Deep-etching electron microscopy of cells of Magnetospirillum magnetotacticum: evidence for filamentous structures connecting the magnetosome chain to the cell surface.
Magnetospirillum magnetotacticum are magnetotactic bacteria that form a single chain of magnetite magnetosomes within its cytoplasm. Here, we studied the ultrastructure of M. magnetotacticum by freeze-fracture and deep-etching to understand the spatial correlation between the magnetosome chain and the cell envelope and its possible implications for magnetotaxis. Magnetosomes were found mainly near the cell envelope, forming chains that were closely associated with the granular cytoplasmic material. The membrane surrounding the magnetosomes could be visualized in deep-etching preparations. Thin connections between magnetosome chains and the cell envelope were observed in deep-etching images. These results strengthen the hypothesis for the existence of structures that transfer the torque from the magnetosome chains to the whole cell during the orientation of magnetotactic bacteria to a magnetic field lines.
Martins
Juliana Lopes
JL
Departamento de Microbiologia Geral, Instituto de Microbiologia Professor Paulo de Góes, CCS, Bloco I, Universidade Federal do Rio de Janeiro, 21941-590, Rio de Janeiro, RJ, Brasil.
Keim
Carolina Neumann
CN
Farina
Marcos
M
Kachar
Bechara
B
Lins
Ulysses
U
D002462:Cell Membrane / Q000648:ultrastructure*; D003593:Cytoplasm / Q000648:ultrastructure; D052203:Ferrosoferric Oxide / Q000032:analysis*; D005613:Freeze Etching; D005614:Freeze Fracturing; D008280:Magnetics; D042201:Magnetospirillum / Q000737:chemistry / Q000648:ultrastructure*; D046529:Microscopy, Electron, Transmission
D052203:Ferrosoferric Oxide