@article {Amir004457, author = {Ariel Amir}, title = {Cell size regulation in bacteria}, elocation-id = {004457}, year = {2014}, doi = {10.1101/004457}, publisher = {Cold Spring Harbor Laboratory}, abstract = {Various rod-shaped 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 inter-division time distributions, and 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. Our results rule out the wide-spread notion of a critical volume or mass governing cell division, and yet explain the observation that initiation of DNA replication occurs (on average) at a growth-rate independent volume per replication fork, and the related exponential dependence of cell size on growth rate.PACS numbers: 87.17.Ee, 87.17.Aa, 87.10.Mn, 87.18.Tt}, URL = {https://www.biorxiv.org/content/early/2014/04/23/004457}, eprint = {https://www.biorxiv.org/content/early/2014/04/23/004457.full.pdf}, journal = {bioRxiv} }