critical dynamics in genetic regulatory networks examples from four kingdoms临界动力学在基因调控网络的例子从四个王国.pdfVIP

Critical Dynamics in Genetic Regulatory Networks: Examples from Four Kingdoms 1 2 2 3 4 Enrique Balleza , Elena R. Alvarez-Buylla , Alvaro Chaos , Stuart Kauffman , Ilya Shmulevich , Maximino Aldana1* ´ ´ ´ ´ ´ ´ 1 Instituto de Ciencias Fısicas, Universidad Nacional Autonoma de Mexico, Cuernavaca, Morelos, Mexico, 2 Instituto de Ecologıa, Universidad Nacional Autonoma de ´ ´ ´ Mexico, San Nicolas de Los Garza, Mexico, 3 Institute of Biocomplexity and Informatics, University of Calgary, Calgary, Alberta, Canada, 4 Institute for Systems Biology, Seattle, Washington, United States of America Abstract The coordinated expression of the different genes in an organism is essential to sustain functionality under the random external perturbations to which the organism might be subjected. To cope with such external variability, the global dynamics of the genetic network must possess two central properties. (a) It must be robust enough as to guarantee stability under a broad range of external conditions, and (b) it must be flexible enough to recognize and integrate specific external signals that may help the organism to change and adapt to different environments. This compromise between robustness and adaptability has been observed in dynamical systems operating at the brink of a phase transition between order and chaos. Such systems are termed critical. Thus, criticality, a precise, measurable, and well characterized property of dynamical systems, makes it possible for robustness and adaptability to coexist in living organisms. In this work we investi