Thesis-PDF - IAP/TU Wien

Figure 4.11: Twice the same Euglena cell as seen with an optical microscope,
using UV-light illumination. The focal plane in the left image is
adjusted such that the part of the pellicle closer to the observer is rendered.
The image one on the right shows the far side of the pellicle. The lightdark
pattern follows the alignment of pellicle strips fusing partly at top and
bottom.
pass helically along the cell (see Fig. 4.11). These strips are intracellular structures
lying immediately beneath the plasmalemma, a continuous tripartite membrane
0.8 − 1µm thick. The pellicle is thus not equivalent to a cell wall, since the latter
is always laid down outside the plasmalemma (like a cellulose wall of plant cells).
The throughs between adjacent strips start as a whorl at the posterior end of
the cell, bifurcate a few times before passing helically along the length of the cells
and then meet again as they reach the canal opening. The strips of the pellicle
curve over and continue into the canal, where the also fuse. Although variation
occurs concerning thickness and shape the form of construction is the same in all
euglenoids. The cross section of a pellicle surface can be seen in Fig. 4.12 (TEM
image) and a schematic drawing in Fig. 4.13.
Figure 4.12: A cross section of an Euglena pellicle. M designates muciferous
bodies, the arrows indicate microtubuli locations. Around the area
where the arrowhead points to, the ridge of the right pellicle strip articulates
inside the groove of the left strip. The muciferous bodies additionally possess
canals leading to this grove and on to the exterior. Scale bar is 0.5 µm.
Image adapted from [84].
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