title: Noise-driven stem cell and progenitor population dynamics.
abstract: BACKGROUND
  The balance between maintenance of the stem cell state and terminal differentiation is influenced by the cellular environment. The switching between these states has long been understood as a transition between attractor states of a molecular network. Herein, stochastic fluctuations are either suppressed or can trigger the transition, but they do not actually determine the attractor states.
  
  
  RESULTS
  We present a novel mathematical concept in which stem cell and progenitor population dynamics are described as a probabilistic process that arises from cell proliferation and small fluctuations in the state of differentiation. These state fluctuations reflect random transitions between different activation patterns of the underlying regulatory network. Importantly, the associated noise amplitudes are state-dependent and set by the environment. Their variability determines the attractor states, and thus actually governs population dynamics. This model quantitatively reproduces the observed dynamics of differentiation and dedifferentiation in promyelocytic precursor cells.
  
  
  CONCLUSIONS
  Consequently, state-specific noise modulation by external signals can be instrumental in controlling stem cell and progenitor population dynamics. We propose follow-up experiments for quantifying the imprinting influence of the environment on cellular noise regulation.
authors.affiliation: Interdisciplinary Centre for Bioinformatics, University of Leipzig, Leipzig, Germany. hoffmann@izbi.uni-leipzig.de
authors.forename: Martin
authors.initials: M
authors.lastname: Hoffmann
authors.forename: Hannah H
authors.initials: HH
authors.lastname: Chang
authors.forename: Sui
authors.initials: S
authors.lastname: Huang
authors.forename: Donald E
authors.initials: DE
authors.lastname: Ingber
authors.forename: Markus
authors.initials: M
authors.lastname: Loeffler
authors.forename: Joerg
authors.initials: J
authors.lastname: Galle
mesh_terms: D000064:Acclimatization; D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D002455:Cell Division; D004777:Environment; D007700:Kinetics; D008954:Models, Biological; D009622:Noise; D011157:Population Dynamics; D012038:Regeneration / Q000502:physiology; D013234:Stem Cells / Q000166:cytology* / Q000502:physiology*