Motile Behaviour of E.Coli: Navigation by a single-celled Nervous System
Much is known about the motile behavior of the bacterium Escherichia coli. Early work on tracking E. coli and learning about its biased random walk was followed by the realization that bacterial flagella rotate rather than wave or beat. Flagellar rotation is controlled by chemoreceptors at the cell surface. Receptor methylation is required for adaptation on the second time scale, which enables cells to make temporal comparisons and swim up spatial gradients of attractants. Without methylation, one still observes partial adaptation, on the minute time scale, as motors remodel and shift their operating points. Motors also adapt to changes in viscous load. When the load suddenly increases, additional force-generating units are added one by one; thus, the flagellum is a mechanosensor as well as a device for generating thrust. Flagellar filaments grow at their distal ends at a rate that does not to depend upon initial lengths. Single-file diffusion appears to be adequate to get flagellin subunits from the base to the tip.
Date: 6 October 2015, 12:00 (Tuesday, 0th week, Michaelmas 2015)
Venue: Oxford Martin School, Old Indian Institute, 34 Broad Street, Oxford
Speaker: Howard C. Berg (Harvard University)
Organising department: Centre for Neural Circuits and Behaviour
Organiser: Fiona Woods (University of Oxford, Department of Physiology Anatomy and Genetics, Centre for Neural Circuits and Behaviour)
Organiser contact email address:
Part of: CNCB Seminar Series
Booking required?: Not required
Audience: Members of the University only
Editor: Fiona Woods