Before revision: Genetically identical microbial cells typically display significant variability in every measurable property. In particular, highly abundant proteins - which can determine cellular behavior - exhibit large variability in copy number among individuals. Their distribution has a universal shape common to different proteins and URLanisms; the same distribution shape is measured both in populations and in single-cell temporal traces. Moreover, different highly expressed proteins are statistically correlated with cell size and with cell-cycle time.
After revision: Cellular phenotype is characterized by different components such as cell size, protein content and cell cycle time. These are global variables that are the outcome of multiple internal microscopic processes. Accordingly, they display some universal statistical properties and scaling relations, such as distribution collapse and relation between moments. Cell size statistics and its relation to growth and division has been mostly studied separately from proteins and other cellular variables. Here we present experimental and theoretical analyses of these phenotype components in a unified framework that reveals their correlations and interactions inside the cell. We measure these components simultaneously in single cells over dozens of generations, quantify their correlations, and compare population to temporal statistics. We find that cell size and highly expressed proteins are statistically correlated with cell size and with cell-cycle time.