• Contents
• Preface

Contents in Brief

Part One: From Gametogenesis to Histogenesis

1 Analysis of Development

2 The Role of Cells in Development

3 Gametogenesis

4 Fertilization

5 Cleavage

6 Cell Fate, Potency, and Determination

7 Genomic Equivalence and the Cytoplasmic Environment

8 Localized Cytoplasmic Determinants

9 Axis Formation and Mesoderm Induction

10 Gastrulation

11 Cell Adhesion and Morphogenesis

12 Neurulation and Axis Induction

13 Ectodermal Organs

14 Endodermal and Mesodermal Organs

Part Two: Control of Gene Expression in Development

15 The Use of Mutants and Transgenic Organisms in the Analysis of Development

16 Transcriptional Control

17 RNA Processing

18 Translational Control and Posttranslational Modifications

19 Genetic and Paragenetic Information

Part Three: Selected Topics in Developmental Biology

20 Cell Differentiation

21 Pattern Formation and Embryonic Fields

22 Genetic and Molecular Analysis of Pattern Formation in the Drosophila Embryo

23 The Role of Hox Genes in Vertebrate Development

24 Genetic and Molecular Analysis of Pattern Formation in Plants

25 Experimental and Genetic Analysis of Caenorhabditis elegans Development

26 Sex Determination

27 Hormonal Control of Development

28 Organismic Growth and Oncogenes

29 Senescence

This text is written for undergraduates and beginning graduate students. Previous course work in cell biology and genetics will help but is not necessary. Chapters 2 and 15 summarize those elements of cell biology and genetics that are needed to make full use of this text. The text is complemented by my web site (http://www.esb.utexas.edu/kalthoff/bio349/), which I use for my own teaching, and which contains regular updates, exam questions, links to movies of interest to developmental biologists, and much more.

My central idea in writing the second as well as the first edition has been to present developmental biology as an ongoing process of enquiry. This emphasis gives the aspiring researcher a taste of things to come, and it introduces those who just seek an education to the ways in which developmental biologists gain their knowledge. In chapter one, I discuss the surgical removal and transplantation of embryonic parts as experimental strategies that have defined embryology as a discipline in its own right. In a preview of genetic analysis in the same chapter, I introduce null alleles and gain-of-function alleles as alternate ways of removing a defined part from a system or allowing it to function at a time or place where it is normally absent. In chapter 15, where genetic and molecular analysis begin in earnest, I present gene overexpression and dominant interference as equivalents to the mutant alleles. Commonly used methods are set aside in boxes for easy reference. Throughout the text, I present key experiments in more detail than usual, and I conclude these parts with a few questions that test the students' understanding of the analytical process. The answers to these questions will be on my web site.

Next to the emphasis on the analytical process, I have found it important to bring out a few general principles of development. For instance, many steps in development rely on overlapping mechanisms that complement or reinforce each other. Spemann referred to this as the principle of double insurance; I introduce this principle in the context of fertilization and then take it up again in chapters on induction and genetic control. Other principles, including stepwise approximation and default programs, are treated in a similar fashion. I hope that these recurring principles will provide a sense of continuity and structure in the plethora of details and new results that can easily clutter the mind.

What I have tried most to preserve in this second edition is the excitement in the field that has come with the new opportunities to bring the modern tools of genetic and molecular analysis to bear on the basic questions that have defined the discipline since its inception. Correspondingly, the subdivision of the text into three major parts is still the same. Part One emphasizes classical methods of analysis and covers the series of embryonic stages from gametogenesis to histogenesis. Interspersed are basic conceptual topics such as nuclear totipotency, cell determination, cytoplasmic localization, induction, and morphogenesis. Part Two introduces the genetic and molecular analysis of development, beginning with a chapter on the use of mutants, DNA cloning, and transgenic organisms. Subsequent chapters explain the concept of differential gene expression with the goal of understanding how the genomic information is used to build a three-dimensional organism that unfolds in time. The chapter on paragenetic information, a topic that was somewhat offbeat in the first edition but has since been recognized by the award of the Nobel Prize to Stanley Prusiner, is still providing the counterpoint to the emphasis on genetic information. Part Three freely combines classical and modern types of analysis and should be the most enjoyable portion of the book. It illustrates how the application of new research tools has led to a better understanding of long-standing issues in development. This part begins with a chapter the classical analysis of pattern formation, perhaps the most central topic in developmental biology. The chapter on the genetic analysis of patterning in Drosophila, which already was the longest one in the first edition, has grown even more, but the award of the Nobel prize to Christiane Nüsslein-Volhard, Eric Wieschaus, and Edward Lewis, gave me the justification to endulge here. Chapters centered on Mus musculus, Arabidopsis thaliana, and Caenorhabditis elegans follow, as do sex determination, hormonal control, and growth.

What is entirely new in the second edition is a chapter on the evolutionary theory of senescence and some of its proximate causes, topics that have matured to the point where I think they merit discussion in a textbook. The chapters on cell adhesion and the extracellular matrix, formerly in Part Three, have been combined and moved to Part One, where they fit in more naturally with gastrulation and organogenesis. And then, of course, both text and illustrations are thoroughly updated. About a third of all references are new, reflecting the rapid progress being made in the field. A similar fraction of illustrations are new or revised substantially, and about half (Jean, do you have a tally?) of the line drawings are now multicolored. To offset the additions, a good number of illustrations and references had to be retired, so that the overall size of the text could be maintained.

Acknowledgments

I feel grateful to some special people who provided inspiration and support for writing this new edition. I still feel connected to my mentor, Klaus Sander, who long ago introduced me to the history and culture of developmental biology. At The University of Texas at Austin, I enjoy the company of a diverse but congenial group of colleagues who, through countless journal club sessions and individual conversations, have broadened my outlook on developmental biology and its practitioners. My wife, Karin, has again been a source of support and balance throughout this project.

It has been a great pleasure to work with Gwen Gage and Kristina Schlegel, two expert computer illustrators who converted my rough drafts into pieces of art. Ondine Cleaver was again part of the team, this time as advisor and coordinator for all illustrations.