title: Analysis of molecular diffusion in ftsK cell-division mutants using laser surgery.
abstract: Escherichia coli cells that lack the carboxy-terminal part of FtsK fail to segregate their chromosomes properly during cytokinesis and tend to form chains. These chains are possibly formed as a result of DNA being trapped in the division planes or a failure to fuse the membrane during septum formation. If so, small molecules might diffuse between the apparent cell compartments. To investigate this theory, we developed an optical workstation that allows simultaneous imaging of and surgical operations on cellular objects in the sub-micrometre range. By surgical incisions of E. coli cell poles, diffusion of propidium iodide (PI) can be followed in real time. This analysis showed that PI was unable to diffuse from one cell equivalent to another in chain-forming ftsK mutants. Thus, the cytoplasm of the cell compartments in the chains seems to be fully separated.
authors.affiliation: Department of Physics, Chalmers University of Technology and Göteborg University, Fysikgränd 3, SE-41296 Göteborg, Sweden.
authors.forename: Mattias
authors.initials: M
authors.lastname: Goksör
authors.forename: Alfredo
authors.initials: A
authors.lastname: Diez
authors.forename: Johan
authors.initials: J
authors.lastname: Enger
authors.forename: Dag
authors.initials: D
authors.lastname: Hanstorp
authors.forename: Thomas
authors.initials: T
authors.lastname: Nyström
mesh_terms: D002455:Cell Division / Q000235:genetics / Q000502:physiology*; D004926:Escherichia coli / Q000235:genetics / Q000502:physiology*; D029968:Escherichia coli Proteins; D005456:Fluorescent Dyes; D007211:Indoles; D053685:Laser Therapy; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D042282:Microdissection; D036641:Microscopy, Fluorescence, Multiphoton; D009154:Mutation; D011419:Propidium / Q000378:metabolism; D013194:Staining and Labeling
chemical_list: D029968:Escherichia coli Proteins; D005456:Fluorescent Dyes; C096452:FtsK protein, E coli; D007211:Indoles; D008565:Membrane Proteins; D011419:Propidium; C007293:DAPI