From molecules to morphology: cellular organization of Tetrahymena thermophila.

Tetrahymena thermophila is both a cell and an organism, which combines great intracellular complexity with a remarkable accessibility to investigation using many different approaches. In this review, we start with a description of the elaborate cortical organization of the Tetrahymena cell, and then proceed inward to consider the mitochondria and then the nuclei. For each of these cellular organelles and organelle-systems, first we familiarize the reader with its location in the cell and its structure and ultrastructure, and then we analyze the molecular mechanisms associated with organelle assembly, function, and subdivision. This analysis includes a molecular inventory of the organelle or organelle system, as well as a review of the consequences of modification, disruption or overexpression of important molecular components of each structure or system. Relevant comparisons to results obtained with other well-studied organisms, from Paramecium to Homo sapiens, are also included. Our goal is to provide investigators, in particular those who are new to this organism, both the background and the motivation to work with this model system and achieve further insight into its organization and dynamics.