Abstract
Skeletal muscle cells are large syncytia, containing hundreds of nuclei positioned regularly along the length of the fiber. During development, nuclei are actively distributed throughout the myotube by the microtubule motor proteins, kinesin-1, and cytoplasmic dynein. Nuclear movement consists of translocation along the long axis of the cell concurrent with three-dimensional rotation of nuclei. In this chapter we describe methods for quantitatively assessing the speed of nuclear rotation in cultured myotubes using live-cell imaging techniques coupled with rigid body kinematic analyses. Additionally, we provide protocols for analyzing nuclear distribution in myotubes.