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Results and Problems in Cell... 2024As epiblast cells initiate development into various somatic cells, they undergo a large-scale reorganization, called gastrulation. The gastrulation of the epiblast cells...
As epiblast cells initiate development into various somatic cells, they undergo a large-scale reorganization, called gastrulation. The gastrulation of the epiblast cells produces three groups of cells: the endoderm layer, the collection of miscellaneous mesodermal tissues, and the ectodermal layer, which includes the neural, epidermal, and associated tissues. Most studies of gastrulation have focused on the formation of the tissues that provide the primary route for cell reorganization, that is, the primitive streak, in the chicken and mouse. In contrast, how gastrulation alters epiblast-derived cells has remained underinvestigated. This chapter highlights the regulation of cell and tissue fate via the gastrulation process. The roles and regulatory functions of neuromesodermal progenitors (NMPs) in the gastrulation process, elucidated in the last decade, are discussed in depth to resolve points of confusion. Chicken and mouse embryos, which form a primitive streak as the site of mesoderm precursor ingression, have been investigated extensively. However, primitive streak formation is an exception, even among amniotes. The roles of gastrulation processes in generating various somatic tissues will be discussed broadly.
Topics: Mice; Animals; Gastrulation; Gastrula; Mesoderm; Endoderm; Embryonic Development
PubMed: 38509251
DOI: 10.1007/978-3-031-39027-2_3 -
Journal of the American Society of... Oct 2020
Topics: Cell Differentiation; Embryonic Stem Cells; Mesoderm; Ureter
PubMed: 32999037
DOI: 10.1681/ASN.2020071055 -
International Journal of Molecular... Jan 2021Skeletal disorders, such as osteoarthritis and bone fractures, are among the major conditions that can compromise the quality of daily life of elderly individuals. To... (Review)
Review
Skeletal disorders, such as osteoarthritis and bone fractures, are among the major conditions that can compromise the quality of daily life of elderly individuals. To treat them, regenerative therapies using skeletal cells have been an attractive choice for patients with unmet clinical needs. Currently, there are two major strategies to prepare the cell sources. The first is to use induced pluripotent stem cells (iPSCs) or embryonic stem cells (ESCs), which can recapitulate the skeletal developmental process and differentiate into various skeletal cells. Skeletal tissues are derived from three distinct origins: the neural crest, paraxial mesoderm, and lateral plate mesoderm. Thus, various protocols have been proposed to recapitulate the sequential process of skeletal development. The second strategy is to extract stem cells from skeletal tissues. In addition to mesenchymal stem/stromal cells (MSCs), multiple cell types have been identified as alternative cell sources. These cells have distinct multipotent properties allowing them to differentiate into skeletal cells and various potential applications for skeletal regeneration. In this review, we summarize state-of-the-art research in stem cell differentiation based on the understanding of embryogenic skeletal development and stem cells existing in skeletal tissues. We then discuss the potential applications of these cell types for regenerative medicine.
Topics: Animals; Bone Development; Bone and Bones; Cell Differentiation; Disease Models, Animal; Embryo, Mammalian; Embryonic Development; Embryonic Stem Cells; Fractures, Bone; Humans; Induced Pluripotent Stem Cells; Mesenchymal Stem Cells; Mesoderm; Neural Crest; Osteoarthritis; Osteoblasts; Regenerative Medicine; Stem Cell Transplantation
PubMed: 33573345
DOI: 10.3390/ijms22031404 -
Cold Spring Harbor Protocols Nov 2022Mesendoderm mantle closure completes the gastrulation movements of the embryo and provides an unparalleled opportunity to study collective cell behaviors within a...
Mesendoderm mantle closure completes the gastrulation movements of the embryo and provides an unparalleled opportunity to study collective cell behaviors within a mesenchymal tissue. Free-edge sheet-like collective movements of these tissues contrast with movements of epithelial tissues in that mesendodermal cells are not constrained by tight junctions or adherens junctions, yet migrate in a coherent and persistent mode over several hours. Mesendoderm cells are the largest motile cells in the embryo and complete a 500-µm migratory path. When mesendoderm is cultured on rigid glass substrates, these cells can exceed 100 µm in length and show a highly persistent leading lamellipodia that can exceed 20 µm from tip to base. These large collectively migrating cells provide a unique imaging opportunity to visualize polarized adhesive and cytoskeletal structures with high-numerical-aperture objectives. Mesendodermal cells in the early embryo originate from around the entirety of the marginal zone and may also be distinguished by their source along the animal-vegetal axis. Here we use the term mesendoderm but note alternative terms for these cells can include head mesoderm, endomesoderm, and prechordal mesoderm. This protocol summarizes microsurgical preparation of mesendoderm tissue explants and "windowed" embryos. Skills needed to dissect fragments of the mesendoderm mantle are marginally greater than those needed to isolate animal cap ectoderm and can be mastered within 2 weeks; skills needed to isolate the mesendoderm "donut" or "ring" or to prepare windowed embryos are significantly greater and may require several additional weeks of training.
Topics: Animals; Gastrulation; Xenopus laevis; Mesoderm; Ectoderm; Pseudopodia
PubMed: 35577524
DOI: 10.1101/pdb.prot097378 -
The International Journal of... 2020Clinical dysmorphology is a medical specialty which requires training to systematically observe aberrations in facial development and to understand patterns in the... (Review)
Review
Clinical dysmorphology is a medical specialty which requires training to systematically observe aberrations in facial development and to understand patterns in the recognition of underlying genetic syndromes. An understanding of normal facial embryology and structure, genetic mechanisms that contribute to facial development and the influence of age, sex, epigenetic, environmental and teratogen effects that contribute to facial dysmorphology are essential. The role of software programmes and databases in achieving diagnoses in subtler phenotypes is growing. A description of specific dysmorphisms of various parts of the human face and key genetic and mechanistic pathways are discussed in this review. Recognizing facial patterns and genetic syndromes efficiently aids in planning appropriate tests, securing an accurate diagnosis, counselling and predicting outcomes and offering interventions and therapies where available.
Topics: Congenital Abnormalities; Craniosynostoses; Embryonic Development; Face; Female; Gene Expression Regulation, Developmental; Humans; Male; Mesoderm; Neural Crest
PubMed: 32658997
DOI: 10.1387/ijdb.190312mb -
Journal of Visualized Experiments : JoVE Jun 2022The body axis of vertebrate embryos is periodically subdivided into 3D multicellular units called somites. While genetic oscillations and molecular prepatterns determine...
The body axis of vertebrate embryos is periodically subdivided into 3D multicellular units called somites. While genetic oscillations and molecular prepatterns determine the initial length-scale of somites, mechanical processes have been implicated in setting their final size and shape. To better understand the intrinsic material properties of somites, a method is developed to culture single-somite explant from zebrafish embryos. Single somites are isolated by first removing the skin of embryos, followed by yolk removal and sequential excision of neighboring tissues. Using transgenic embryos, the distribution of various sub-cellular structures can be observed by fluorescent time-lapse microscopy. Dynamics of explanted somites can be followed for several hours, thus providing an experimental framework for studying tissue-scale shape changes at single-cell resolution. This approach enables direct mechanical manipulation of somites, allowing for dissection of the material properties of the tissue. Finally, the technique outlined here can be readily extended for explanting other tissues such as the notochord, neural plate, and lateral plate mesoderm.
Topics: Animals; Mesoderm; Notochord; Somites; Zebrafish
PubMed: 35781468
DOI: 10.3791/63196 -
Current Topics in Developmental Biology 2020Gastrulation is a central process in mammalian development in which a spatiotemporally coordinated series of events driven by cross-talk between adjacent embryonic and... (Review)
Review
Gastrulation is a central process in mammalian development in which a spatiotemporally coordinated series of events driven by cross-talk between adjacent embryonic and extra-embryonic tissues results in stereotypical morphogenetic cell behaviors, massive cell proliferation and the acquisition of distinct cell identities. Gastrulation provides the blueprint of the body plan of the embryo, as well as generating extra-embryonic cell types of the embryo to make a connection with its mother. Gastrulation involves the specification of mesoderm and definitive endoderm from pluripotent epiblast, concomitant with a highly ordered elongation of tissue along the anterior-posterior (AP) axis. Interestingly, cells with an endoderm identity arise twice during mouse development. Cells with a primitive endoderm identity are specified in the preimplantation blastocyst, and which at gastrulation intercalate with the emergent definitive endoderm to form a mosaic tissue, referred to as the gut endoderm. The gut endoderm gives rise to the gut tube, which will subsequently become patterned along its AP axis into domains possessing unique visceral organ identities, such as thyroid, lung, liver and pancreas. In this way, proper endoderm development is essential for vital organismal functions, including the absorption of nutrients, gas exchange, detoxification and glucose homeostasis.
Topics: Animals; Embryo, Mammalian; Endoderm; Gastrointestinal Tract; Gastrulation; Germ Layers; Mesoderm; Mice; Morphogenesis
PubMed: 31959298
DOI: 10.1016/bs.ctdb.2019.11.012 -
Current Opinion in Cell Biology Dec 2021Cranial muscles have been the focus of many studies over the years because of their unique developmental programs and relative resistance to illnesses. In addition, head... (Review)
Review
Cranial muscles have been the focus of many studies over the years because of their unique developmental programs and relative resistance to illnesses. In addition, head muscles possess clonal relationships with heart muscles and have been highly remodeled during vertebrate evolution. Here, we provide an overview of recent findings that have helped to redefine the boundaries and lineages of cranial mesoderm. These studies have important implications regarding the emergence of muscle connective tissues, which can share a common origin with skeletal muscle. We also highlight new regulatory networks of various muscle subgroups, particularly those derived from the most caudal arches, which remain poorly defined. Finally, we suggest future research avenues to characterize the nature of their intrinsic specificities and their emergence during evolution.
Topics: Animals; Head; Mesoderm; Muscle, Skeletal; Skull; Vertebrates
PubMed: 34500235
DOI: 10.1016/j.ceb.2021.06.005 -
Current Topics in Developmental Biology 2024The anterior-to-posterior (head-to-tail) body axis is extraordinarily diverse among vertebrates but conserved within species. Body axis development requires a population... (Review)
Review
The anterior-to-posterior (head-to-tail) body axis is extraordinarily diverse among vertebrates but conserved within species. Body axis development requires a population of axial progenitors that resides at the posterior of the embryo to sustain elongation and is then eliminated once axis extension is complete. These progenitors occupy distinct domains in the posterior (tail-end) of the embryo and contribute to various lineages along the body axis. The subset of axial progenitors with neuromesodermal competency will generate both the neural tube (the precursor of the spinal cord), and the trunk and tail somites (producing the musculoskeleton) during embryo development. These axial progenitors are called Neuromesodermal Competent cells (NMCs) and Neuromesodermal Progenitors (NMPs). NMCs/NMPs have recently attracted interest beyond the field of developmental biology due to their clinical potential. In the mouse, the maintenance of neuromesodermal competency relies on a fine balance between a trio of known signals: Wnt/β-catenin, FGF signalling activity and suppression of retinoic acid signalling. These signals regulate the relative expression levels of the mesodermal transcription factor Brachyury and the neural transcription factor Sox2, permitting the maintenance of progenitor identity when co-expressed, and either mesoderm or neural lineage commitment when the balance is tilted towards either Brachyury or Sox2, respectively. Despite important advances in understanding key genes and cellular behaviours involved in these fate decisions, how the balance between mesodermal and neural fates is achieved remains largely unknown. In this chapter, we provide an overview of signalling and gene regulatory networks in NMCs/NMPs. We discuss mutant phenotypes associated with axial defects, hinting at the potential significant role of lesser studied proteins in the maintenance and differentiation of the progenitors that fuel axial elongation.
Topics: Animals; Body Patterning; Mesoderm; Gene Expression Regulation, Developmental; Humans; Signal Transduction; T-Box Domain Proteins; Cell Differentiation; Head
PubMed: 38729677
DOI: 10.1016/bs.ctdb.2024.02.012 -
Developmental Dynamics : An Official... May 2023Mammalian calvarium is composed of flat bones developed from two origins, neural crest, and mesoderm. Cells from both origins exhibit similar behavior but express...
BACKGROUND
Mammalian calvarium is composed of flat bones developed from two origins, neural crest, and mesoderm. Cells from both origins exhibit similar behavior but express distinct transcriptomes. It is intriguing to ask whether genes shared by both origins play similar or distinct roles in development. In the present study, we have examined the role of Pdgfra, which is expressed in both neural crest and mesoderm, in specific lineages during calvarial development.
RESULTS
We found that in calvarial progenitor cells, Pdgfra is needed to maintain normal proliferation and migration of neural crest cells but only proliferation of mesoderm cells. Later in calvarial osteoblasts, we found that Pdgfra is necessary for both proliferation and differentiation of neural crest-derived cells, but not for differentiation of mesoderm-derived cells. We also examined the potential interaction between Pdgfra and other signaling pathway involved in calvarial osteoblasts but did not identify significant alteration of Wnt or Hh signaling activity in Pdgfra genetic models.
CONCLUSIONS
Pdgfra is required for normal calvarial development in both neural crest cells and mesoderm cells, but these lineages exhibit distinct responses to alteration of Pdgfra activity.
Topics: Animals; Cell Differentiation; Skull; Receptor Protein-Tyrosine Kinases; Signal Transduction; Neural Crest; Mesoderm; Mammals
PubMed: 36606407
DOI: 10.1002/dvdy.564