Cell, Vol. 44, 5-6, January 17, 1966, Copyright 0 1966 by Cell Press

Book Reviews

Exploring the Diversity of Animal Development

Developmental Biology By Scott F. Gilbert Sunderland, Massachusetts: Sinauer Associates. (1985). 726 pp. $33.95.

Developmental Biology, by Scott Gilbert, is an excellent and comprehensive textbook of animal development. Written in the classic tradition of E. B. Wilson, it presents the grandeur of animal diversity and, at the same time, conveys the excitement being generated as new tech- niques are applied to developing systems.

Following several chapters that introduce the basics of comparative embryonic morphology, the text is organized by processes rather than by systems. There are, for exam- ple, chapters on pattern formation, cytopiasmic localiza- tion, and determination as well as several on the control of nucleic acid formation and function. Each of these em- braces a wide range of animal systems, rather than focus- ing only on the “typical” or popular model systems. The reader is offered insight into how our understanding of specific developmental processes has evolved from rec- ognition to initial definition to critical dissection, using methods of experimental embryology and then biochem- istry. As is usual in Sinauer texts, there are “Sidelights and Speculations” sections interspersed with the text. These highlight notable exceptions to the norm, suggest possi- ble future applications of emerging techniques, and pre- sent many other, often eclectic, ideas.

For the professional or graduate-level developmental bi- ologist, this text is a delight to read. The writing is crisp and well focused, with a style that engages the reader, and the copious illustrations are generally clear and informative.

For the undergraduate student and instructor, this text is challenging. Most students do not arrive in a develop- mental biology class with background in comparative ani- mal biology, cellular biology or molecular biology; these initiates may easily become overwhelmed by the volume of intertwined examples. Also, when focusing on pro- cesses, there is a tendency to lose a sense of the whole organism. For example, a student interested in early deter- minative events during Drosophila development would need to read parts of four separate chapters. Thus, in- structors using this text for undergraduates will need to outline carefully their expectations of the students, and devote considerable attention to integrating systems and concepts.

Gilbert’s selection of material is as exhaustive as that in any text available today, and certainly more interesting than most. A few surprising omissions are consideration of oncogenes and growth factors (except NGF), presenta- tion and speculation related to genetic engineering, and

also discussions of the bases for congenital defects. How- ever, these are minor concerns, and do not diminish my excitement and enthusiasm towards Gilbert’s outstanding text. I highly recommend it for advanced undergraduate and graduate courses in ceil and molecular deveiopmen- tal biology.

Drew M. Noden Anatomy Department New York State College of Veterinary Medicine Cornell University Ithaca, New York 14853

Cell Membranes before the Impact of Molecular Genetics

Ceil Membranes. Methods and Reviews. Volume 2. Edited by E. Elson, W. Frazier, and L. Giaser. New York: Plenum Press. (1984). 371 pp. $52.50.

It would not be too gross an oversimplification to suggest that much of the mystery surrounding the surface mem- branes of mammalian ceils would be dispelled if we un- derstood how proteins work as receptors and as channels and pumps. Add to this list some insight into the cytoskeie- ton and its membrane attachments and we would have a working knowledge of the ceil surface to rival the insight enjoyed by workers in any other field of ceil biology. Thus, a monograph purporting to educate the scientific public about cell membranes should provide some new insight into at least one of these three areas of study.

The measure of a monograph on any subject in biology also depends on the timeliness of the information being transmitted, and here editors of monographs on mem- brane studies in recent years have had to contend with a special problem: When was the power of molecular genetics going to hit membrane biology?

information about the primary structures of certain types of membrane proteins has been painfully difficult to obtain, due partly to the difficulties in purifying and analyzing hydrophobic peptides. Other membrane pro- teins of monumental size seemed beyond the reach of conventional peptide sequencing for practical reasons. Molecular genetics has clearly come to the rescue. Readers of Cell and Nature over the past eighteen months have been treated to an avalanche of structural infor- mation about membrane proteins that had previously resisted decades of analysis by workers using conven- tional methods. Amino acid sequences of many important ceil surface receptors and channel-pumps seem to have been solved almost overnight-or so it would appear to a casual reader. This list of membrane protein triumphs in-

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eludes the receptors for insulin, epidermal growth factor, transferrin, interleukin II, and low density lipoproteins. Transport molecules that are now known in intimate detail include the sodium channel, the glucose carrier, pumps for sodium and calcium, and the acetylcholine receptor- channel.

Cell Membranes. Methods and Reviews was commis- sioned before this explosion could be forecast and this has affected to varying degrees the timeliness of the mes- sages in different chapters. The great excitement gener- ated by the discovery that different fibronectin molecules can be produced from one gene via differential RNA splic- ing is not described in the chapter on fibronectin since these results were obviously reported sometime after this essay was submitted to the publisher. This makes the chapter appear more outdated than it deserves to be, es- pecially since it is a superb analysis of a large and cum- bersome literature about an extremely complex surface membrane molecule. Similarly, the chapter on the acetyl- choline receptor lacks the newly acquired structural data on the polypeptide subunits that comprise this intricate protein. This omission is not a serious problem, however, since the chapter is primarily an analysis of methods used to measure channel functions rather than a general sur- vey of the experimental findings. Although the new se- quence data provided by molecular genetics are certainly exciting, they will remain largely uninterpretable until good functional correlations can be carried out. Thus, the chapter in this monograph is just as valuable without the embellishment of long lists of nucleotides and amino acids.

Of the hormone receptors that are hooked up to cyclic AMP production and its consequences, the /I-adrenergic receptor stands alone in terms of the biochemical com- plexity that has been uncovered. Activation of this recep- tor is coupled to adenylate cyclase action that is tightly controlled by at least two guanine nucleotide binding pro- teins with opposing actions. Each protein is composed of two subunits: one common to both, the other ADP- ribosylated in response to different bacterial toxins. A beautifully crafted overview of this subject appears in this monograph.

Receptors coupled to the cytoskeleton and other struc- tures that are responsible for directed cell motility are be- lieved by many to hold a key to a proper understanding of chemotaxis. Two articles deal with the current state of in- formation about chemotaxis in leukocytes and cellular slime molds. Although the latter are thought to be the “sim- pler” system, as the authors concede, the take-away mes- sage from this chapter is not so obvious. A particularly clear discussion of the possible roles that calcium may play in regulating cell motility appears in the chapter on leukocytes.

Three chapters are devoted to an analysis of proteins that make up the membrane skeleton of human erythro- cytes. This area has enjoyed some success in recent years, but the major findings have been summarized repeatedly in many different reviews. In spite of this over- exposure, each of the chapters in this monograph focuses on areas not well described in other places. One chapter

on assembly of spectrin is really unique, since it describes research from a single laboratory-one that has pioneered in the study of skeletal assembly in the avian erythrocyte. A companion chapter, also from the same laboratory, pro- vides speculation on how membrane skeletal functional domains might be regulated. Both are well worth serious reading.

Contributions of molecular biology to an understanding of membrane skeletal structure and function have lagged behind the impressive achievements in receptor and channel biology cited above. Even at this writing there are still too little dataon the structure of genes encoding spec- trin and related proteins to complain about their absence in this monograph. It would be unwise, however, for any- one to plan another monograph on membrane skeletal proteins without anticipating major contributions from the cloning projects now in full swing in many laboratories.

Vincent T. Marchesi Department of Pathology Yale University School of Medicine New Haven, Connecticut 06510