----------------------------------------------------------------------- BIOINFORMATICS COLLOQUIUM School of Computational Sciences George Mason University ----------------------------------------------------------------------- Steps toward Models of Gene Regulatory Networks John Grefenstette George Mason University Tuesday, February 8, 2005 4:30 pm Verizon Auditorium, Prince William Campus Understanding the integrated behavior of genetic regulatory networks, is emerging as a dominant problem in systems biology. One approach to the modeling of gene regulatory networks involves the use of abstract network models in which each gene is represented by a node, each regulatory input is represented by an edge, and each gene's expression activity is represented by a Boolean function of its regulatory inputs (Kauffman, 1993). Important issues in the development of such models include the topology of the network (including the distribution of input- and output-connectivity) and the class of Boolean functions used by each gene (e.g., canalyzing, post functions, etc.). This work seeks to examine these assumptions through the construction and analysis of a class of biochemical gene regulation models that include plausible biochemical mechanisms including genes and gene products, dimerization, binding sites, activators and repressors. This talk will describe the biochemical model in more detail, and discuss how the regulatory logic, the topology and the dynamics of the resulting gene regulation networks depend on the underlying parameters. For example, we have observed a highly biased set of Boolean functions arising from the biochemical model under a range of parameters. We will also discuss the dynamics of the result networks, including conditions under which they operate in chaotic, complex and ordered regimes. ---------------------------------------------------------------------- Refreshments are served at 4:00 pm. Find the schedule and directions at http://www.binf.gmu.edu/colloq.html