NANOFILAMENT DEPENDENT MOTILITY IN DINOFLAGELLATES

In dinoflagellates, as in many eukaryotes, several kinds of nanofilaments have been described: some are organized in bundies showing a strict periodicity, some are not; most are contractile upon a rise in Ca2+ concentration, some are not. In any case, their contractile properties appear to be ATP independent. They are present in all cell types studied so far, and are typically found in association with the centrioles-basal bodies where they are suggested to play a role in MTOC structure, position and function. Nanofilaments are all about 2-4 nm in diameter, interact with microtubules, and are insoluble filaments, though to a variable extent. We propose that the nanofilaments may play a structural and/or active role complementary to intermediate filaments.