Phenotype switching in polymorphic Tetrahymena: a single-cell Jekyll and Hyde.
For nearly half a century, phenotype switching in the group of polymorphic species of the ciliate genus Tetrahymena has been the subject of investigations of the underlying mechanisms, the accompanying biochemical and structural changes, and the evolution of polymorphic survival strategy. Beginning with the pioneering systematic studies by Furgason in 1940 of hymenostome ciliates, the experimental approach rapidly expanded to include investigations of growth, nutrition, physiology, morphology, and morphogenesis in the polymorphic species. Recently, with progress in elucidation of the novel signaling ligand and identification of elements of the subsequent signal transduction cascade, in addition to the growing catalog of intracellular events associated with differentiation in these unicellular eukaryotes, we have begun to address the mechanistic basis of polymorphism. This review summarizes and integrates the history and recent discoveries concerning Tetrahymena polymorphic cells. We are now poised to answer fundamental questions about this interesting pathway of cell differentiation.
Ryals
Phillip E
PE
Department of Biochemistry and Molecular Biology, Mississippi State University, Mississippi State 39762, USA.
Smith-Somerville
Harriett E
HE
Buhse
Howard E
HE
D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D048429:Cell Size / Q000502:physiology*; D005247:Feeding Behavior / Q000502:physiology; D046911:Macromolecular Substances; D023421:Models, Animal; D010641:Phenotype; D015398:Signal Transduction / Q000502:physiology*; D013768:Tetrahymena / Q000166:cytology / Q000378:metabolism*
D046911:Macromolecular Substances