title: Multicellular life cycle of magnetotactic prokaryotes.
abstract: Most multicellular organisms, prokaryotes as well as animals, plants, and algae have a unicellular stage in their life cycle. Here, we describe an uncultured prokaryotic magnetotactic multicellular organism that reproduces by binary fission. It is multicellular in all the stages of its life cycle, and during most of the life cycle the cells organize into a hollow sphere formed by a functionally coordinated and polarized single-cell layer that grows by increasing the cell size. Subsequently, all the cells divide synchronously; the organism becomes elliptical, and separates into two equal spheres with a torsional movement in the equatorial plane. Unicellular bacteria similar to the cells that compose these organisms have not been found. Molecular biology analysis showed that all the organisms studied belong to a single genetic population phylogenetically related to many-celled magnetotactic prokaryotes in the delta sub-group of the proteobacteria. This appears to be the first report of a multicellular prokaryotic organism that proliferates by dividing into two equal multicellular organisms each similar to the parent one.
authors.affiliation: Instituto de Ciências Biomédicas, Bloco F, Universidade Federal do Rio de Janeiro, 21941-590 Rio de Janeiro, RJ, Brazil.
authors.forename: Carolina N
authors.initials: CN
authors.lastname: Keim
authors.forename: Juliana L
authors.initials: JL
authors.lastname: Martins
authors.forename: Fernanda
authors.initials: F
authors.lastname: Abreu
authors.forename: Alexandre Soares
authors.initials: AS
authors.lastname: Rosado
authors.forename: Henrique Lins
authors.initials: HL
authors.lastname: de Barros
authors.forename: Radovan
authors.initials: R
authors.lastname: Borojevic
authors.forename: Ulysses
authors.initials: U
authors.lastname: Lins
authors.forename: Marcos
authors.initials: M
authors.lastname: Farina
mesh_terms: D001938:Brazil; D002455:Cell Division; D004269:DNA, Bacterial / Q000737:chemistry / Q000302:isolation & purification; D004275:DNA, Ribosomal / Q000737:chemistry / Q000302:isolation & purification; D020564:Deltaproteobacteria / Q000145:classification / Q000166:cytology* / Q000302:isolation & purification / Q000502:physiology*; D020459:Genes, rRNA; D019015:Geologic Sediments / Q000382:microbiology; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D010802:Phylogeny; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology; D017422:Sequence Analysis, DNA; D014871:Water Microbiology
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S