Chordate origins and evolution : the molecular evolutionary road to vertebrates / Noriyuki Satoh.

Format:

Book

Author/Creator:

Satoh, Noriyuki, author.

Contributor:

EBSCOhost.

Language:

English

Subjects (All):

Chordata--Evolution.

Chordata.

Physical Description:

1 online resource (xiii, 206 pages.)

Place of Publication:

London ; San Diego, CA : Academic Press, [2016]

System Details:

text file

Summary:

Chordate Origins and Evolution. The Molecular Evolutionary Road to Vertebrates addresses this topic from various points of view, based on recent advances in paleontology, molecular phylogeny, comparative genomics, and evolutionary developmental biology. The origin and evolution of chordates is one of the most mysterious and intriguing phenomena in evolutionary developmental biology, and since Charles Darwin proposed the concept of organismal evolution in 1859, chordate evolution and origins have been studied, discussed, and debated vigorously for more than 150 years. Although understanding advanced relatively little through the late 1980s, sine the early 1990s molecular developmental biological techniques have allowed these questions to be addressed by evo-devo investigations. Many previous opinions, hypotheses, or theories have been re-examined, and/or new hypotheses proposed for the evolutionary scenarios of deuterostome and chordate origins. The expansion of our understanding of chordate evolution has elevated evo-devo research to one of the most exciting topics in biology. This fascinating work focuses on echinoderms (starfish, sea urchins, and others), hemichordates (acorn worms, etc.), cephalochordates (lancelets), urochordates or tunicates (ascidians, larvaceans and others), and vertebrates. Evolution of these groups is generally covered independently, on a larger scale: ambulacrarians (echi-hemi) and chordates (cephlo-uro+vert); and until now, discussion of these topics has been somewhat fragmented. This volume provides a unified presentation of the essential information that will be useful to a variety of readers, including general biologists, zoologists, evolutionary developmental biologists, evolutionary biologists, paleontologists, molecular phylogenists, and comparative genomics researchers, among others. Key Features, Provides valuable information regarding each phylum and an integrative understanding of molecular mechanisms involved in the origin and evolution of chordates. Covers the most significant advances in this field to give readers an understanding of the thought-provoking biological issues involved, Discusses the evolutionary scenario of chordates based on two major characteristic features of animals-feeding (energy sources) and reproduction-as the two main forces driving animal evolution, benefiting dialogue for future studies Book jacket.

Contents:

1 Deuterostomes and Chordates

1.1 A Brief Background 1

1.2 Deuterostomes and Chordates 2

1.2.1 Deuterostomes 3

1.2.2 Ambulacraria 3

1.2.3 Chordates 4

1.2.4 Olfactores 5

1.3 Deuterostome Phyla 5

1.3.1 Echinoderms 5

1.3.2 Hemichordates 7

1.3.3 Cephalochordates 10

1.3.4 Urochordates (Tunicates) 12

1.3.5 Vertebrates 15

1.4 Conclusions 16

2 Hypotheses on Chordate Origins

2.1 The Annelid Theory 19

2.2 The Auricularia Hypothesis 19

2.3 The Calcichordate Hypothesis 21

2.4 The Pedomorphosis Scenario: Was the Ancestor Sessile or Free-Living? 23

2.5 The New Inversion Hypothesis 26

2.6 The Enteropneust Hypothesis 27

2.6.1 A New Enteropneust Hypothesis 27

2.7 The Aboral-Dorsalization Hypothesis 28

2.8 Conclusions 30

3 Fossil Records

3.1 The Cambrian and Ediacaran Periods 31

3.2 Crown, Stem, and Total Croups 34

3.3 Fossil Records of Invertebrate Deuterostomes 35

3.3.1 Echinoderms 35

3.3.2 Hemichordates 38

3.3.3 Cephalochordates 38

3.3.4 Urochordates (Tunicates) 39

3.4 Fossil Records of Vertebrates 40

3.4.1 Cyclostome-Like Fossils 42

3.4.2 Early Vertebrate Fossils 42

3.4.3 Conodont Elements 42

3.5 Conclusions 43

4 Molecular Phylogeny

4.1 Molecular Phylogeny of Metazoans 46

4.2 Molecular Phylogeny of Deuterostome Taxa 47

4.2.1 Ambulacraria and Chordata: Two Major Croups of Deuterostomes 47

4.2.2 Cephalochordates Came First Among Chordates and Then Urochordates + Vertebrates as Olfactores 47

4.2.3 Timing of the Emergence of Deuterostome Groups 51

4.3 Relationships Within Each Deuterostome Phylum 52

4.3.1 Echinoderms 52

4.3.2 Hemichordates 52

4.3.3 Cephalochordates 53

4.3.4 Urochordates (Tunicates) 53

4.3.5 Vertebrates 54

4.4 Xenacoelomorpha 54

4.5 MicroRNAs 56

4.6 Conclusions 58

5 Comparative Genomics of Deuterostomes

5.1 Genome Decoding 59

5.2 Genomic Features of Five Representative Deuterostome Taxa 60

5.2.1 Echinoderm Genomes 60

5.2.2 Hemichordate Genomes 63

5.2.3 Cephalochordate Genome 66

5.2.4 Urochordate Genomes 67

5.2.5 Vertebrate Genomes 68

5.3 Gene Families in Deuterostomes and the Ancestral Gene Set 70

5.3.1 Gene Families in Deuterostomes 71

5.3.2 Expansion of Gene Families in Deuterostomes 71

5.4 Exon-Intron Structures 73

5.5 Synteny 75

5.5.1 Macrosynteny 75

5.5.2 Microsynteny 76

5.6 Conserved Noncoding Sequences 76

5.7 Repetitive Elements 78

5.8 Taxonomically Restricted Genes 78

5.9 Conclusions 78

6 The Origins of Chordates

6.1 Evaluation of Hypotheses for Chordate Origins 81

6.1.1 How Do We Interpret Deuterostome Evolution? 81

6.1.2 The Chordate Ancestor Was Free-Living 83

6.1.3 The Auricularia Hypothesis Is Not Supported 83

6.1.4 The Calcichordate Hypothesis Cannot Be Accepted 84

6.1.5 The Annelid Hypothesis Is Not Related to the Origins of Chordates 84

6.1.6 The Enteropneust Hypothesis and Inversion Hypothesis Need Reconsideration 85

6.2 The Pharyngeal Gene Cluster and the Origin of Deuterostomes 85

6.3 Hox and Chordate Evolution 89

6.3.1 Ambulacrarian Hox Genes 91

6.3.2 Cephalochordate Hox Genes 91

6.3.3 Urochordate Hox Genes 92

6.3.4 Vertebrate Hox Genes 92

6.3.5 Deuterostome Posterior Hox Genes: An Unsolved Origin 94

6.4 ParaHox Genes 94

6.5 Conclusions 95

7 The New Organizers Hypothesis for Chordate Origins

7.1 Chordate Features 97

7.2 The New Organizers Hypothesis of Chordate Origins 99

7.3 Cephalochordate Embryogenesis: Primitive Chordate Body-Plan Formation 100

7.4 Chordate Features and Molecular Developmental Mechanisms 103

7.5 The Notochord: A Mesodermal Novelty 103

7.5.1 Brachyury: A Key Transcription Factor for Notochord Formation 105

7.5.2 Regulatory Networks of Brachyury 106

7.6 Somites (Myotomes): A Mesodermal Novelty 109

7.7 The Postanal Tail: A Mesodermal Novelty 111

7.8 The Dorsal Central Nervous System: An Ectodermal Novelty 113

7.8.1 The Gene Regulatory Network for Neural Development 113

7.8.2 Regionalization of the Central Nervous System 116

7.9 Hatschek's Pit: An Ectodermal Novelty 116

7.10 The Endostyle: An Endodermal Novelty 118

7.11 Conclusions 120

8 The Dorsoventral-Axis Inversion Hypothesis: The Embryogenetic Basis for the Appearance of Chordates

8.1 Spemann's Organizer, the Nieuwkoop Center, and the Three-Signal Model 122

8.1.1 Spemann's Organizer 124

8.1.2 The Nieuwkoop Center 124

8.1.3 The Three-Signal Model 124

8.2 Axial Patterning of Deuterostome Body Plans 125

8.2.1 The Animal-Vegetal Axis and Formation of Endomesoderm 125

8.2.2 The Anteroposterior Axis 126

8.2.3 The Dorsoventral Dimension and the inversion Hypothesis 126

8.2.4 Left-Right Asymmetry and the Nodal Signal 127

8.3 Interpretation of the Dorsoventral-Axis Inversion Hypothesis 130

8.3.1 Nodal Function in Mesoderm Formation 131

8.3.2 Interpretation of the Dorsoventral-Axis Inversion 131

8.4 Conclusions 133

9 The Enteropneust Hypothesis and Its Interpretation

9.1 The Stomochord and Other Organs Proposed as Antecedents to the Notochord 136

9.1.1 The Stomochord 136

9.1.2 ThePygochord 136

9.1.3 The Annelid Axochord 138

9.2 The Nervous System of Enteropneusts 139

9.2.1 The Dorsal Collar Cord 139

9.2.2 Gene Expression Profiles in Epidermis along the Anteroposterior Axis 140

9.2.3 Gene Expression Profiles along the DV Axis 140

9.3 The Spemann's Organizer-Like System in Hemichordates 140

9.4 Interpretations of the Enteropneust Hypothesis 141

9.5 Conclusions 142

10 Chord ate Evolution: An Extension of the New Organizers Hypothesis

10.1 Evolution of Vertebrates 144

10.1.1 Neural Crest 144

10.1.2 The Placodes 147

10.1.3 The Cardiopharyngeal Field 149

10.1.4 Cartilage and Bone 152

10.1.5 Adaptive Immune System 153

10.2 Evolution of Urochordates 154

10.2.1 Precocious Mode of Embryonic Development 154

10.2.2 Asexual Reproduction of Colonial Ascidians 154

10.2.3 Pluripotent Stem-Like Cells for Bud Formation 155

10.2.4 The Development of Colony Specificity 156

10.3 Conclusion 156

11 How Did Chordates Originate and Evolve?

11.1 The Three-Phylum System of Chordates 157

11.2 Mechanisms Involved in Origination of Deuterostome Novelties 159

11.3 Horizontal Gene Transfer 159

11.3.1 Acquisition of Cellulose Biosynthetic Ability and Urochordate Evolution 160

11.3.2 Genes Encoding Enzymes Involved in Sialic Acid Metabolism 163

11.4 The Significance of Gene Duplication in Deuterostome Evolution 164

11.5 Significance of Domain Shuffling in Chordate Evolution 167

11.6 The Significance of Structural Genes in Metazoan Evolution 167

11.7 The Phylotypic Stage 168

11.8 Conclusions 170

12 Summary and Perspective

12.1 Summary 171

12.2 Perspective 174.

Notes:

Electronic reproduction. Ipswich, MA Available via World Wide Web.

Description based on print version record.

ISBN:

9780128030066

0128030062

Publisher Number:

99978179581

Access Restriction:

Restricted for use by site license.