for E. coli B/r-A.
• Incorporation of variable septation enzyme activity into the model.
• Analysis of model outputs, including predicted ratios of cell doubling time and fission size coefficients of variation, and parent-offspring cycle time correlations.

Main Results:

• The model successfully predicted a ratio of cell doubling time to fission size coefficient of variations that agreed with reported experimental data.
• The model also predicted a negative correlation between parent-offspring cycle times, consistent with empirical observations.
• Chromosome replication timing was found to be largely unaffected by the simulated variations in septation enzyme activity.

Conclusions:

• Fluctuations in septation enzyme activity during the D period are a likely primary source of cell cycle temporal imprecision in E. coli.
• The proposed mechanism provides a consistent explanation for observed cell cycle variations.
• This finding contributes to a deeper understanding of bacterial cell cycle regulation and variability.