Figure 19-5. Microtubule-organizing center.
Figure 19-5. Microtubule-organizing center.

Figure 19-5Microtubule-organizing center

(a) Fluorescence micrograph of a Chinese hamster ovary cell stained with antibodies specific for tubulin and a centrosomal protein. The microtubules (green) are seen to radiate from a central point, the microtubule-organizing center (MTOC), near the nucleus. The MTOC (yellow) is detected with an antibody to Cep135, a protein in the pericentriolar material. (b) Electron micrograph of the MTOC in an animal cell. The pair of centrioles (red), C and C′, in the center are oriented at right angles; thus one is seen in cross section, and one longitudinally. Surrounding the centrioles is a cloud of material, the pericentriolar (PC) matrix, which contains γ-tubulin and pericentrin. Embedded within the MTOC, but not contacting the centrioles, are the (−) ends of microtubules (MT; yellow). [Part (a) courtesy of R. Kuriyama; part (b) from B. R. Brinkley, 1987, in Encyclopedia of Neuroscience, vol. II, Birkhauser Press, p. 665; courtesy of B. R. Brinkley.]

From: Section 19.1, Microtubule Structures

Cover of Molecular Cell Biology
Molecular Cell Biology. 4th edition.
Lodish H, Berk A, Zipursky SL, et al.
New York: W. H. Freeman; 2000.
Copyright © 2000, W. H. Freeman and Company.

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