DESMIN FILAMENTS IN THE ELECTROCYTES OF THE ELECTRIC ORGAN OF THE ELECTRIC-EEL ELECTROPHORUS-ELECTRICUS

Desmin protein is an abundant constituent of the intermediate filament s in the electrocytes of the electric organ of the electric eel Electr ophorus electricus. Polyclonal antibodies were raised against purified desmin from the electric organ and used for immunolabeling of the pro tein in reconstituted filaments. In thick sections of the main electri c organ that has been stained with fluorescein-labeled desmin-specific antibodies, light microscope revealed a diffuse meshwork of desmin fi laments dispersed in the cytoplasm of electrocytes. In the region unde r the membrane, the immunostaining was slightly more intense than else where. The meshwork of intermediate filaments composed of desmin was e xamined by electron microscopy of the main electric organ. Immuno-gold labeling demonstrated a widespread meshwork of desmin filaments in th e cytoplasm and in close association with the plasma membrane. These o bservations suggest that intermediate filaments play a role in the mai ntenance of the morphology of electrocytes and, as an intracellular me shwork spanning the width of the cell, they may contribute to the orga nization of the intracellular compartments.