HOX Genes

Preface

Chapter 1 The Bithorax Complex of Drosophila

1. Pseudoallelism and the History of the BX-C

2. The Ed Lewis Model

3. Molecular Genetics of the BX-C

4. Initiation and Maintenance Phases in BX-C Regulation

5. Initiators, Maintenance Elements, and Segment-Specific Enhancers

6. Organization of the Cis-Regulatory Regions into Chromosomal Domains

7. Chromatin Boundaries Flank the Parasegment-Specific Domains

8. Boundaries Versus Insulators and Long-Distance Interactions

9. Mixing the Old and the New

10. Colinearity in the BX-C

Chapter 2 Evolution of the Hox Gene Complex from an Evolutionary Ground State

1. Introduction

2. The Lewis Model

3. The Developmental and Evolutionary Ground State

4. Mechanisms of Epistatic Hox-Hox Interactions

5. The Evolutionary Origin of the Hox Cluster

6. Duplication and Divergence as a General Evolutionary Principle

7. Conclusion

Acknowledgments

Chapter 3 Hox Specificity

1. An Introduction to the Problem

2. Too Many Binding Sites, Not Enough Specificity

3. How Specific Do Hox Proteins Need to be?

4. Hox Cofactors

5. What Do In Vivo Hox-Binding Sites Look Like?

6. Insights into Hox Specificity from Structural Studies

7. Activity Regulation of Hox Proteins: The Role of Hox Collaborators

8. Insights into Hoxasome Function from cis‐Regulatory Element Architecture

9. Conclusions

Acknowledgments

Chapter 8 Hox Genes and Segmentation of the Vertebrate Hindbrain

1. Introduction

2. Hindbrain Segmentation

3. Expression of Hox Genes in the Hindbrain

4. Hox Gene Regulatory Networks in Hindbrain Segmentation

Acknowledgments

Chapter 5 Hox Genes in Neural Patterning and Circuit Formation in the Mouse Hindbrain

1. Introduction

2. Basic Anatomical Background and Cellular Mechanisms of Hindbrain Development

3. The Impact of Segmental Patterning on Sensory Nuclei Columnar Organization and Projection Patterns

4. Rostrocaudal Profiles and Sequential Phases of Hox Gene Expression: From Progenitor Patterning to Postmitotic Neuron Connectivity

5. Hox Gene Function: Lessons from Mouse Knockouts

Acknowledgments

Chapter Six Hox Networks and the Origins of Motor Neuron Diversity

1. Introduction

2. Spinal Motor Neuron Diversity

3. Hox Expression in Developing Motor Neurons

4. Hox Proteins Determine Motor Neuron Columnar Identity and Connectivity

5. Hox Transcriptional Networks and the Specification of Motor Pool Identities

6. Restriction and Refinement of Hox Activities During Motor Neuron Differentiation

7. Conclusions

Chapter 7 Establishment of Hox Vertebral Identities in the Embryonic Spine Precursors

1. Introduction

2. Initial Hox Gene Activation in Paraxial Mesoderm Precursors in the Epiblast

3. Molecular Control of Temporal Colinearity

4. Converting Temporal into Spatial Colinearity

5. Posterior Prevalence is Required for the Establishment of Spatial Colinearity

6. Spatial Dissociation of Segmentation and Hox Gene Activation Programs

7. Definitive Positioning of Hox Gene Boundaries in the Somites

8. Positioning of Hox Gene Boundaries in the Forming Segments

9. Conclusion: Determination of the Axial Fate of Vertebral Precursors

Acknowledgments

Chapter 8 Hox, Cdx, and Anteroposterior Patterning in the Mouse Embryo

1. The Hox and Cdx Gene Family

2. Similarities and Differences in the Two Expression Phases of Hox and Cdx Genes in the Mouse Embryo

3. Hox and Cdx Gene Expression and A-P Patterning

4. Conclusion

Acknowledgments

Chapter 9 Hox Genes and Vertebrate Axial Pattern

1. Introduction

2. Hox Genes and the Axial Skeleton

3. Hox Function in Axial Patterning

4. Conclusions - The Nature of the Mammalian "Hox Code"