Figure 3. Membrane distortions are found at the rear end of filamentous MARV particles.

MARV infected cells were embedded and sectioned in their in situ orientation and the morphology of filamentous viruses was examined in electron tomograms of 300 nm thick sections. (A, B) Digital slices of tomograms showing typical examples of (A) distorted ends and (B) intact, round ends of filamentous viruses. Scale bars 100 nm. (C) Quantification of the distance of distorted and round virus ends from the nearest cellular membrane. Distances were measured in 3D tomograms and assigned to one of three distance classes >250 nm, 50–250 nm, <50 nm. At a distance <50 nm from the nearest cell membrane, most virus ends are distorted. At a distance >250 nm away from the nearest cell membrane the majority of virus ends is intact and round.