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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 -
Seminars in Cell & Developmental Biology Nov 2022Gastrulation is a fundamental process during embryonic development, conserved across all multicellular animals [1]. In the majority of metazoans, gastrulation is... (Review)
Review
Gastrulation is a fundamental process during embryonic development, conserved across all multicellular animals [1]. In the majority of metazoans, gastrulation is characterised by large scale morphogenetic remodeling, leading to the conversion of an early pluripotent embryonic cell layer into the three primary 'germ layers': an outer ectoderm, inner endoderm and intervening mesoderm layer. The morphogenesis of these three layers of cells is closely coordinated with cellular diversification, laying the foundation for the generation of the hundreds of distinct specialized cell types in the animal body. The process of gastrulation has for a long time attracted tremendous attention in a broad range of experimental systems ranging from sponges to mice. In humans the process of gastrulation starts approximately 14 days after fertilization and continues for slightly over a week. However our understanding of this important process, as it pertains to human, is limited. Donations of human fetal material at these early stages are exceptionally rare, making it nearly impossible to study human gastrulation directly. Therefore, our understanding of human gastrulation is predominantly derived from animal models such as the mouse [2,3] and from studies of limited collections of fixed whole samples and histological sections of human gastrulae [4-7], some of which date back to over a century ago. More recently we have been gaining valuable molecular insights into human gastrulation using in vitro models of hESCs [8-12] and increasingly, in vitro cultured human and non-human primate embryos [13-16]. However, while methods have been developed to culture human embryos into this stage (and probably beyond), current ethical standards prohibit the culture of human embryos past 14 days again limiting our ability to experimentally probe human gastrulation. This review discusses recent molecular insights from the study of a rare CS 7 human gastrula obtained as a live sample and raises several questions arising from this recent study that it will be interesting to address in the future using emerging models of human gastrulation.
Topics: Animals; Ectoderm; Endoderm; Female; Gastrula; Gastrulation; Humans; Mesoderm; Mice; Pregnancy
PubMed: 35606274
DOI: 10.1016/j.semcdb.2022.05.004 -
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 -
Journal of Biomedical Science Jun 2022The molecular mechanisms that regulate embryogenesis and cardiac development are calibrated by multiple signal transduction pathways within or between different cell... (Review)
Review
The molecular mechanisms that regulate embryogenesis and cardiac development are calibrated by multiple signal transduction pathways within or between different cell lineages via autocrine or paracrine mechanisms of action. The heart is the first functional organ to form during development, which highlights the importance of this organ in later stages of growth. Knowledge of the regulatory mechanisms underlying cardiac development and adult cardiac homeostasis paves the way for discovering therapeutic possibilities for cardiac disease treatment. Serum response factor (SRF) is a major transcription factor that controls both embryonic and adult cardiac development. SRF expression is needed through the duration of development, from the first mesodermal cell in a developing embryo to the last cell damaged by infarction in the myocardium. Precise regulation of SRF expression is critical for mesoderm formation and cardiac crescent formation in the embryo, and altered SRF levels lead to cardiomyopathies in the adult heart, suggesting the vital role played by SRF in cardiac development and disease. This review provides a detailed overview of SRF and its partners in their various functions and discusses the future scope and possible therapeutic potential of SRF in the cardiovascular system.
Topics: Gene Expression Regulation, Developmental; Heart; Mesoderm; Myocardium; Serum Response Factor; Transcription Factors
PubMed: 35681202
DOI: 10.1186/s12929-022-00820-3 -
Developmental Biology Oct 2021To date, the role of miRNAs on pluripotency and differentiation of ESCs into specific lineages has been studied extensively. However, the specific role of miRNAs during...
To date, the role of miRNAs on pluripotency and differentiation of ESCs into specific lineages has been studied extensively. However, the specific role of miRNAs during lateral and paraxial mesoderm cell fate decision is still unclear. To address this, we firstly determined miRNA profile of mouse ESCs differentiating towards lateral and paraxial lineages which were detected using Flk1 and PDGFαR antibodies, and of myogenic and hematopoietic differentiation potential of purified paraxial and lateral mesodermal cells within these populations. miRNAs associated with lateral and paraxial mesoderm, and their targets were identified using bioinformatics tools. The targets of the corresponding miRNAs were validated after transfection into mouse ESCs. The roles of the selected miRNAs in lateral, and paraxial mesoderm formation were assessed along with hematopoietic and myogenic differentiation capacity. Among the miRNAs, mmu-miR-126a-3p, mmu-miR-335-5p and mmu-miR-672-5p, upregulated in lateral mesoderm cells, and mmu-miR-10b-5p, mmu-miR-196a-5p and mmu-miR-615-3p, upregulated in paraxial mesoderm cells. While transient co-transfection of mmu-miR-126a-3p, mmu-miR-335-5p and mmu-miR-672-5p increased the number of lateral mesodermal cells, co-transfection of mmu-miR-10b-5p, mmu-miR-196a-5p and mmu-miR-615-3p increased the number of paraxial mesodermal cells. Moreover, differentiation potential of the lateral mesodermal cells into hematopoietic cell lineage increased upon co-transfection of mmu-miR-126a-3p, mmu-miR-335-5p and mmu-miR-672-5p and differentiation potential of the paraxial mesodermal cells into skeletal muscle lineage were increased upon co-transfection of mmu-miR-10b-5p, mmu-miR-196a-5p and mmu-miR-615-3p. In conclusion, we determined the miRNA profile of lateral and paraxial mesodermal cells and co-transfection of miRNAs increased differentiation potential of both lateral and paraxial mesodermal cells transiently.
Topics: Animals; Cell Differentiation; Computational Biology; Embryoid Bodies; Embryonic Stem Cells; Hematopoiesis; Mesoderm; Mice; MicroRNAs; Muscle Development; Transfection; Up-Regulation
PubMed: 34245726
DOI: 10.1016/j.ydbio.2021.07.002 -
PLoS Biology Jan 2021Collective migration of cohesive tissues is a fundamental process in morphogenesis and is particularly well illustrated during gastrulation by the rapid and massive...
Collective migration of cohesive tissues is a fundamental process in morphogenesis and is particularly well illustrated during gastrulation by the rapid and massive internalization of the mesoderm, which contrasts with the much more modest movements of the ectoderm. In the Xenopus embryo, the differences in morphogenetic capabilities of ectoderm and mesoderm can be connected to the intrinsic motility of individual cells, very low for ectoderm, high for mesoderm. Surprisingly, we find that these seemingly deep differences can be accounted for simply by differences in Rho-kinases (Rock)-dependent actomyosin contractility. We show that Rock inhibition is sufficient to rapidly unleash motility in the ectoderm and confer it with mesoderm-like properties. In the mesoderm, this motility is dependent on two negative regulators of RhoA, the small GTPase Rnd1 and the RhoGAP Shirin/Dlc2/ArhGAP37. Both are absolutely essential for gastrulation. At the cellular and tissue level, the two regulators show overlapping yet distinct functions. They both contribute to decrease cortical tension and confer motility, but Shirin tends to increase tissue fluidity and stimulate dispersion, while Rnd1 tends to favor more compact collective migration. Thus, each is able to contribute to a specific property of the migratory behavior of the mesoderm. We propose that the "ectoderm to mesoderm transition" is a prototypic case of collective migration driven by a down-regulation of cellular tension, without the need for the complex changes traditionally associated with the epithelial-to-mesenchymal transition.
Topics: Actomyosin; Animals; Cell Movement; Down-Regulation; Ectoderm; Embryo, Nonmammalian; Epithelial-Mesenchymal Transition; GTPase-Activating Proteins; Gastrulation; Gene Expression Regulation, Developmental; Mesoderm; Morphogenesis; Protein Transport; Signal Transduction; Tissue Distribution; Xenopus Proteins; Xenopus laevis; rho GTP-Binding Proteins
PubMed: 33406067
DOI: 10.1371/journal.pbio.3001060 -
Developmental Cell Jun 2023Oscillator systems achieve synchronization when oscillators are coupled. The presomitic mesoderm is a system of cellular oscillators, where coordinated genetic activity...
Oscillator systems achieve synchronization when oscillators are coupled. The presomitic mesoderm is a system of cellular oscillators, where coordinated genetic activity is necessary for proper periodic generation of somites. While Notch signaling is required for the synchronization of these cells, it is unclear what information the cells exchange and how they react to this information to align their oscillatory pace with that of their neighbors. Combining mathematical modeling and experimental data, we found that interaction between murine presomitic mesoderm cells is controlled by a phase-gated and unidirectional coupling mechanism and results in deceleration of their oscillation pace upon Notch signaling. This mechanism predicts that isolated populations of well-mixed cells synchronize, revealing a stereotypical synchronization in the mouse PSM and contradicting expectations from previously applied theoretical approaches. Collectively, our theoretical and experimental findings reveal the underlying coupling mechanisms of the presomitic mesoderm cells and provide a framework to quantitatively characterize their synchronization.
Topics: Mice; Animals; Biological Clocks; Somites; Mesoderm; Models, Theoretical; Signal Transduction; Gene Expression Regulation, Developmental; Receptors, Notch
PubMed: 37098349
DOI: 10.1016/j.devcel.2023.04.002 -
Development (Cambridge, England) May 2023Cardiac lineage specification in the mouse is controlled by TGFβ and WNT signaling. From fly to fish, BMP has been identified as an indispensable heart inducer. A...
Cardiac lineage specification in the mouse is controlled by TGFβ and WNT signaling. From fly to fish, BMP has been identified as an indispensable heart inducer. A detailed analysis of the role of Bmp4 and its effectors Smad1/5, however, was still missing. We show that Bmp4 induces cardiac mesoderm formation in murine embryonic stem cells in vitro. Bmp4 first activates Wnt3 and upregulates Nodal. pSmad1/5 and the WNT effector Tcf3 form a complex, and together with pSmad2/3 activate mesoderm enhancers and Eomes. They then cooperate with Eomes to consolidate the expression of many mesoderm factors, including T. Eomes and T form a positive- feedback loop and open additional enhancers regulating early mesoderm genes, including the transcription factor Mesp1, establishing the cardiac mesoderm lineage. In parallel, the neural fate is suppressed. Our data confirm the pivotal role of Bmp4 in cardiac mesoderm formation in the mouse. We describe in detail the consecutive and cooperative actions of three signaling pathways, BMP, WNT and Nodal, and their effector transcription factors, during cardiac mesoderm specification.
Topics: Mice; Animals; Cell Differentiation; Heart; Transcription Factors; Mesoderm; Transforming Growth Factor beta; Wnt Signaling Pathway; Bone Morphogenetic Protein 4
PubMed: 37082965
DOI: 10.1242/dev.201450 -
Seminars in Cell & Developmental Biology Jul 2022Human pluripotent stem cells can differentiate into any cell type given appropriate signals and hence have been used to research early human development of many tissues... (Review)
Review
Human pluripotent stem cells can differentiate into any cell type given appropriate signals and hence have been used to research early human development of many tissues and diseases. Here, we review the major biological factors that regulate cartilage and bone development through the three main routes of neural crest, lateral plate mesoderm and paraxial mesoderm. We examine how these routes have been used in differentiation protocols that replicate skeletal development using human pluripotent stem cells and how these methods have been refined and improved over time. Finally, we discuss how pluripotent stem cells can be employed to understand human skeletal genetic diseases with a developmental origin and phenotype, and how developmental protocols have been applied to gain a better understanding of these conditions.
Topics: Bone and Bones; Cartilage; Cell Differentiation; Humans; Mesoderm; Neural Crest; Pluripotent Stem Cells
PubMed: 34949507
DOI: 10.1016/j.semcdb.2021.11.024 -
Developmental Dynamics : An Official... Sep 2021Before limbs or fins, can be patterned and grow they must be initiated. Initiation of the limb first involves designating a portion of lateral plate mesoderm along the... (Review)
Review
Before limbs or fins, can be patterned and grow they must be initiated. Initiation of the limb first involves designating a portion of lateral plate mesoderm along the flank as the site of the future limb. Following specification, a myriad of cellular and molecular events interact to generate a bud that will grow and form the limb. The past three decades has provided a wealth of understanding on how those events generate the limb bud and how variations in them result in different limb forms. Comparatively, much less attention has been given to the earliest steps of limb formation and what impacts altering the position and initiation of the limb have had on evolution. Here, we first review the processes and pathways involved in these two phases of limb initiation, as determined from amniote model systems. We then broaden our scope to examine how variation in the limb initiation module has contributed to biological diversity in amniotes. Finally, we review what is known about limb initiation in fish and amphibians, and consider what mechanisms are conserved across vertebrates.
Topics: Animals; Biological Evolution; Extremities; Gene Expression Regulation, Developmental; Limb Buds; Mesoderm; Vertebrates
PubMed: 33522040
DOI: 10.1002/dvdy.308