Online Supplemental Material for
J. Cell Biol. 10.1083/jcb.200612010
Nickell et al.
- Figure S1 Electron tomogram of vitrified ROS.
- Figure S2 Isosurface representation of a ROS.
- Figure S3 Cryoelectron micrograph of compressed ROS discs.
- Figure S4 Distribution of spacers in discs.
- Video 1 Single-axis tilt series for a ROS.
- Video 2 Electron tomogram and isosurface representation of a ROS.
Figure S1. Electron tomogram of vitrified ROS. The electron tomogram is represented in three orthogonal slices through the volume of the ROS. (a and b) An x-y slice (a) and a y-z slice (b) display the high order and regular arrangement of stacked discs. (c) An x-z slice shows the high concentration of rhodopsin found in disc membranes. The reconstruction was not binned, and the pixel size is 1.1 nm. The boxed areas are visualized by isosurface representation in Fig. S2. Bar, 100 nm.
Figure S2. Isosurface representation of a ROS. (a) A subvolume containing eight discs (yellow) and the plasma membrane (blue) are visualized. Areas of high density (dark yellow), presumably rhodopsin, can be differentiated from less dense areas (light yellow). (b) A top view of a single disc is shown. Spacers are shown that connect adjacent discs to each other (red) and the rim region of discs to the plasma membrane (orange).
Figure S3. Cryoelectron micrograph of compressed ROS discs. A top view of features that appear to be free discs is shown in micrographs from a single transmission projection. The images suggest that the compression of discs can lead to the breakage of one edge (indicated by the asterisks). Bars, 100 nm.
Figure S4. Distribution of spacers in discs. (a and b) A schematic of the top view of an amphibian disc (a) and a murine disc (b) is shown. Previous reports have localized spacer structures predominantly at the disc periphery and incisure regions (a). This study on the murine ROS suggests that spacer structures are distributed throughout the disc area (b).
Video 1. Single-axis tilt series for a ROS. The video shows the single-axis tilt series obtained from a region on the EM grid containing a ROS. The tilt angle is indicated at the top right-hand corner of the frame.
Video 2. Electron tomogram and isosurface representation of a ROS. The video provides a three-dimensional tour through an electron tomogram and isosurface representation of a ROS. In the isosurface representation, discs are colored yellow, and the plasma membrane is colored blue. High density regions in the discs are represented in dark yellow, and lower density regions are represented in light yellow. Spacers connecting adjacent discs to each other are shown in red, and spacers connecting the rim region of discs to the plasma membrane are shown in orange. Other details can be found in Figs. 3 and 4.