The Coordination of Cell Growth and Division: A Comparison of Models

Abstract

During steady-state, balanced exponential growth of cells in culture, all extensive properties of the culture increase exponentially at the same specific growth rate, k. That is,

$$ G(t) = {G_0}{e^{{kt}}} $$

where G = total content of DNA, RNA, protein, lipids, polysaccharides, etc., or total number of cells, nuclei, ribosomes, mitochondria, etc. Although these macroscopic descriptors of the growth of a cell culture increase in a deterministic fashion, the growth and division of individual cells is highly variable. For instance, the ages of cells at division are broadly distributed, with a coefficient of variation (CV = standard deviation/mean) of typically 20%. Size at division is also quite variable: CV ≃ 10%.