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Journal of Computational Biology : a... Jul 2019
Topics: Animals; Endoderm; Gene Expression Regulation, Developmental; Gene Regulatory Networks; Genome; Mesoderm
PubMed: 31166788
DOI: 10.1089/cmb.2019.0097 -
Cells & Development Dec 2021In vertebrate embryos the presomitic mesoderm becomes progressively segmented into somites at the anterior end while extending along the anterior-posterior axis. A...
In vertebrate embryos the presomitic mesoderm becomes progressively segmented into somites at the anterior end while extending along the anterior-posterior axis. A commonly adopted model to explain how this tissue elongates is that of posterior growth, driven in part by the addition of new cells from uncommitted progenitor populations in the tailbud. However, in zebrafish, much of somitogenesis is associated with an absence of overall volume increase, and posterior progenitors do not contribute new cells until the final stages of somitogenesis. Here, we perform a comprehensive 3D morphometric analysis of the paraxial mesoderm and reveal that extension is linked to a volumetric decrease and an increase in cell density. We also find that individual cells decrease in volume over successive somite stages. Live cell tracking confirms that much of this tissue deformation occurs within the presomitic mesoderm progenitor zone and is associated with non-directional rearrangement. Taken together, we propose a compaction-extension mechanism of tissue elongation that highlights the need to better understand the role tissue intrinsic and extrinsic forces in regulating morphogenesis.
Topics: Animals; Embryonic Development; Mesoderm; Morphogenesis; Somites; Zebrafish
PubMed: 34597846
DOI: 10.1016/j.cdev.2021.203748 -
Cold Spring Harbor Perspectives in... Aug 2020During embryonic development, the heart arises from various sources of undifferentiated mesodermal progenitors, with an additional contribution from ectodermal neural... (Review)
Review
During embryonic development, the heart arises from various sources of undifferentiated mesodermal progenitors, with an additional contribution from ectodermal neural crest cells. Mesodermal cardiac progenitors are plastic and multipotent, but are nevertheless specified to a precise heart region and cell type very early during development. Recent findings have defined both this lineage plasticity and early commitment of cardiac progenitors, using a combination of single-cell and population analyses. In this review, we discuss several aspects of cardiac progenitor specification. We discuss their markers, fate potential in vitro and in vivo, early segregation and commitment, and also intrinsic and extrinsic cues regulating lineage restriction from multipotency to a specific cell type of the heart. Finally, we also discuss the subdivisions of the cardiopharyngeal field, and the shared origins of the heart with other mesodermal derivatives, including head and neck muscles.
Topics: Animals; Basic Helix-Loop-Helix Transcription Factors; Cell Differentiation; Cell Lineage; Embryonic Development; Gene Expression Regulation, Developmental; Head; Heart; Humans; Mesoderm; Muscle, Skeletal; Neural Crest; Signal Transduction; Single-Cell Analysis; Stem Cells
PubMed: 31818856
DOI: 10.1101/cshperspect.a036731 -
Cells May 2023Elongation of the posterior body axis is distinct from that of the anterior trunk and head. Early drivers of posterior elongation are the neural plate/tube and...
Elongation of the posterior body axis is distinct from that of the anterior trunk and head. Early drivers of posterior elongation are the neural plate/tube and notochord, later followed by the presomitic mesoderm (PSM), together with the neural tube and notochord. In axolotl, posterior neural plate-derived PSM is pushed posteriorly by convergence and extension of the neural plate. The PSM does not go through the blastopore but turns anteriorly to join the gastrulated paraxial mesoderm. To gain a deeper understanding of the process of axial elongation, a detailed characterization of PSM morphogenesis, which precedes somite formation, and of other tissues (such as the epidermis, lateral plate mesoderm and endoderm) is needed. We investigated these issues with specific tissue labelling techniques (DiI injections and GFP tissue grafting) in combination with optical tissue clearing and 3D reconstructions. We defined a spatiotemporal order of PSM morphogenesis that is characterized by changes in collective cell behaviour. The PSM forms a cohesive tissue strand and largely retains this cohesiveness even after epidermis removal. We show that during embryogenesis, the PSM, as well as the lateral plate and endoderm move anteriorly, while the net movement of the axis is posterior.
Topics: Neural Plate; Mesoderm; Morphogenesis; Embryonic Development; Muscles
PubMed: 37174713
DOI: 10.3390/cells12091313 -
Developmental Dynamics : An Official... Mar 2011The endoderm gives rise to the lining of the esophagus, stomach and intestines, as well as associated organs. To generate a functional intestine, a series of highly... (Review)
Review
The endoderm gives rise to the lining of the esophagus, stomach and intestines, as well as associated organs. To generate a functional intestine, a series of highly orchestrated developmental processes must occur. In this review, we attempt to cover major events during intestinal development from gastrulation to birth, including endoderm formation, gut tube growth and patterning, intestinal morphogenesis, epithelial reorganization, villus emergence, as well as proliferation and cytodifferentiation. Our discussion includes morphological and anatomical changes during intestinal development as well as molecular mechanisms regulating these processes.
Topics: Animals; Cell Differentiation; Endoderm; Humans; Intestinal Mucosa; Intestines; Mesoderm; Vertebrates
PubMed: 21246663
DOI: 10.1002/dvdy.22540 -
Mechanisms of Development Feb 2015During fin morphogenesis, several mesenchyme condensations occur to give rise to the dermal skeleton. Although each of them seems to create distinctive and unique... (Review)
Review
During fin morphogenesis, several mesenchyme condensations occur to give rise to the dermal skeleton. Although each of them seems to create distinctive and unique structures, they all follow the premises of the same morphogenetic principle. Holmgren's principle of delamination was first proposed to describe the morphogenesis of skeletal elements of the cranium, but Jarvik extended it to the development of the fin exoskeleton. Since then, some cellular or molecular explanations, such as the "flypaper" model (Thorogood et al.), or the evolutionary description by Moss, have tried to clarify this topic. In this article, we review new data from zebrafish studies to meet these criteria described by Holmgren and other authors. The variety of cell lineages involved in these skeletogenic condensations sheds light on an open discussion of the contributions of mesoderm- versus neural crest-derived cell lineages to the development of the head and trunk skeleton. Moreover, we discuss emerging molecular studies that are disclosing conserved regulatory mechanisms for dermal skeletogenesis and similarities during fin development and regeneration, which may have important implications in the potential use of the zebrafish fin as a model for regenerative medicine.
Topics: Animal Fins; Animals; Humans; Mesoderm; Models, Animal; Morphogenesis; Regeneration; Skull
PubMed: 25460362
DOI: 10.1016/j.mod.2014.11.002 -
Genomics May 2010Here, we review a recently discovered developmental mechanism. Anterior-posterior positional information for the vertebrate trunk is generated by sequential interactions... (Review)
Review
Here, we review a recently discovered developmental mechanism. Anterior-posterior positional information for the vertebrate trunk is generated by sequential interactions between a timer in the early non-organiser mesoderm and the Spemann organiser. The timer is characterised by temporally colinear activation of a series of Hox genes in the early ventral and lateral mesoderm (i.e., the non-organiser mesoderm) of the Xenopus gastrula. This early Hox gene expression is transient, unless it is stabilised by signals from the Spemann organiser. The non-organiser mesoderm (NOM) and the Spemann organiser undergo timed interactions during gastrulation which lead to the formation of an anterior-posterior axis and stable Hox gene expression. When separated from each other, neither non-organiser mesoderm nor the Spemann organiser is able to induce anterior-posterior pattern formation of the trunk. We present a model describing that NOM acquires transiently stable hox codes and spatial colinearity after involution into the gastrula and that convergence and extension then continually bring new cells from the NOM within the range of organiser signals that cause transfer of the mesodermal pattern to a stable pattern in neurectoderm and thereby create patterned axial structures. In doing so, the age of the non-organiser mesoderm, but not the age of the organiser, defines positional values along the anterior-posterior axis. We postulate that the temporal information from the non-organiser mesoderm is linked to mesodermal Hox expression. The role of the organiser was investigated further and this turns out to be only the induction of neural tissue. Apparently, development of a stable axial hox pattern requires neural hox patterning.
Topics: Animals; Gastrula; Gene Expression Regulation, Developmental; Homeodomain Proteins; Mesoderm; Neural Plate; Signal Transduction; Xenopus Proteins; Xenopus laevis
PubMed: 19944143
DOI: 10.1016/j.ygeno.2009.11.002 -
The FEBS Journal Apr 2016During embryonic development, formation of individual vertebrae requires that the paraxial mesoderm becomes divided into regular segmental units known as somites.... (Review)
Review
During embryonic development, formation of individual vertebrae requires that the paraxial mesoderm becomes divided into regular segmental units known as somites. Somites are sequentially formed at the anterior end of the presomitic mesoderm (PSM) resulting from functional interactions between the oscillatory activity of signals promoting segmentation and a moving wavefront of tissue competence to those signals, eventually generating a constant flow of new somites at regular intervals. According to the current model for somitogenesis, the wavefront results from the combined activity of two opposing functional gradients in the PSM involving the Fgf, Wnt and retinoic acid (RA) signaling pathways. Here, I use published data to evaluate the wavefront model. A critical analysis of those studies seems to support a role for Wnt signaling, but raise doubts regarding the extent to which Fgf and RA signaling contribute to this process.
Topics: Animals; Humans; Mesoderm; Morphogenesis; Signal Transduction; Somites
PubMed: 26662366
DOI: 10.1111/febs.13622 -
Hepatology Communications Mar 2021The hepatic mesenchyme has been studied extensively in the context of liver fibrosis; however, much less is known regarding the role of mesenchymal cells during liver... (Review)
Review
The hepatic mesenchyme has been studied extensively in the context of liver fibrosis; however, much less is known regarding the role of mesenchymal cells during liver regeneration. As our knowledge of the cellular and molecular mechanisms driving hepatic regeneration deepens, the key role of the mesenchymal compartment during the regenerative response has been increasingly appreciated. Single-cell genomics approaches have recently uncovered both spatial and functional zonation of the hepatic mesenchyme in homeostasis and following liver injury. Here we discuss how the use of preclinical models, from in vivo mouse models to organoid-based systems, are helping to shape our understanding of the role of the mesenchyme during liver regeneration, and how these approaches should facilitate the precise identification of highly targeted, pro-regenerative therapies for patients with liver disease.
Topics: Animals; Cells, Cultured; Hepatic Stellate Cells; Humans; Liver; Liver Diseases; Liver Regeneration; Mesoderm; Mice
PubMed: 33681672
DOI: 10.1002/hep4.1628 -
Developmental Biology Mar 2018The murine pancreas buds from the ventral embryonic endoderm at approximately 8.75 dpc and a second pancreas bud emerges from the dorsal endoderm by 9.0 dpc. Although it...
The murine pancreas buds from the ventral embryonic endoderm at approximately 8.75 dpc and a second pancreas bud emerges from the dorsal endoderm by 9.0 dpc. Although it is clear that secreted signals from adjacent mesoderm-derived sources are required for both the appropriate emergence and further refinement of the pancreatic endoderm, neither the exact signals nor the requisite tissue sources have been defined in mammalian systems. Herein we use DiI fate mapping of cultured murine embryos to identify the embryonic sources of both the early inductive and later condensed pancreatic mesenchyme. Despite being capable of supporting pancreas induction from dorsal endoderm in co-culture experiments, we find that in the context of the developing embryo, the dorsal aortae as well as the paraxial, intermediate, and lateral mesoderm derivatives only transiently associate with the dorsal pancreas bud, producing descendants that are decidedly anterior to the pancreas bud. Unlike these other mesoderm derivatives, the axial (notochord) descendants maintain association with the dorsal pre-pancreatic endoderm and early pancreas bud. This fate mapping data points to the notochord as the likely inductive source in vivo while also revealing dynamic morphogenetic movements displayed by individual mesodermal subtypes. Because none of the mesoderm examined above produced the pancreatic mesenchyme that condenses around the induced bud to support exocrine and endocrine differentiation, we also sought to identify the mesodermal origins of this mesenchyme. We identify a portion of the coelomic mesoderm that contributes to the condensed pancreatic mesenchyme. In conclusion, we identify a portion of the notochord as a likely source of the signals required to induce and maintain the early dorsal pancreas bud, demonstrate that the coelomic mesothelium contributes to the dorsal and ventral pancreatic mesenchyme, and provide insight into the dynamic morphological rearrangements of mesoderm-derived tissues during early organogenesis stages of mammalian development.
Topics: Animals; Embryo, Mammalian; Mesoderm; Mice; Organogenesis; Pancreas
PubMed: 29329912
DOI: 10.1016/j.ydbio.2018.01.003