Branched swarming patterns on a synthetic medium formed by wild-type Bacillus subtilis strain 3610: detection of different cellular morphologies and constellations of cells as the complex architecture develops.
After optimizing the conditions, including nutrients and temperature, swarming of Bacillus subtilis 3610 was obtained on a synthetic, fully defined medium. The swarms formed highly branched (dendritic) patterns, generated by successive waves of moving cells. A detailed microscopic in situ analysis of swarms 1 and 2 revealed varied cell morphologies and a remarkable series of events, with cells assembling into different 'structures', as the architecture of the swarm developed. Long filamentous cells begin to form before the onset of the first swarming (11 h) and are again observed at later stages in the interior of individual mature dendrites. Swarm 2, detected at 18-22 h, is accompanied by the rapid movement of a wave of dispersed (non-filamentous) cells. Subsequently at the forward edge of this swarm, individual cells begin to cluster together, gradually forming de novo the shape of a dendrite tip with progressive lengthening of this new structure 'backwards' towards the swarm centre. In both swarms 1 and 2, after the initial clustering of cells, there is the progressive appearance of a spreading monolayer of rafts (4-5 non-filamented cells, neatly aligned). The alternative possible roles of the rafts in the development of the swarm are discussed.
Julkowska
Daria
D
Department of Molecular Biology, University of Gdansk, 80-822 Gdansk, Poland.|Institut de Génétique et Microbiologie, Bât. 409, UMR CNRS 8621, Université Paris-Sud, 91405 Orsay cedex, France.
Obuchowski
Michal
M
Department of Molecular Biology, University of Gdansk, 80-822 Gdansk, Poland.|Institut de Génétique et Microbiologie, Bât. 409, UMR CNRS 8621, Université Paris-Sud, 91405 Orsay cedex, France.
Holland
I Barry
IB
Institut de Génétique et Microbiologie, Bât. 409, UMR CNRS 8621, Université Paris-Sud, 91405 Orsay cedex, France.
Séror
Simone J
SJ
Institut de Génétique et Microbiologie, Bât. 409, UMR CNRS 8621, Université Paris-Sud, 91405 Orsay cedex, France.
D001412:Bacillus subtilis / Q000254:growth & development* / Q000502:physiology*; D003470:Culture Media / Q000737:chemistry; D007091:Image Processing, Computer-Assisted; D018715:Microscopy, Video / Q000295:instrumentation; D009068:Movement; D013696:Temperature
D003470:Culture Media