Lysogen stability is determined by the frequency of activity bursts from the fate-determining gene.
The ability of living cells to maintain an inheritable memory of their gene-expression state is key to cellular differentiation. Bacterial lysogeny serves as a simple paradigm for long-term cellular memory. In this study, we address the following question: in the absence of external perturbation, how long will a cell stay in the lysogenic state before spontaneously switching away from that state? We show by direct measurement that lysogen stability exhibits a simple exponential dependence on the frequency of activity bursts from the fate-determining gene, cI. We quantify these gene-activity bursts using single-molecule-resolution mRNA measurements in individual cells, analyzed using a stochastic mathematical model of the gene-network kinetics. The quantitative relation between stability and gene activity is independent of the fine details of gene regulation, suggesting that a quantitative prediction of cell-state stability may also be possible in more complex systems.
Department of Physics, University of Illinois, Urbana, IL, USA.
Chenghang
C
Zong
Lok-hang
LH
So
Leonardo A
LA
Sepúlveda
Samuel O
SO
Skinner
Ido
I
Golding
D010582:Bacteriophage lambda / Q000235:genetics / Q000502:physiology; D004926:Escherichia coli / Q000235:genetics / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics / Q000502:physiology*; D005814:Genes, Viral / Q000502:physiology; D016680:Genome, Bacterial / Q000502:physiology; D042822:Genomic Instability / Q000235:genetics*; D008242:Lysogeny / Q000235:genetics*; D008954:Models, Biological; D030781:Organisms, Genetically Modified; D012097:Repressor Proteins / Q000235:genetics / Q000502:physiology*; D054334:Viral Regulatory and Accessory Proteins / Q000235:genetics / Q000502:physiology*
D012097:Repressor Proteins; D054334:Viral Regulatory and Accessory Proteins; C016649:phage repressor proteins