Can we analytically predict cell population properties based on single-cell properties?

Abstract

Many bacterial cells like Escherichia coli grow exponentially in size and divide symmetrically. The division time and exponential growth rate are not constant. Fluctuations in these single-cell properties affect the properties of populations of cells, such as the growth rate of the number of cells and the distribution of cell ages and sizes within a population. This paper is about finding the relations between single-cell behaviour and cell population properties. There is an existing single-cell behaviour model that comes short when describing the right correlations between growth rates of mother cells and daughter cells. We devise a new model that models bacterial growth rate in a way that is much more faithful to experimental data. We analytically derive population properties for this new model as well as for the existing model. This includes an analytical cell size distribution, something which up until this point has only been derived for a very simplistic single-cell division model.