Bistable systems are very common modules in natural biological systems. In this work, well-characterized biological components are used to construct a genetic toggle switch in S. cerevisiae through mutual inhibition. Mathematical modeling is combined with molecular biology to design and construct the genetic toggle switch. We show that, guided by modeling predictions, we can achieve bistability by tuning the system. I will illustrate the artificial "cell differentiation", both experimentally and mathematically, by starting the switch from a specific initial condition that expressions of both repressors are turned off.

This work demonstrates the use of synthetic gene networks to uncover general regulatory mechanisms in natural biological systems.

About the speaker: Dr. Xiao Wang is currently a Research Associate working with Dr. James Collins at Boston University's Center for BioDynamics. There he is developing mathematical models and computational algorithms to help understand and construct complex synthetic networks in eukaryotic cells from bottom up. Dr. Wang received his Ph.D. in Operations Research/ Bioinformatics & Computational Biology from The University of North Carolina at Chapel Hill in 2006. During his Ph.D., Dr. Wang also studied the yeast pheromone response pathway and used mathematical models to uncover novel regulatory roles of MAP kinase.