title: Cell division in a minimal bacterium in the absence of ftsZ.
abstract: Mycoplasma genomes exhibit an impressively low amount of genes involved in cell division and some species even lack the ftsZ gene, which is found widespread in the microbial world and is considered essential for cell division by binary fission. We constructed a Mycoplasma genitalium ftsZ null mutant by gene replacement to investigate the role of this gene and the presence of alternative cell division mechanisms in this minimal bacterium. Our results demonstrate that ftsZ is non-essential for cell growth and reveal that, in the absence of the FtsZ protein, M. genitalium can manage feasible cell divisions and cytokinesis using the force generated by its motile machinery. This is an alternative mechanism, completely independent of the FtsZ protein, to perform cell division by binary fission in a microorganism. We also propose that the mycoplasma cytoskeleton, a complex network of proteins involved in many aspects of the biology of these microorganisms, may have taken over the function of many genes involved in cell division, allowing their loss in the regressive evolution of the streamlined mycoplasma genomes.
authors.affiliation: Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Lluch-Senar
authors.forename: Enrique
authors.initials: E
authors.lastname: Querol
authors.forename: Jaume
authors.initials: J
authors.lastname: Piñol
mesh_terms: D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics*; D002455:Cell Division; D048749:Cytokinesis; D003598:Cytoskeletal Proteins / Q000235:genetics*; D017353:Gene Deletion; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D045704:Mycoplasma genitalium / Q000166:cytology* / Q000235:genetics / Q000254:growth & development; D014170:Transformation, Genetic
chemical_list: D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; C071525:FtsZ protein, Bacteria