title: Tracking operator state fluctuations in gene expression in single cells.
abstract: We report the results of operator state fluctuations in gene expression for the entire bacterial growth cycle, using single-cell analysis and synthetic unregulated and negative-feedback transcription regulatory gene circuits. In the unregulated circuit, during the cell cycle, we observe a crossover from log-normal-to-normal distribution of expressed proteins and an unusual linear dependence of their standard deviation on the mean gene expression levels. With negative-feedback circuits we find the existence of bimodality as the cell cycle progresses. We suggest that such long-tail and bimodal distributions may be used as selection mechanisms in developmental switches and for assigning cell identity.
authors.affiliation: National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India.
authors.forename: B
authors.initials: B
authors.lastname: Banerjee
authors.forename: S
authors.initials: S
authors.lastname: Balasubramanian
authors.forename: G
authors.initials: G
authors.lastname: Ananthakrishna
authors.forename: T V
authors.initials: TV
authors.lastname: Ramakrishnan
authors.forename: G V
authors.initials: GV
authors.lastname: Shivashankar
mesh_terms: D016880:Anisotropy; D001419:Bacteria / Q000378:metabolism*; D018407:Bacterial Physiological Phenomena; D001703:Biophysics / Q000379:methods*; D002453:Cell Cycle; D002455:Cell Division; D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism; D005434:Flow Cytometry; D015964:Gene Expression Regulation, Bacterial; D005809:Genes, Regulator; D017930:Genes, Reporter; D007700:Kinetics; D008954:Models, Biological; D008957:Models, Genetic; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D012097:Repressor Proteins; D013997:Time Factors; D014158:Transcription, Genetic
chemical_list: D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D004247:DNA