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Development (Cambridge, England) Sep 2020Actomyosin networks are some of the most crucial force-generating components present in developing tissues. The contractile forces generated by these networks are... (Review)
Review
Actomyosin networks are some of the most crucial force-generating components present in developing tissues. The contractile forces generated by these networks are harnessed during morphogenesis to drive various cell and tissue reshaping events. Recent studies of these processes have advanced rapidly, providing us with insights into how these networks are initiated, positioned and regulated, and how they act via individual contractile pulses and/or the formation of supracellular cables. Here, we review these studies and discuss the mechanisms that underlie the construction and turnover of such networks and structures. Furthermore, we provide an overview of how ratcheted processivity emerges from pulsed events, and how tissue-level mechanics are the coordinated output of many individual cellular behaviors.
Topics: Actin Cytoskeleton; Actomyosin; Animals; Epithelium; Humans; Morphogenesis
PubMed: 32878903
DOI: 10.1242/dev.186502 -
Plant, Cell & Environment Nov 2017Exposure to ultraviolet B (UV-B) light regulates numerous aspects of plant metabolism, morphology and physiology through the differential expression of hundreds of... (Review)
Review
Exposure to ultraviolet B (UV-B) light regulates numerous aspects of plant metabolism, morphology and physiology through the differential expression of hundreds of genes. Photomorphogenic responses to UV-B are mediated by the photoreceptor UV RESISTANCE LOCUS8 (UVR8). Considerable progress has been made in understanding UVR8 action: the structural basis of photoreceptor function, how interaction with CONSTITUTIVELY PHOTOMORPHOGENIC 1 initiates signaling and how REPRESSOR OF UV-B PHOTOMORPHOGENESIS proteins negatively regulate UVR8 action. In addition, recent research shows that UVR8 mediates several responses through interaction with other signaling pathways, in particular auxin signaling. Nevertheless, many aspects of UVR8 action remain poorly understood. Most research to date has been undertaken with Arabidopsis, and it is important to explore the functions and regulation of UVR8 in diverse plant species. Furthermore, it is essential to understand how UVR8, and UV-B signaling in general, regulates processes under natural growth conditions. Ultraviolet B regulates the expression of many genes through UVR8-independent pathways, but the activity and importance of these pathways in plants growing in sunlight are poorly understood.
Topics: Models, Biological; Morphogenesis; Plant Proteins; Plants; Signal Transduction; Ultraviolet Rays
PubMed: 28183154
DOI: 10.1111/pce.12934 -
Pediatric Cardiology Oct 2019If viewed as a movie, heart morphogenesis appears to unfold in a continuous and seamless manner. At the mechanistic level, however, a series of discreet and separable... (Review)
Review
If viewed as a movie, heart morphogenesis appears to unfold in a continuous and seamless manner. At the mechanistic level, however, a series of discreet and separable processes sequentially underlie heart development. This is evident in examining the expansion of the ventricular wall, which accounts for most of the contractile force of each heartbeat. Ventricular wall expansion is driven by cardiomyocyte proliferation coupled with a morphogenetic program that causes wall thickening rather than lengthening. Although most studies of these processes have focused on heart-intrinsic processes, it is increasingly clear that extracardiac events influence or even direct heart morphogenesis. In this review, we specifically consider mechanisms responsible for coordinating cardiomyocyte proliferation and ventricular wall expansion in mammalian development, relying primarily on studies from mouse development where a wealth of molecular and genetic data have been accumulated.
Topics: Animals; Cell Proliferation; Heart Ventricles; Insulin-Like Growth Factor Binding Protein 2; Mice; Morphogenesis; Myocytes, Cardiac
PubMed: 31342113
DOI: 10.1007/s00246-019-02164-6 -
Journal of Mammary Gland Biology and... Dec 2016Understanding the complex events leading to formation of an epithelial-based organ such as the breast requires a detailed insight into the crosstalk between epithelial... (Review)
Review
Understanding the complex events leading to formation of an epithelial-based organ such as the breast requires a detailed insight into the crosstalk between epithelial and stromal compartments. These interactions occur both through heterotypic cellular interactions and between cells and matrix components. While in vivo models may partially capture these complex interactions, there is a need for in- vitro models to study these events. In this review we discuss cell-cell interactions in breast development focusing on the stem cell niche and branching morphogenesis. Given the recent understanding that the basic developmental events underlying branching morphogenesis are closely related to pathways important to cancer progression, i.e. epithelial plasticity and epithelial to mesenchymal transition (EMT), we will also discuss aspects relevant to cancer progression. In cancer, the adoption of mesenchymal phenotype by the malignant cells allows stromal invasion and subsequent intravasation to blood- or lymphatic vessels, a route that is a prerequisite for metastasis. A number of publications have demonstrated that tumor initiating cells, sometimes referred to as cancer stem cells adapt an EMT phenotype that renders them more resistant to apoptosis and drug therapy. The mechanism behind this phenomenon is currently unknown but this may partially explain relapse in breast cancer patients. Increased understanding of branching morphogenesis in the breast gland and the regulation of EMT and its reverse process mesenchymal to epithelial transition (MET) may hold the keys for future development of methods/drugs that neutralize the invading properties of cancer cells.
Topics: Animals; Breast; Breast Neoplasms; Disease Progression; Epithelial Cells; Epithelial-Mesenchymal Transition; Female; Humans; Morphogenesis; Neoplastic Stem Cells
PubMed: 27815674
DOI: 10.1007/s10911-016-9366-3 -
Developmental Dynamics : An Official... Feb 2017The mouse prostate is a male sex-accessory gland comprised of a branched ductal network arranged into three separate bilateral lobes: the anterior, dorsolateral, and... (Review)
Review
The mouse prostate is a male sex-accessory gland comprised of a branched ductal network arranged into three separate bilateral lobes: the anterior, dorsolateral, and ventral lobes. Prostate ductal development is the primary morphogenetic event in prostate development and requires a complex regulation of spatiotemporal factors. This review provides an overview of prostate development and the major genetic regulators and signaling pathways involved. To identify new areas for further study, we briefly highlight the likely important, but relatively understudied, role of the extracellular matrix (ECM). Finally, we point out the potential importance of the ECM in influencing the behavior and prognosis of prostate cancer. Developmental Dynamics 246:89-99, 2017. © 2016 Wiley Periodicals, Inc.
Topics: Animals; Extracellular Matrix; Gene Expression Regulation, Developmental; Humans; Male; Mice; Morphogenesis; Organogenesis; Prostate; Prostatic Neoplasms; Signal Transduction
PubMed: 27884054
DOI: 10.1002/dvdy.24478 -
ELife Jan 2023Shape transformations of epithelial tissues in three dimensions, which are crucial for embryonic development or in vitro organoid growth, can result from active forces...
Shape transformations of epithelial tissues in three dimensions, which are crucial for embryonic development or in vitro organoid growth, can result from active forces generated within the cytoskeleton of the epithelial cells. How the interplay of local differential tensions with tissue geometry and with external forces results in tissue-scale morphogenesis remains an open question. Here, we describe epithelial sheets as active viscoelastic surfaces and study their deformation under patterned internal tensions and bending moments. In addition to isotropic effects, we take into account nematic alignment in the plane of the tissue, which gives rise to shape-dependent, anisotropic active tensions and bending moments. We present phase diagrams of the mechanical equilibrium shapes of pre-patterned closed shells and explore their dynamical deformations. Our results show that a combination of nematic alignment and gradients in internal tensions and bending moments is sufficient to reproduce basic building blocks of epithelial morphogenesis, including fold formation, budding, neck formation, flattening, and tubulation.
Topics: Models, Biological; Morphogenesis; Epithelium; Epithelial Cells; Embryonic Development
PubMed: 36649186
DOI: 10.7554/eLife.75878 -
Developmental Dynamics : An Official... Mar 2016
Topics: Animals; Humans; Morphogenesis
PubMed: 26708750
DOI: 10.1002/dvdy.24381 -
ELife Nov 2017Computational modelling of the heart tube during development reveals the interplay between tissue asymmetry and growth that helps our hearts take shape.
Computational modelling of the heart tube during development reveals the interplay between tissue asymmetry and growth that helps our hearts take shape.
Topics: Animals; Body Patterning; Embryonic Development; Heart; Imaging, Three-Dimensional; Mice; Morphogenesis; Organogenesis
PubMed: 29179812
DOI: 10.7554/eLife.32709 -
Developmental Biology May 2015The epiblast is a single cell-layered epithelium which generates through gastrulation all tissues in an amniote embryo proper. Specification of the epiblast as a cell... (Review)
Review
The epiblast is a single cell-layered epithelium which generates through gastrulation all tissues in an amniote embryo proper. Specification of the epiblast as a cell lineage in early development is coupled with that of the trophoblast and hypoblast, two lineages dedicated to forming extramebryonic tissues. The complex relationship between molecular specification and morphogenetic segregation of these three lineages is not well understood. In this review I will compare the ontogeny of epithelial epiblast in different amniote groups and emphasize the diversity in cell biological mechanisms employed by each group to reach this conserved epithelial structure as the pre-requisite for gastrulation. The limitations of associating cell fate with cell shape and position will also be discussed. In most amniote groups, bi-potential precursors for the epiblast and hypoblast, similar to the inner cell mass in the eutherian mammals, are not associated with an apolar, inside location in the blastocyst. Conversely, a blastocyst cell with epithelial morphology and superficial location is not indicative of its trophoblast fate. The polar trophoblast is absent in all amniotes except for the eutherian mammals. In the avian, reptilian and eutherian groups, epithelialization of the epiblast occurs after its fate specification and involves a mesenchymal-to-epithelial transition (MET) process, whereas in the monotremes and marsupials, pre-epiblast cells adopt an epithelial morphology prior to their commitment to the epiblast fate. The conservation of an epithelialized epiblast is viewed as an adaptation to evolutionary constraints placed on pre-gastrulation ectoderm in the ancestral amniote. The relationship between epiblast MET and epiblast pluripontency will also be discussed. Whether such an MET/epithelialization process is advantageous for the self-renewal and/or differentiation of human epiblast stem cells in vitro is unclear.
Topics: Animals; Birds; Cell Polarity; Cell Transdifferentiation; Embryonic Development; Epithelium; Germ Layers; Humans; Mammals; Mesoderm; Models, Biological; Morphogenesis; Reptiles; Species Specificity; Trophoblasts
PubMed: 25446532
DOI: 10.1016/j.ydbio.2014.10.003 -
Mechanisms of Development Jun 2017On Growth and Form has stood at the forefront of our understanding of the development of biological form for the past century. In this essay, I take a look at how modern... (Review)
Review
On Growth and Form has stood at the forefront of our understanding of the development of biological form for the past century. In this essay, I take a look at how modern techniques are enabling unprecedented insight into the spatio-temporal regulation of development, which facilitates testing of the ideas that D'Arcy Thompson laid down so brilliantly 100years ago.
Topics: Animals; Developmental Biology; Humans; Morphogenesis
PubMed: 28351699
DOI: 10.1016/j.mod.2017.03.003