-
Nature Communications Aug 2020Visceral organs, such as the lungs, stomach and liver, are derived from the fetal foregut through a series of inductive interactions between the definitive endoderm (DE)...
Visceral organs, such as the lungs, stomach and liver, are derived from the fetal foregut through a series of inductive interactions between the definitive endoderm (DE) and the surrounding splanchnic mesoderm (SM). While DE patterning is fairly well studied, the paracrine signaling controlling SM regionalization and how this is coordinated with epithelial identity is obscure. Here, we use single cell transcriptomics to generate a high-resolution cell state map of the embryonic mouse foregut. This identifies a diversity of SM cell types that develop in close register with the organ-specific epithelium. We infer a spatiotemporal signaling network of endoderm-mesoderm interactions that orchestrate foregut organogenesis. We validate key predictions with mouse genetics, showing the importance of endoderm-derived signals in mesoderm patterning. Finally, leveraging these signaling interactions, we generate different SM subtypes from human pluripotent stem cells (hPSCs), which previously have been elusive. The single cell data can be explored at: https://research.cchmc.org/ZornLab-singlecell .
Topics: Animals; Cell Lineage; Digestive System; Endoderm; Gene Expression Profiling; Gene Expression Regulation, Developmental; Gene Regulatory Networks; Humans; Internet; Mesoderm; Mice, Inbred C57BL; Organogenesis; Signal Transduction; Single-Cell Analysis; Transcription Factors
PubMed: 32855417
DOI: 10.1038/s41467-020-17968-x -
Science Advances Jan 2024Spatiotemporal patterns widely occur in biological, chemical, and physical systems. Particularly, embryonic development displays a diverse gamut of repetitive patterns... (Review)
Review
Spatiotemporal patterns widely occur in biological, chemical, and physical systems. Particularly, embryonic development displays a diverse gamut of repetitive patterns established in many tissues and organs. Branching treelike structures in lungs, kidneys, livers, pancreases, and mammary glands as well as digits and bones in appendages, teeth, and palates are just a few examples. A fascinating instance of repetitive patterning is the sequential segmentation of the primary body axis, which is conserved in all vertebrates and many arthropods and annelids. In these species, the body axis elongates at the posterior end of the embryo containing an unsegmented tissue. Meanwhile, segments sequentially bud off from the anterior end of the unsegmented tissue, laying down an exquisite repetitive pattern and creating a segmented body plan. In vertebrates, the paraxial mesoderm is sequentially divided into somites. In this review, we will discuss the most prominent models, the most puzzling experimental data, and outstanding questions in vertebrate somite segmentation.
Topics: Animals; Body Patterning; Somites; Mesoderm; Vertebrates; Embryonic Development; Gene Expression Regulation, Developmental
PubMed: 38277458
DOI: 10.1126/sciadv.adk8937 -
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 -
Nature Communications Jul 2020Human embryogenesis is hallmarked by two phases of yolk sac development. The primate hypoblast gives rise to a transient primary yolk sac, which is rapidly superseded by... (Review)
Review
Human embryogenesis is hallmarked by two phases of yolk sac development. The primate hypoblast gives rise to a transient primary yolk sac, which is rapidly superseded by a secondary yolk sac during gastrulation. Moreover, primate embryos form extraembryonic mesoderm prior to gastrulation, in contrast to mouse. The function of the primary yolk sac and the origin of extraembryonic mesoderm remain unclear. Here, we hypothesise that the hypoblast-derived primary yolk sac serves as a source for early extraembryonic mesoderm, which is supplemented with mesoderm from the gastrulating embryo. We discuss the intricate relationship between the yolk sac and the primate embryo and highlight the pivotal role of the yolk sac as a multifunctional hub for haematopoiesis, germ cell development and nutritional supply.
Topics: Animals; Cell Differentiation; Embryonic Development; Embryonic Germ Cells; Hematopoiesis; Mesoderm; Primates; Yolk Sac
PubMed: 32724077
DOI: 10.1038/s41467-020-17575-w -
Developmental Cell Oct 2023The mammalian body plan is shaped by rhythmic segmentation of mesoderm into somites, which are transient embryonic structures that form down each side of the neural...
The mammalian body plan is shaped by rhythmic segmentation of mesoderm into somites, which are transient embryonic structures that form down each side of the neural tube. We have analyzed the genome-wide transcriptional and chromatin dynamics occurring within nascent somites, from early inception of somitogenesis to the latest stages of body plan establishment. We created matched gene expression and open chromatin maps for the three leading pairs of somites at six time points during mouse embryonic development. We show that the rate of somite differentiation accelerates as development progresses. We identified a conserved maturation program followed by all somites, but somites from more developed embryos concomitantly switch on differentiation programs from derivative cell lineages soon after segmentation. Integrated analysis of the somitic transcriptional and chromatin activities identified opposing regulatory modules controlling the onset of differentiation. Our results provide a powerful, high-resolution view of the molecular genetics underlying somitic development in mammals.
Topics: Pregnancy; Female; Mice; Animals; Somites; Embryonic Development; Mesoderm; Cell Differentiation; Chromatin; Mammals
PubMed: 37499658
DOI: 10.1016/j.devcel.2023.07.003 -
Developmental Cell Jun 2023Mesenchymal-epithelial transitions are fundamental drivers of development and disease, but how these behaviors generate epithelial structure is not well understood....
Mesenchymal-epithelial transitions are fundamental drivers of development and disease, but how these behaviors generate epithelial structure is not well understood. Here, we show that mesenchymal-epithelial transitions promote epithelial organization in the mouse node and notochordal plate through the assembly and radial intercalation of three-dimensional rosettes. Axial mesoderm rosettes acquire junctional and apical polarity, develop a central lumen, and dynamically expand, coalesce, and radially intercalate into the surface epithelium, converting mesenchymal-epithelial transitions into higher-order tissue structure. In mouse Par3 mutants, axial mesoderm rosettes establish central tight junction polarity but fail to form an expanded apical domain and lumen. These defects are associated with altered rosette dynamics, delayed radial intercalation, and formation of a small, fragmented surface epithelial structure. These results demonstrate that three-dimensional rosette behaviors translate mesenchymal-epithelial transitions into collective radial intercalation and epithelial formation, providing a strategy for building epithelial sheets from individual self-organizing units in the mammalian embryo.
Topics: Animals; Mice; Mesoderm; Epithelium; Cell Differentiation; Embryo, Mammalian; Morphogenesis; Mammals
PubMed: 37080203
DOI: 10.1016/j.devcel.2023.03.018 -
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 -
ELife Dec 2022How cellular metabolic state impacts cellular programs is a fundamental, unresolved question. Here, we investigated how glycolytic flux impacts embryonic development,...
How cellular metabolic state impacts cellular programs is a fundamental, unresolved question. Here, we investigated how glycolytic flux impacts embryonic development, using presomitic mesoderm (PSM) patterning as the experimental model. First, we identified fructose 1,6-bisphosphate (FBP) as an in vivo sentinel metabolite that mirrors glycolytic flux within PSM cells of post-implantation mouse embryos. We found that medium-supplementation with FBP, but not with other glycolytic metabolites, such as fructose 6-phosphate and 3-phosphoglycerate, impaired mesoderm segmentation. To genetically manipulate glycolytic flux and FBP levels, we generated a mouse model enabling the conditional overexpression of dominant active, cytoplasmic PFKFB3 (cytoPFKFB3). Overexpression of cytoPFKFB3 indeed led to increased glycolytic flux/FBP levels and caused an impairment of mesoderm segmentation, paralleled by the downregulation of Wnt-signaling, reminiscent of the effects seen upon FBP-supplementation. To probe for mechanisms underlying glycolytic flux-signaling, we performed subcellular proteome analysis and revealed that cytoPFKFB3 overexpression altered subcellular localization of certain proteins, including glycolytic enzymes, in PSM cells. Specifically, we revealed that FBP supplementation caused depletion of Pfkl and Aldoa from the nuclear-soluble fraction. Combined, we propose that FBP functions as a flux-signaling metabolite connecting glycolysis and PSM patterning, potentially through modulating subcellular protein localization.
Topics: Animals; Mice; Mesoderm; Glycolysis; Embryonic Development; Embryo, Mammalian; Wnt Signaling Pathway; Phosphotransferases
PubMed: 36469462
DOI: 10.7554/eLife.83299 -
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