Varying division planes of secondary constrictions in spheroidal Escherichia coli cells.
Planes of successive divisions in Escherichia coli have been proposed to be either parallel or perpendicular to each other, restricted to one or two dimensions. To test the hypothesis that divisions can occur in planes alternating in three dimensions, a method was developed to generate cells with secondary constrictions during growth in suspension. The method involves a combination of thymine limitation (to manipulate chromosome replication rate) and mecillinam treatment (to inhibit penicillin-binding protein 2). The former modifies timing of terminations, the latter results in spheroidal cells. Such cells displayed secondary constrictions after adding deoxyguanosine (accelerating replication rate), thus temporarily enhancing division signals. The successive constrictions were seen to develop in planes that were tilted relative to each other, and in positions related to those of the nucleoids, visualized by staining with DAPI (4',6-diamidino-2-phenylindole dihydrochloride hydrate). Visualizing cell envelopes with FM 4-64 by confocal scanning laser microscopy supported the conclusion that planes of successive divisions can alternate in three dimensions.
Zaritsky
Arieh
A
Department of Life Sciences, Ben-Gurion University of the Negev, PO Box 653, Be'er-Sheva 84105, Israel.
Woldringh
Conrad L
CL
Section of Molecular Cytology, Institute for Molecular Cell Biology, BioCentrum, University of Amsterdam, Kruislaan 316, 1098 SM Amsterdam, The Netherlands.
Fishov
Itzhak
I
Department of Life Sciences, Ben-Gurion University of the Negev, PO Box 653, Be'er-Sheva 84105, Israel.
Vischer
Norbert O E
NOE
Section of Molecular Cytology, Institute for Molecular Cell Biology, BioCentrum, University of Amsterdam, Kruislaan 316, 1098 SM Amsterdam, The Netherlands.
Einav
Monica
M
Department of Life Sciences, Ben-Gurion University of the Negev, PO Box 653, Be'er-Sheva 84105, Israel.
D002455:Cell Division; D004926:Escherichia coli / Q000166:cytology* / Q000254:growth & development; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence