POSTERS - BLAST X - University of Utah

BLAST X Mon. Evening Session
PREDATAXIS BEHAVIOR IN MYXOCOCCUS XANTHUS
Jeb Berleman, Jodie Scott, Tatiana Chumley, and John R. Kirby *
University of Iowa, Department of Microbiology, Iowa City, IA 52246, USA
Spatial organization of cells is important for both multicellular development and tactic
responses to a changing environment. We find that the slow-moving, gliding bacterium,
Myxococcus xanthus, utilizes a Che-like pathway to regulate multicellular rippling during
predation of other microbial species. Tracking of GFP-labeled cells indicates directed
movement of M. xanthus cells during the formation of rippling wave structures. Quantitative
analysis of rippling indicates that ripple wavelength is adaptable and dependent on prey cell
availability. Methylation of the receptor, FrzCD, is required for this adaptation: a frzF
methyltransferase mutant is unable to construct ripples, whereas a frzG methylesterase mutant
forms numerous, tightly packed ripples. Both the frzF and frzG mutant strains are defective in
directing cell movement through prey colonies. These data indicate that the transition to an
organized multicellular state during predation in M. xanthus relies on the tactic behavior of
individual cells, mediated by a Che-like signal transduction pathway. Predataxis behavior differs
from chemotaxis behavior in that it seems to depend heavily on tactile-stimulation, as opposed
to chemical-stimulation.
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