Sunday 30 November 2003
Cilia and flagella comprise a microtubular backbone (the ciliary axoneme), which is surrounded by plasma membrane and is nucleated and organized by the basal body, which is a cylindrical structure that consists of nine microtubule triplets and is located underneath the cell membrane.
Flagella, as motile cilia, appeared very early in evolution to provide unicellular organisms with motility in water. Adaptation to non-aquatic life in plants resulted in the almost complete elimination of these organelles, except for gametic transport in some phylogenetic groups.
In contrast, cilia and flagella were retained and employed for a wide variety of functions requiring fluid movement in complex multicellular animals.
See also: stereocilia
Pazour GJ, Rosenbaum JL. Intraflagellar transport and cilia-dependent diseases. Trends Cell Biol. 2002 Dec ;12(12):551-5. PMID : 12495842
Marshall W. Size control in dynamic organelles. Trends Cell Biol. 2002 Sep;12(9):414-9. PMID: 12220861