Fungi take shape: Fungal Morphogenesis, by David Moore

Cambridge University Press, 1998. £70.00 (469 pages)ISBN 0 521 55295 8Because fungi are generally thought of as unicellular organisms, their importance in the field of morphogenesis and development has been largely ignored. However, fungi form specialized, highly regulated, multicellular structures, such as elaborate fruiting bodies for the dispersal of sexual spores, and conidiophores for the production of asexual spores. Intracellular, intercellular and external signals are integrated to determine the timing and spatial location for development within a fungal organism. Fungi are extremely plastic: most fungal cells are totipotent, such that the entire organism can be regenerated not only from spores but also from hyphal fragments. This property differentiates fungal cell lines from most animal cell lineages, such as those in the mammalian haematopoietic system, where cells have increasingly limited choices as development proceeds. The plasticity of fungal cells is a boon to the experimentalist because the signals and resulting developmental decisions can be studied in any cell.In his book Fungal Morphogenesis, David Moore discusses the biochemistry, genetics and physiology of development throughout the fungal kingdom and attempts to relate these data to animal development. As a backdrop, Moore devotes a large section of the monograph to a discussion of the metabolic pathways involved in nutrient absorption and utilization and how these pathways are regulated by environmental factors. Of particular interest is the section in Chapter 3 that covers secondary metabolites – fungal products derived from metabolic intermediates, typically during non-optimal nutritional conditions. These side-products of metabolism include a large number of drugs such as penicillin antibiotics and the ergot alkaloids (some of which are used to treat migraine headaches) as well as toxins such as the hepatocarcinogen aflatoxin B1. While not discussed in detail in this book, some of the signalling pathways that regulate fungal morphogenesis are also involved in secondary metabolite production. Moore continues to the main topic of the book, morphogenesis, by describing the different structures and tissues found in fungi, and the molecular bases for the development of these patterns and their regulation. Especially relevant is Chapter 5, which describes the genetic regulation of filamentous differentiation and its connections to the regulatory molecules encoded at the mating-type loci of various fungi.Fungal Morphogenesis is a comprehensive book, covering most aspects of an exciting and important field. It is a daunting task to describe development over an entire kingdom, yet Moore manages to incorporate data from all classes of fungi into an overall synthesis of fungal development. He describes all of the current models of fungal morphogenesis and most of the relevant research. The extensive reference list includes the most pertinent fungal research over the past forty years.There are, however, two significant faults with this book. First, the book misses its target audience. Written with too much mycological jargon to be comprehended easily by biologists whose expertise is outside the immediate field, it lacks the experimental detail and criticality needed to appeal to fungal biologists. Second, the book ignores most of the wealth of knowledge that has been gained from studying the ascomycete Saccharomyces cerevisiae (the common baker’s yeast). Studies of this fungus have yielded an enormous amount of information on the molecular bases of many key fungal cell-biological processes, including mating, meiosis, the cell cycle, bud growth and the developmental switch from solitary yeast cells to pseudohyphal filaments. This progress is in large part due to the uniquely high tractability of S. cerevisiae as an experimental system (although it is likely that ongoing fungal genome sequencing efforts will help to narrow this experimental gap between S. cerevisiae and other systems). By virtually excluding S. cerevisiae from his synthesis of fungal morphogenesis, Moore ignores the most extensively studied fungus and deprives his readers of highly significant information. Nonetheless, the sheer breadth of work discussed in this book, together with its extensive bibliography, might make this book a useful reference for those willing to accept its shortcomings.