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Current Topics in Developmental Biology 2021Neurons develop dendritic morphologies that bear cell type-specific features in dendritic field size and geometry, branch placement and density, and the types and... (Review)
Review
Neurons develop dendritic morphologies that bear cell type-specific features in dendritic field size and geometry, branch placement and density, and the types and distributions of synaptic contacts. Dendritic patterns influence the types and numbers of inputs a neuron receives, and the ways in which neural information is processed and transmitted in the circuitry. Even subtle alterations in dendritic structures can have profound consequences on neuronal function and are implicated in neurodevelopmental disorders. In this chapter, I review how growing dendrites acquire their exquisite patterns by drawing examples from diverse neuronal cell types in vertebrate and invertebrate model systems. Dendrite morphogenesis is shaped by intrinsic and extrinsic factors such as transcriptional regulators, guidance and adhesion molecules, neighboring cells and synaptic partners. I discuss molecular mechanisms that regulate dendrite morphogenesis with a focus on five aspects of dendrite patterning: (1) Dendritic cytoskeleton and cellular machineries that build the arbor; (2) Gene regulatory mechanisms; (3) Afferent cues that regulate dendritic arbor growth; (4) Space-filling strategies that optimize dendritic coverage; and (5) Molecular cues that specify dendrite wiring. Cell type-specific implementation of these patterning mechanisms produces the diversity of dendrite morphologies that wire the nervous system.
Topics: Dendrites; Morphogenesis
PubMed: 33706919
DOI: 10.1016/bs.ctdb.2020.12.008 -
Journal of Dental Research Sep 2023
Topics: Skull; Mesenchymal Stem Cells; Morphogenesis
PubMed: 37465936
DOI: 10.1177/00220345231184211 -
Current Topics in Developmental Biology 2021As multi-cellular organisms evolved from small clusters of cells to complex metazoans, biological tubes became essential for life. Tubes are typically thought of as... (Review)
Review
As multi-cellular organisms evolved from small clusters of cells to complex metazoans, biological tubes became essential for life. Tubes are typically thought of as mainly playing a role in transport, with the hollow space (lumen) acting as a conduit to distribute nutrients and waste, or for gas exchange. However, biological tubes also provide a platform for physiological, mechanical, and structural functions. Indeed, tubulogenesis is often a critical aspect of morphogenesis and organogenesis. C. elegans is made up of tubes that provide structural support and protection (the epidermis), perform the mechanical and enzymatic processes of digestion (the buccal cavity, pharynx, intestine, and rectum), transport fluids for osmoregulation (the excretory system), and execute the functions necessary for reproduction (the germline, spermatheca, uterus and vulva). Here we review our current understanding of the genetic regulation, molecular processes, and physical forces involved in tubulogenesis and morphogenesis of the epidermal, digestive and excretory systems in C. elegans.
Topics: Animals; Caenorhabditis elegans; Female; Morphogenesis; Organogenesis
PubMed: 33992152
DOI: 10.1016/bs.ctdb.2020.12.012 -
Nature Reviews. Genetics Sep 2023Major differences in facial morphology distinguish vertebrate species. Variation of facial traits underlies the uniqueness of human individuals, and abnormal... (Review)
Review
Major differences in facial morphology distinguish vertebrate species. Variation of facial traits underlies the uniqueness of human individuals, and abnormal craniofacial morphogenesis during development leads to birth defects that significantly affect quality of life. Studies during the past 40 years have advanced our understanding of the molecular mechanisms that establish facial form during development, highlighting the crucial roles in this process of a multipotent cell type known as the cranial neural crest cell. In this Review, we discuss recent advances in multi-omics and single-cell technologies that enable genes, transcriptional regulatory networks and epigenetic landscapes to be closely linked to the establishment of facial patterning and its variation, with an emphasis on normal and abnormal craniofacial morphogenesis. Advancing our knowledge of these processes will support important developments in tissue engineering, as well as the repair and reconstruction of the abnormal craniofacial complex.
Topics: Humans; Quality of Life; Morphogenesis; Neural Crest; Epigenesis, Genetic
PubMed: 37095271
DOI: 10.1038/s41576-023-00594-w -
Developmental Biology Aug 2022Myriads forces are at play during morphogenesis. Their concerted activity shapes individual cells, tissues and the whole embryo, representing the most awe-inspiring... (Review)
Review
Myriads forces are at play during morphogenesis. Their concerted activity shapes individual cells, tissues and the whole embryo, representing the most awe-inspiring marvel of developmental biology. In spite of their prevalence, the potential instructive role of cell mechanics in fate determination and patterning has remained long neglected, in part due to the difficulties in translating the physical world of cells in molecular terms. The recent discovery of the principles of mechanotransduction, of how these impact on gene expression, is however starting to change this scenario, making mechanotransduction finally amenable to experimental dissection through genetics, molecular and bioengineering approaches. Here we review this emerging field, and a series of discoveries that potently bring back cell mechanics at the centerstage of vertebrate developmental biology. We discuss the role of actomyosin contractility as integrating platform between morphogens, lateral inhibition and mechanosignaling. We also review data indicating that supracellular pulling forces, coupled with solid-to-fluid changes in the material contexture of embryonic fields, may act as overarching mechanical "organizers". The evidence also indicates that a continuum of forces is what ultimately locks "self-organizing" movements with cell fate, from the earliest pre-implantation decisions to the fine details of organogenesis. Notably, similar mechanisms are reawakened in organoids and in adult tissues during regeneration. Developmental biology has been correctly depicted, but recently often forgotten, as the "mother" of all biological disciplines. Investigations in developmental mechanics may revamp interest, and have a broad impact in the fields of regenerative medicine, stem cells and cancer biology.
Topics: Actomyosin; Animals; Embryonic Development; Mechanotransduction, Cellular; Morphogenesis; Organogenesis; Vertebrates
PubMed: 35580730
DOI: 10.1016/j.ydbio.2022.05.005 -
Seminars in Cell & Developmental Biology Dec 2021Self-organization is an all-important feature of living systems that provides the means to achieve specialization and functionality at distinct spatio-temporal scales.... (Review)
Review
Self-organization is an all-important feature of living systems that provides the means to achieve specialization and functionality at distinct spatio-temporal scales. Herein, we review this concept by addressing the packing organization of cells, the sorting/compartmentalization phenomenon of cell populations, and the propagation of organizing cues at the tissue level through traveling waves. We elaborate on how different theoretical models and tools from Topology, Physics, and Dynamical Systems have improved the understanding of self-organization by shedding light on the role played by mechanics as a driver of morphogenesis. Altogether, by providing a historical perspective, we show how ideas and hypotheses in the field have been revisited, developed, and/or rejected and what are the open questions that need to be tackled by future research.
Topics: Humans; Morphogenesis; Signal Transduction
PubMed: 34417092
DOI: 10.1016/j.semcdb.2021.07.003 -
Seminars in Cell & Developmental Biology Dec 2021Research using avian embryos has led to major conceptual advances in developmental biology, virology, immunology, genetics and cell biology. The avian embryo has several... (Review)
Review
Research using avian embryos has led to major conceptual advances in developmental biology, virology, immunology, genetics and cell biology. The avian embryo has several significant advantages, including ready availability and ease of accessibility, rapid development with marked similarities to mammals and a high amenability to manipulation. As mechanical forces are increasingly recognised as key drivers of morphogenesis, this powerful model system is shedding new light on the mechanobiology of embryonic development. Here, we highlight progress in understanding how mechanical forces direct key morphogenetic processes in the early avian embryo. Recent advances in quantitative live imaging and modelling are elaborating upon traditional work using physical models and embryo manipulations to reveal cell dynamics and tissue forces in ever greater detail. The recent application of transgenic technologies further increases the strength of the avian model and is providing important insights about previously intractable developmental processes.
Topics: Animals; Bird Diseases; Embryonic Development; Gastrulation
PubMed: 34147339
DOI: 10.1016/j.semcdb.2021.06.001 -
Nature Communications Dec 2022Immunoglobulin family and carbohydrate vascular addressins encoded by Madcam1 and St6gal1 control lymphocyte homing into intestinal tissues, regulating immunity and...
Immunoglobulin family and carbohydrate vascular addressins encoded by Madcam1 and St6gal1 control lymphocyte homing into intestinal tissues, regulating immunity and inflammation. The addressins are developmentally programmed to decorate endothelial cells lining gut post-capillary and high endothelial venules (HEV), providing a prototypical example of organ- and segment-specific endothelial specialization. We identify conserved NKX-COUP-TFII composite elements (NCCE) in regulatory regions of Madcam1 and St6gal1 that bind intestinal homeodomain protein NKX2-3 cooperatively with venous nuclear receptor COUP-TFII to activate transcription. The Madcam1 element also integrates repressive signals from arterial/capillary Notch effectors. Pan-endothelial COUP-TFII overexpression induces ectopic addressin expression in NKX2-3 capillaries, while NKX2-3 deficiency abrogates expression by HEV. Phylogenetically conserved NCCE are enriched in genes involved in neuron migration and morphogenesis of the heart, kidney, pancreas and other organs. Our results define an NKX-COUP-TFII morphogenetic code that targets expression of mucosal vascular addressins.
Topics: Endothelial Cells; Morphogenesis; Veins; Arteries; Cell Movement
PubMed: 36460642
DOI: 10.1038/s41467-022-34991-2 -
Nature Reviews. Molecular Cell Biology Aug 2021The cytoskeleton - comprising actin filaments, microtubules and intermediate filaments - serves instructive roles in regulating cell function and behaviour during... (Review)
Review
The cytoskeleton - comprising actin filaments, microtubules and intermediate filaments - serves instructive roles in regulating cell function and behaviour during development. However, a key challenge in cell and developmental biology is to dissect how these different structures function and interact in vivo to build complex tissues, with the ultimate aim to understand these processes in a mammalian organism. The preimplantation mouse embryo has emerged as a primary model system for tackling this challenge. Not only does the mouse embryo share many morphological similarities with the human embryo during its initial stages of life, it also permits the combination of genetic manipulations with live-imaging approaches to study cytoskeletal dynamics directly within an intact embryonic system. These advantages have led to the discovery of novel cytoskeletal structures and mechanisms controlling lineage specification, cell-cell communication and the establishment of the first forms of tissue architecture during development. Here we highlight the diverse organization and functions of each of the three cytoskeletal filaments during the key events that shape the early mammalian embryo, and discuss how they work together to perform key developmental tasks, including cell fate specification and morphogenesis of the blastocyst. Collectively, these findings are unveiling a new picture of how cells in the early embryo dynamically remodel their cytoskeleton with unique spatial and temporal precision to drive developmental processes in the rapidly changing in vivo environment.
Topics: Animals; Blastocyst; Cell Communication; Cell Division; Cell Lineage; Cytoskeleton; Embryo, Mammalian; Embryonic Development; Humans; Morphogenesis
PubMed: 33927361
DOI: 10.1038/s41580-021-00363-9 -
The EMBO Journal Oct 2019Tissue morphogenesis in multicellular organisms is brought about by spatiotemporal coordination of mechanical and chemical signals. Extensive work on how mechanical... (Review)
Review
Tissue morphogenesis in multicellular organisms is brought about by spatiotemporal coordination of mechanical and chemical signals. Extensive work on how mechanical forces together with the well-established morphogen signalling pathways can actively shape living tissues has revealed evolutionary conserved mechanochemical features of embryonic development. More recently, attention has been drawn to the description of tissue material properties and how they can influence certain morphogenetic processes. Interestingly, besides the role of tissue material properties in determining how much tissues deform in response to force application, there is increasing theoretical and experimental evidence, suggesting that tissue material properties can abruptly and drastically change in development. These changes resemble phase transitions, pointing at the intriguing possibility that important morphogenetic processes in development, such as symmetry breaking and self-organization, might be mediated by tissue phase transitions. In this review, we summarize recent findings on the regulation and role of tissue material properties in the context of the developing embryo. We posit that abrupt changes of tissue rheological properties may have important implications in maintaining the balance between robustness and adaptability during embryonic development.
Topics: Animals; Biomechanical Phenomena; Cell Differentiation; Embryonic Development; Humans; Morphogenesis; Rheology; Signal Transduction
PubMed: 31512749
DOI: 10.15252/embj.2019102497