Qualitative Crosstalk Analysis of Wnt and Notch Signaling in Mammalian Skin

The Qualitative networks framework allows to construct discrete executable models of biological systems. An efficient symbolic algorithm can be used to verify that all stable states of such a model are consistent with a set of requirements derived from the laboratory experimental data. Here we consider the crosstalk between the Notch and Wnt pathways that play a key role in the regulation of cell proliferation and differentiation. We extend the analysis of our model of interaction between these pathways in mammalian skin. By further constraining the requirements from the model, we formulate a hypothesis that the ligand Jagged, which is part of the Notch pathway, is a downstream target of Wnt signaling. This prediction has been recently validated experimentally by Estrach et al.. ? Current address: Computer Science Department, Stanford University, Stanford, CA 94305. E-mail: marc.schaub@a3.epfl.ch ?? Current address: Microsoft Research, Cambridge CB3 0FB, UK.