M. xanthus is a very interesting bacterium, its most striking ability is that of forming fruiting bodies (see picture).
Myxococcus is rod shaped deltaproteobacteria which is a natural inhabitant of the soil and its genome is being sequenced at the moment in the TIGR.
Under starvation conditions, this bacterium undergoes a drastic process of aggregation (roughly 100,000 cells!) that in a matter of hours culminates into forming a fruiting body. The cells that are located in the center of the fruiting body differentiate into environmentally resistant spores.
Single cells can be motile by what is called “adventurous motility” (A). When cell density increases, the organism switches to “social motility” (S).
Interestingly the motility system of myxococcus is not dependent on flagella like most bacteria, but instead relies on twitching pili: short extracellular appendages.
Enthralling!, we have in front of us a fascinating example of developing complexity. I can’t wait for the genome, and subsequently papers, to come and see what underlies in this proto-social behaviour.