Modeling cell size regulation: From single-cell level statistics to molecular mechanisms and population level effects

Most microorganisms regulate their cell size. We review here some of the mathematical formulations of the problem of cell size regulation. We focus on coarse-grained stochastic models and the statistics they generate. We review the biologically relevant insights obtained from these models. We then describe cell cycle regulation and their molecular implementations, protein number regulation, and population growth, all in relation to size regulation. Finally, we discuss several future directions for developing understanding beyond phenomenological models of cell size regulation.