 The
cytoskeleton, pictured to the right, consists of:
- Microfilaments (5-7 nm in
diameter),
- Microtubules (24 nm in
diameter), and
- A more diverse group of
intermediate filaments with diameters between those of
microfilaments and microtubules (10-15 nm).
All these structures are assembled in
cytoplasm from specific protein subunits. Parallel arrays of these
structures can be seen by LM using immunocytology (Fig. 2-29), which works very well for cytoskeletal
components.
Examine the ultrastructural
appearance of the three cytoskeletal structures in Figs. 2-29
through 2-34. Microtubules become
organized at mitosis by a pair of structures called centrioles which
are part of the centrosome (Fig. 2-32).
Compare microfilaments and
microtubules in terms of their major protein components and their
functions.
Which of these 3 cytoskeletal protein groups is of special
importance in immunohistochemical tests done by pathologists to
identify cells and why?
How about the
nucleus? |
