Hana El-Samad is a faculty member in the department of Biochemistry and Biophysics at the University of California, San Francisco and the California Institute for Quantitative Biosciences (QB3), where she holds the Grace Boyer Junior Endowed Chair in Biophysics. She is a 2009 Packard Fellow, and was awarded the 2011 Donald. P Eckman Award. Dr. El-Samad joined UCSF after obtaining a doctorate degree in Mechanical Engineering from the University of California, Santa Barbara, preceded by a Masters Degree in Electrical Engineering from the Iowa State University. Dr. El-Samad's research group emphasizes the role of control theory and dynamical systems in the study of biological networks. Her research interests include the investigation of stress responses and biological stochastic phenomena, in addition to the establishment of computational and technological infrastructures that allow for their quantitative probing in single cells.
Cells are chemical reactors where reactions among molecules such as DNA, RNA, and proteins implement the sophisticated programs that support life. Biological molecules undergo thermal motion, and even when they have the propensity to react together, they only do so probabilistically. Therefore, biological processes are fundamentally stochastic because of the very nature of these probabilistic biochemical reactions. This stochasticity, which manifests as cell to cell variability in mRNA and protein levels even in clonal populations of genetically identical cells, is accurately quantifiable with modern experimental techniques. In this talk, I illustrate using a number of examples of how an iterative cycle of rigorous computational modeling and quantitative experimentation can generate profound insights into the control mechanisms used by cells to dampen or exploit their stochastic fluctuations. I also discuss the challenges inherent in connecting measurements of stochastic biochemical circuits to their modeling and analysis, and highlight many exciting opportunities in this field.
