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Fig. 2. Longitudinal thin sections through actin bundles in bristles of 54-hour
pupae. These sections were selected because they show junctions between
adjacent modules. If this plate is rotated 90° so the viewer is looking
across the bundles, the 12-nm period owing to the fascin crosslinks can be
easily recognized. This period is indicated by the bars in (b) and (c), but it
is especially visible near the base of each micrograph. If the bristle is bent
before fixation, the overlap between adjacent modules separates at the point
of overlap (a). As the module shortens, the number of filaments found in the
overlap region decreases (b). Shortly thereafter a distinct gap is seen
between adjacent modules (c).