title: Small square (SS) net structure of the narrow Z-line.
mesh_terms: D000199:Actins; D000818:Animals; D003599:Cytoskeleton / Q000648:ultrastructure*; D005399:Fishes; D046911:Macromolecular Substances; D008954:Models, Biological; D009132:Muscles / Q000648:ultrastructure*
chemical_list: D000199:Actins; D046911:Macromolecular Substances