by Jonathan Slack. Blackwell Science (2001) 321 pages. ISBN 0-632-05233-3 £16.50
Developmental biology is not one of the easiest of subjects to study. The richness in diversity of body forms and the surprising contortions embryos often go through to produce them (aspects of the subject that lure many into the field), make it especially hard for someone new to get a good handle on what is going on. Added to the complicated embryological interactions is the ever-increasing number of genes (often with confusing names) that are being identified as key players in these processes and whose products function through complex interactions with other gene products. Textbooks on developmental biology have the challenging task of presenting this subject to students in an engaging and clear manner. They have to strike a balance, presenting sufficient detail to be informative but not so much that they are confusing and the fundamental principles are lost in a sea of detail.
By these criteria, the book Essential Developmental Biology succeeds admirably. It is aimed at students at the undergraduate level and is intended to give a good grounding in the principles and experimental approaches of developmental biology. It does not try to be an exhaustive treatment of the subject, but sets out to explain the central themes of development through a few well-chosen model organisms and systems. The book is eminently readable, written in a straightforward and easy-to-understand style. The numerous figures - line drawings, uncluttered and consistent in style - are clear and effectively illustrate the point being made. Perhaps my only quibble about the book is that at times it is too descriptive, cataloging what is known about a particular developmental process instead of conveying a sense of the debates and changing opinions in the field.
The text is divided into three broad sections. The first introduces general aspects of development that are useful in understanding the two subsequent sections. The second describes the development of a selection of model organisms, and the last section deals with organogenesis and regeneration.
The first section begins with a brief introductory chapter that describes the origin of developmental biology, the centrality of the subject to other fields of biology and its relevance to, and impact on, society. The remainder of the section follows a logical progression, starting with a chapter that describes the basic questions in development, and going on in other chapters to touch upon processes common to the development of most organisms, such as gametogenesis, fertilization, inductive interactions and morphogenetic movements during early embryogenesis. There is a chapter devoted to some of the molecular pathways that play important roles during development. One feature students will find especially useful is an appendix to this chapter, describing families of four categories of molecule especially important to development - transcription factors, inducing factors, cell adhesion molecules and extracellular matrix components. This appendix serves as a quick reference and will prevent students from being overwhelmed by the increasing numbers of molecules being discovered to function during development. There is a chapter on genetic techniques used in the study of development, such as mutagenesis and transgenesis, and a separate one on other more general techniques, such as microscopy, cell labeling, in situ hybridization, etc.
The second section is devoted to six model organisms - Xenopus laevis, the zebrafish, the chick, the mouse, Drosophila melanogaster and Caenorhabditis elegans. The introductory chapter in this section compares the various model organisms so that one gets a feel for their advantages and disadvantages (in terms of amenability to physical and genetic manipulation, cost, etc.) and can understand why someone might choose to work on one particular organism rather than another. Each of the subsequent chapters in this section focuses on one of the model organisms. Each begins with a fairly comprehensive, yet concise, overview of the early development of that organism. This is followed, in most cases, by a description of some of the major insights into development to arise from work in that organism. The chapter on flies, for example, describes the interactions of the gap, pair rule and segment polarity genes in the establishment of anterior-posterior pattern, whereas the chapter on frogs highlights in some detail the molecular interactions thus far known to be important for dorsoventral patterning and inductive interactions.
The last section of the book is devoted to the development of a few organ systems and regeneration. The first chapter in this section provides background information about various tissue types. The following chapters deal with the development of the nervous system, mesodermal organs (such as the kidney, gonads and limbs), imaginal discs in flies and regeneration in planarians and vertebrates. These chapters effectively use the development of these various organs to illustrate underlying developmental processes and the genetic pathways that control them.
Overall, I think this is a very good introductory text for developmental biology. It is clear, concise, and does a fairly good job of explaining a difficult subject. The book, true to its title, nicely presents the essentials required for a student to traverse the rough terrain of development.
