Molecular Embryology: How Molecules Give Birth to Animals Book

	Introduction
Ch. 1	Growth of an Embryo is Founded on Repeated Cell Division	1
	Does a Vital Force Direct Animal Development?	1
	The Division of Embryonic Cells	4
	Cell Fate and Cell Lineage	7
	Cell Division in the Threadworm	8
	Cell Division in Fruit Files	12
	Cell Division in Frogs	17
	Cell Division in Mouse Embryos	21
Ch. 2	How an Embryo Acquires the Correct Shape as its Cells Divide	25
	The Way a Cell Divides Can Determine the Size and Position of its Daughter Cells and so Influence the Shape of the Embryo	25
	Change in Cell Shape, Localized Cell Division, and Cell Death Can Influence the Shape of an Embryo	28
	Secretion of Molecules by Cells Influences Embryonic Structure	30
	Some Cells Migrate to Form Tissues in Distant Parts of the Embryo	31
	Cell Adhesions Influence the Shape of the Embryo	34
	Types of Cell Adhesion	36
	The Importance of Cell Adhesion Molecules	37
Ch. 3	How Differences in Molecular Composition between Embryonic Cells Originate	41
	Asymmetric Cell Division and Signaling between Cells	41
	Asymmetric Division and Cell Signaling in C. Elegans	44
	Uneven Subdivision of the Egg Cytoplasm in Drosophila	46
	Asymmetric Division and Cell Signaling in Frogs	50
	The Origin of Differences in Cell Composition in Mouse Embryos	53
Ch. 4	Signal Molecules Induce Changes in Cell Composition throughout Vertebrate Development	57
	Hans Spemann Revealed the Importance of Inductive Signals in Vertebrates	57
	Neural Inductions	61
	Induction of Eyes, Feathers, and Other Body Structures	64
	Harrison's Experiments on Limb Formation	65
	The Origin of Cells that Lay Down the Structure of a Chick's Wing	67
	The Source of Signals that Induce the Structure of a Chick's Wing	70
	Signaling Cell Position	73
Ch. 5	Differences in Embryonic Cell Composition Result from Activation of Different Genes	79
	Mendel First Demonstrated the Importance of Genes in Development	79
	Mendel's Results Led to the Discovery that Genes are Made of DNA	83
	Weismann Wrongly Suggested that Different Cells of an Embryo Contain Different Genes	88
	Genes are Differentially Activated during Development	91
	Two-Step Activation of Embryonic Genes	93
	Specific Transcription Factors Are Keys to the Final Step in Gene Activation	96
	Techniques for Studying the Action of Genes in Development	100
Ch. 6	Experiments on Drosophila Reveal that Specific Transcription Factors Are Keys that Unlock Embryonic Genes	111
	The Breakthrough of Nusslein-Volhard and Weischaus	111
	The Bicoid Protein: a Specific Transcription Factor that Initiates Gene Activation from Front to Rear	114
	The Bicoid Protein Is a Morphogen	117
	Changing Patterns of Gene Activity along the Length of the Drosophila Embryo	119
	Patterns of Gene Activation down Each Side of the Drosophila Embryo	121
	The Formation of Cells and Organs of Differing Structure in Drosophila	125
Ch. 7	The Frontiers of Research in Molecular Embryology	131
	Signal Molecules and their Action	131
	Recent Research on C. Elegans	133
	Recent Research on Drosophila	138
	Recent Research on Xenopus	141
	Recent Research on Mice	144
	Recent Research on Limb Development	145
	Afterthoughts	146
	Glossary	149
	Index	159