Xenopus Development

"Xenopus frogs have long been used as model organisms in basic and biomedical research. These frogs have helped unlock basic developmental and cellular processes that have led to scientific breakthroughs and have had practical application in cancer research and regenerative medicine. Xenopus Developmentdiscusses the biology and development of this important genus, and will be a great tool to researchers using these frogs in their research. Divided into four sections, the highlights key Xenopus development from embryo to metamorphosis, and the cellular processes, organogenesis, and biological development"-- "Provides broad overview of the developmental biology of both Xenopus laevis and Xenopus tropicalis"-- � Read more... Abstract: * Provides broad overview of the developmental biology of both Xenopus laevis and Xenopus tropicalis * Cellular to systems development in key biomedical model organisms * Timely synthesis of the field of Xenopus biology * Highlights key biomedical and basic biological findings unlocked by Xenopus . � Read more... Xenopus Development 5 Copyright 6 Contents 7 Contributors 9 Preface 11 Section I Oocyte and Early Embryo 13 1 Transcription in the Xenopus Oocyte Nucleus 15 Introduction 15 LBC structure: The standard model 16 Chromomeres and loops 16 Transcription on LBC loops 19 Transcripts produced during oogenesis 21 In situ hybridization of nascent transcripts on individual LBC loops 22 Appendix 23 Acknowledgments 23 References 25 2 RNA Localization during Oogenesis in Xenopus laevis 28 Xenopus oocytes as a model system for exploring RNA localization 28 Cis -elements and the role of short repeated motifs 31 Proteins, RNAs, and the endoplasmic reticulum 37 Mechanism(s) for RNA localization to the vegetal cortex 41 Looking toward the future 45 References 47 3 From Oocyte to Fertilizable Egg: Regulated mRNA Translation and the Control of Maternal Gene Expression 50 Mechanisms of mRNA translational control: Global versus selective targeting 50 Sequestration of maternal mRNA contributes to control of gene expression during Xenopus oogenesis 52 Future perspectives 63 Acknowledgments 65 References 65 4 Polarity of Xenopus Oocytes and Early Embryos 72 Oocyte polarity and embryonic axes 72 Development of A–V polarity during oogenesis 73 Vegetal hemisphere maternal factors 76 Vegetal cortex 78 Animal hemisphere maternal factors 79 Asymmetry of inorganic maternal factors 80 Maternal determination of planar and basolateral polarity and L–R asymmetry 80 Conclusions 82 References 82 5 Germ-Cell Specification in Xenopus 87 Background 87 Formation of the Xenopus germline 88 Molecular components of germ plasm 92 Do chromatin modifications play a role in Xenopus PGC specification? 103 Concluding remarks 104 Acknowledgments 104 References 104 Section II Midblastula Transition, Gastrulation, and Neurulation 113 6 The Xenopus Embryo as a Model System to Study Asymmetric Furrowing in Vertebrate Epithelial Cells 115 Introduction 115 MELK is a cell cycle-regulated kinase involved in development and cancer 116 MELK in Xenopus laevis embryo cytokinesis 117 Asymmetric furrowing is a mode of cytokinesis conserved throughout evolution 118 The Xenopus embryo as a model system to analyze asymmetric furrowing 121 Conclusions 121 Acknowledgments 121 References 122 7 Induction and Differentiation of the Xenopus Ciliated Embryonic Epidermis 124 Introduction 124 Nonneural ectoderm specification 126 Ontogeny of the mucociliary epithelium 129 Perspectives and outstanding questions 136 Concluding remarks 137 References 137 8 Wnt Signaling during Early Xenopus Development 142 Introduction 142 Wnt “canonical” and “noncanonical” pathways: Complexity and uncertainties 143 Major processes regulated by Wnts during early Xenopus development 152 Wnt signaling at postgastrula stages 161 References 166 9 Neural Tube Closure in Xenopus 175 Introduction 175 Narrowing and elongation of the neural plate 177 Cell-shape changes causing neural tube morphogenesis 180 Complete tube closure assisted by nonneural ectoderm 186 References 194 Section III Metamorphosis and Organogenesis 199 10 Primordial Germ Cell Migration 201 References 207 11 Development of Gonads, Sex Determination, and Sex Reversal in Xenopus 211 Origin and structure of undifferentiated gonad 211 Sexual differentiation of the gonads 215 Development of testis 216 Spermatogenesis 216 Development of ovary 217 Sex determination 218 Sex reversal 220 Conclusions 222 References 223 12 The Xenopus Pronephros: A Kidney Model Making Leaps toward Understanding Tubule Development 227 Introduction 227 Xenopus embryonic kidney development 228 Xenopus as a model of disease and regeneration 235 Modulation of gene expression 236 Imaging 240 Screens 242 Conclusions 244 Acknowledgments 244 References 244 13 Development of Neural Tissues in Xenopus laevis 251 Introduction 251 Xenopus as a model system of neural development 252 Neural specification 252 Formation of the anterior–posterior axis 257 Neurulation and dorsal–ventral patterning 258 Neural plate border specification and neural crest induction 260 Neural crest delamination and migration 264 Molecular regulation of neurogenesis 266 Conclusions 269 Acknowledgments 269 References 269 14 The Development of the Immune System in Xenopus 276 Introduction 276 The establishment of innate immunity components during Xenopus ontogeny 277 The establishment of the adaptive immune system components 279 Selection of T and B cell repertoires 287 Immunity during ontogeny 289 Immunological issues at metamorphosis 294 Conclusion 298 Acknowledgments 299 References 299 15 Neural Regeneration in Xenopus Tadpoles during Metamorphosis 305 Spinal cord regeneration 306 Lens regeneration 310 Neural retina regeneration 311 Optic nerve regeneration 312 Role of neural regeneration during tail regeneration 313 Role of neural regeneration during limb regeneration 315 Telencephalon and mesencephalon regeneration 316 Summary and future perspectives 317 Acknowledgments 317 References 318 Section IV Novel Techniques and Approaches 321 16 Atomic Force Microscopy Imaging of Xenopus laevis Oocyte Plasma Membrane 323 Introduction 323 Atomic force microscopy 324 Sample preparation protocols for AFM imaging of Xenopus laevis oocyte plasma membrane 326 AFM imaging of Xenopus laevis oocyte plasma membrane 329 Conclusions and future perspectives 334 References 335 17 Size Scaling of Subcellular Organelles and Structures in Xenopus laevis and Xenopus tropicalis 337 Introduction to organelle scaling 337 Xenopus interspecies scaling 338 Advantages of studying two closely related Xenopus species 340 Interspecies nuclear scaling 340 Interspecies mitotic spindle scaling 342 Interspecies mitotic chromosome scaling 344 Techniques: X. tropicalis egg extracts 345 Xenopus developmental scaling 346 Developmental nuclear scaling 346 Developmental mitotic spindle scaling 346 Developmental mitotic chromosome scaling 349 Techniques: Xenopus embryo extracts 351 Functions of organelle scaling 351 Future directions 353 Acknowledgments 354 References 354 18 A Model for Retinal Regeneration in Xenopus 358 Xenopus as a model animal for the study of retinal regeneration 358 X. laevis: A new animal model of retinal regeneration 362 Culture models for the study of X. laevis retinal regeneration 364 A transgenic approach to retinal regeneration 369 X. tropicalis: A novel animal model for retinal regeneration 374 A hypothetical model for retinal regeneration and future perspectives on retinal regeneration studies 374 Acknowledgments 376 References 376 19 The Xenopus Model for Regeneration Research 380 Introduction 380 Xenopus tadpole tail regeneration 381 Xenopus limb as a model for stimulating regeneration 387 Lens regeneration 390 Conclusions 391 Acknowledgments 391 References 391 20 Genomics and Genome Engineering in Xenopus 395 Introduction 395 Xenopus genomics 396 Xenopus genome engineering 404 Acknowledgments 410 References 410 Index 415 Supplemental Images 426 Content: Xenopus Development Copyright Contents Contributors Preface Section I Oocyte and Early Embryo 1 Transcription in the Xenopus Oocyte Nucleus Introduction LBC structure: The standard model Chromomeres and loops Transcription on LBC loops Transcripts produced during oogenesis In situ hybridization of nascent transcripts on individual LBC loops Appendix Acknowledgments References 2 RNA Localization during Oogenesis in Xenopus laevis Xenopus oocytes as a model system for exploring RNA localization Cis -elements and the role of short repeated motifs. Proteins, RNAs, and the endoplasmic reticulumMechanism(s) for RNA localization to the vegetal cortex Looking toward the future References 3 From Oocyte to Fertilizable Egg: Regulated mRNA Translation and the Control of Maternal Gene Expression Mechanisms of mRNA translational control: Global versus selective targeting Sequestration of maternal mRNA contributes to control of gene expression during Xenopus oogenesis Future perspectives Acknowledgments References 4 Polarity of Xenopus Oocytes and Early Embryos Oocyte polarity and embryonic axes. Development of A-V polarity during oogenesisVegetal hemisphere maternal factors Vegetal cortex Animal hemisphere maternal factors Asymmetry of inorganic maternal factors Maternal determination of planar and basolateral polarity and L-R asymmetry Conclusions References 5 Germ-Cell Specification in Xenopus Background Formation of the Xenopus germline Molecular components of germ plasm Do chromatin modifications play a role in Xenopus PGC specification? Concluding remarks Acknowledgments References Section II Midblastula Transition, Gastrulation, and Neurulation. 6 The Xenopus Embryo as a Model System to Study Asymmetric Furrowing in Vertebrate Epithelial CellsIntroduction MELK is a cell cycle-regulated kinase involved in development and cancer MELK in Xenopus laevis embryo cytokinesis Asymmetric furrowing is a mode of cytokinesis conserved throughout evolution The Xenopus embryo as a model system to analyze asymmetric furrowing Conclusions Acknowledgments References 7 Induction and Differentiation of the Xenopus Ciliated Embryonic Epidermis Introduction Nonneural ectoderm specification Ontogeny of the mucociliary epithelium. Perspectives and outstanding questionsConcluding remarks References 8 Wnt Signaling during Early Xenopus Development Introduction Wnt "canonical" and "noncanonical" pathways: Complexity and uncertainties Major processes regulated by Wnts during early Xenopus development Wnt signaling at postgastrula stages References 9 Neural Tube Closure in Xenopus Introduction Narrowing and elongation of the neural plate Cell-shape changes causing neural tube morphogenesis Complete tube closure assisted by nonneural ectoderm References Section III Metamorphosis and Organogenesis.

Frogs from the genus Xenopus have long been used as model organisms in basic and biomedical research. These frogs have helped unlock key fundamental developmental and cellular processes that have led to important scientific breakthroughs and have had practical application in embryology, cancer research and regenerative medicine. Xenopus Development is a vital resource on the biology and development of these key model organisms, and will be a great tool to researchers using these frogs in various disciplines of biological science.

Xenopus Development is divided into four sections, the first three highlight key processes in Xenopus development from embryo to metamophosis. These sections focus on the cellular processes, organogenesis and embryo development. The final section highlights novel techniques and approaches being used in Xenopus research.

Providing thorough and detailed coverage, Xenopus Development, will be a timely and welcome volume for those working in cell and molecular biology, genetics, developmental biology and biomedical research.

• Provides broad overview of the developmental biology of both Xenopus laevis and Xenopus tropicalis
• Explores cellular to systems development in key biomedical model organisms
• Timely synthesis of the field of Xenopus biology
• Highlights key biomedical and basic biological findings unlocked by Xenopus

Frogs from the genus Xenopus have long been used as model organisms in basic and biomedical research. These frogs have helped unlock key fundamental developmental and cellular processes that have led to important scientific breakthroughs and have had practical application in embryology, cancer research and regenerative medicine. Xenopus Development is a vital resource on the biology and development of these key model organisms, and will be a great tool to researchers using these frogs in various disciplines of biological science. Xenopus Development is divided into four sections, the first three highlight key processes in Xenopus development from embryo to metamophosis. These sections focus on the cellular processes, organogenesis and embryo development. The final section highlights novel techniques and approaches being used in Xenopus research. Providing thorough and detailed coverage, Xenopus Development , will be a timely and welcome volume for those working in cell and molecular biology, genetics, developmental biology and biomedical research. Provides broad overview of the developmental biology of both Xenopus laevis and Xenopus tropicalis Explores cellular to systems development in key biomedical model organisms Timely synthesis of the field of Xenopus biology Highlights key biomedical and basic biological findings unlocked by Xenopus Xenopus Frogs Have Long Been Used As Model Organisms In Basic And Biomedical Research. These Frogs Have Helped Unlock Basic Developmental And Cellular Processes That Have Led To Scientific Breakthroughs And Have Had Practical Application In Cancer Research And Regenerative Medicine. Xenopus Development Discusses The Biology And Development Of This Important Genus, And Will Be A Great Tool To Researchers Using These Frogs In Their Research. Divided Into Four Sections, The Highlights Key Xenopus Development From Embryo To Metamorphosis, And The Cellular Processes, Organogenesis, And Biological Development-- Provides Broad Overview Of The Developmental Biology Of Both Xenopus Laevis And Xenopus Tropicalis-- Edited By Malgorzata Kloc, Jacek Z. Kubiak. Includes Bibliographical References And Index.