Methods in Cell Biology: Tetrahymena thermophila

Edited by:
  • David J. Asai &
  • James D. Forney
Academic Press, $125.00 (US),, 2000 ISBN 0-12-544164-9 | ISBN: 0-12-544164-9

In explaining his choice of experimental system, Nobel laureate Thomas Cech recently described Tetrahymena thermophila as “weird”. Few would dispute this; rather, T. thermophila biologists generally revel in the unique features that have facilitated the many fundamental discoveries made using this large, single-celled eukaryote. T. thermophila is a ciliated protozoan, a relative of those swimming cells observed by Robert Hooke and Antonie van Leeuwenhoek. T. thermophila has become the ciliate of choice for biological studies, due to its excellent cytology, rapid growth to high density, readily controlled vegetative and sexual lifestyles, and ease of transformation. Like all ciliates, T. thermophila segregates the functions of germline maintenance and somatic gene expression into two nuclei: a more canonically structured, mostly transcriptionally silent, micronucleus; and a highly fragmented, amplified, transcriptionally competent macronucleus. This nuclear dualism has expedited discoveries including the original identification of self-splicing RNA and telomerase. T. thermophila also contributes prominently to studies of cytoskeleton, transcription, chromatin and chromosome maintenance.

The most recent volume of Methods in Cell Biology, Tetrahymena thermophila, is an essential how-to manual, especially for those new to the system. The book is organized in four sections, starting with a comprehensive overview of the features of T. thermophila biology that make this ciliate interesting evolutionarily and experimentally. The second section contains basic methods such as strain growth and storage, analysis by microscopy and gene mapping. Also included are a large number of tricks for separately manipulating the micronuclear and macronuclear genomes. These allow such feats as the expression of varied doses of an essential gene and the maintenance of a lethal mutation in the germ line without somatic expression. Because the mitotic micronucleus is dispensable for vegetative growth and the macronucleus divides amitotically, it is possible to study mutants deficient in mitotic chromosome maintenance without adverse effects on viability.

The third section, dedicated to techniques for the study of specific research questions, covers varied topics ranging from sophisticated cellular electrophysiology to biochemical analysis of purified proteins. Each of these protocols will be of value only to a narrow set of experimenters, but together they illustrate the wide scope of T. thermophila experimental biology.

The volume concludes with a set of optimized protocols for molecular genetic manipulations. This section, although short, will be heavily used. Many laboratories have invested years of effort developing and improving techniques for the transformation of either nucleus. These techniques have already been shared, as is typical in the T. thermophila community, but their presentation in a collected form will make starting up easier for newcomers.

The chief weaknesses of the text are not surprising. With over 50 contributors, the composition of the chapters varies in style and quality. As a whole, the volume speaks to the power of T. thermophila as an experimental system, but concise arguments for the use of this organism are hidden at the ends of the introductory chapters. More problematic, considering that the volume strives to be a current source of reference, is that some of the protocols are already dated and some new efforts, such as genomics, go unmentioned. Considering the use of non-standard codons in T. thermophila, a chapter describing heterologous expression methods, including the construction of synthetic genes, would have been useful.

The editors accomplish their primary goal: presenting a comprehensive manual for the use of T. thermophila in the laboratory. Most importantly, they consolidate classical and molecular techniques into a single presentation, facilitating use of complementary tools and thus generating a whole more valuable than the sum of its parts. Yet, in a sense, the greatest achievement of this volume is its ability to inform and remind all biologists of the power of T. thermophila as an experimental system. Some of the leaders in the T. thermophila community work diligently to increase awareness of the usefulness of this organism. These missionaries would be wise to share this new volume with the broader biological community, for it demonstrates many times over that the effectiveness of T. thermophila as a model system is enhanced by its unique features.