flagella

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.

Function

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

References

 Wemmer KA, Marshall WF. Flagellar motility: all pull together. Curr Biol. 2004 Dec 14;14(23):R992-3. PMID: 15589146

 Ibanez-Tallon I, Heintz N, Omran H. To beat or not to beat: roles of cilia in development and disease. Hum Mol Genet. 2003 Apr 2;12(Suppl 1):R27-35. PMID: 12668594

 El Zein L, Omran H, Bouvagnet P. Lateralization defects and ciliary dyskinesia: lessons from algae. Trends Genet. 2003 Mar;19(3):162-7. PMID: 12615011

 Pazour GJ, Rosenbaum JL. Intraflagellar transport and cilia-dependent diseases. Trends Cell Biol. 2002 Dec;12(12):551-5. PMID: 12495842

 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