Swarming motility: it better be wet.
When grown on a soft agar surface in a rich medium, cells of Salmonella typhimurium elongate, produce extra flagella and move over the surface in a coordinated manner. In mutants with defects in the chemotaxis signaling pathway, the agar plates remain dry and the cells' flagella are short. Recent work shows that the anti-sigma factor controlling late-gene flagellar synthesis is secreted less by flagella when things are dry: the flagellum senses wetness.
Berg
Howard C
HC
Department of Molecular and Cellular Biology, Harvard University, 16 Divinity Avenue, Cambridge, Massachusetts 02138, USA. hberg@mcb.harvard.edu
D001426:Bacterial Proteins / Q000378:metabolism*; D001692:Biological Transport / Q000502:physiology; D002633:Chemotaxis / Q000502:physiology*; D005407:Flagella / Q000378:metabolism* / Q000502:physiology; D005408:Flagellin / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D012486:Salmonella typhimurium; D015398:Signal Transduction / Q000502:physiology; D014867:Water / Q000378:metabolism
D001426:Bacterial Proteins; D014867:Water; D005408:Flagellin; C071266:FlgM protein, Bacteria