In this project, the PI will integrate experiment and theory to measure and understand the relationship between fluctuations of various observed quantities and the responses of a living system to designed (pulsatile) perturbations. The approach centers on a unique technology that the PI has developed and implemented, combining microfluidics, single-cell imaging, quantitative analysis, and stochastic modeling of growth and division of Caulobacter crescentus. The project seeks to employ this approach to evaluate models for growth control and the degree to which cells trade energy, speed, and accuracy; identify relations constraining the statistics of cell-cycle periods under steady and changing conditions; and engineer a system in which the interactions between cells in a population can be modulated to study spontaneous symmetry breaking. These goals are important for establishing the fundamental physics of systems far from equilibrium. They also provide examples as to how scaling and fluctuation relations can be used to provide direct constraints on regulatory dynamics. In this way, these studies complement common biological methods for assembling information about molecular concentrations and interactions. The investigator seeks to bring core concepts of the project, such as the importance of going beyond averages to study statistical distributions, to a broader audience interested in living systems. To this end, the PI will develop a summer course to introduce high school teachers to basic concepts in probability, energy, and entropy in biological systems through hands-on experimentation and self-guided web-based tutorials.
This project is being jointly supported by the Physics of Living Systems program in the Division of Physics and the Cellular Dynamics and Function Program in the Division of Molecular and Cellular Biosciences.
