Hidden influences on cell-cycle duration

Variability in cell-cycle duration is thought to result from random fluctuations in basic molecular processes such as messenger RNA or protein production and degradation. Based on precise measurement of cell-cycle duration in thousands of mammalian cells, Nathalie Balaban and colleagues now report counter-intuitive correlations among cousin cells, when such correlations are lost between mother and daughter cells. Based on a fully deterministic model that recapitulates their data, the authors propose that observed cellular heterogeneities in response to antibiotics or drug treatments may be attributable to processes less random than previously thought.