Research

Spatial Stochastic Simulation of Cellular Polarization in Yeast Mating

Cell polarization is a fundamental process that underlies many aspects of cell and developmental biology. In the polarization process, cellular components that were previously uniformly distributed become asymmetrically localized to create the complexity of form and function that are the hallmark of biological systems. One of the best-studied examples of cell polarization is the growth of the mating projection (shmoo) during yeast mating. Yeast cells localize specific proteins to the front of the cell in response to a spatial gradient of mating pheromone secreted by the partner. The spatial sensing and response exhibit remarkable sensitivity, dynamic range, and robustness.
We develop mathematical models that describe the spatial dynamics of yeast cell polarization in response to spatial gradients of mating pheromone. Our multidisciplinary effort of modeling and simulation intertwined with experiment has as its objectives to understand the role of stochasticity in the cell polarization process and to develop the next-generation computational algorithms and software for spatial stochastic simulation of cell polarization in general.
Figure 1: Single stochastic trajectory of activated G-protein (Gamma-Beta sub-unit)
Figure 2: Ensemble of 1000 stochastic trajectories of activated G-protein (Gamma-Beta sub-unit)

This work is in collaboration with Professor Mustafa Khammash (UCSB Department of Mechanical Engineering), and Professor Tau-Mu Yi (UC Irvine, Department of Developmental and Cell Biology), and their research groups.