The destiny of an embryo is the anatomy of the organism. The development of the structure of an organism at any level is what we developmental biologists seek to explain. A good description of anatomy is thus a crucial prerequisite of our science, and often provides inspiration for new lines of research.FIG1 

The C. elegans Atlas
 By David H. Hall and Zeynep F. Altun
 Cold Spring Harbor Laboratory Press (2008) 348 pages
 ISBN 978-087969715-0
 $125 (wire binding)

The C. elegans Atlas
 By David H. Hall and Zeynep F. Altun
 Cold Spring Harbor Laboratory Press (2008) 348 pages
 ISBN 978-087969715-0
 $125 (wire binding)

The strikingly invariant cell lineage of Caenorhabditis elegansleads to the essentially invariant anatomy described in the stunningly beautiful book, The C. elegans Atlas, by David Hall and Zeynep Altun. The images and description provided in it are a great resource for learning the anatomy of C. elegans, knowledge that is essential for a wide range of experiments. For example, if you can see a cell, you can kill it with laser irradiation and thereby assess its function. Such ablation experiments are performed routinely to investigate the developmental, behavioral and physiological consequences of deficits in particular cells, and not understanding the worm's detailed anatomy is a limiting factor in such analyses. The images in this atlas show one how to find many C. elegans cells.

The major content of the 348-page book is its 192 figures, most with multiple panels, which often consist of multiple images. The figures include informative schematics, Nomarski differential interference optic micrographs,epifluorescence images, scanning electron micrographs, and color-coded transmission electron micrographs. However, the book is printed in landscape format, 24 inches wide when open, nine inches high. This format works wonderfully on a table, but is inconvenient to place next to a microscope. When I first saw the book, I assumed it was designed to accommodate the elongated shape of these worms; however, only a few figures actually use the width of the pages, and only one stretches to nine inches. Also, there are no two-page spreads, something I expected and looked forward to. It is unclear whether the priority was to produce graphics for a web-accessible version.

I had a serious problem writing this review: my students repeatedly took this book from my office

That said, every few pages hold some new delight. Figure 4.1 shows the plumbing of the excretory system in a gorgeous schematic. The structure of the C. elegans nervous system with its 302 neurons has always been inspirational; this book makes it more accessible. For example, Figure 3.14 shows wiring bundles from the ventral nerve cord to the various commissures;if you were not fascinated by axon guidance before, you will be after seeing these diagrams. Chapter 7 nicely describes the alimentary system and its development. In particular, a set of figures clearly illustrates the 180°twist that occurs in the intestine during embryogenesis. The chapter on muscle uses a wide array of images to explain the ultrastructure of C. elegans obliquely striated muscle at the level of the fibers, cells and muscle quadrants. The hermaphrodite reproductive system (chapter 8) is covered so extensively that I learned new and interesting details about body parts that I have been studying for decades.

By contrast, the pericellular structures are given short shrift (chapter 10). Even though there are nice reagents for visualizing extracellular matrix,this chapter relies more on text than on figures. Moreover, there is relatively little information on the male included in this atlas. Part of the reason is that the ultrastructure of the male is less well known; it is only now being elucidated by Scott Emmons, David Hall and colleagues. However,there is considerable information at the light microscopic level. Perhaps there will have to be a sequel to this book that includes this new information.

If you want to think about organogenesis, these images allow you to understand how the cells are arranged and what they contact. The cell lineage diagrams of John Sulston, H. Robert Horvitz, Judith Kimble and Einhard Schierenberg hint at a profound logic that underlies the development of this worm, but being able to see the positions of the cells is essential for understanding cell-cell communication, cell migration and morphogenesis. This atlas combines in a digestible fashion the cell lineage information with the positions and morphologies of specific cells. It allows the reader to visualize fully the end points of morphogenesis, and thus to comprehend the many developmental experiments that can be performed on this organism.

In the few descriptions of developmental anatomy and genetics in this atlas, some information is already out of date. However, the vast majority of the content is timeless, making this a reference work that one will want to go back to repeatedly.

As you might expect from a phylum comprising about a million species, there is considerable anatomical diversity, but many individual cells are easily recognizable among species. Thus, the detail presented about C. elegans has a high probability of applying to other nematodes.

I had a serious problem writing this review: my students repeatedly took this book from my office. Indeed, one student lamented that “there are not enough pictures”. Overall, the authors have done an excellent job balancing completeness and readability. However, the authors' superb website, www.wormatlas.org,will presumably have all these images, and more, at some time. Nonetheless,any serious student of nematodes would want to have this book on their laboratory coffee table. And, anyone who is reading one of the now 10,000 C. elegans papers, will likewise want access to this book.