Interdisciplinary Seminar in Nonlinear Science

Title: Towards a digital bacterium
Speaker: Thierry Emonet
Speaker Info: U Chicago
Brief Description:
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In recent years, single-cell biology has focused on the relationship between the stochastic nature of molecular interactions and variability of cellular processes. In addressing this problem, most efforts in computational biology have isolated one particular scale of interest, concentrating on either intracellular, cellular or population dynamics. Our long-term goal is to develop a modular computation framework able to cross scales and related stochastic events at the intracellular level to the behavior of a single cell and ultimately to the dynamics of a population of cells. In this talk I will relate our first steps towards that goal. As a test-bed for our approach we are using bacterial chemotaxis. E. coli bacteria can sense their environment and use that information to control their flagellar motors and move closer to sources of nutrients. To understand how a single E. coli processes information we decomposed the chemotaxis pathway into simpler information processing units. We then modeled each unit analytically and/or numerically, and tested model predictions with data from measurements in single cells. Finally, we constructed a digital bacterium equipped with the necessary modules to perform chemotaxis: receptors, adaptation module, intracellular signal carriers (response regulator), motors and flagella. Digital chemotaxis assays consisting of more than 1000 independent digital cells swimming in a 3D environment reproduced experimental data from both single cells and bacterial populations. Our analysis sheds new light on the relationship between behavioral variability and adaptation in a single cell.
Date: Friday, October 21, 2005
Time: 2:00PM
Where: Tech M416
Contact Person: Mary Catsicopoulos
Contact email: maryc@northwestern.edu
Contact Phone: 847/491-5586
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