Supporting Online Material

The Molecular Architecture of Axonemes Revealed by Cryoelectron Tomography
Daniela Nicastro, Cindi Schwartz, Jason Pierson, Richard Gaudette, Mary E. Porter, J. Richard McIntosh

Supporting Online Material

This supplement contains:
Materials and Methods
SOM Text
Figs. S1 to S4
Movies S1 to S6

This file is in Adobe Acrobat PDF format.

Movie S1
Movie illustrating the process of particle averaging. Each movie frame displays a tomographic slice through a Chlamydomonas doublet microtubule (MT); from the start to the end of the movie the number of repeats included in the averages increases from 1 to 160. With an increasing number of particles, including ones that lay in the structure at different orientations relative to the axis of tilt and thus to the missing wedge, the signal-to-noise ratio increases and both resolution and contrast become more isotropic. The streaks that appear at diverse orientations show the missing wedge artifacts associated with individual images as they add to the average. A/B, A- and B-tubule; ODA, outer dynein arms; RS, radial spokes.

Movie S2
A display of the averaged image data from a sea urchin sperm axoneme, together with a graphic model of the ODA average, generated with IMOD. This display of planes of image data cut at multiple positions and orientations shows how well the graphic models displayed in the paper fit the data. The colors represent: docking complex (pink), intermediate/light chain-complex (green), Outer-Outer-Dynein-linkers (red and yellow), the dynein motor domains and surrounding structures (blue), A-tubule (gray); initially the MT is viewed from proximal to distal. A thickened MT wall between the A- and B-tubule is highlighted in red inside the MT doublet. The dynein stalk domain was not routinely resolved in our data, but a single stalk is visible at the beginning of this movie.

Movie S3
Volume-rendered 96 nm repeat of an outer doublet MT and associated structures, reconstructed from a Chlamydomonas wild type axoneme. At various time-points of the movie the I1 complex and nexin link are highlighted.

Movie S4
Same as Movie S3 but from the pf9-mutant of Chlamydomonas.

Movie S5
Movie of serial tomographic slices cut through the averaged pf9-mutant of Chlamydomonas: the right image is in cross-section, and the red line indicates the orientation and position of the slice displayed in the left image; the latter is a longitudinal section viewed from the B-tubule of the adjacent doublet.

Movie S6
Movie of the averaged image data together with a graphic model, generated with IMOD, showing a doublet and associated material reconstructed from a Chlamydomonas axoneme. The rotating graphical model first summarizes the doublet-associated structures from the pf9-mutant, and at the end the I1 complex is indicated in wild type. (For explanation of the colors refer to Fig. 5, C and D).

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