Movie of a B16 melanoma cell that was transfected with GFP VASP and mCherry actin and infected with baculovirus. Video frames were acquired on a confocal (spinning disc) microscope at intervals of 3 sec. Baculovirus moves at speeds of up to 50 microns per minute.
Movie of a fish fibroblast that was transfected with RFP-actin and infected with baculovirus.
Enlarged region of a fish fibroblast that was transfected with actin-GFP and infected with baculovirus tagged with mCherry.
Baculovirus associated actin comet in a negatively-stained cytoskeleton of an infected fish fibroblast. The image was recorded in a conventional transmission electron microscope.
Movie shows a scan in Z of a cryo-electron tomogram of a baculovirus comet tail in a B16 melanoma cell and a model of the tracked filaments. Actin filaments belonging to the cell cytoskeleton appear in grey as also a single microtubule.
Details of the cryo-tomogram showing branch junctions in the comet tail (A, insets). Filaments marked in yellow in B occupy the core region swept by the baculovirus particle. Transections of this region indicated that an average of four actin filaments are required for propulsion (C).
Movie shows a scan in Z of an electron tomogram of a baculovirus comet tail in a B16 melanoma cell embedded in negative stain. The resolution of the actin filaments was of high enough quality to allow determination of the fast polymerizing “barbed” ends by image analysis. As shown, the fast polymerizing ends of the filaments in the fish-bone like array are directed forwards.
Further tomograms of comet tails embedded in negative stain, together with the models derived by filament tracking. The tomograms can be downloaded (tomogram A, tomogram C) and inspected with software package IMOD.
- Mueller J, Pfanzelter J, Winkler C, Narita A, Le Clainche C, Nemethova M, Carlier MF, Maeda Y, Welch MD, Ohkawa T, Schmeiser C, Resch GP, Small JV. Electron tomography and simulation of baculovirus actin comet tails support a tethered filament model of pathogen propulsion. PLoS Biol. 2014 Jan;12(1):e1001765.