How do skeletal muscle fibers become multinucleated?

Skeletal muscle fibers become multinucleated during embryonic development. Myoblasts, which are the precursor cells to muscle fibers, fuse together to form myotubes. These myotubes then fuse with other myotubes to create larger muscle fibers. The nuclei from the individual myoblasts are retained in the fused muscle fiber, resulting in a multinucleated structure.