Principles of Development / Edition 4

by Lewis Wolpert, Cheryll Tickle

Overview

Offering the ideal depth and coverage for an undergraduate course, Principles of Development, Fourth Edition, focuses on common principles rather than overwhelming students with an encyclopedic level of detail. The fourth edition features more examples from human development and medicine; a fully revised and updated chapter on evolutionary developmental biology; expanded coverage of experimental evidence and tools; new end-of-chapter questions in both essay and multiple-choice formats; and an enhanced Companion Website.

Product Details

ISBN-13:	9780199554287
Publisher:	Oxford University Press
Publication date:	12/01/2010
Edition description:	Older Edition
Pages:	720
Product dimensions:	8.20(w) x 10.60(h) x 1.00(d)

About the Author

Lewis Wolpert is Emeritus Professor of Biology at University College London.

Cheryll Tickle is Professor Emeritus at the University of Bath.

Alfonso Martinez Arias is Professor of Developmental Mechanics at the University of Cambridge.

Table of Contents

Contents
Chapter 1 History and basic concepts
Box 1A Basic stages of Xenopus laevis development
The origins of developmental biology
1.1 Aristotle first defined the problem of epigenesis and preformation
1.2 Cell theory changed the conception of embryonic development and heredity
Box 1B The mitotic cell cycle
1.3 Two main types of development were originally proposed
1.4 The discovery of induction showed that one group of cells could determine the development of neighboring cells
1.5 The study of development was stimulated by the coming together of genetics and development
1.6 Development is studied mainly through selected model organisms
1.7 The first developmental genes were identified as spontaneous mutations
Summary
A conceptual tool kit
1.8 Development involves the emergence of pattern, change in form, cell differentiation, and growth
Box 1C Germ layers
1.9 Cell behavior provides the link between gene action and developmental processes
1.10 Genes control cell behavior by specifying which proteins are made
1.11 The expression of developmental genes is under tight control
Box 1D Tracking gene expression in embryos
Box 1E Signal transduction and intracellular signaling
1.12 Development is progressive and the fate of cells becomes determined at different times
1.13 Inductive interactions can make cells different from each other
Box 1F When development goes awry
1.14 The response to inductive signals depends on the state of the cell
1.15 Patterning can involve the interpretation of positional information
1.16 Lateral inhibition can generate spacing patterns
1.17 Localization of cytoplasmic determinants and asymmetric cell division can make daughter cells different from each other
1.18 The embryo contains a generative rather than a descriptive program
1.19 The reliability of development is achieved by a variety of means
1.20 The complexity of embryonic development is due to the complexity of cells themselves
1.21 Development is intimately involved in evolution
Summary
SUMMARY TO CHAPTER 1
Chapter 2 Development of the Drosophila body plan
2.1 The early Drosophila embryo is a multinucleate syncytium
2.2 Cellularization is followed by gastrulation and segmentation
2.3 After hatching, the Drosophila larva develops through several larval stages, pupates, and then undergoes metamorphosis to become an adult
2.4 Many developmental genes have been identified in Drosophila through induced large-scale genetic screening
Box 2A Mutagenesis and genetic screening strategy for identifying developmental mutants in Drosophila
Setting up the body axes
2.5 The body axes are set up while the Drosophila embryo is still a syncytium
2.6 Maternal factors set up the body axes and direct the early stage of Drosophila development
2.7 Three classes of maternal genes specify the antero-posterior axis
2.8 bicoid provides an antero-posterior gradient of a morphogen
2.9 The posterior pattern is controlled by the gradients of Nanos and Caudal proteins
2.10 The anterior and posterior extremities of the embryo are specified by cell-surface receptor activation
2.11 The dorso-ventral polarity of the embryo is specified by localization of maternal proteins in the egg vitelline envelope
2.12 Positional information along the dorso-ventral axis is provided by the Dorsal protein
Box 2B The Toll signaling pathway: a multifunctional pathway
Summary
Localization of maternal determinants during oogenesis
2.13 The antero-posterior axis of the Drosophila egg is specified by signals from the preceding egg chamber and by interactions of the oocyte with follicle cells
2.14 Localization of maternal mRNAs to either end of the egg depends on the reorganization of the oocyte cytoskeleton
2.15 The dorso-ventral axis of the egg is specified by movement of the oocyte nucleus followed by signaling between oocyte and follicle cells
Summary
Patterning the early embryo
2.16 The antero-posterior axis is divided up into broad regions by gap-gene expression
2.17 Bicoid protein provides a positional signal for the anterior expression of zygotic hunchback
Box 2C P-element-mediated transformation
Boc 2D Targeted gene expression and misexpression screening
2.18 The gradient in Hunchback protein activates and represses other gap genes
2.19 The expression of zygotic genes along the dorso-ventral axis is controlled by Dorsal protein
2.20 The Decapentaplegic protein acts as a morphogen to pattern the dorsal region
Summary
Activation of the pair-rule genes and the establishment of parasegments
2.21 Parasegments are delimited by expression of pair-rule genes in a periodic pattern
2.22 Gap-gene activity positions stripes of pair-rule gene expression
Summary
Segmentation genes and compartments
2.23 Expression of the engrailed gene delimits a cell-lineage boundary and defines a compartment
Box 2E Genetic mosaics and mitotic recombination
2.24 Segmentation genes stabilize parasegment boundaries and set up a focus of signaling at the boundary that patterns the segment
2.25 Insect epidermal cells become individually polarized in an antero-posterior direction in the plane of the epithelium
Box 2F Planar cell polarity in Drosophila
2.26 Some insects use different mechanisms for patterning the body plan
Summary
Specification of segment identity
2.27 Segment identity in Drosophila is specified by Hox genes
2.28 Homeotic selector genes of the bithorax complex are responsible for diversification of the posterior segments
2.29 The Antennapedia complex controls specification of anterior regions
2.30 The order of Hox gene expression corresponds to the order of genes along the chromosome
2.31 The Drosophila head region is specified by genes other than the Hox genes
Summary
SUMMARY TO CHAPTER 2
Chapter 3 Vertebrate development I: life cycles and experimental techniques
Vertebrate life cycles and outlines of development
3.1 The frog Xenopus laevis is the model amphibian for developmental studies
3.2 The zebrafish embryo develops around a large mass of yolk
3.3 Birds and mammals resemble each other and differ from Xenopus in some important features of early development
3.4 The early chicken embryo develops as a flat disc of cells overlying a massive yolk
3.5 Early development in the mouse involves the allocation of cells to form the placenta and extra-embryonic membranes
Experimental approaches to studying vertebrate development
Box 3A Gene-expression profiling by DNA microarray
3.6 Not all techniques are equally applicable to all vertebrates
3.7 Fate mapping and lineage tracing reveal which cells in the early embryo give rise to which adult structures
Box 3B Insertional mutagenesis and gene knock-outs in mice: Cre/loxP
3.8 Developmental genes can be identified by spontaneous mutation and by large-scale mutagenesis screens
Box 3C Large-scale mutagenesis in zebrafish
3.9 Transgenic techniques enable animals to be produced with mutations in specific genes
3.10 Gene function can also be tested by transient transgenesis and gene silencing
3.11 Gene regulatory networks in embryonic development can be revealed by chromatin immunoprecipitation techniques
SUMMARY TO CHAPTER 3
Chapter 4 Vertebrate development II: axes and germ layers
Setting up the body axes
4.1 The animal-vegetal axis is maternally determined in Xenopus and zebrafish
Box 4A Intercellular protein signals in vertebrate development
4.2 Localized stabilization of the transcriptional regulator β-catenin specifies the future dorsal side and the location of the main embryonic organizer in Xenopus and zebrafish
4.3 Signaling centers develop on the dorsal side of Xenopus and zebrafish blastulas
4.4 The antero-posterior and dorso-ventral axes of the chick blastoderm are related to the primitive streak
4.5 The definitive antero-posterior and dorso-ventral axes of the mouse embryo are not recognizable early in development
4.6 Movement of the distal visceral endoderm indicates the definitive antero-posterior axis in the mouse embryo
4.7 The bilateral symmetry of the early embryo is broken to produce left-right asymmetry of internal organs
Box 4B Fine-tuning Nodal signaling



Summary
The origin and specification of the germ layers
4.8 A fate map of the amphibian blastula is constructed by following the fate of labeled cells
4.9 The fate maps of vertebrates are variations on a basic plan
4.10 Cells of early vertebrate embryos do not yet have their fates determined and regulation is possible
Box 4C Identical twins
Box 4D Preimplantation genetic screening
4.11 In Xenopus the endoderm and ectoderm are specified by maternal factors, but the mesoderm is induced from ectoderm by signals from the vegetal region
4.12 Mesoderm induction occurs during a limited period in the blastula stage
4.13 Zygotic gene expression is turned on in Xenopus at the mid-blastula transition
4.14 Mesoderm-inducing and patterning signals in Xenopus are produced by the vegetal region, the organizer, and the ventral mesoderm
4.15 Members of the TGF-β family have been identified as mesoderm inducers
4.16 The zygotic expression of mesoderm-inducing and patterning signals in Xenopus is activated by the combined actions of maternal VegT and Wnt signaling
4.17 Signals from the organizer pattern the mesoderm dorso-ventrally by antagonizing the effects of ventral signals
4.18 Threshold responses to gradients of signaling proteins are likely to pattern the mesoderm
Box 4E A zebrafish gene regulatory network
4.19 Mesoderm induction and patterning in the chick and mouse occurs during primitive-streak formation
Summary
SUMMARY TO CHAPTER 4
Chapter 5 Vertebrate development III: the early nervous system and the somites
The role of the organizer and neural induction
5.1 The inductive capacity of the organizer changes during gastrulation
5.2 The neural plate is induced in the ectoderm
Box 5A Chromatin-remodeling complexes
Box 5B The FGF signaling pathway
5.3 The nervous system is initially patterned by signals from the mesoderm
5.4 Neural crest cells arise from the borders of the neural plate
Summary
Somite formation and antero-posterior patterning
5.5 Somites are formed in a well-defined order along the antero-posterior axis
Box 5C The Notch signaling pathway
Box 5D Retinoic acid-a small-molecule intercellular signal
5.6 Identity of somites along the antero-posterior axis is specified by Hox gene expression
Box 5E The Hox genes
5.7 Deletion or overexpression of Hox genes causes changes in axial patterning
5.8 Hox gene expression is activated in an anterior to posterior pattern
5.9 The fate of somite cells is determined by signals from the adjacent tissues
Summary
The initial regionalization of the vertebrate brain
5.10 Local signaling centers pattern the brain along the antero-posterior axis
5.11 The hindbrain is segmented into rhombomeres by boundaries of cell-lineage restriction
Box 5F Eph receptors and their ephrin ligands
5.12 Hox genes provide positional information in the developing hindbrain
5.13 Neural crest cells from the hindbrain migrate to populate the branchial arches
5.14 The embryo is patterned by the neurula stage into organ-forming regions that can still regulate
Summary
SUMMARY TO CHAPTER 5
Chapter 6 Development of nematodes, sea urchins, and ascidians
Nematodes
Box A Gene silencing by antisense RNA and RNA interference (RNAi)
6.1 The antero-posterior axis in Caenorhabditis elegans is determined by asymmetric cell division
6.2 The dorso-ventral axis in Caenorhabditis elegans is determined by cell-cell interactions
6.3 Both asymmetric divisions and cell-cell interactions specify cell fate in the early nematode embryo
6.4 Hox genes specify positional identity along the antero-posterior axis in Caenorhabditis elegans
6.5 The timing of events in nematode development is under genetic control that involves microRNAs
Box 6B Gene silencing by microRNAs
6.6 Vulval development is initiated by the induction of a small number of cells by short-range signals from a single inducing cell
Summary
Echinoderms
6.7 The sea-urchin embryo develops into a free-swimming larva
6.8 The sea-urchin egg is polarized along the animal-vegetal axis
6.9 The sea-urchin fate map is finely specified, yet considerable regulation is possible
6.10 The vegetal region of the sea-urchin embryo acts as an organizer
6.11 The sea-urchin vegetal region is demarcated by the nuclear accumulation of β-catenin
6.12 The genetic control of the skeletogenic pathway is known in considerable detail
6.13 The oral-aboral axis in sea urchins is related to the plane of the first cleavage
6.14 The oral ectoderm acts as an organizing region for the oral-aboral axis
Summary
Ascidians
6.15 Animal-vegetal and antero-posterior axes in the ascidian embryo are defined before first cleavage
6.16 In ascidians, muscle is specified by localized cytoplasmic factors
6.17 Notochord, neural precursors, and mesenchyme in ascidians require inducing signals from neighboring cells
Summary
SUMMARY TO CHAPTER 6
Chapter 7 Plant development
7.1 The model plant Arabidopsis thaliana has a short life-cycle and a small diploid genome
Embryonic development
7.2 Plant embryos develop through several distinct stages
Box 7A Angiosperm embryogenesis
7.3 Gradients of the signal molecule auxin establish the embryonic apical-basal axis
7.4 Plant somatic cells can give rise to embryos and seedlings
Box 7B Transgenic plants
Summary
Meristems
7.5 A meristem contains a small, central zone of self-renewing stem cells
7.6 The size of the stem-cell area in the meristem is kept constant by a feedback loop to the organizing center
7.7 The fate of cells from different meristem layers can be changed by changing their position
7.8 A fate map for the embryonic shoot meristem can be deduced using clonal analysis
7.9 Meristem development is dependent on signals from other parts of the plant
7.10 Gene activity patterns the proximo-distal and adaxial-abaxial axes of leaves developing from the shoot meristem
7.11 The regular arrangement of leaves on a stem is generated by regulated auxin transport
7.12 Root tissues are produced from Arabidopsis root apical meristems by a highly stereotyped pattern of cell divisions
7.13 Root hairs are specified by a combination of positional information and lateral inhibition
Summary

Flower development and control of flowering
7.14 Homeotic genes control organ identity in the flower
Box 7C The basic model for the patterning of the Arabidopsis flower
7.15 The Antirrhinum flower is patterned dorso-ventrally as well as radially
7.16 The internal meristem layer can specify floral meristem patterning
7.17 The transition of a shoot meristem to a floral meristem is under environmental and genetic control
Summary
SUMMARY TO CHAPTER 7
Chapter 8 Morphogenesis: change in form in the early embryo
Box 8A Change in cell shape and cell movement
Cell adhesion
Box 8B Cell-adhesion molecules and cell junctions
8.1 Sorting out of dissociated cells demonstrates differences in cell adhesiveness in different tissues
8.2 Cadherins can provide adhesive specificity
Summary
Cleavage and formation of the blastula
8.3 The orientation of the mitotic spindle determines the plane of cleavage at cell division
8.4 Cells become polarized in the sea-urchin blastula and the mouse morula
8.5 Fluid accumulation as a result of tight-junction formation and ion transport forms the blastocoel of the mammalian blastocyst
8.6 Internal cavities can be created by cell death
Summary
Gastrulation movements
8.7 Gastrulation in the sea urchin involves cell migration and invagination
Box 8C Convergent extension
8.8 Mesoderm invagination in Drosophila is due to changes in cell shape that are controlled by genes that pattern the dorso-ventral axis
8.9 Germ-band extension in Drosophila involves myosin-dependent remodeling of cell junctions and cell intercalation
8.10 Dorsal closure in Drosophila and ventral closure in Caenorhabditis elegans are brought about by the action of filopodia
8.11 Vertebrate gastrulation involves several different types of tissue movement
Summary
Neural-tube formation
8.12 Neural-tube formation is driven by changes in cell shape and convergent extension
Summary
Cell migration
8.13 Neural crest migration is controlled by environmental cues
Summary
Directed dilation
8.14 Later extension and stiffening of the notochord occurs by directed dilation
8.15 Circumferential contraction of hypodermal cells elongates the nematode embryo
8.16 The direction of cell enlargement can determine the form of a plant leaf
Summary
SUMMARY TO CHAPTER 8
Chapter 9 Germ cells, fertilization, and sex
The development of germ cells
9.1 Germ-cell fate is specified in some embryos by a distinct germ plasm in the egg
9.2 In mammals germ cells are induced by cell-cell interactions during development
9.3 Germ cells migrate from their site of origin to the gonad
9.4 Germ cells are guided to their final destination by chemical signals
9.5 Germ-cell differentiation involves a halving of chromosome number by meiosis
Box 9A Polar bodies
9.6 Oocyte development can involve gene amplification and contributions from other cells
9.7 Factors in the cytoplasm maintain the pluripotency of the egg
9.8 In mammals some genes controlling embryonic growth are 'imprinted'
Summary
Fertilization
9.9 Fertilization involves cell-surface interactions between egg and sperm
9.10 Changes in the egg envelope at fertilization block polyspermy
9.11 Sperm-egg fusion causes a calcium wave that results in egg activation
Summary
Determination of the sexual phenotype
9.12 The primary sex-determining gene in mammals is on the Y chromosome
9.13 Mammalian sexual phenotype is regulated by gonadal hormones
9.14 The primary sex-determining signal in Drosophila is the number of X chromosomes, and is cell autonomous
9.15 Somatic sexual development in Caenorhabditis is determined by the number of X chromosomes
9.16 Most flowering plants are hermaphrodites, but some produce unisexual flowers
9.17 Determination of germ-cell sex depends on both genetic constitution and intercellular signals
9.18 Various strategies are used for dosage compensation of X-linked genes
Summary
SUMMARY TO CHAPTER 9
Chapter 10 Cell differentiation and stem cells
The control of gene expression
10.1 Control of transcription involves both general and tissue-specific transcriptional regulators
10.2 External signals can activate gene expression
10.3 The maintenance and inheritance of patterns of gene activity depend on chemical and structural modifications to chromatin, as well as on gene-regulatory proteins
Box 10A Histones and Hox genes
Summary
Models of cell differentiation
10.4 All blood cells are derived from multipotent stem cells
10.5 Colony-stimulating factors and intrinsic changes control differentiation of the hematopoietic lineages
10.6 Developmentally regulated globin gene expression is controlled by regulatory sequences far distant from the coding regions
10.7 The epithelia of adult mammalian skin and gut are continually replaced by derivatives of stem cells
10.8 The MyoD family of genes determines differentiation into muscle
10.9 The differentiation of muscle cells involves withdrawal from the cell cycle, but is reversible
10.10 Skeletal muscle and neural cells can be renewed from stem cells in adults
10.11 Embryonic neural crest cells differentiate into a wide range of different cell types
10.12 Programmed cell death is under genetic control
Summary
The plasticity of gene expression
10.13 Nuclei of differentiated cells can support development
10.14 Patterns of gene activity in differentiated cells can be changed by cell fusion
10.15 The differentiated state of a cell can change by transdifferentiation
10.16 Embryonic stem cells can proliferate and differentiate into many cell types in culture
Box 10B Testing ES cell potential in tetraploid blastocysts
10.17 Stem cells could be a key to regenerative medicine
Box 10C Induced pluripotent stem cells
10.18 Various approaches can be used to generate differentiated cells for cell-replacement therapies
Summary
SUMMARY TO CHAPTER 10
Chapter 11 Organogenesis
The vertebrate limb
11.1 The vertebrate limb develops from a limb bud
11.2 Genes expressed in the lateral plate mesoderm are involved in specifying the position and type of limb
11.3 The apical ectodermal ridge is required for limb outgrowth
11.4 Patterning of the limb bud involves positional information
11.5 How position along the proximo-distal axis of the limb bud is specified is still a matter of debate
11.6 The polarizing region specifies position along the limb's antero-posterior axis
Box 11A Positional information and morphogen gradients
11.7 Sonic hedgehog produced by the polarizing region is likely to be the primary morphogen patterning the antero-posterior axis of the limb
Box 11B Too many fingers: mutations that affect antero-posterior patterning can cause polydactyly
Box 11C Sonic hedgehog signaling and the primary cilium
11.8 Transcription factors might specify digit identity
11.9 The dorso-ventral axis of the limb is controlled by the ectoderm
11.10 Development of the limb is integrated by interactions between signaling centers
11.11 Different interpretations of the same positional signals give different limbs
11.12 Hox genes establish the polarizing region and also provide positional values for limb patterning
11.13 Self-organization may be involved in the development of the limb bud
Box 11D Reaction-diffusion mechanisms
11.14 Limb muscle is patterned by the connective tissue
11.15 The initial development of cartilage, muscles, and tendons is autonomous
11.16 Joint formation involves secreted signals and mechanical stimuli
11.17 Separation of the digits is the result of programmed cell death
Summary
Insect wings and legs
11.18 Positional signals from compartment boundaries pattern the wing imaginal disc
11.19 A signaling center at the boundary between dorsal and ventral compartments patterns the Drosophila wing along the dorso-ventral axis
11.20 The leg disc is patterned in a similar manner to the wing disc, except for the proximo-distal axis
11.21 Butterfly wing markings are organized by additional positional fields
11.22 Different imaginal discs can have the same positional values
Summary
Vertebrate and insect eyes
11.23 The vertebrate eye develops from the neural tube and the ectoderm of the head
11.24 Patterning of the Drosophila eye involves cell-cell interactions
11.25 Eye development in Drosophila is initiated by the actions of the same transcription factors that specify eye-precursor cells in vertebrates
Summary
Internal organs: insect tracheal system, vertebrate lungs, kidneys, blood vessels, heart, and teeth
11.26 The Drosophila tracheal system is a model for branching morphogenesis
11.27 The vertebrate lung also develops by branching of epithelial tubes
11.28 The development of kidney tubules involves reciprocal induction by the ureteric bud and surrounding mesenchyme
11.29 The vascular system develops by vasculogenesis followed by angiogenesis
11.30 The development of the vertebrate heart involves specification of a mesodermal tube that is patterned along its long axis
11.31 A homeobox gene code specifies tooth identity
Summary
SUMMARY TO CHAPTER 11
Chapter 12 Development of the nervous system
Specification of cell identity in the nervous system
12.1 Neurons in Drosophila arise from proneural clusters
12.2 The development of neurons in Drosophila involves asymmetric cell divisions and timed changes in gene expression
Box 12A Specification of the sensory organs of adult Drosophila
12.3 Specification of vertebrate neuronal precursors also involves lateral inhibition
12.4 Neurons are formed in the proliferative zone of the vertebrate neural tube and migrate outwards
Box 12B Timing the birth of cortical neurons
12.5 The pattern of differentiation of cells along the dorso-ventral axis of the spinal cord depends on ventral and dorsal signals
12.6 Neuronal subtypes in the ventral spinal cord are specified by the ventral to dorsal gradient of Shh
12.7 Spinal cord motor neurons at different dorso-ventral positions project to different trunk and limb muscles
12.8 Antero-posterior pattern in the spinal cord is determined in response to secreted signals from the node and adjacent mesoderm
Summary
Axon navigation
12.9 The growth cone controls the path taken by a growing axon
12.10 Motor neuron axons in the chick limb are guided by ephrin-Eph interactions
12.11 Axons crossing the midline are both attracted and repelled
12.12 Neurons from the retina make ordered connections with visual centers in the brain
Summary
Synapse formation and refinement
12.13 Synapse formation involves reciprocal interactions
12.14 Many motor neurons die during normal development
12.15 Neuronal cell death and survival involve both intrinsic and extrinsic factors
12.16 The map from eye to brain is refined by neural activity
Summary
SUMMARY TO CHAPTER 12
Chapter 13 Growth and post-embryonic development
Growth
13.1 Tissues can grow by cell proliferation, cell enlargement, or accretion
13.2 Cell proliferation is controlled by regulating entry into the cell cycle
13.3 Cell division in early development can be controlled by an intrinsic developmental program
13.4 Organ size can be controlled by both intrinsic growth programs and extracellular signals
13.5 The amount of nourishment an embryo receives can have profound effects in later life
13.6 Determination of organ size involves coordination of cell growth, cell division, and cell death
Box 13A Gradients of signaling molecules could determine organ size
13.7 Body size is also controlled by the neuroendocrine system in both insects and mammals
13.8 Growth of the long bones occurs in the growth plates
13.9 Growth of vertebrate striated muscle is dependent on tension
13.10 Cancer can result from mutations in genes that control cell multiplication and differentiation
13.11 Hormones control many features of plant growth
Summary
Molting and metamorphosis
13.12 Arthropods have to molt in order to grow
13.13 Metamorphosis is under environmental and hormonal control
Summary
Aging and senescence
13.14 Genes can alter the timing of senescence
13.15 Cell senescence blocks cell multiplication
Summary
SUMMARY TO CHAPTER 13
Chapter 14 Regeneration
Limb and organ regeneration
14.1 Amphibian limb regeneration involves cell dedifferentiation and new growth
14.2 The limb blastema gives rise to structures with positional values distal to the site of amputation
14.3 Retinoic acid can change proximo-distal positional values in regenerating limbs
14.4 Insect limbs intercalate positional values by both proximo-distal and circumferential growth
14.5 Heart regeneration in the zebrafish involves the resumption of cell division by cardiomyocytes
14.6 The mammalian peripheral nervous system can regenerate
Summary
Regeneration in Hydra
14.7 Hydra grows continuously but regeneration does not require growth
14.8 The head region of Hydra acts both as an organizing region and as an inhibitor of inappropriate head formation
14.9 Genes controlling regeneration in Hydra are similar to those expressed in vertebrate embryos
Summary
SUMMARY TO CHAPTER 14
Chapter 15 Evolution and development
Box 15A 'Darwin's finches'
The evolution of development
15.1 Genomic evidence is throwing light on the origin of metazoans
15.2 Multicellular organisms evolved from single-celled ancestors
Summary
The evolutionary modification of embryonic development
15.3 Hox gene complexes have evolved through gene duplication
15.4 Changes in Hox genes generated the elaboration of vertebrate and arthropod body plans
15.5 The position and number of paired appendages in insects is dependent on Hox gene expression
15.6 The basic body plan of arthropods and vertebrates is similar, but the dorso-ventral axis is inverted
15.7 Limbs evolved from fins
15.8 Vertebrate and insect wings make use of evolutionarily conserved developmental mechanisms
15.9 The evolution of developmental differences can be based on changes in just a few genes
15.10 Embryonic structures have acquired new functions during evolution
Summary
Changes in the timing of developmental processes
15.11 Evolution can be due to changes in the timing of developmental events
15.12 The evolution of life histories has implications for development
Summary
SUMMARY TO CHAPTER 15

Editorial Reviews

"This new edition is a significant and positive step in presenting a complex field of study to undergraduate students."—Craig M. Scott, Clarion University

"I like the boxes in each chapter. Experimental technique boxes work well when the reader just wants to look up a technique. Boxes are also a good way to highlight concepts, or to go into detail on subjects that may or may not be covered in lectures."—Deborah Garrity, Colorado State University

"Very clear writing style that the students will appreciate, and very clear figures."—Margaret Saha, College of William and Mary

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