Abstract for the talk at 04.02.2014 (15:15 h)VW Seminar
Haleh Ebadi (Bioinformatik, Universität Leipzig)
Biological control networks with Boolean functions
Boolean networks are discrete dynamical systems for modeling regulation and signaling in living cells. We investigate a particular class of Boolean functions with inhibiting inputs exerting a veto (forced zero) on the output. We give analytical expressions for the sensitivity of these functions and provide evidence for their role in natural systems. In an intracellular signal transduction network [Helikar et al., PNAS (2008)], the functions with veto are over-represented by a factor exceeding the over-representation of threshold functions and canalyzing functions in the same system. In addition, we present a study on inferring the topology of the biological control networks from dynamics. We strive to quantify how the number of observed single state transitions and/or short trajectories reduces the number of interaction matrices consistent with the set of observations. As a test-bed, we use several established Boolean models of cell cycle control in living organisms. The numerical study also uses ensembles of randomly reshuffled matrices as a null model. We find that the original interaction matrices are easier to reconstruct than the shuffled surrogates.