Open AccessSwarming Differentiation and Swimming Motility in Bacillus subtilis Are Controlled by swrA , a Newly Identified Dicistronic Operon
Author(s) -
Cinzia Calvio,
Francesco Celandroni,
Emilia Ghelardi,
Giuseppe Amati,
Sara Salvetti,
Fabrizio Ceciliani,
Alessandro Galizzi,
Sonia Senesi
Publication year - 2005
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.187.15.5356-5366.2005
Subject(s) - flagellum , operon , bacillus subtilis , biology , swarming motility , swarming (honey bee) , motility , gene , locus (genetics) , genetics , chemotaxis , mutant , complementation , microbiology and biotechnology , bacteria , quorum sensing , virulence , receptor
The number and disposition of flagella harbored by eubacteria are regulated by a specific trait successfully maintained over generations. The genes governing the number of flagella in Bacillus subtilis have never been identified, although the ifm locus has long been recognized to influence the motility phenotype of this microorganism. The characterization of a spontaneous ifm mutant of B. subtilis, displaying diverse degrees of cell flagellation in both liquid and solid media, raised the question of how the ifm locus governs the number and assembly of functional flagella. The major finding of this investigation is the characterization of a newly identified dicistronic operon, named swrA, that controls both swimming motility and swarming differentiation in B. subtilis. Functional analysis of the swrA operon allowed swrAA (previously named swrA [D. B. Kearns, F. Chu, R. Rudner, and R. Losick, Mol. Microbiol. 52:357-369, 2004]) to be the first gene identified in B. subtilis that controls the number of flagella in liquid environments and the assembly of flagella in response to cell contact with solid surfaces. Evidence is given that the second gene of the operon, swrAB, is essential for enabling the surface-adhering cells to undergo swarming differentiation. Preliminary data point to a molecular interaction between the two gene products.