Hemmersbach, R., Bräucker, R. (2002) Gravity-Related Behaviour in Ciliates and Flagellates. In Cogoli, A. (ed): Advances in Space Biology and Medicine.
Unicellular organisms, like protists, use gravity as a most reliable
environmental parameter for spatial orientation. Thus,
gravisensitive protists offer ideal model systems contributing to
answering the question whether gravisensation is a common cellular
capacity. During the last decades, the gravity related behaviour in
several protozoa, mainly ciliates and flagellates, has been
investigated. Though the species differ in cell sizes and living
conditions, similar mechanisms of graviperception based on
mechanosensitive principles seem to exist.