The Microbial Models of Molecular Biology: From Genes to Genomes (review)

Rowland H. Davis, a distinguished researcher in molecular genetics and metabolism through his work with the fungus Neurospora crassa, has contributed a thoughtful chronology of the emergence of molecular biology, from the unique perspective of the choices of organisms employed for critical, landmark studies. He posits that microbial models have "positioned us for our twenty-first-century, postgenomic exploration of biological variation and complexity" (p. viii). His book is written for biologists who strive to learn about systems at all levels of complexity. The text is supported with extensive footnotes and references, as well as comprehensive name (of investigators) and subject indices. It would be valuable reading for advanced undergraduate students, graduate students, and postdoctoral fellows, to acquaint them with how and why biologists select specific organisms in pursuing fundamental questions. Moreover, there are three short appendices that serve as primers on (1) Life Cycles and Principles of Genetics, (2) Macromolecules and the Central Dogma, and (3) Genetic Engineering. This brief treatment of fundamental principles serves as a concise review and, for physical scientists, mathematicians, and computer scientists involved in interdisciplinary research problems, a good introduction.

Davis aims to describe the revolution that ensued after microbes became the focus of genetics studies. He articulates three goals in writing the book: (1) to show how the few microbial model systems were chosen for study; (2) to describe how each model, as influenced by prevailing attitudes and technology, was eclipsed by the succeeding model; and (3) to show that the models served biology well in a transitional period, the products of which now have us poised again to investigate the complexity of living organisms in their environments.

Davis's narrative, punctuated with descriptions of people, historical times, and methods of study, reads more like a fireside reminiscence than classroom lecture notes—yet the material is substantive, carefully annotated, and technically authoritative. He begins by distinguishing between model systems: "organisms widely used for particular research projects" (p. 6), and model organisms: "organisms whose biology is understood at many different levels—organisms that can be used as a representative or basis of comparison for a large taxon or kingdom of life" (p. 13). Davis briefly establishes the context of the field of genetics at the turn of the twentieth century, work that relied on the use of higher organisms with grossly macroscopic, visible traits. Then, in chronological order of ascendance to the status of model organism, he devotes individual chapters to the exploitation of Neurospora, Aspergillus, yeast, E. coli, and the T and temperate bacteriophages to examine the nature and action of genes.

These sections are followed by chapters describing the establishment of the double helix model of DNA, the reprise of the prominence of prokaryotes as models, cytoplasmic inheritance, and organellar genetics. Two more chapters contrast the establishment of yeast as a "supermodel" and the reemergence of filamentous fungi as a model group. The closing chapters of the book include a discussion of the critical role played by biochemistry in enabling the discoveries made with model organisms; a call for the integration of studies in physiology and metabolism; and a recapitulation of the impact of genomics on biological research. Lastly, Davis reviews the legacy provided by these model organisms as biological science looks to embrace, at a detailed level, the complex subjects now made accessible through the integrated application of molecular tools.

Davis answers questions about how choices of study systems are made, starting with the state of research on genetics and inheritance—shedding light on the personalities, biases, training, and eccentricities of scientists, and even the influence of geographic isolation and the amassing of a group of intense investigators. He eloquently reminds us that science is a process that builds on what has come before and is dependent on cross-talk as well as healthy competition. He points out that many problems of biology that were crucial in motivating the reductionists to...