Before revision: The sizes in a population of genetically identical Escherichia coli cells is known to vary, independent of growth stage. Multiple genes and proteins involved in cell division and DNA segregation are involved in regulating cell size. At the same time, physical factors such as temperature, growth rate and population size also appear to affect cell sizes. How these physical factors interact with the genetically encoded ones to produce such effects is however not clearly understood .
After revision: The sizes in a population of genetically identical Escherichia coli variability in cell size of an isogenic population of Escherichia coli has been widely reported in experiment. The probability density function (PDF) of cell lengths has been variously described by exponential and lognormal functions. While temperature, population density and growth rate have all been shown to affect E. coli cell size distributions, and recent models have validated a link between growth rate and cell size through DNA replication, cell size variability is thought to emerge from growth rate variability. A mechanistic link that could distinguish the source of stochasticity, could improve our understanding of cell size regulation .