Cytological analysis of Tetrahymena thermophila.

Since their first detection in pond water, large ciliates such as Tetrahymena thermophila, have captivated school children and scientists alike with the elegance of their swimming and the beauty of their cortical organization. Indeed, cytology - simply looking at cells - is an important component of most areas of study in cell biology and is particularly intriguing in the large, complex Tetrahymena cell. Cytological analysis of Tetrahymena is critical for the study of the microtubule cytoskeleton, membrane trafficking, complex nuclear movements and interactions, and the cellular remodeling during conjugation, to name a few topics. We briefly review previously reported cytological techniques for both light and electron microscopy, and point the reader to resources to learn about those protocols. We go on to present new and emerging technologies for the study of these marvelous cells. These include the use of fluorescent-protein tagging to localize cellular components in live cells, as well as for tracking the dynamic behavior of proteins using pulse labeling and fluorescence recovery after photobleaching. For electron microscopy, cellular and antigenic preservation has been improved with the use of cryofixation and freeze-substitution. The technologies described here advance Tetrahymena cell biology to the cutting-edge of cytological analysis.