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Sudderick ZR, Glover JD. Periodic pattern formation during embryonic development. Biochem Soc Trans 2024; 52:75-88. [PMID: 38288903 PMCID: PMC10903485 DOI: 10.1042/bst20230197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 12/21/2023] [Accepted: 01/08/2024] [Indexed: 02/29/2024]
Abstract
During embryonic development many organs and structures require the formation of series of repeating elements known as periodic patterns. Ranging from the digits of the limb to the feathers of the avian skin, the correct formation of these embryonic patterns is essential for the future form and function of these tissues. However, the mechanisms that produce these patterns are not fully understood due to the existence of several modes of pattern generation which often differ between organs and species. Here, we review the current state of the field and provide a perspective on future approaches to studying this fundamental process of embryonic development.
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Affiliation(s)
- Zoe R. Sudderick
- The Roslin Institute & R(D)SVS, University of Edinburgh, Edinburgh, U.K
| | - James D. Glover
- The Roslin Institute & R(D)SVS, University of Edinburgh, Edinburgh, U.K
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2
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Grall E, Feregrino C, Fischer S, De Courten A, Sacher F, Hiscock TW, Tschopp P. Self-organized BMP signaling dynamics underlie the development and evolution of digit segmentation patterns in birds and mammals. Proc Natl Acad Sci U S A 2024; 121:e2304470121. [PMID: 38175868 PMCID: PMC10786279 DOI: 10.1073/pnas.2304470121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 11/03/2023] [Indexed: 01/06/2024] Open
Abstract
Repeating patterns of synovial joints are a highly conserved feature of articulated digits, with variations in joint number and location resulting in diverse digit morphologies and limb functions across the tetrapod clade. During the development of the amniote limb, joints form iteratively within the growing digit ray, as a population of distal progenitors alternately specifies joint and phalanx cell fates to segment the digit into distinct elements. While numerous molecular pathways have been implicated in this fate choice, it remains unclear how they give rise to a repeating pattern. Here, using single-cell RNA sequencing and spatial gene expression profiling, we investigate the transcriptional dynamics of interphalangeal joint specification in vivo. Combined with mathematical modeling, we predict that interactions within the BMP signaling pathway-between the ligand GDF5, the inhibitor NOGGIN, and the intracellular effector pSMAD-result in a self-organizing Turing system that forms periodic joint patterns. Our model is able to recapitulate the spatiotemporal gene expression dynamics observed in vivo, as well as phenocopy digit malformations caused by BMP pathway perturbations. By contrasting in silico simulations with in vivo morphometrics of two morphologically distinct digits, we show how changes in signaling parameters and growth dynamics can result in variations in the size and number of phalanges. Together, our results reveal a self-organizing mechanism that underpins amniote digit segmentation and its evolvability and, more broadly, illustrate how Turing systems based on a single molecular pathway may generate complex repetitive patterns in a wide variety of organisms.
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Affiliation(s)
- Emmanuelle Grall
- Zoology, Department of Environmental Sciences, University of Basel, Basel4051, Switzerland
| | - Christian Feregrino
- Zoology, Department of Environmental Sciences, University of Basel, Basel4051, Switzerland
| | - Sabrina Fischer
- Zoology, Department of Environmental Sciences, University of Basel, Basel4051, Switzerland
| | - Aline De Courten
- Zoology, Department of Environmental Sciences, University of Basel, Basel4051, Switzerland
| | - Fabio Sacher
- Zoology, Department of Environmental Sciences, University of Basel, Basel4051, Switzerland
| | - Tom W. Hiscock
- Institute of Medical Sciences, University of Aberdeen, AberdeenAB25 2ZD, Scotland, United Kingdom
| | - Patrick Tschopp
- Zoology, Department of Environmental Sciences, University of Basel, Basel4051, Switzerland
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3
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Watanabe H, Maishi N, Hoshi-Numahata M, Nishiura M, Nakanishi-Kimura A, Hida K, Iimura T. Skeletal-Vascular Interactions in Bone Development, Homeostasis, and Pathological Destruction. Int J Mol Sci 2023; 24:10912. [PMID: 37446097 DOI: 10.3390/ijms241310912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 06/28/2023] [Accepted: 06/28/2023] [Indexed: 07/15/2023] Open
Abstract
Bone is a highly vascularized organ that not only plays multiple roles in supporting the body and organs but also endows the microstructure, enabling distinct cell lineages to reciprocally interact. Recent studies have uncovered relevant roles of the bone vasculature in bone patterning, morphogenesis, homeostasis, and pathological bone destruction, including osteoporosis and tumor metastasis. This review provides an overview of current topics in the interactive molecular events between endothelial cells and bone cells during bone ontogeny and discusses the future direction of this research area to find novel ways to treat bone diseases.
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Affiliation(s)
- Haruhisa Watanabe
- Department of Pharmacology, Faculty and Graduate School of Dental Medicine, Hokkaido University, N13 W7, Sapporo 060-8586, Hokkaido, Japan
| | - Nako Maishi
- Department of Vascular Biology, Faculty and Graduate School of Dental Medicine, Hokkaido University, N13 W7, Sapporo 060-8586, Hokkaido, Japan
| | - Marie Hoshi-Numahata
- Department of Pharmacology, Faculty and Graduate School of Dental Medicine, Hokkaido University, N13 W7, Sapporo 060-8586, Hokkaido, Japan
| | - Mai Nishiura
- Department of Pharmacology, Faculty and Graduate School of Dental Medicine, Hokkaido University, N13 W7, Sapporo 060-8586, Hokkaido, Japan
| | - Atsuko Nakanishi-Kimura
- Department of Pharmacology, Faculty and Graduate School of Dental Medicine, Hokkaido University, N13 W7, Sapporo 060-8586, Hokkaido, Japan
| | - Kyoko Hida
- Department of Vascular Biology, Faculty and Graduate School of Dental Medicine, Hokkaido University, N13 W7, Sapporo 060-8586, Hokkaido, Japan
| | - Tadahiro Iimura
- Department of Pharmacology, Faculty and Graduate School of Dental Medicine, Hokkaido University, N13 W7, Sapporo 060-8586, Hokkaido, Japan
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4
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Dalwadi MP, Pearce P. Universal dynamics of biological pattern formation in spatio-temporal morphogen variations. Proc Math Phys Eng Sci 2023. [DOI: 10.1098/rspa.2022.0829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2023] Open
Abstract
In biological systems, chemical signals termed morphogens self-organize into patterns that are vital for many physiological processes. As observed by Turing in 1952, these patterns are in a state of continual development, and are usually transitioning from one pattern into another. How do cells robustly decode these spatio-temporal patterns into signals in the presence of confounding effects caused by unpredictable or heterogeneous environments? Here, we answer this question by developing a general theory of pattern formation in spatio-temporal variations of ‘pre-pattern’ morphogens, which determine gene-regulatory network parameters. Through mathematical analysis, we identify universal dynamical regimes that apply to wide classes of biological systems. We apply our theory to two paradigmatic pattern-forming systems, and predict that they are robust with respect to non-physiological morphogen variations. More broadly, our theoretical framework provides a general approach to classify the emergent dynamics of pattern-forming systems based on how the bifurcations in their governing equations are traversed.
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5
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Kuznetsov M. Robust controlled formation of Turing patterns in three-component systems. Phys Rev E 2022; 105:014209. [PMID: 35193238 DOI: 10.1103/physreve.105.014209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 01/04/2022] [Indexed: 06/14/2023]
Abstract
Over the past few decades, formation of Turing patterns in reaction-diffusion systems has been shown to be the underlying process in several examples of biological morphogenesis, confirming Alan Turing's hypothesis, put forward in 1952. However, theoretical studies suggest that Turing patterns formation via classical "short-range activation and long-range inhibition" concept in general can happen within only narrow parameter ranges. This feature seemingly contradicts the accuracy and reproducibility of biological morphogenesis given the stochasticity of biochemical processes and the influence of environmental perturbations. Moreover, it represents a major hurdle to synthetic engineering of Turing patterns. In this work it is shown that this problem can be overcome in some systems under certain sets of interactions between their elements, one of which is immobile and therefore corresponding to a cell-autonomous factor. In such systems Turing patterns formation can be guaranteed by a simple universal control under any values of kinetic parameters and diffusion coefficients of mobile elements. This concept is illustrated by analysis and simulations of a specific three-component system, characterized in absence of diffusion by a presence of codimension two pitchfork-Hopf bifurcation.
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Affiliation(s)
- Maxim Kuznetsov
- Division of Theoretical Physics, P.N. Lebedev Physical Institute of the Russian Academy of Sciences, Moscow 119991, Russia and Nikolsky Mathematical Institute, Peoples Friendship University of Russia (RUDN University), Moscow 117198, Russia
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6
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Towler OW, Shore EM. BMP signaling and skeletal development in fibrodysplasia ossificans progressiva (FOP). Dev Dyn 2022; 251:164-177. [PMID: 34133058 PMCID: PMC9068236 DOI: 10.1002/dvdy.387] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 05/07/2021] [Accepted: 05/20/2021] [Indexed: 01/03/2023] Open
Abstract
Fibrodysplasia ossificans progressiva (FOP) is an ultra-rare genetic disease caused by increased BMP pathway signaling due to mutation of ACVR1, a bone morphogenetic protein (BMP) type 1 receptor. The primary clinical manifestation of FOP is extra-skeletal bone formation (heterotopic ossification) within soft connective tissues. However, the underlying ACVR1 mutation additionally alters skeletal bone development and nearly all people born with FOP have bilateral malformation of the great toes as well as other skeletal malformations at diverse anatomic sites. The specific mechanisms through which ACVR1 mutations and altered BMP pathway signaling in FOP influence skeletal bone formation during development remain to be elucidated; however, recent investigations are providing a clearer understanding of the molecular and developmental processes associated with ACVR1-regulated skeletal formation.
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Affiliation(s)
- Oscar Will Towler
- The Center for Research in FOP & Related Disorders, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA,Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Eileen M. Shore
- The Center for Research in FOP & Related Disorders, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA,Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA,Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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7
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Diaz-Cuadros M, Pourquié O, El-Sherif E. Patterning with clocks and genetic cascades: Segmentation and regionalization of vertebrate versus insect body plans. PLoS Genet 2021; 17:e1009812. [PMID: 34648490 PMCID: PMC8516289 DOI: 10.1371/journal.pgen.1009812] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Oscillatory and sequential processes have been implicated in the spatial patterning of many embryonic tissues. For example, molecular clocks delimit segmental boundaries in vertebrates and insects and mediate lateral root formation in plants, whereas sequential gene activities are involved in the specification of regional identities of insect neuroblasts, vertebrate neural tube, vertebrate limb, and insect and vertebrate body axes. These processes take place in various tissues and organisms, and, hence, raise the question of what common themes and strategies they share. In this article, we review 2 processes that rely on the spatial regulation of periodic and sequential gene activities: segmentation and regionalization of the anterior-posterior (AP) axis of animal body plans. We study these processes in species that belong to 2 different phyla: vertebrates and insects. By contrasting 2 different processes (segmentation and regionalization) in species that belong to 2 distantly related phyla (arthropods and vertebrates), we elucidate the deep logic of patterning by oscillatory and sequential gene activities. Furthermore, in some of these organisms (e.g., the fruit fly Drosophila), a mode of AP patterning has evolved that seems not to overtly rely on oscillations or sequential gene activities, providing an opportunity to study the evolution of pattern formation mechanisms.
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Affiliation(s)
- Margarete Diaz-Cuadros
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Pathology, Brigham and Women’s Hospital, Boston, Massachusetts, United States of America
| | - Olivier Pourquié
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Pathology, Brigham and Women’s Hospital, Boston, Massachusetts, United States of America
- Harvard Stem Cell Institute, Harvard University, Cambridge, Massachusetts, United States of America
| | - Ezzat El-Sherif
- Division of Developmental Biology, Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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8
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Sozen B, Cornwall-Scoones J, Zernicka-Goetz M. The dynamics of morphogenesis in stem cell-based embryology: Novel insights for symmetry breaking. Dev Biol 2021; 474:82-90. [PMID: 33333067 PMCID: PMC8259461 DOI: 10.1016/j.ydbio.2020.12.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 12/05/2020] [Accepted: 12/07/2020] [Indexed: 12/14/2022]
Abstract
Breaking embryonic symmetry is an essential prerequisite to shape the initially symmetric embryo into a highly organized body plan that serves as the blueprint of the adult organism. This critical process is driven by morphogen signaling gradients that instruct anteroposterior axis specification. Despite its fundamental importance, what triggers symmetry breaking and how the signaling gradients are established in time and space in the mammalian embryo remain largely unknown. Stem cell-based in vitro models of embryogenesis offer an unprecedented opportunity to quantitatively dissect the multiple physical and molecular processes that shape the mammalian embryo. Here we review biochemical mechanisms governing early mammalian patterning in vivo and highlight recent advances to recreate this in vitro using stem cells. We discuss how the novel insights from these model systems extend previously proposed concepts to illuminate the extent to which embryonic cells have the intrinsic capability to generate specific, reproducible patterns during embryogenesis.
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Affiliation(s)
- Berna Sozen
- California Institute of Technology, Division of Biology and Biological Engineering, 1200 E. California Boulevard, Pasadena, CA, 91125, USA; Yale University School of Medicine, Department of Genetics, New Haven, CT, 06510, USA.
| | - Jake Cornwall-Scoones
- California Institute of Technology, Division of Biology and Biological Engineering, 1200 E. California Boulevard, Pasadena, CA, 91125, USA; Developmental Dynamics Laboratory, The Francis Crick Institute, London, NW1 1AT, UK
| | - Magdalena Zernicka-Goetz
- California Institute of Technology, Division of Biology and Biological Engineering, 1200 E. California Boulevard, Pasadena, CA, 91125, USA; Mammalian Embryo and Stem Cell Group, University of Cambridge, Department of Physiology, Development and Neuroscience, Cambridge, CB2 3EG, UK.
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9
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Galea GL, Zein MR, Allen S, Francis-West P. Making and shaping endochondral and intramembranous bones. Dev Dyn 2020; 250:414-449. [PMID: 33314394 PMCID: PMC7986209 DOI: 10.1002/dvdy.278] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 11/13/2020] [Accepted: 11/20/2020] [Indexed: 12/13/2022] Open
Abstract
Skeletal elements have a diverse range of shapes and sizes specialized to their various roles including protecting internal organs, locomotion, feeding, hearing, and vocalization. The precise positioning, size, and shape of skeletal elements is therefore critical for their function. During embryonic development, bone forms by endochondral or intramembranous ossification and can arise from the paraxial and lateral plate mesoderm or neural crest. This review describes inductive mechanisms to position and pattern bones within the developing embryo, compares and contrasts the intrinsic vs extrinsic mechanisms of endochondral and intramembranous skeletal development, and details known cellular processes that precisely determine skeletal shape and size. Key cellular mechanisms are employed at distinct stages of ossification, many of which occur in response to mechanical cues (eg, joint formation) or preempting future load‐bearing requirements. Rapid shape changes occur during cellular condensation and template establishment. Specialized cellular behaviors, such as chondrocyte hypertrophy in endochondral bone and secondary cartilage on intramembranous bones, also dramatically change template shape. Once ossification is complete, bone shape undergoes functional adaptation through (re)modeling. We also highlight how alterations in these cellular processes contribute to evolutionary change and how differences in the embryonic origin of bones can influence postnatal bone repair. Compares and contrasts Endochondral and intramembranous bone development Reviews embryonic origins of different bones Describes the cellular and molecular mechanisms of positioning skeletal elements. Describes mechanisms of skeletal growth with a focus on the generation of skeletal shape
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Affiliation(s)
- Gabriel L Galea
- Developmental Biology and Cancer, UCL GOS Institute of Child Health, London, UK.,Comparative Bioveterinary Sciences, Royal Veterinary College, London, UK
| | - Mohamed R Zein
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK
| | - Steven Allen
- Comparative Bioveterinary Sciences, Royal Veterinary College, London, UK
| | - Philippa Francis-West
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK
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10
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Towler OW, Peck SH, Kaplan FS, Shore EM. Dysregulated BMP signaling through ACVR1 impairs digit joint development in fibrodysplasia ossificans progressiva (FOP). Dev Biol 2020; 470:136-146. [PMID: 33217406 DOI: 10.1016/j.ydbio.2020.11.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 11/01/2020] [Accepted: 11/10/2020] [Indexed: 12/30/2022]
Abstract
The development of joints in the mammalian skeleton depends on the precise regulation of multiple interacting signaling pathways including the bone morphogenetic protein (BMP) pathway, a key regulator of joint development, digit patterning, skeletal growth, and chondrogenesis. Mutations in the BMP receptor ACVR1 cause the rare genetic disease fibrodysplasia ossificans progressiva (FOP) in which extensive and progressive extra-skeletal bone forms in soft connective tissues after birth. These mutations, which enhance BMP-pSmad1/5 pathway activity to induce ectopic bone, also affect skeletal development. FOP can be diagnosed at birth by symmetric, characteristic malformations of the great toes (first digits) that are associated with decreased joint mobility, shortened digit length, and absent, fused, and/or malformed phalanges. To elucidate the role of ACVR1-mediated BMP signaling in digit skeletal development, we used an Acvr1R206H/+;Prrx1-Cre knock-in mouse model that mimics the first digit phenotype of human FOP. We have determined that the effects of increased Acvr1-mediated signaling by the Acvr1R206H mutation are not limited to the first digit but alter BMP signaling, Gdf5+ joint progenitor cell localization, and joint development in a manner that differently affects individual digits during embryogenesis. The Acvr1R206H mutation leads to delayed and disrupted joint specification and cleavage in the digits and alters the development of cartilage and endochondral ossification at sites of joint morphogenesis. These findings demonstrate an important role for ACVR1-mediated BMP signaling in the regulation of joint and skeletal formation, show a direct link between failure to restrict BMP signaling in the digit joint interzone and failure of joint cleavage at the presumptive interzone, and implicate impaired, digit-specific joint development as the proximal cause of digit malformation in FOP.
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Affiliation(s)
- O Will Towler
- Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, 3450 Hamilton Walk, 309A Stemmler Hall, Philadelphia, PA 19104, United States; Center for Research in FOP & Related Disorders, Perelman School of Medicine, University of Pennsylvania, 3450 Hamilton Walk, 309A Stemmler Hall, Philadelphia, PA 19104, United States
| | - Sun H Peck
- Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, 3450 Hamilton Walk, 309A Stemmler Hall, Philadelphia, PA 19104, United States; Center for Research in FOP & Related Disorders, Perelman School of Medicine, University of Pennsylvania, 3450 Hamilton Walk, 309A Stemmler Hall, Philadelphia, PA 19104, United States
| | - Frederick S Kaplan
- Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, 3450 Hamilton Walk, 309A Stemmler Hall, Philadelphia, PA 19104, United States; Department of Medicine, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Boulevard, Perelman Center for Advanced Medicine, Philadelphia, PA 19104, United States; Center for Research in FOP & Related Disorders, Perelman School of Medicine, University of Pennsylvania, 3450 Hamilton Walk, 309A Stemmler Hall, Philadelphia, PA 19104, United States
| | - Eileen M Shore
- Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, 3450 Hamilton Walk, 309A Stemmler Hall, Philadelphia, PA 19104, United States; Department of Genetics, Perelman School of Medicine, University of Pennsylvania, 415 Curie Boulevard, Clinical Research Building, Philadelphia, PA 19104, United States; Center for Research in FOP & Related Disorders, Perelman School of Medicine, University of Pennsylvania, 3450 Hamilton Walk, 309A Stemmler Hall, Philadelphia, PA 19104, United States.
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11
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Cornwall Scoones J, Banerjee DS, Banerjee S. Size-Regulated Symmetry Breaking in Reaction-Diffusion Models of Developmental Transitions. Cells 2020; 9:E1646. [PMID: 32659915 PMCID: PMC7407810 DOI: 10.3390/cells9071646] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 07/03/2020] [Accepted: 07/06/2020] [Indexed: 12/26/2022] Open
Abstract
The development of multicellular organisms proceeds through a series of morphogenetic and cell-state transitions, transforming homogeneous zygotes into complex adults by a process of self-organisation. Many of these transitions are achieved by spontaneous symmetry breaking mechanisms, allowing cells and tissues to acquire pattern and polarity by virtue of local interactions without an upstream supply of information. The combined work of theory and experiment has elucidated how these systems break symmetry during developmental transitions. Given that such transitions are multiple and their temporal ordering is crucial, an equally important question is how these developmental transitions are coordinated in time. Using a minimal mass-conserved substrate-depletion model for symmetry breaking as our case study, we elucidate mechanisms by which cells and tissues can couple reaction-diffusion-driven symmetry breaking to the timing of developmental transitions, arguing that the dependence of patterning mode on system size may be a generic principle by which developing organisms measure time. By analysing different regimes of our model, simulated on growing domains, we elaborate three distinct behaviours, allowing for clock-, timer- or switch-like dynamics. Relating these behaviours to experimentally documented case studies of developmental timing, we provide a minimal conceptual framework to interrogate how developing organisms coordinate developmental transitions.
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Affiliation(s)
- Jake Cornwall Scoones
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA;
| | - Deb Sankar Banerjee
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, USA;
| | - Shiladitya Banerjee
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, USA;
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