title: The structure of a simple Z line.
abstract: The structural simplicity of the Z line in fish muscle fibers allows direct visualization of its basic geometry. Models which postulate termination of the I filaments at the edges of the Z line and the direct linkage of I filaments belonging to the two adjacent sarcomeres by Z filaments crossing the whole width of the Z line give the best fit to the electron micrographs. The structure of fish Z lines is not significantly altered by the use of different fixation procedures and by changes in sarcomere length.
mesh_terms: D000818:Animals; D005399:Fishes / Q000033:anatomy & histology*; D006652:Histological Techniques; D008854:Microscopy, Electron; D008954:Models, Biological; D008961:Models, Structural; D009132:Muscles / Q000166:cytology*