Jack July

Microtubules (green) traverse cells, establishing lines for shipping of cellular cargo, aiding cells in structural integrity, and helping to drive cell division.  Loss of their integrity in neurons can result in failure of normal development; malfunction in muscle cells can lead to defects in the ability of muscle fibers to contract normally.  In the above image, the top muscle fiber comes from a mouse with muscular dystrophy, and clearly lacks the organization of the normal muscle fiber below.  From JCB.