Assessment of flhDC mRNA levels in Serratia liquefaciens swarm cells.
We reported previously that artificial overexpression of the flhDC operon in liquid-grown Serratia liquefaciens resulted in the formation of filamentous, multinucleated, and hyperflagellated cells that were indistinguishable from surface-induced swarm cells (L. Eberl, G. Christiansen, S. Molin, and M. Givskov, J. Bacteriol. 178:554-559, 1996). In the present report we show by means of reporter gene measurements, Northern analysis, and in situ reverse transcription-PCR that the amount of flhDC mRNA in surface-grown swarm cells does not exceed the maximum level found in nondifferentiated, vegetative cells. This suggests that surface-induced S. liquefaciens swarm cell differentiation, although dependent on flhDC gene expression, does not occur through elevated flhDC mRNA levels.
Tolker-Nielsen
T
T
Department of Microbiology, The Technical University of Denmark, DK-2800 Lyngby, Denmark.
Christensen
A B
AB
Holmstrøm
K
K
Eberl
L
L
Rasmussen
T B
TB
Sternberg
C
C
Heydorn
A
A
Molin
S
S
Givskov
M
M
D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics; D004268:DNA-Binding Proteins / Q000032:analysis* / Q000235:genetics; D029968:Escherichia coli Proteins; D015870:Gene Expression; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D007544:Isopropyl Thiogalactoside / Q000494:pharmacology; D009876:Operon; D012329:RNA, Bacterial / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis; D011993:Recombinant Fusion Proteins / Q000235:genetics; D012705:Serratia / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development*; D015534:Trans-Activators / Q000032:analysis* / Q000235:genetics
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D015534:Trans-Activators; C090552:flhC protein, E coli; C090553:flhD protein, E coli; D007544:Isopropyl Thiogalactoside