Specific attachment of morphologically-distinct intermediate filaments to desmosomes and hemidesmosomes in the epidermis of the tadpole of the anuran, Pseudis paradoxus.

Polarization microscopy disclosed the presence of strongly birefringent intracellular structures in the basal cells of the epidermis of the tadpole of the anuran Pseudis paradoxus. The electron microscopic picture of the birefringent structures showed that they were composed of thick intermediate filaments (average diameter: 11.2 +/- 0.8 nm) oriented in a parallel disposition to form closely packed bundles which attached to the hemidesmosomes present on the basal surface of the cells of the basal layer of the epidermis. Thinner intermediate filaments (average diameter: 8.2 +/- 0.8 nm) were localized to the cortical zone of the cytoplasm; these thinner intermediate filaments converged upon the sites of cell-to-cell adhesion (desmosomes).