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Current Topics in Developmental Biology 2020In birds as in all amniotes, the site of gastrulation is a midline structure, the primitive streak. This appears as cells in the one cell-thick epiblast undergo... (Review)
Review
In birds as in all amniotes, the site of gastrulation is a midline structure, the primitive streak. This appears as cells in the one cell-thick epiblast undergo epithelial-to-mesenchymal transition to ingress and form definitive mesoderm and endoderm. Global movements involving tens of thousands of cells in the embryonic epiblast precede gastrulation. They position the primitive streak precursors from a marginal position (equivalent to the situation in anamniotes) along the future antero-posterior axis (typical for amniotes). These epithelial movements continue in modified form during gastrulation, when they are accompanied by collective movements of different class in the forming mesoderm and endoderm. Here I discuss the nature of these collective cell movements shaping the embryo, their interplay with signaling events controlling fate specification and significance in an evolutionary perspective.
Topics: Animals; Cell Movement; Chick Embryo; Chickens; Endoderm; Gastrula; Gastrulation; Gene Expression Regulation, Developmental; Mesoderm; Signal Transduction; Zebrafish Proteins; Zygote
PubMed: 31959297
DOI: 10.1016/bs.ctdb.2019.11.015 -
Development (Cambridge, England) Jun 2020The lateral plate mesoderm (LPM) forms the progenitor cells that constitute the heart and cardiovascular system, blood, kidneys, smooth muscle lineage and limb skeleton... (Review)
Review
The lateral plate mesoderm (LPM) forms the progenitor cells that constitute the heart and cardiovascular system, blood, kidneys, smooth muscle lineage and limb skeleton in the developing vertebrate embryo. Despite this central role in development and evolution, the LPM remains challenging to study and to delineate, owing to its lineage complexity and lack of a concise genetic definition. Here, we outline the processes that govern LPM specification, organization, its cell fates and the inferred evolutionary trajectories of LPM-derived tissues. Finally, we discuss the development of seemingly disparate organ systems that share a common LPM origin.
Topics: Animals; Cardiovascular System; Cell Differentiation; Cell Lineage; Embryonic Development; Gene Expression Regulation, Developmental; Humans; Mesoderm; Stem Cells; Transcription Factors
PubMed: 32561665
DOI: 10.1242/dev.175059 -
Current Topics in Developmental Biology 2024For almost a century, developmental biologists have appreciated that the ability of the embryonic organizer to induce and pattern the body plan is intertwined with its... (Review)
Review
For almost a century, developmental biologists have appreciated that the ability of the embryonic organizer to induce and pattern the body plan is intertwined with its differentiation into axial mesoderm. Despite this, we still have a relatively poor understanding of the contribution of axial mesoderm to induction and patterning of different body regions, and the manner in which axial mesoderm-derived information is interpreted in tissues of changing competence. Here, with a particular focus on the nervous system, we review the evidence that axial mesoderm notochord and prechordal mesoderm/mesendoderm act as organizers, discuss how their influence extends through the different axes of the developing organism, and describe how the ability of axial mesoderm to direct morphogenesis impacts on its role as a local organizer.
Topics: Mesoderm; Morphogenesis; Nervous System; Body Patterning; Brain; Face; Germ Layers
PubMed: 38556460
DOI: 10.1016/bs.ctdb.2024.02.007 -
ELife Jun 2022Advanced imaging techniques reveal details of the interactions between the two layers of the embryonic midgut that influence its ultimate shape.
Advanced imaging techniques reveal details of the interactions between the two layers of the embryonic midgut that influence its ultimate shape.
Topics: Animals; Drosophila; Endoderm; Gene Expression Regulation, Developmental; Mesoderm; Morphogenesis
PubMed: 35771125
DOI: 10.7554/eLife.80416 -
Current Topics in Developmental Biology 2015The developmental mechanisms that control head muscle formation are distinct from those that operate in the trunk. Head and neck muscles derive from various mesoderm... (Review)
Review
The developmental mechanisms that control head muscle formation are distinct from those that operate in the trunk. Head and neck muscles derive from various mesoderm populations in the embryo and are regulated by distinct transcription factors and signaling molecules. Throughout the last decade, developmental, and lineage studies in vertebrates and invertebrates have revealed the peculiar nature of the pharyngeal mesoderm that forms certain head muscles and parts of the heart. Studies in chordates, the ancestors of vertebrates, revealed an evolutionarily conserved cardiopharyngeal field that progressively facilitates the development of both heart and craniofacial structures during vertebrate evolution. This ancient regulatory circuitry preceded and facilitated the emergence of myogenic cell types and hierarchies that exist in vertebrates. This chapter summarizes studies related to the origins, signaling circuits, genetics, and evolution of the head musculature, highlighting its heterogeneous characteristics in all these aspects, with a special focus on the FGF-ERK pathway. Additionally, we address the processes of head muscle regeneration, and the development of stem cell-based therapies for treatment of muscle disorders.
Topics: Animals; Gene Expression Regulation, Developmental; Heart; Humans; Mesoderm; Models, Biological; Muscle Development; Myocardium; Signal Transduction; Skull
PubMed: 26589919
DOI: 10.1016/bs.ctdb.2015.07.022 -
Current Topics in Developmental Biology 2015
Topics: Animals; Craniofacial Abnormalities; Gene Expression Regulation, Developmental; Humans; Mesoderm; Morphogenesis; Neural Crest; Signal Transduction; Skull; Transcription Factors
PubMed: 26589940
DOI: 10.1016/S0070-2153(15)00137-4 -
Anatomical Record (Hoboken, N.J. : 2007) Aug 2022The process by which upper respiratory tract structures have changed over deep evolutionary time is, in part, reflected in the process of embryologic development. The...
The process by which upper respiratory tract structures have changed over deep evolutionary time is, in part, reflected in the process of embryologic development. The nasopharynx in particular is a centrally located space bounded by components of the respiratory portion of the nasal cavity, cranial base, soft palate, and Eustachian tube. The development of these components can be understood both in terms of embryologic structures such as the branchial arches and paraxial mesoderm and through fossil evidence dating as far back as the earliest agnathan fish of the Cambrian Period. Understanding both the evolution and development of these structures has been an immeasurable benefit to the otolaryngologist seeking to model disease etiology of both common and rare conditions. This discussion is a primer for those who may be unfamiliar with the central importance of the nasopharynx both in terms of our evolutionary history and early embryological development of vital cranial and upper respiratory tract structures.
Topics: Animals; Biological Evolution; Branchial Region; Developmental Biology; Mesoderm; Nasopharynx; Skull
PubMed: 35665451
DOI: 10.1002/ar.24950 -
Seminars in Cell & Developmental Biology Jul 2022The discovery of mesoderm inducing signals helped usher in the era of molecular developmental biology, and today the mechanisms of mesoderm induction and patterning are... (Review)
Review
The discovery of mesoderm inducing signals helped usher in the era of molecular developmental biology, and today the mechanisms of mesoderm induction and patterning are still intensely studied. Mesoderm induction begins during gastrulation, but recent evidence in vertebrates shows that this process continues after gastrulation in a group of posteriorly localized cells called neuromesodermal progenitors (NMPs). NMPs reside within the post-gastrulation embryonic structure called the tailbud, where they make a lineage decision between ectoderm (spinal cord) and mesoderm. The majority of NMP-derived mesoderm generates somites, but also contributes to lateral mesoderm fates such as endothelium. The discovery of NMPs provides a new paradigm in which to study vertebrate mesoderm induction. This review will discuss mechanisms of mesoderm induction within NMPs, and how they have informed our understanding of mesoderm induction more broadly within vertebrates as well as animal species outside of the vertebrate lineage. Special focus will be given to the signaling networks underlying NMP-derived mesoderm induction and patterning, as well as emerging work on the significance of partial epithelial-mesenchymal states in coordinating cell fate and morphogenesis.
Topics: Animals; Body Patterning; Cell Differentiation; Gastrulation; Gene Expression Regulation, Developmental; Mesoderm; Somites
PubMed: 34840081
DOI: 10.1016/j.semcdb.2021.11.010 -
Experimental & Molecular Medicine Aug 2020Pluripotent stem cells (PSCs) are attractive regenerative therapy tools for skeletal tissues. However, a deep understanding of skeletal development is required in order... (Review)
Review
Pluripotent stem cells (PSCs) are attractive regenerative therapy tools for skeletal tissues. However, a deep understanding of skeletal development is required in order to model this development with PSCs, and for the application of PSCs in clinical settings. Skeletal tissues originate from three types of cell populations: the paraxial mesoderm, lateral plate mesoderm, and neural crest. The paraxial mesoderm gives rise to the sclerotome mainly through somitogenesis. In this process, key developmental processes, including initiation of the segmentation clock, formation of the determination front, and the mesenchymal-epithelial transition, are sequentially coordinated. The sclerotome further forms vertebral columns and contributes to various other tissues, such as tendons, vessels (including the dorsal aorta), and even meninges. To understand the molecular mechanisms underlying these developmental processes, extensive studies have been conducted. These studies have demonstrated that a gradient of activities involving multiple signaling pathways specify the embryonic axis and induce cell-type-specific master transcription factors in a spatiotemporal manner. Moreover, applying the knowledge of mesoderm development, researchers have attempted to recapitulate the in vivo development processes in in vitro settings, using mouse and human PSCs. In this review, we summarize the state-of-the-art understanding of mesoderm development and in vitro modeling of mesoderm development using PSCs. We also discuss future perspectives on the use of PSCs to generate skeletal tissues for basic research and clinical applications.
Topics: Animals; Bone Development; Bone and Bones; Humans; Mesoderm; Pluripotent Stem Cells; Somites; Wound Healing
PubMed: 32788657
DOI: 10.1038/s12276-020-0482-1 -
The International Journal of... 2018Somites are epithelial blocks of paraxial mesoderm that define the vertebrate embryonic segments. They are responsible for imposing the metameric pattern observed in... (Review)
Review
Somites are epithelial blocks of paraxial mesoderm that define the vertebrate embryonic segments. They are responsible for imposing the metameric pattern observed in many tissues of the adult such as the vertebrae, and they give rise to most of the axial skeleton and skeletal muscles of the trunk. Due to its easy accessibility in the egg, the chicken embryo has provided an ideal model to study somite development. Somites were first described in the chicken embryo by Malpighi in the 17 century, soon after the invention of the microscope. Most of the major concepts relating to somite segmentation and differentiation result from studies performed in the chicken embryo (Brand-Saberi and Christ, 2000). In this review, we will discuss how studies on somites in avian embryos have contributed to our understanding of key developmental processes such as segmentation, control of bilateral symmetry or axis regionalization.
Topics: Animals; Body Patterning; Cell Differentiation; Cell Lineage; Chick Embryo; Chickens; Embryology; Embryonic Development; Gene Expression Regulation, Developmental; History, 17th Century; History, 19th Century; History, 20th Century; History, 21st Century; Humans; Mesoderm; Mice; Somites; Vertebrates; Zebrafish
PubMed: 29616740
DOI: 10.1387/ijdb.180036op