The distribution of troponin-like proteins on thin filaments of the bay scallop, aequipecten irradians.

Antibodies reacting either with bay scallop troponin-C-like protein or both bay scallop troponin-I-like protein and a possible scallop troponin-T were used to determine the distribution of the troponin complex on bay scallop striated muscle thin filaments. Both antibodies cause thin filaments to associate laterally and electron microscopy of such aggregates indicates a periodicity of approximately 38 nm, a distribution characteristic of proteins comprising the troponin complex in vertebrate and arthropod striated muscle. These studies therefore provide additional evidence for the presence of thin filament-linked regulation in bay scallops.