Which of the following plays a central role in the mitotic spindle formation in cellular division?

Centrosome plays a critical role in mitotic spindle formation. Gamma-Tubulin is a constituent of Microtubules, which are necessary for the formation and function of the mitotic spindle. Microtubules an integral component of the cellular cytoskeleton consists of cytoplasmic tubes 25 nm in diameter. These are cylinders of 13 longitudinally arranged protofilaments, each consisting of dimers of a-tubulin and b-tubulin. Cytoplasmic microtubules are composed of tubulin (55 kD) and several accessory proteins called microtubular associated proteins (300 kD and 60 kD). They are also involved in the intracellular movement of endocytic and exocytic vesicles and form the major structural components of cilia and flagella. They are a major component of axons and dendrites, in which they maintain structure and paicipate in the axoplasmic flow of material along these neuronal processes. Ref: Harper's Illustrated Biochemistry, 26th Edition, Page 577 ; Textbook of Biochemistry By D M Vasudevan, 3rd Edition, Pages 235, 238