Abstract
Various bacteria such as the canonical gram negative Escherichia coli or the well-studied gram positive Bacillus subtilis divide symmetrically after they approximately double their volume. Their size at division is not constant, but is typically distributed over a narrow range. Here, we propose an analytically tractable model for cell size control, and calculate the cell size and interdivision time distributions, as well as the correlations between these variables. We suggest ways of extracting the model parameters from experimental data, and show that existing data for E. coli supports partial size control, and a particular explanation: a cell attempts to add a constant volume from the time of initiation of DNA replication to the next initiation event. This hypothesis accounts for the experimentally observed correlations between mother and daughter cells as well as the exponential dependence of size on growth rate.
- Received 23 December 2013
DOI:https://doi.org/10.1103/PhysRevLett.112.208102
© 2014 American Physical Society
Focus
How Bacteria Keep Track of their Size
Published 23 May 2014
A new theory suggests that bacterial cells regulate their size by directly measuring their increase in volume during growth.
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