Quantitative Modeling the Saccharomyces cerevisiae FLR1 Regulatory Network Using an S-System Formalism

Abstract

We address the problem of finding a mathematicalmodel for the genetic network regulating the stress response ofthe yeast Saccharomyces cerevisiae to the fungicide mancozeb.An S-system formalism was used to model the interactions ofthis 5 gene network. Parameter estimation was accomplishedby decoupling the resulting system of nonlinear ordinarydifferential equations into a larger nonlinear algebraic system,and using the Levenberg-Marquardt algorithm to fit themodels predictions to experimental data. The introduction ofconstraints in the model, related to the putative topology ofthe network, was explored. The results show that forcing thenetwork connectivity to adhere to this topology did not leadto better results than the ones obtained using an unrestrictednetwork topology. Overall, the modeling approach obtainedpartial success when trained on the non-mutant datasets,although further work is required if one wishes to obtain moreaccurate prediction of the time courses.