SummaryThe creation of models for heterogeneous and complex cellular networks is a central goal of Systems Biology. When modeling a biological network, one may wish to account for certain aspects in detail, while a bird's eye perspective would seem more appropriate for other parts. Multi-level models combine such overview and detail representations. We illustrate multi-level modeling with gene regulation of the Tryptophan operon in E. coli. We review three discrete event modeling formalisms and discuss model design therein: DEVS, STATECHARTS, and stochastic π-CALCULUS. This introductory presentation already reveals some of their respective virtues and shortcomings.
Polariry: Effect of nonsense mutation on the genetic expression of tryptophan operon in E. coli