Model of MT organization in skeletal muscle fibers at steady-state. (A) MTs nucleating from Golgi elements grow parallel or antiparallel to existing MTs, thereby forming small bundles, which are guided or restricted by the dystrophin bands positioned along Z lines, M bands, and longitudinal stripes. MTs starting at an oblique angle reorient upon contact with other MTs or dystrophin bands, as observed (B) in GFP-tubulin–expressing fibers. The MT lattice that results is both durable and dynamic. Bars, 2 µm.