Gastrulation From Embryonic Pattern to Form

Cover
Series page
Copyright
Contributors
Preface
	Preface
		Acknowledgments
Chapter 1
	Setting up for gastrulation: D. melanogaster
		Introduction
		Establishment of embryonic polarity occurs in oocytes
		Navigating the maternal-to-zygotic transition
		Gene expression patterns establish the prospective germ layers
		Gene regulatory interactions prepare cells for diverse cell movements at gastrulation
		Dynamic feedback between genetic patterning and physical tissue morphogenesis
		References
Chapter 2
	Setting up for gastrulation in zebrafish
		Introduction
		Maternal factors and dorsal-ventral patterning
			Defining and delimiting dorsal: Maternal β-catenin with or without Wnt
			Determinants at the vegetal pole
			Turning BMP on by shutting down the organizer
		Transforming blastula tissues to form the germ layers
			It takes two to tango: TGFβ heterodimers specify mesendoderm
			Exposure matters, inhibition needed, no feedback required when nodal organizes
			Cohabiting or dwelling alone, location matters in mesendoderm patterning
			Pattering along, toddler loses endoderm
			Mom´s got skin in the game, patterning the ectoderm and the enveloping layer
		Conclusion
		Acknowledgments
		References
Chapter 3
	Signaling events regulating embryonic polarity and formation of the primitive streak in the chick embryo
		Introduction
			Embryonic regulation
		Role of the posterior marginal zone in initiation of primitive streak formation
		Molecular basis of primitive streak induction by the posterior marginal zone
			cVg1 (GDF1)
			Wnt8C
			Pitx2
		The hypoblast inhibits primitive streak formation
		Hypoblast, endoblast and definitive endoderm
		Formation and shaping of the primitive streak
		Mechanisms ensuring that gastrulation is initiated only in one place
			Inhibitors
			Communication
		Comparison to other model organisms
		Summary and conclusions
		References
Chapter 4
	Comparative analysis of human and mouse development: From zygote to pre-gastrulation
		Introduction
		Pre-implantation development: From zygote to blastocyst formation
		Implantation and the role of trophectoderm
		Epiblast epithelization and pro-amniotic cavity formation
		Pre-gastrulation patterning and establishment of the anterior-posterior axis
		Conclusions
		References
		Further reading
Chapter 5
	The cellular and molecular mechanisms that establish the mechanics of Drosophila gastrulation
		Overview
		Apical constriction: Force generation at the molecular and cellular level
		Tissue invagination: Integrating cells across the tissue
		RhoA signaling: Activating contractility and coordinating cell behavior
		Gene regulation: Cell signaling centers and tissue geometry
		Late gastrulation: Subsequent mesoderm EMT and spreading
		Concluding remarks
		References
Chapter 6
	Cellular, molecular, and biophysical control of epithelial cell intercalation
		Convergent extension: A conserved mechanism for shaping epithelia
		Cell rearrangements during convergent extension in the Drosophila embryo
		The molecular basis of epithelial cell intercalation
		Biophysical control of epithelial cell intercalation
		Breaking planar symmetry
		Toll receptors direct planar polarity and cell intercalation
		Regulation of planar polarity at compartment boundaries
		Control of junctional and medial myosin by G protein-coupled receptors
		Current questions and future challenges
		Acknowledgments
		References
		Further reading
Chapter 7
	Gastrulation in the sea urchin
		A sequential overview of sea urchin gastrulation
		Setting the stage for gastrulation: Specification of the vegetal plate
		The pigment cells invade the blastocoel shortly after the skeletogenic cells
		Mechanistic studies of primary invagination
		Specification of endoderm
		Cells at the tip of the advancing archenteron are necessary for establishing right-left asymmetry
		Homing of the primordial germ cells to the coelomic pouches
		Summary
		Acknowledgments
		References
Chapter 8
	Tunicate gastrulation
		Introduction: Tunicates-their place on the evolutionary tree and their contribution to our understanding of embryology
		Events leading up to gastrulation
			Cleavage patterns
			Ooplasmic segregation/PEM
			Origin of germ layers
		Mechanisms of gastrulation
			Endoderm-intrinsic forces in gastrulation
		Gastrulation in other tunicates
			Colonial tunicates
			The thaliaceans: Salps, doliods and pyrosomes
		Peri-gastrulation events
			Notochord development
			Neural induction and neurulation
		Conclusion
		Acknowledgments
		References
Chapter 9
	Mesoderm and endoderm internalization in the Xenopus gastrula
		Introduction
		Outline of Xenopus gastrulation
		Bottle cell formation
		Dorsal multilayer invagination
			Apical layer processes
			Deep cell movements
			Convergent extension by parallel intercalation
		Peak involution of the dorsal Xbra domain
		Ventral internal involution
		Orthogonal convergent extension of the dorsal Xbra domain
		Internalization of the vegetal cell mass by ingression-type deep bottle cell migration
		Blastopore closure
		Conclusions
		Acknowledgments
		References
Chapter 10
	Convergent extension in the amphibian, Xenopus laevis
		Introduction
		Active, force-producing CE occurs in presumptive notochordal and somitic mesoderm and in presumptive hindbrain-spinal  ...
		CE is driven by both radial intercalation (RI) and mediolateral intercalation (MI) of cells
		Mechanisms underlying the RI component of CE
		The mechanism and function of mediolateral intercalation behavior (MIB) in mesodermal CE
		The node and cable network (NCN) and iterated actomyosin contraction is the ``power stroke´´ of MIB
		Cell-on-cell traction rather than cell on matrix traction generates most of the tissue-level, tensile forces driving c ...
		Balanced traction, regulation of contraction, and the logic of cell intercalation
		An epithelial, junction remodeling model of notochordal cell intercalation
		Comparison of the mesenchymal, cell-on-cell traction (CCT) model and the epithelial junction remodeling (EJR) model o ...
		Computational models of CE by MIB mediated CCT
		Large scale patterning of MIB is essential for Normal CE function
		Patterning of mesodermal CE relative to other landmarks and presumptive tissues
		Neural cell intercalation and CE
		Forces and mechanics of the progressive expression of mesodermal MIB
		Evaluating the contributions of the epithelial and deep layers to forces driving CE
		The role of tissue boundary formation, Eph/Ephrin signaling, and tissue surface tension in CE
		Late elongation and straightening of the body plan is driven by notochord straightening and elongation, and elongatio ...
		Late endoderm elongation
		CE as a large-scale mechanical patterning mechanism
		Outlook
		References
Chapter 11
	Mechanisms of zebrafish epiboly: A current view
		Introduction and overview
			Setting the stage for epiboly
		Epiboly initiation
		Epiboly progression
			EVL morphogenesis during epiboly progression
		Deep cell movements
		E-YSN and yolk cell microtubules
		Conclusions and perspectives
		Acknowledgments
		References
		Further reading
Chapter 12
	Zebrafish gastrulation: Putting fate in motion
		The fundamentals of germ layer specification and patterning
			Nodal signaling and mesendoderm patterning
				Setting up the Nodal signaling domain
				Dose-dependent responses to Nodal signaling
			Ectoderm specification: The default cell fate?
		Shaping the zebrafish gastrula: Cell and tissue morphogenesis
			Mesendoderm internalization movements
				Dual role of Nodal signals in mesendoderm specification and internalization
				Directed cell migration, a key mechanism to ensure germ layer segregation
				Establishment of inside-out polarity in the zebrafish gastrula
				Maintaining epiblast/hypoblast tissue boundary
			Animal pole-directed mesendoderm migration-A path that comes in many flavors
				Dorsal mesendoderm migration: Integrating autonomous cell motility amid a collective
				Ventrolateral mesendoderm migration: The role of Apelin signaling
				Endoderm migration-A `guided random walk?
		Outlook
		Acknowledgments
			Glossary
		References
Chapter 13
	Cellular and molecular mechanisms of convergence and extension in zebrafish
		Overview of zebrafish C&E
		C&E of the mesoderm
			Axial mesoderm: Chordamesoderm
			Axial mesoderm: Prechordal plate
			Paraxial mesoderm
			Lateral mesoderm
			Ventral mesoderm
		C&E of the endoderm
		C&E of the neuroectoderm
			Neural plate
			Neural keel
		Interactions between germ layers influence C&E
			Mesoderm-neuroectoderm interactions
			Endoderm-mesoderm interactions
		Concluding remarks
		References
Chapter 14
	Movements of chick gastrulation
		Introduction: Morphology of the early embryo
		Early movements in the epiblast position the gastrulation site before its formation
			Initial positioning of gastrulation regulators
			Rearrangement of the primitive streak precursors and global movements in the epiblast
		Cooperative EMT triggers the formation of the initial primitive streak
		Movements during gastrulation
			Cell behaviors in the primitive streak
			Tension created by ingression at the primitive streak drives movements in the entire epiblast
			Movements into the lower layers
		End of gastrulation stage
		Summary and conclusions
		References
Chapter 15
	Guts and gastrulation: Emergence and convergence of endoderm in the mouse embryo
		Preimplantation development, the blastocyst and emergence of the first endoderm population in the mouse
		Anterior visceral endoderm (AVE), a derivative of the primitive endoderm (PrE) establishes the anterior-posterior axis ...
		Gastrulation: Convergence of signals driving exit from pluripotency and acquisition of distinct cell identities in tim ...
		Morphogenetic cell behaviors at the primitive streak: The gastrulation EMT
		Morphogenetic cell behaviors driving gut endoderm formation
		Gut endoderm morphogenesis coincides with germ layer segregation
		Behavior of VE cells at the midline
		Single-cell transcriptomic studies support the dual origin of the gut endoderm
		The epigenetic landscape of embryonic (definitive) and extra-embryonic (visceral) endoderm
		Mesendoderm and the mouse
		Transforming the gut endoderm into the gut tube: Ventral folding
		Patterning the gut tube and the emergence of organ identities
		Concluding remarks
		Acknowledgments
		References