  Heterogeneity in physical and functional characteristics of cells (e.g. size,
cycle time, growth rate, protein concentration) proliferates within an isogenic
population due to stochasticity in intracellular biochemical processes and in
the distribution of resources during divisions. Conversely, it is limited in
part by the inheritance of cellular components between consecutive generations.
Here we introduce a new experimental method for measuring proliferation of
heterogeneity in bacterial cell characteristics, based on measuring how two
sister cells become different from each other over time. Our measurements
provide the inheritance dynamics of different cellular properties, and the
"inertia" of cells to maintain these properties along time. We find that
inheritance dynamics are property-specific, and can exhibit long-term memory
(~10 generations) that works to restrain variation among cells. Our results can
reveal mechanisms of non-genetic inheritance in bacteria and help understand
how cells control their properties and heterogeneity within isogenic cell
populations.
