Modeling the Control of Yeast Cell Differentiation

Tim Galitski, Institute for Systems Biology

Genome-scale network analyses suggest a hierarchical view of the cell in which groups of interacting molecules form biological modules, and biological modules interact in complex networks that control the properties of a cell. Employing this framework, we studied the control of yeast cell differentiation. On solid growth media with limiting nitrogen source, diploid budding-yeast cells differentiate from the yeast form to a filamentous, adhesive, and invasive form. Using a combination of genomics, integrative network analysis, genetics, molecular biology, and dynamic simulations, we have developed a model of this cell differentiation. This model involves interactions between two key modules, a MAP-kinase cascade and the cell-cycle oscillator.