Microtubules and 10 nm-filaments in the retinal pigment epithelium during the diurnal light-dark-cycle.

Microtubules and 10 nm-filaments appear to be involved in the functions of the retinal pigment epithelium (RPE). The presence of microtubules in the RPE of light-adapted eyes, but not in dark-adapted eyes, suggests that they may be involved primarily in organelle movement. On the other hand, the random and constant presence of 10 nm-filaments within the basal portion of the PE implies a cytoskeletal role for these filaments.