Mathematical Biology Seminar Jim Keener University of Utah Wednesday March 10, 2010 3:05pm in LCB 215 Mechanisms of length regulation of flagella in Salmonella Abstract: The construction of flagellar motors is a carefully regulated genetic process. Among the structures that are built are the hook and the filament. The length of the hook is tightly controlled while the length of filaments is less so. However, if a filament is broken off it will regrow, while a broken hook will not regrow. The question that will be addressed in this talk is how Salmonella detects and regulates the length of these structures. This is related to the more general question of how physical properties (such as size or length) can be detected by chemical signals and what those mechanisms are. This is related, for example, to the question of how bacterial populations can determine the size of the colony in which they live (quorum sensing). In this talk, I will present mathematical models for the regulation of hook and filament length and for quorum sensing in bacterial populations, detailing the significant differences between these as well as identifying their common features.