title: On the origin of branches in Escherichia coli.
abstract: Some Escherichia coli strains with impaired cell division form branched cells at high frequencies during certain growth conditions. Here, we show that neither FtsI nor FtsZ activity is required for the development of branches. Buds did not form at specific positions along the cell surface during high-branching conditions. Antibiotics affecting cell wall synthesis had a positive effect on branch formation in the case of ampicillin, cephalexin, and penicillin G, whereas mecillinam and D-cycloserine had no substantial effect. Altering the cell morphology by nutritional shifts showed that changes in morphology preceded branching, indicating that the cell's physiological state rather than specific medium components induced branching. Finally, there was no increased probability for bud formation in the daughters of a cell with a bud or branch, showing that bud formation is a random event. We suggest that branch formation is caused by abnormalities in cell wall elongation rather than by aberrant cell division events.
authors.affiliation: Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, S-751 24, Uppsala, Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Gullbrand
authors.forename: T
authors.initials: T
authors.lastname: Akerlund
authors.forename: K
authors.initials: K
authors.lastname: Nordström
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins; D002455:Cell Division; D002473:Cell Wall / Q000187:drug effects / Q000378:metabolism; D015169:Colony Count, Microbial; D003470:Culture Media; D003598:Cytoskeletal Proteins; D004926:Escherichia coli / Q000254:growth & development* / Q000648:ultrastructure*; D005455:Fluorescent Antibody Technique; D006602:Hexosyltransferases / Q000235:genetics / Q000378:metabolism; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism; D002267:Muramoylpentapeptide Carboxypeptidase; D046915:Penicillin-Binding Proteins; D010458:Peptidyl Transferases / Q000235:genetics / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002352:Carrier Proteins; D003470:Culture Media; D003598:Cytoskeletal Proteins; C071525:FtsZ protein, Bacteria; D009097:Multienzyme Complexes; D046915:Penicillin-Binding Proteins; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase