Cells live in uncertain, dynamic environments and have many mechanisms for sensing and responding to changes in their surroundings. However, sudden fluctuations in the environment can be catastrophic if a population relies solely on sensory responses, which have a delay associated with them. Cells can reconcile this by using a stochastic approach, creating phenotypic diversity within an isogenic population to hedge against environmental uncertainty. In this talk I will discuss the multiple antibiotic resistance network in enteric bacteria. Using a combination of time-lapse microscopy experiments and stochastic modeling I will show that cells can use feedback to generate dynamics and noise in expression of a key regulatory protein, providing transient antibiotic resistance at the single-cell level. Further, I will discuss how noise in an upstream regulator can propagate to downstream genes to orchestrate a coordinated response to environmental stresses.
Mary Dunlop is an Assistant Professor in the School of Engineering at the University of Vermont. Her research combines dynamic, single-cell experiments and computational modeling to study how microorganisms use feedback to respond to changes in their environment. She graduated from Princeton University in 2002 with a B.S.E. in Mechanical and Aerospace Engineering and a minor in Computer Science. She received her Ph.D. in 2008 from the California Institute of Technology, where she studied dynamics and noise in gene regulation. She then conducted postdoctoral research on biofuel production at the Department of Energy’s Joint BioEnergy Institute and Lawrence Berkeley National Lab. She is the recipient of a Department of Energy Early Career Award and a National Science Foundation CAREER Award.