Gene regulation under growth conditions. A model for the regulation of initiation of replication in Escherichia coli.
A stochastic model is presented to describe gene regulation during growth conditions (non-steady-state), with an emphasis on the distribution of gene activation times. A non-Poissonian distribution, with a smaller variability than in steady-state, is obtained when gene activation by the regulatory protein(s) occurs before the protein(s) reach their saturation concentration. The model is applied to the regulation of initiation of chromosomal replication in Escherichia coli. The rate of initiation is shown to depend linearly on the concentration of the initiator molecule, DnaA, in good agreement with recently published data. It is suggested that the variability of initiation times could be growth rate dependent, with slow growing cells being more synchronized than fast growing ones.
Laboratoire de Physique Statistique, Ecole Normale Supérieure, Paris, France.
J
J
Herrick
D
D
Bensimon
D000818:Animals; D004261:DNA Replication / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development; D005786:Gene Expression Regulation / Q000502:physiology*; D008957:Models, Genetic; D015533:Transcriptional Activation