ISI Web of Knowledge Take the next step  
Web of Science®
 
Previous Record (inactive) Record 1  of  1 Next Record (inactive)
Record from Web of Science®
An excitable gene regulatory circuit induces transient cellular differentiation
Author(s): Suel GM, Garcia-Ojalvo J, Liberman LM, Elowitz MB
Source: NATURE    Volume: 440    Issue: 7083    Pages: 545-550    Published: MAR 23 2006  
Times Cited: 138     References: 24     
Abstract: Certain types of cellular differentiation are probabilistic and transient(1-3). In such systems individual cells can switch to an alternative state and, after some time, switch back again. In Bacillus subtilis, competence is an example of such a transiently differentiated state associated with the capability for DNA uptake from the environment. Individual genes and proteins underlying differentiation into the competent state have been identified(4,5), but it has been unclear how these genes interact dynamically in individual cells to control both spontaneous entry into competence and return to vegetative growth. Here we show that this behaviour can be understood in terms of excitability in the underlying genetic circuit. Using quantitative fluorescence time-lapse microscopy, we directly observed the activities of multiple circuit components simultaneously in individual cells, and analysed the resulting data in terms of a mathematical model. We find that an excitable core module containing positive and negative feedback loops can explain both entry into, and exit from, the competent state. We further tested this model by analysing initiation in sister cells, and by re-engineering the gene circuit to specifically block exit. Excitable dynamics driven by noise naturally generate stochastic and transient responses(6), thereby providing an ideal mechanism for competence regulation.
Document Type: Article
Language: English
Reprint Address: Elowitz, MB (reprint author), CALTECH, Div Biol, Pasadena, CA 91125 USA
Addresses:
1. CALTECH, Div Biol, Pasadena, CA 91125 USA
2. CALTECH, Dept Appl Phys, Pasadena, CA 91125 USA
3. Univ Politecn Catalunya, Dept Fis & Engn Nucl, E-08222 Terrassa, Spain
Publisher: NATURE PUBLISHING GROUP, MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
Subject Category: Multidisciplinary Sciences
IDS Number: 024DV
ISSN: 0028-0836
DOI: 10.1038/nature04588
Previous Record (inactive) Record 1  of  1 Next Record (inactive)
Record from Web of Science®
  
Thomson Reuters Logo