title: Mysterious hexagonal pyramids on the surface of Pyrobaculum cells.
abstract: In attempts to induce putative temperate viruses, we UV-irradiated cells of the hyperthermophilic archaeon Pyrobaculum oguniense. Virus replication could not be detected; however, we observed the development of pyramidal structures with 6-fold symmetry on the cell surface. The hexagonal basis of the pyramids was continuous with the cellular cytoplasmic membrane and apparently grew via the gradual expansion of the 6 triangular lateral faces, ultimately protruding through the S-layer. When the base of these isosceles triangles reached approximately 200 nm in length, the pyramids opened like flower petals. The origin and function of these mysterious nanostructures remain unknown.
authors.affiliation: Department of Microbiology, Institut Pasteur, 25 rue du Dr. Roux, Paris 75015, France.
authors.forename: Elena
authors.initials: E
authors.lastname: Rensen
authors.affiliation: Department of Microbiology, Institut Pasteur, 25 rue du Dr. Roux, Paris 75015, France.
authors.forename: Mart
authors.initials: M
authors.lastname: Krupovic
authors.affiliation: Department of Microbiology, Institut Pasteur, 25 rue du Dr. Roux, Paris 75015, France. Electronic address: david.prangishvili@pasteur.fr.
authors.forename: David
authors.initials: D
authors.lastname: Prangishvili
mesh_terms: D002462:Cell Membrane / Q000648:ultrastructure*; D046529:Microscopy, Electron, Transmission; D041543:Pyrobaculum / Q000528:radiation effects* / Q000648:ultrastructure* / Q000821:virology; D014466:Ultraviolet Rays
keywords: Archaeaon; Hyperthermophile; Pyrobaculum; UV-irradiation