In this project the PI will combine the tracking and imaging technologies to understand what flagella do as cells run and tumble. Using current technology the PI will be able to track cells, either prokaryotic or eukaryotic, that move even faster than E. coli, which, if grown on a rich medium, swims nearly 40 diameters per second. One of the goals of the project is to compare the run-tumble behavior of cells with different numbers of flagella. Another goal is to study mutants in which the concentration of the response regulator CheY-P is constant. The latter experiments can confirm or rule out the possibility that flagellar coordination is driven by fluctuations in the concentration of the response regulator CheY-P, fluctuations known to occur in wild-type cells. In addition the PI will visualize single filaments in flagellar bundles. Bacterial motility is profoundly important for human health, where it helps promote infections, including those complicated by biofilm formation. Bacterial chemotaxis is the best understood behavioral system in biology, with the understanding of chemoreception, signal transduction, and motor output sufficiently complete to inspire productive mathematical modeling. The PI will establish a facility where the behavior of any organism can be characterized and students will participate. The PI will utilize the talents of physics undergraduates, both for programming and for tracking, which will introduce them to this exciting interdisciplinary field.
