Microtubules

Microtubules are one part of a cell’s cytoskeleton which are about 25nm in diameter and composed of tubulin subunits. A basic depiction of a microtubules structure is displayed in Figure 1. Their formation and growth is regulated by the centrosome. Microtubular spindle fibers are produced by the centrosome during cell division for chromosome separation.

Figure 1. Microtubules structure.

Microtubules serve several different functions. The rigid cylinders are responsible for keeping the cylindrical shape in nerve cell processes. They also aid in organelle movement throughout the cytoplasm by forming tracks which the organelles use contractile proteins to crawl along.

Keyword in references:

Danyiar Nurgaliev, Timur Gatanov, and Daniel J. Needleman, Automated Identification of Microtubules in Cellular Electron Tomography. Methods in Cell Biology, 2010, 97.

Mitosis: Taking the Measure of the Spindle Length