Microtubules Hollow cylindrical structure composed of microtubule proteins and microtubule associated proteins. Presented in cytosol. a Control of the membranous organelle positioning and intracellular material transport; take part in the assembly of flagella(鞭毛)， cilia(纤毛)，centrosomes(中心体)，spindle(纺锤体)； regulate cell motility,cell division and cell morphology. This document is produced by trial version of Print2Flash.Visit www.printflash.com for more information