Centrioles
This high magnification electron micrograph reveals the microtubule structure of centrioles composing the diplosome. The two centrioles are oriented perpendicularly to each other, with the upper one cut in cross section. The diplosome is often located near the nucleus in a region of the cell called the centrosome or the microtubule-organizing center (MTOC). The MTOC is surrounded by a cloud of pericentriolar material from which microtubules emanate. 120,000x
Centrioles >
Centrioles consists of nine microtubule triplets assembled into a cylinder averaging 0.2 microns in diameter and 0.5 microns in length. Note that each triplet consists of two incomplete microtubules and one complete microtubule. In the lower centriole these microtubules are seen in longitudinal section.
Diplosome >
The diplosome is formed by two, perpendicularly-oriented centrioles. They are embedded in a matrix of pericentriolar proteins which are part of the larger microtubule organizing center (MTOC) or centrosome.
MTOC >
The MTOC includes the diplosome along with a dynamic matrix of proteins that together constitute the primary site for microtubule assembly, extending microtubules for intracellular transport as well as forming the mitotic spindle during cell division. Numerous individual microtubules are visible radiating out from the MTOC.
- Individual microtubules
The MTOC includes the diplosome along with a dynamic matrix of proteins that together constitute the primary site for microtubule assembly, extending microtubules for intracellular transport as well as forming the mitotic spindle during cell division. Numerous individual microtubules are visible radiating out from the MTOC.
Image source >
This image was generated by Dr. Johannes A. G. Rhodin, “An Atlas of Histology” (Oxford Press, 1974) and maintained in the University of Michigan collection.
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