Figure 4

Short membrane tubes prominently accumulate on the D13 network. HeLa cells infected without IPTG were prepared as for Fig. 2. Sections, 150 nm in thickness, were labeled with anti-D13 and subjected to dual-axis tilt series acquisition by transmission EM. Two slices of the reconstructed tomogram; the surface of the section (Z:5) displays anti-D13 labeling and identifies the D13-positive network structure in Tokuyasu sections. The slice Z:127 illustrates that the D13 network is filled with short membrane tubes (white arrowheads) that appear as white lines due to the negative contrasting in the Tokuyasu method. A subset of the short membrane tubes is rendered in light blue, while the ER cisternae that accumulate close by are rendered in green. The slices are taken from the supplemental Movie S4.