1
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Schijven D, Soheili-Nezhad S, Fisher SE, Francks C. Exome-wide analysis implicates rare protein-altering variants in human handedness. Nat Commun 2024; 15:2632. [PMID: 38565598 PMCID: PMC10987538 DOI: 10.1038/s41467-024-46277-w] [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: 07/21/2023] [Accepted: 02/20/2024] [Indexed: 04/04/2024] Open
Abstract
Handedness is a manifestation of brain hemispheric specialization. Left-handedness occurs at increased rates in neurodevelopmental disorders. Genome-wide association studies have identified common genetic effects on handedness or brain asymmetry, which mostly involve variants outside protein-coding regions and may affect gene expression. Implicated genes include several that encode tubulins (microtubule components) or microtubule-associated proteins. Here we examine whether left-handedness is also influenced by rare coding variants (frequencies ≤ 1%), using exome data from 38,043 left-handed and 313,271 right-handed individuals from the UK Biobank. The beta-tubulin gene TUBB4B shows exome-wide significant association, with a rate of rare coding variants 2.7 times higher in left-handers than right-handers. The TUBB4B variants are mostly heterozygous missense changes, but include two frameshifts found only in left-handers. Other TUBB4B variants have been linked to sensorineural and/or ciliopathic disorders, but not the variants found here. Among genes previously implicated in autism or schizophrenia by exome screening, DSCAM and FOXP1 show evidence for rare coding variant association with left-handedness. The exome-wide heritability of left-handedness due to rare coding variants was 0.91%. This study reveals a role for rare, protein-altering variants in left-handedness, providing further evidence for the involvement of microtubules and disorder-relevant genes.
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Affiliation(s)
- Dick Schijven
- Language & Genetics Department, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Sourena Soheili-Nezhad
- Language & Genetics Department, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands
| | - Simon E Fisher
- Language & Genetics Department, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Clyde Francks
- Language & Genetics Department, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands.
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands.
- Department of Cognitive Neuroscience, Radboud University Medical Center, Nijmegen, The Netherlands.
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2
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Truchado-García M, Perry KJ, Cavodeassi F, Kenny NJ, Henry JQ, Grande C. A Small Change With a Twist Ending: A Single Residue in EGF-CFC Drives Bilaterian Asymmetry. Mol Biol Evol 2022; 40:6947033. [PMID: 36537201 PMCID: PMC9907556 DOI: 10.1093/molbev/msac270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 11/28/2022] [Accepted: 12/05/2022] [Indexed: 12/24/2022] Open
Abstract
Asymmetries are essential for proper organization and function of organ systems. Genetic studies in bilaterians have shown signaling through the Nodal/Smad2 pathway plays a key, conserved role in the establishment of body asymmetries. Although the main molecular players in the network for the establishment of left-right asymmetry (LRA) have been deeply described in deuterostomes, little is known about the regulation of Nodal signaling in spiralians. Here, we identified orthologs of the egf-cfc gene, a master regulator of the Nodal pathway in vertebrates, in several invertebrate species, which includes the first evidence of its presence in non-deuterostomes. Our functional experiments indicate that despite being present, egf-cfc does not play a role in the establishment of LRA in gastropods. However, experiments in zebrafish suggest that a single amino acid mutation in the egf-cfc gene in at least the common ancestor of chordates was the necessary step to induce a gain of function in LRA regulation. This study shows that the egf-cfc gene likely appeared in the ancestors of deuterostomes and "protostomes", before being adopted as a mechanism to regulate the Nodal pathway and the establishment of LRA in some lineages of deuterostomes.
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Affiliation(s)
| | - Kimberly J Perry
- Department of Cell and Developmental Biology, University of Illinois, Urbana, IL 61801
| | - Florencia Cavodeassi
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain,Institute of Medical and Biomedical Education, St George's University of London, Cranmer Terrace, London SW17 0RE, United Kingdom
| | - Nathan J Kenny
- Natural History Museum, Cromwell Road, London, United Kingdom,Department of Biochemistry (Te Tari Matū Koiora), University of Otago, Dunedin, (Aotearoa) New Zealand
| | - Jonathan Q Henry
- Department of Cell and Developmental Biology, University of Illinois, Urbana, IL 61801,The Marine Biological Laboratory, Woods Hole, MA 02543
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3
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Negretti MI, Böse N, Petri N, Kremnyov S, Tsikolia N. Nodal asymmetry and hedgehog signaling during vertebrate left–right symmetry breaking. Front Cell Dev Biol 2022; 10:957211. [PMID: 36172285 PMCID: PMC9511907 DOI: 10.3389/fcell.2022.957211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 08/04/2022] [Indexed: 11/13/2022] Open
Abstract
Development of visceral left–right asymmetry in bilateria is based on initial symmetry breaking followed by subsequent asymmetric molecular patterning. An important step is the left-sided expression of transcription factor pitx2 which is mediated by asymmetric expression of the nodal morphogen in the left lateral plate mesoderm of vertebrates. Processes leading to emergence of the asymmetric nodal domain differ depending on the mode of symmetry breaking. In Xenopus laevis and mouse embryos, the leftward fluid flow on the ventral surface of the left–right organizer leads through intermediate steps to enhanced activity of the nodal protein on the left side of the organizer and subsequent asymmetric nodal induction in the lateral plate mesoderm. In the chick embryo, asymmetric morphogenesis of axial organs leads to paraxial nodal asymmetry during the late gastrulation stage. Although it was shown that hedgehog signaling is required for initiation of the nodal expression, the mechanism of its asymmetry remains to be clarified. In this study, we established the activation of hedgehog signaling in early chick embryos to further study its role in the initiation of asymmetric nodal expression. Our data reveal that hedgehog signaling is sufficient to induce the nodal expression in competent domains of the chick embryo, while treatment of Xenopus embryos led to moderate nodal inhibition. We discuss the role of symmetry breaking and competence in the initiation of asymmetric gene expression.
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Affiliation(s)
| | - Nina Böse
- Anatomy and Embryology, University Medical Center Göttingen, Göttingen, Germany
| | - Natalia Petri
- Department of Embryology, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Stanislav Kremnyov
- Department of Embryology, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, Moscow, Russia
| | - Nikoloz Tsikolia
- Anatomy and Embryology, University Medical Center Göttingen, Göttingen, Germany
- *Correspondence: Nikoloz Tsikolia,
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4
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Handedness and its genetic influences are associated with structural asymmetries of the cerebral cortex in 31,864 individuals. Proc Natl Acad Sci U S A 2021; 118:2113095118. [PMID: 34785596 PMCID: PMC8617418 DOI: 10.1073/pnas.2113095118] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/12/2021] [Indexed: 01/01/2023] Open
Abstract
Left-handedness occurs in roughly 10% of people, but whether it involves altered brain anatomy has remained unclear. We measured left to right asymmetry of the cerebral cortex in 28,802 right-handers and 3,062 left-handers. There were small average differences between the two handedness groups in brain regions important for hand control, language, vision, and working memory. Genetic influences on handedness were associated with some of these brain asymmetries, especially of language-related regions. This suggests links between handedness and language during human development and evolution. One implicated gene is NME7, which also affects placement of the visceral organs (heart, liver, etc.) on the left to right body axis—a possible connection between brain and body asymmetries in embryonic development. Roughly 10% of the human population is left-handed, and this rate is increased in some brain-related disorders. The neuroanatomical correlates of hand preference have remained equivocal. We resampled structural brain image data from 28,802 right-handers and 3,062 left-handers (UK Biobank population dataset) to a symmetrical surface template, and mapped asymmetries for each of 8,681 vertices across the cerebral cortex in each individual. Left-handers compared to right-handers showed average differences of surface area asymmetry within the fusiform cortex, the anterior insula, the anterior middle cingulate cortex, and the precentral cortex. Meta-analyzed functional imaging data implicated these regions in executive functions and language. Polygenic disposition to left-handedness was associated with two of these regional asymmetries, and 18 loci previously linked with left-handedness by genome-wide screening showed associations with one or more of these asymmetries. Implicated genes included six encoding microtubule-related proteins: TUBB, TUBA1B, TUBB3, TUBB4A, MAP2, and NME7—mutations in the latter can cause left to right reversal of the visceral organs. There were also two cortical regions where average thickness asymmetry was altered in left-handedness: on the postcentral gyrus and the inferior occipital cortex, functionally annotated with hand sensorimotor and visual roles. These cortical thickness asymmetries were not heritable. Heritable surface area asymmetries of language-related regions may link the etiologies of hand preference and language, whereas nonheritable asymmetries of sensorimotor cortex may manifest as consequences of hand preference.
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5
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Tassinari R, Cavallini C, Olivi E, Taglioli V, Zannini C, Ventura C. Unveiling the morphogenetic code: A new path at the intersection of physical energies and chemical signaling. World J Stem Cells 2021; 13:1382-1393. [PMID: 34786150 PMCID: PMC8567452 DOI: 10.4252/wjsc.v13.i10.1382] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/16/2021] [Accepted: 09/10/2021] [Indexed: 02/06/2023] Open
Abstract
In this editorial, we discuss the remarkable role of physical energies in the control of cell signaling networks and in the specification of the architectural plan of both somatic and stem cells. In particular, we focus on the biological relevance of bioelectricity in the pattern control that orchestrates both developmental and regenerative pathways. To this end, the narrative starts from the dawn of the first studies on animal electricity, reconsidering the pioneer work of Harold Saxton Burr in the light of the current achievements. We finally discuss the most recent evidence showing that bioelectric signaling is an essential component of the informational processes that control pattern specification during embryogenesis, regeneration, or even malignant transformation. We conclude that there is now mounting evidence for the existence of a Morphogenetic Code, and that deciphering this code may lead to unprecedented opportunities for the development of novel paradigms of cure in regenerative and precision medicine.
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Affiliation(s)
- Riccardo Tassinari
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems – ELDOR LAB, Bologna 40129, Italy
| | - Claudia Cavallini
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems – ELDOR LAB, Bologna 40129, Italy
| | - Elena Olivi
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems – ELDOR LAB, Bologna 40129, Italy
| | - Valentina Taglioli
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems – ELDOR LAB, Bologna 40129, Italy
| | - Chiara Zannini
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems – ELDOR LAB, Bologna 40129, Italy
| | - Carlo Ventura
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems – ELDOR LAB, Bologna 40129, Italy
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6
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Richardson MK. Theories, laws, and models in evo-devo. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2021; 338:36-61. [PMID: 34570438 PMCID: PMC9292786 DOI: 10.1002/jez.b.23096] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 07/01/2021] [Accepted: 07/16/2021] [Indexed: 12/17/2022]
Abstract
Evolutionary developmental biology (evo‐devo) is the study of the evolution of developmental mechanisms. Here, I review some of the theories, models, and laws in evo‐devo, past and present. Nineteenth‐century evo‐devo was dominated by recapitulation theory and archetypes. It also gave us germ layer theory, the vertebral theory of the skull, floral organs as modified leaves, and the “inverted invertebrate” theory, among others. Newer theories and models include the frameshift theory, the genetic toolkit for development, the ABC model of flower development, the developmental hourglass, the zootype, Urbilateria, and the hox code. Some of these new theories show the influence of archetypes and recapitulation. Interestingly, recent studies support the old “primordial leaf,” “inverted invertebrate,” and “segmented head” theories. Furthermore, von Baer's first three laws may now need to be rehabilitated, and the hourglass model modified, in view of what Abzhanov has pointed out about the maternal‐zygotic transition. There are many supposed “laws” of evo‐devo but I argue that these are merely generalizations about trends in particular lineages. I argue that the “body plan” is an archetype, and is often used in such a way that it lacks any scientific meaning. Looking to the future, one challenge for evo‐devo will be to develop new theories and models to accommodate the wealth of new data from high‐throughput sequencing, including single‐cell sequencing. One step in this direction is the use of sophisticated in silico analyses, as in the “transcriptomic hourglass” models. Laws and other universal concepts, past and present, are reviewed. I show that many concepts focus on conserved aspects of development. The puzzle remains as to how embryonic phenotype, natural selection, and developmental mechanisms can be aligned to give an integrated view of evolution and development.
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Affiliation(s)
- Michael K Richardson
- Sylvius Laboratory, Institute of Biology, University of Leiden, Leiden, The Netherlands
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7
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The genetic architecture of structural left-right asymmetry of the human brain. Nat Hum Behav 2021; 5:1226-1239. [PMID: 33723403 PMCID: PMC8455338 DOI: 10.1038/s41562-021-01069-w] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 02/05/2021] [Indexed: 01/31/2023]
Abstract
Left-right hemispheric asymmetry is an important aspect of healthy brain organization for many functions including language, and it can be altered in cognitive and psychiatric disorders. No mechanism has yet been identified for establishing the human brain's left-right axis. We performed multivariate genome-wide association scanning of cortical regional surface area and thickness asymmetries, and subcortical volume asymmetries, using data from 32,256 participants from the UK Biobank. There were 21 significant loci associated with different aspects of brain asymmetry, with functional enrichment involving microtubule-related genes and embryonic brain expression. These findings are consistent with a known role of the cytoskeleton in left-right axis determination in other organs of invertebrates and frogs. Genetic variants associated with brain asymmetry overlapped with those associated with autism, educational attainment and schizophrenia. Comparably large datasets will likely be required in future studies, to replicate and further clarify the associations of microtubule-related genes with variation in brain asymmetry, behavioural and psychiatric traits.
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8
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Investigation of Drug Efficacy by Screening Bioactive Chemical Effects on Plant Cell Subcellular Architecture. Methods Mol Biol 2020. [PMID: 33270192 DOI: 10.1007/978-1-0716-0954-5_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
New biologically active compounds are regularly discovered through screening procedures using microorganisms. This very cheap procedure is followed by drug discovery that is usually seen as a highly focused approach, testing new compounds on animals or cell lines. In vivo assays of candidate drugs in mammals are expensive and sometimes not affordable at the preliminary stages of drug development. Early screening approaches in transgenic plants would allow chemotherapeutic drug candidates further selection before their characterization in expensive biological models. The proposed screening approach is based on cell subcellular architecture observations in transgenic plants within a short time of treatment, which is better than observing the effects of compounds on growth.
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9
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Levin M. The Biophysics of Regenerative Repair Suggests New Perspectives on Biological Causation. Bioessays 2020; 42:e1900146. [PMID: 31994772 DOI: 10.1002/bies.201900146] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 12/03/2019] [Indexed: 12/13/2022]
Abstract
Evolution exploits the physics of non-neural bioelectricity to implement anatomical homeostasis: a process in which embryonic patterning, remodeling, and regeneration achieve invariant anatomical outcomes despite external interventions. Linear "developmental pathways" are often inadequate explanations for dynamic large-scale pattern regulation, even when they accurately capture relationships between molecular components. Biophysical and computational aspects of collective cell activity toward a target morphology reveal interesting aspects of causation in biology. This is critical not only for unraveling evolutionary and developmental events, but also for the design of effective strategies for biomedical intervention. Bioelectrical controls of growth and form, including stochastic behavior in such circuits, highlight the need for the formulation of nuanced views of pathways, drivers of system-level outcomes, and modularity, borrowing from concepts in related disciplines such as cybernetics, control theory, computational neuroscience, and information theory. This approach has numerous practical implications for basic research and for applications in regenerative medicine and synthetic bioengineering.
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Affiliation(s)
- Michael Levin
- Allen Discovery Center at Tufts University, Medford, MA, 02155, USA.,Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
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10
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Bao Y, Wu S, Chu LT, Kwong HK, Hartanto H, Huang Y, Lam ML, Lam RHW, Chen TH. Early Committed Clockwise Cell Chirality Upregulates Adipogenic Differentiation of Mesenchymal Stem Cells. ACTA ACUST UNITED AC 2020; 4:e2000161. [PMID: 32864891 DOI: 10.1002/adbi.202000161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 08/03/2020] [Indexed: 11/11/2022]
Abstract
Cell chirality is observed with diverse forms and coordinates various left-right (LR) asymmetry in tissue morphogenesis. To give rise to such diversity, cell chirality may be coupled with cell differentiation. Here, using micropatterned human mesenchymal stem cells (hMSCs), an early committed clockwise (CW) cell chirality that can itself upregulate the adipogenic differentiation is reported. hMSC chirality enables a positively tilted chiral orientation on micropatterned stripes. When cultured as single cells on circular micropatterns, an anticlockwise (ACW)-biased nucleus rotation and swirling pattern of actin filament are observed. Interestingly, with adipogenic induction for 3-6 days, such chirality is reversed to negative chiral orientation and CW-biased rotation, which is earlier than the maturation of other differentiation markers, and consistently expressed in terminally differentiated adipocytes. Using latrunculin A (LatA), cytochalasin D (CD), and nocodazole (Noco) that forces a CW-biased actin filament and nucleus rotation resembling the early differentiated chirality upon adipogenic induction, an upregulation of adipogenic differentiation is found. The result demonstrates that the early differentiated chirality may serve as a mechanical precursor to engage the lineage commitment, suggesting a feedback mechanism of chiral actin in regulating cell differentiation and LR morphogenesis.
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Affiliation(s)
- Yuanye Bao
- Department of Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region
| | - Siying Wu
- Department of Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region
| | - Lok Ting Chu
- Department of Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region
| | - Hoi Kwan Kwong
- Department of Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region
| | - Hogi Hartanto
- Department of Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region
| | - Yaozhun Huang
- Department of Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region
| | - Miu Ling Lam
- School of Creative Media, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region
| | - Raymond H W Lam
- Department of Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region
| | - Ting-Hsuan Chen
- Department of Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region
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11
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Tung A, Levin M. Extra-genomic instructive influences in morphogenesis: A review of external signals that regulate growth and form. Dev Biol 2020; 461:1-12. [PMID: 31981561 DOI: 10.1016/j.ydbio.2020.01.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 01/21/2020] [Accepted: 01/21/2020] [Indexed: 12/18/2022]
Abstract
Embryonic development and regeneration accomplish a remarkable feat: individual cells work together to create or repair complex anatomical structures. What is the source of the instructive signals that specify these invariant and robust organ-level outcomes? The most frequently studied source of morphogenetic control is the host genome and its transcriptional circuits. However, it is now apparent that significant information affecting patterning also arrives from outside of the body. Both biotic and physical factors, including temperature and various molecular signals emanating from pathogens, commensals, and conspecific organisms, affect developmental outcomes. Here, we review examples in which anatomical patterning decisions are strongly impacted by lateral signals that originate from outside of the zygotic genome. The endogenous pathways targeted by these influences often show transgenerational effects, enabling them to shape the evolution of anatomies even faster than traditional Baldwin-type assimilation. We also discuss recent advances in the biophysics of morphogenetic controls and speculate on additional sources of important patterning information which could be exploited to better understand the evolution of bodies and to design novel approaches for regenerative medicine.
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Affiliation(s)
- Angela Tung
- Department of Biology and Allen Discovery Center at Tufts University, Medford, MA, USA
| | - Michael Levin
- Department of Biology and Allen Discovery Center at Tufts University, Medford, MA, USA; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA.
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12
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Davison A. Flipping Shells! Unwinding LR Asymmetry in Mirror-Image Molluscs. Trends Genet 2020; 36:189-202. [PMID: 31952839 DOI: 10.1016/j.tig.2019.12.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 11/08/2019] [Accepted: 12/06/2019] [Indexed: 12/11/2022]
Abstract
In seeking to understand the establishment of left-right (LR) asymmetry, a limiting factor is that most animals are ordinarily invariant in their asymmetry, except when manipulated or mutated. It is therefore surprising that the wider scientific field does not appear to fully appreciate the remarkable fact that normal development in molluscs, especially snails, can flip between two chiral types without pathology. Here, I describe recent progress in understanding the evolution, development, and genetics of chiral variation in snails, and place it in context with other animals. I argue that the natural variation of snails is a crucial resource towards understanding the invariance in other animal groups and, ultimately, will be key in revealing the common factors that define cellular and organismal LR asymmetry.
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Affiliation(s)
- Angus Davison
- School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD, UK.
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13
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Davison A, McDowell GS, Holden JM, Johnson HF, Wade CM, Chiba S, Jackson DJ, Levin M, Blaxter ML. Formin, an opinion. Development 2020; 147:147/1/dev187427. [PMID: 31919229 DOI: 10.1242/dev.187427] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
| | - Gary S McDowell
- Center for Regenerative and Developmental Biology, and Department of Biology, Tufts University, Medford, MA 02155, USA
| | | | - Harriet F Johnson
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SA, UK
| | | | - Satoshi Chiba
- Community and Ecosystem Ecology, Division of Ecology and Evolutionary Biology, Graduate School of Life Sciences, Tohoku University, Aobayama, Sendai 980-8578, Japan
| | - Daniel J Jackson
- Department of Geobiology, University of Göttingen, Göttingen 37077, Germany
| | - Michael Levin
- Center for Regenerative and Developmental Biology, and Department of Biology, Tufts University, Medford, MA 02155, USA
| | - Mark L Blaxter
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SA, UK
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14
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Bérard A, Levin M, Sadler T, Healy D. Selective Serotonin Reuptake Inhibitor Use During Pregnancy and Major Malformations: The Importance of Serotonin for Embryonic Development and the Effect of Serotonin Inhibition on the Occurrence of Malformations. Bioelectricity 2019; 1:18-29. [PMID: 34471805 DOI: 10.1089/bioe.2018.0003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Bioelectric signaling is transduced by neurotransmitter pathways in many cell types. One of the key mediators of bioelectric control mechanisms is serotonin, and its transporter SERT, which is targeted by a broad class of blocker drugs (selective serotonin reuptake inhibitors [SSRIs]). Studies showing an increased risk of multiple malformations associated with gestational use of SSRI have been accumulating but debate remains on whether SSRI as a class has the potential to generate these malformations. This review highlights the importance of serotonin for embryonic development; the effect of serotonin inhibition during early pregnancy on the occurrence of multiple diverse malformations that have been shown to occur in human pregnancies; that the risks outweigh the benefits of SSRI use during gestation in populations of mild to moderately depressed pregnant women, which encompass the majority of pregnant depressed women; and that the malformations seen in human pregnancies constitute a pattern of malformations consistent with the known mechanisms of action of SSRIs. We present at least three mechanisms by which SSRI can affect development. These studies highlight the relevance of basic bioelectric and neurotransmitter mechanism for biomedicine.
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Affiliation(s)
- Anick Bérard
- Faculty of Pharmacy, University of Montreal; Research Center, CHU Sainte-Justine, Montreal, Quebec, Canada
| | - Michael Levin
- Allen Discovery Center at Tufts University, Department of Biology, Medford, Massachusetts
| | - Thomas Sadler
- Department of Pediatrics, School of Medicine, University of Utah, Salt Lake City, Utah
| | - David Healy
- Department of Psychiatry, Hergest Unit, Bangor, United Kingdom
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15
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Abstract
For over a century, the centrosome has been an organelle more easily tracked than understood, and the study of its peregrinations within the cell remains a chief underpinning of its functional investigation. Increasing attention and new approaches have been brought to bear on mechanisms that control centrosome localization in the context of cleavage plane determination, ciliogenesis, directional migration, and immunological synapse formation, among other cellular and developmental processes. The Golgi complex, often linked with the centrosome, presents a contrasting case of a pleiomorphic organelle for which functional studies advanced somewhat more rapidly than positional tracking. However, Golgi orientation and distribution has emerged as an area of considerable interest with respect to polarized cellular function. This chapter will review our current understanding of the mechanism and significance of the positioning of these organelles.
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16
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Epithelial Cell Chirality Revealed by Three-Dimensional Spontaneous Rotation. Proc Natl Acad Sci U S A 2018; 115:12188-12193. [PMID: 30429314 DOI: 10.1073/pnas.1805932115] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Our understanding of the left-right (LR) asymmetry of embryonic development, in particular the contribution of intrinsic handedness of the cell or cell chirality, is limited due to the confounding systematic and environmental factors during morphogenesis and a ack of physiologically relevant in vitro 3D platforms. Here we report an efficient two-layered biomaterial platform for determining the chirality of individual cells, cell aggregates, and self-organized hollow epithelial spheroids. This bioengineered niche provides a uniform defined axis allowing for cells to rotate spontaneously with a directional bias toward either clockwise or counterclockwise directions. Mechanistic studies reveal an actin-dependent, cell-intrinsic property of 3D chirality that can be mediated by actin cross-linking via α-actinin-1. Our findings suggest that the gradient of extracellular matrix is an important biophysicochemical cue influencing cell polarity and chirality. Engineered biomaterial systems can serve as an effective platform for studying developmental asymmetry and screening for environmental factors causing birth defects.
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17
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Bioelectrical coupling in multicellular domains regulated by gap junctions: A conceptual approach. Bioelectrochemistry 2018; 123:45-61. [DOI: 10.1016/j.bioelechem.2018.04.013] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 04/13/2018] [Accepted: 04/17/2018] [Indexed: 12/16/2022]
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18
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Kim K, Yoshinaga N, Bhattacharyya S, Nakazawa H, Umetsu M, Teizer W. Large-scale chirality in an active layer of microtubules and kinesin motor proteins. SOFT MATTER 2018; 14:3221-3231. [PMID: 29670958 DOI: 10.1039/c7sm02298k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
During the early developmental process of organisms, the formation of left-right laterality requires a subtle mechanism, as it is associated with other principal body axes. Any inherent chiral feature in an egg cell can in principal trigger this spontaneous breaking of chiral symmetry. Individual microtubules, major cytoskeletal filaments, are known as chiral objects. However, to date there lacks convincing evidence of a hierarchical connection of the molecular nature of microtubules to large-scale chirality, particularly at the length scale of an entire cell. Here we assemble an in vitro active layer, consisting of microtubules and kinesin motor proteins, on a glass surface. Upon inclusion of methyl cellulose, the layered system exhibits a long-range active nematic phase, characterized by the global alignment of gliding MTs. This nematic order spans over the entire system size in the millimeter range and, remarkably, allows hidden collective chirality to emerge as counterclockwise global rotation of the active MT layer. The analysis based on our theoretical model suggests that the emerging global nematic order results from the local alignment of MTs, stabilized by methyl cellulose. It also suggests that the global rotation arises from the MTs' intrinsic curvature, leading to preferential handedness. Given its flexibility, this layered in vitro cytoskeletal system enables the study of membranous protein behavior responsible for important cellular developmental processes.
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Affiliation(s)
- Kyongwan Kim
- WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Sendai 980-8577, Japan
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19
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McLaughlin KA, Levin M. Bioelectric signaling in regeneration: Mechanisms of ionic controls of growth and form. Dev Biol 2018; 433:177-189. [PMID: 29291972 PMCID: PMC5753428 DOI: 10.1016/j.ydbio.2017.08.032] [Citation(s) in RCA: 132] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 08/23/2017] [Accepted: 08/28/2017] [Indexed: 12/11/2022]
Abstract
The ability to control pattern formation is critical for the both the embryonic development of complex structures as well as for the regeneration/repair of damaged or missing tissues and organs. In addition to chemical gradients and gene regulatory networks, endogenous ion flows are key regulators of cell behavior. Not only do bioelectric cues provide information needed for the initial development of structures, they also enable the robust restoration of normal pattern after injury. In order to expand our basic understanding of morphogenetic processes responsible for the repair of complex anatomy, we need to identify the roles of endogenous voltage gradients, ion flows, and electric fields. In complement to the current focus on molecular genetics, decoding the information transduced by bioelectric cues enhances our knowledge of the dynamic control of growth and pattern formation. Recent advances in science and technology place us in an exciting time to elucidate the interplay between molecular-genetic inputs and important biophysical cues that direct the creation of tissues and organs. Moving forward, these new insights enable additional approaches to direct cell behavior and may result in profound advances in augmentation of regenerative capacity.
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Affiliation(s)
- Kelly A McLaughlin
- Allen Discovery Center, Department of Biology, Tufts University, 200 Boston Ave., Suite 4700, Medford, MA 02155, United States.
| | - Michael Levin
- Allen Discovery Center, Department of Biology, Tufts University, 200 Boston Ave., Suite 4700, Medford, MA 02155, United States
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20
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Alqadah A, Hsieh YW, Xiong R, Chuang CF. Stochastic left-right neuronal asymmetry in Caenorhabditis elegans. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0407. [PMID: 27821536 DOI: 10.1098/rstb.2015.0407] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/20/2016] [Indexed: 12/28/2022] Open
Abstract
Left-right asymmetry in the nervous system is observed across species. Defects in left-right cerebral asymmetry are linked to several neurological diseases, but the molecular mechanisms underlying brain asymmetry in vertebrates are still not very well understood. The Caenorhabditis elegans left and right amphid wing 'C' (AWC) olfactory neurons communicate through intercellular calcium signalling in a transient embryonic gap junction neural network to specify two asymmetric subtypes, AWCOFF (default) and AWCON (induced), in a stochastic manner. Here, we highlight the molecular mechanisms that establish and maintain stochastic AWC asymmetry. As the components of the AWC asymmetry pathway are highly conserved, insights from the model organism C. elegans may provide a window onto how brain asymmetry develops in humans.This article is part of the themed issue 'Provocative questions in left-right asymmetry'.
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Affiliation(s)
- Amel Alqadah
- Department of Biological Sciences, University of Illinois at Chicago, IL 60607, USA
| | - Yi-Wen Hsieh
- Department of Biological Sciences, University of Illinois at Chicago, IL 60607, USA
| | - Rui Xiong
- Department of Biological Sciences, University of Illinois at Chicago, IL 60607, USA
| | - Chiou-Fen Chuang
- Department of Biological Sciences, University of Illinois at Chicago, IL 60607, USA
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21
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McDowell G, Rajadurai S, Levin M. From cytoskeletal dynamics to organ asymmetry: a nonlinear, regulative pathway underlies left-right patterning. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0409. [PMID: 27821521 DOI: 10.1098/rstb.2015.0409] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/15/2016] [Indexed: 12/25/2022] Open
Abstract
Consistent left-right (LR) asymmetry is a fundamental aspect of the bodyplan across phyla, and errors of laterality form an important class of human birth defects. Its molecular underpinning was first discovered as a sequential pathway of left- and right-sided gene expression that controlled positioning of the heart and visceral organs. Recent data have revised this picture in two important ways. First, the physical origin of chirality has been identified; cytoskeletal dynamics underlie the asymmetry of single-cell behaviour and patterning of the LR axis. Second, the pathway is not linear: early disruptions that alter the normal sidedness of upstream asymmetric genes do not necessarily induce defects in the laterality of the downstream genes or in organ situs Thus, the LR pathway is a unique example of two fascinating aspects of biology: the interplay of physics and genetics in establishing large-scale anatomy, and regulative (shape-homeostatic) pathways that correct molecular and anatomical errors over time. Here, we review aspects of asymmetry from its intracellular, cytoplasmic origins to the recently uncovered ability of the LR control circuitry to achieve correct gene expression and morphology despite reversals of key 'determinant' genes. We provide novel functional data, in Xenopus laevis, on conserved elements of the cytoskeleton that drive asymmetry, and comparatively analyse it together with previously published results in the field. Our new observations and meta-analysis demonstrate that despite aberrant expression of upstream regulatory genes, embryos can progressively normalize transcriptional cascades and anatomical outcomes. LR patterning can thus serve as a paradigm of how subcellular physics and gene expression cooperate to achieve developmental robustness of a body axis.This article is part of the themed issue 'Provocative questions in left-right asymmetry'.
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Affiliation(s)
- Gary McDowell
- Biology Department, Tufts University, 200 Boston Avenue, Suite 4600, Medford, MA 02155-4243, USA.,Allen Discovery Center, Tufts University, 200 Boston Avenue, Suite 4600, Medford, MA 02155-4243, USA
| | - Suvithan Rajadurai
- Biology Department, Tufts University, 200 Boston Avenue, Suite 4600, Medford, MA 02155-4243, USA.,Allen Discovery Center, Tufts University, 200 Boston Avenue, Suite 4600, Medford, MA 02155-4243, USA
| | - Michael Levin
- Biology Department, Tufts University, 200 Boston Avenue, Suite 4600, Medford, MA 02155-4243, USA .,Allen Discovery Center, Tufts University, 200 Boston Avenue, Suite 4600, Medford, MA 02155-4243, USA
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22
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Wan LQ, Chin AS, Worley KE, Ray P. Cell chirality: emergence of asymmetry from cell culture. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0413. [PMID: 27821525 DOI: 10.1098/rstb.2015.0413] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/22/2016] [Indexed: 11/12/2022] Open
Abstract
Increasing evidence suggests that intrinsic cell chirality significantly contributes to the left-right (LR) asymmetry in embryonic development, which is a well-conserved characteristic of living organisms. With animal embryos, several theories have been established, but there are still controversies regarding mechanisms associated with embryonic LR symmetry breaking and the formation of asymmetric internal organs. Recently, in vitro systems have been developed to determine cell chirality and to recapitulate multicellular chiral morphogenesis on a chip. These studies demonstrate that chirality is indeed a universal property of the cell that can be observed with well-controlled experiments such as micropatterning. In this paper, we discuss the possible benefits of these in vitro systems to research in LR asymmetry, categorize available platforms for single-cell chirality and multicellular chiral morphogenesis, and review mathematical models used for in vitro cell chirality and its applications in in vivo embryonic development. These recent developments enable the interrogation of the intracellular machinery in LR axis establishment and accelerate research in birth defects in laterality.This article is part of the themed issue 'Provocative questions in left-right asymmetry'.
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Affiliation(s)
- Leo Q Wan
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180, USA .,Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180, USA.,Center for Modeling, Simulation and Imaging in Medicine, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180, USA
| | - Amanda S Chin
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180, USA
| | - Kathryn E Worley
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180, USA
| | - Poulomi Ray
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180, USA.,Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180, USA
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23
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Pai VP, Willocq V, Pitcairn EJ, Lemire JM, Paré JF, Shi NQ, McLaughlin KA, Levin M. HCN4 ion channel function is required for early events that regulate anatomical left-right patterning in a nodal and lefty asymmetric gene expression-independent manner. Biol Open 2017; 6:1445-1457. [PMID: 28818840 PMCID: PMC5665463 DOI: 10.1242/bio.025957] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 08/12/2017] [Indexed: 12/13/2022] Open
Abstract
Laterality is a basic characteristic of all life forms, from single cell organisms to complex plants and animals. For many metazoans, consistent left-right asymmetric patterning is essential for the correct anatomy of internal organs, such as the heart, gut, and brain; disruption of left-right asymmetry patterning leads to an important class of birth defects in human patients. Laterality functions across multiple scales, where early embryonic, subcellular and chiral cytoskeletal events are coupled with asymmetric amplification mechanisms and gene regulatory networks leading to asymmetric physical forces that ultimately result in distinct left and right anatomical organ patterning. Recent studies have suggested the existence of multiple parallel pathways regulating organ asymmetry. Here, we show that an isoform of the hyperpolarization-activated cyclic nucleotide-gated (HCN) family of ion channels (hyperpolarization-activated cyclic nucleotide-gated channel 4, HCN4) is important for correct left-right patterning. HCN4 channels are present very early in Xenopus embryos. Blocking HCN channels (Ih currents) with pharmacological inhibitors leads to errors in organ situs. This effect is only seen when HCN4 channels are blocked early (pre-stage 10) and not by a later block (post-stage 10). Injections of HCN4-DN (dominant-negative) mRNA induce left-right defects only when injected in both blastomeres no later than the 2-cell stage. Analysis of key asymmetric genes' expression showed that the sidedness of Nodal, Lefty, and Pitx2 expression is largely unchanged by HCN4 blockade, despite the randomization of subsequent organ situs, although the area of Pitx2 expression was significantly reduced. Together these data identify a novel, developmental role for HCN4 channels and reveal a new Nodal-Lefty-Pitx2 asymmetric gene expression-independent mechanism upstream of organ positioning during embryonic left-right patterning.
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Affiliation(s)
- Vaibhav P Pai
- Allen Discovery Center at Tufts University, 200 Boston Ave, Suite 4600, Medford, MA 02155, USA
| | - Valerie Willocq
- Allen Discovery Center at Tufts University, 200 Boston Ave, Suite 4600, Medford, MA 02155, USA
| | - Emily J Pitcairn
- Allen Discovery Center at Tufts University, 200 Boston Ave, Suite 4600, Medford, MA 02155, USA
| | - Joan M Lemire
- Allen Discovery Center at Tufts University, 200 Boston Ave, Suite 4600, Medford, MA 02155, USA
| | - Jean-François Paré
- Allen Discovery Center at Tufts University, 200 Boston Ave, Suite 4600, Medford, MA 02155, USA
| | - Nian-Qing Shi
- Department of Medicine at University of Wisconsin-Madison, Madison, WI 53792, USA
| | - Kelly A McLaughlin
- Allen Discovery Center at Tufts University, 200 Boston Ave, Suite 4600, Medford, MA 02155, USA
| | - Michael Levin
- Allen Discovery Center at Tufts University, 200 Boston Ave, Suite 4600, Medford, MA 02155, USA
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24
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Alqadah A, Hsieh YW, Morrissey ZD, Chuang CF. Asymmetric development of the nervous system. Dev Dyn 2017; 247:124-137. [PMID: 28940676 DOI: 10.1002/dvdy.24595] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 09/09/2017] [Accepted: 09/18/2017] [Indexed: 12/13/2022] Open
Abstract
The human nervous system consists of seemingly symmetric left and right halves. However, closer observation of the brain reveals anatomical and functional lateralization. Defects in brain asymmetry correlate with several neurological disorders, yet our understanding of the mechanisms used to establish lateralization in the human central nervous system is extremely limited. Here, we review left-right asymmetries within the nervous system of humans and several model organisms, including rodents, Zebrafish, chickens, Xenopus, Drosophila, and the nematode Caenorhabditis elegans. Comparing and contrasting mechanisms used to develop left-right asymmetry in the nervous system can provide insight into how the human brain is lateralized. Developmental Dynamics 247:124-137, 2018. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Amel Alqadah
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois
| | - Yi-Wen Hsieh
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois
| | - Zachery D Morrissey
- Graduate Program in Neuroscience, University of Illinois at Chicago, Chicago, Illinois
| | - Chiou-Fen Chuang
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois.,Graduate Program in Neuroscience, University of Illinois at Chicago, Chicago, Illinois
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25
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Miyachi Y. H +/K +-ATPase-Inhibition Causes Left-Right Aortic Arch Inversion in Mouse Development. Reprod Sci 2017; 24:1334-1339. [PMID: 28110633 DOI: 10.1177/1933719116687654] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
An organ known as a "node" forms during embryogenesis and plays a vital role in determining laterality in vertebrates. However, according to some reports in vertebrates, left-right patterning may be determined long before the node has developed. In this study, we analyzed left-right asymmetry formation in mammals based on ion-signaling factors, which has never been attempted before. First, a proton pump inhibitor was injected into pregnant mice to investigate whether H+/K+-ATPase is involved in the differentiation of pharyngeal arch arteries during embryonic development. Injection of 30 mg/kg of lansoprazole early in the organogenesis period increased the penetrance of right aortic arch formation by 34% compared to a saline injection. Furthermore, administration of a proton pump inhibitor resulted in strong expression of PI3K/phosphor-AKT, which led to potent inhibition of apoptosis induction factors such as BAD. This could relate to why the right pharyngeal arch arteries, which should have disappeared during differentiation, remained intact. The other important point is that proton pump inhibitors suppressed calcineurin signaling, and Wnt5a expression was significantly higher than in the controls. This research is particularly notable for demonstrating that administration of an H+/K+-ATPase inhibitor could cause dextroposition of the fetal vasculature. Moreover, since previous publications have reported that H+/K+-ATPase plays a role in asymmetry in other species, this article adds important information for developmental biology in that the role of H+/K+-ATPase in asymmetry is conserved in the mouse model, suggesting that rodents are not unique and that a common mechanism may function across vertebrates.
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Affiliation(s)
- Yukihisa Miyachi
- 1 Laboratory for Occupational Safety and Health, National Cerebral and Cardiovascular Center Research Institute, Suita-shi, Osaka, Japan
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26
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Dasgupta A, Amack JD. Cilia in vertebrate left-right patterning. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150410. [PMID: 27821522 PMCID: PMC5104509 DOI: 10.1098/rstb.2015.0410] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/01/2016] [Indexed: 01/10/2023] Open
Abstract
Understanding how left-right (LR) asymmetry is generated in vertebrate embryos is an important problem in developmental biology. In humans, a failure to align the left and right sides of cardiovascular and/or gastrointestinal systems often results in birth defects. Evidence from patients and animal models has implicated cilia in the process of left-right patterning. Here, we review the proposed functions for cilia in establishing LR asymmetry, which include creating transient leftward fluid flows in an embryonic 'left-right organizer'. These flows direct asymmetric activation of a conserved Nodal (TGFβ) signalling pathway that guides asymmetric morphogenesis of developing organs. We discuss the leading hypotheses for how cilia-generated asymmetric fluid flows are translated into asymmetric molecular signals. We also discuss emerging mechanisms that control the subcellular positioning of cilia and the cellular architecture of the left-right organizer, both of which are critical for effective cilia function during left-right patterning. Finally, using mosaic cell-labelling and time-lapse imaging in the zebrafish embryo, we provide new evidence that precursor cells maintain their relative positions as they give rise to the ciliated left-right organizer. This suggests the possibility that these cells acquire left-right positional information prior to the appearance of cilia.This article is part of the themed issue 'Provocative questions in left-right asymmetry'.
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Affiliation(s)
- Agnik Dasgupta
- Department of Cell and Developmental Biology, State University of New York, Upstate Medical University, Syracuse, NY 13210, USA
| | - Jeffrey D Amack
- Department of Cell and Developmental Biology, State University of New York, Upstate Medical University, Syracuse, NY 13210, USA
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27
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Klar AJS. Split hand/foot malformation genetics supports the chromosome 7 copy segregation mechanism for human limb development. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150415. [PMID: 27821526 PMCID: PMC5104513 DOI: 10.1098/rstb.2015.0415] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/11/2016] [Indexed: 12/17/2022] Open
Abstract
Genetic aberrations of several unlinked loci cause human congenital split hand/foot malformation (SHFM) development. Mutations of the DLX5 (distal-less) transcription factor-encoding gene in chromosome 7 cause SHFM through haploinsufficiency, but the vast majority of cases result from heterozygous chromosomal aberrations of the region without mutating the DLX5 gene. To resolve this paradox, we invoke a chromosomal epigenetic mechanism for limb development. It is composed of a monochromatid gene expression phenomenon that we discovered in two fission yeasts with the selective chromosome copy segregation phenomenon that we discovered in mouse cells. Accordingly, one daughter cell inherits both expressed DLX5 copies while the other daughter inherits both epigenetically silenced ones from a single deterministic cell of the developing limb. Thus, differentiated daughter cells after further proliferation will correspondingly produce proximal/distal-limb tissues. Published results of a Chr. 7 translocation with a centromere-proximal breakpoint situated over 41 million bases away from the DLX locus, centromeric and DLX5-region inversions have satisfied key genetic and developmental biology predictions of the mechanism. Further genetic tests of the mechanism are proposed. We propose that the DNA double helical structure itself causes the development of sister cells' gene regulation asymmetry. We also argue against the conventionally invoked morphogen model of development.This article is part of the themed issue 'Provocative questions in left-right asymmetry'.
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Affiliation(s)
- Amar J S Klar
- Gene Regulation and Chromosome Biology Laboratory, National Cancer Institute, Center for Cancer Research, National Institutes of Health, Building 539, Room 154, Frederick, MD 21702-1201, USA
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28
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Levin M, Klar AJS, Ramsdell AF. Introduction to provocative questions in left-right asymmetry. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150399. [PMID: 27821529 PMCID: PMC5104499 DOI: 10.1098/rstb.2015.0399] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/26/2016] [Indexed: 12/13/2022] Open
Abstract
Left-right asymmetry is a phenomenon that has a broad appeal-to anatomists, developmental biologists and evolutionary biologists-because it is a morphological feature of organisms that spans scales of size and levels of organization, from unicellular protists, to vertebrate organs, to social behaviour. Here, we highlight a number of important aspects of asymmetry that encompass several areas of biology-cell-level, physiological, genetic, anatomical and evolutionary components-and that are based on research conducted in diverse model systems, ranging from single cells to invertebrates to human developmental disorders. Together, the contributions in this issue reveal a heretofore-unsuspected variety in asymmetry mechanisms, including ancient chirality elements that could underlie a much more universal basis to asymmetry development, and provide much fodder for thought with far reaching implications in biomedical, developmental, evolutionary and synthetic biology. The new emerging theme of binary cell-fate choice, promoted by asymmetric cell division of a deterministic cell, has focused on investigating asymmetry mechanisms functioning at the single cell level. These include cytoskeleton and DNA chain asymmetry-mechanisms that are amplified and coordinated with those employed for the determination of the anterior-posterior and dorsal-ventral axes of the embryo.This article is part of the themed issue 'Provocative questions in left-right asymmetry'.
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Affiliation(s)
- Michael Levin
- Biology Department, Allen Discovery Center at Tufts University, Medford, MA 02155, USA
| | - Amar J S Klar
- Gene Regulation and Chromosome Biology Laboratory, National Cancer Institute, Center for Cancer Research, Frederick, MD 21702, USA
| | - Ann F Ramsdell
- Department of Cell Biology and Anatomy, School of Medicine and Program in Women's and Gender Studies, College of Arts and Sciences, University of South Carolina, Columbia, SC 29208, USA
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29
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McDowell GS, Lemire JM, Paré JF, Cammarata G, Lowery LA, Levin M. Conserved roles for cytoskeletal components in determining laterality. Integr Biol (Camb) 2016; 8:267-86. [PMID: 26928161 DOI: 10.1039/c5ib00281h] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Consistently-biased left-right (LR) patterning is required for the proper placement of organs including the heart and viscera. The LR axis is especially fascinating as an example of multi-scale pattern formation, since here chiral events at the subcellular level are integrated and amplified into asymmetric transcriptional cascades and ultimately into the anatomical patterning of the entire body. In contrast to the other two body axes, there is considerable controversy about the earliest mechanisms of embryonic laterality. Many molecular components of asymmetry have not been widely tested among phyla with diverse bodyplans, and it is unknown whether parallel (redundant) pathways may exist that could reverse abnormal asymmetry states at specific checkpoints in development. To address conservation of the early steps of LR patterning, we used the Xenopus laevis (frog) embryo to functionally test a number of protein targets known to direct asymmetry in plants, fruit fly, and rodent. Using the same reagents that randomize asymmetry in Arabidopsis, Drosophila, and mouse embryos, we show that manipulation of the microtubule and actin cytoskeleton immediately post-fertilization, but not later, results in laterality defects in Xenopus embryos. Moreover, we observed organ-specific randomization effects and a striking dissociation of organ situs from effects on the expression of left side control genes, which parallel data from Drosophila and mouse. Remarkably, some early manipulations that disrupt laterality of transcriptional asymmetry determinants can be subsequently "rescued" by the embryo, resulting in normal organ situs. These data reveal the existence of novel corrective mechanisms, demonstrate that asymmetric expression of Nodal is not a definitive marker of laterality, and suggest the existence of amplification pathways that connect early cytoskeletal processes to control of organ situs bypassing Nodal. Counter to alternative models of symmetry breaking during neurulation (via ciliary structures absent in many phyla), our data suggest a widely-conserved role for the cytoskeleton in regulating left-right axis formation immediately after fertilization of the egg. The novel mechanisms that rescue organ situs, even after incorrect expression of genes previously considered to be left-side master regulators, suggest LR patterning as a new context in which to explore multi-scale redundancy and integration of patterning from the subcellular structure to the entire bodyplan.
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Affiliation(s)
- Gary S McDowell
- Biology Department, and Center for Regenerative and Developmental Biology, Tufts University, 200 Boston Avenue, Suite 4600, Medford, MA 02155-4243, USA. and Biology Department, Boston College, Chestnut Hill, MA, USA
| | - Joan M Lemire
- Biology Department, and Center for Regenerative and Developmental Biology, Tufts University, 200 Boston Avenue, Suite 4600, Medford, MA 02155-4243, USA.
| | - Jean-Francois Paré
- Biology Department, and Center for Regenerative and Developmental Biology, Tufts University, 200 Boston Avenue, Suite 4600, Medford, MA 02155-4243, USA.
| | | | | | - Michael Levin
- Biology Department, and Center for Regenerative and Developmental Biology, Tufts University, 200 Boston Avenue, Suite 4600, Medford, MA 02155-4243, USA.
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30
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Liu W, Bao Y, Lam ML, Xu T, Xie K, Man HS, Chan EY, Zhu N, Lam RHW, Chen TH. Nanowire Magnetoscope Reveals a Cellular Torque with Left-Right Bias. ACS NANO 2016; 10:7409-7417. [PMID: 27389867 DOI: 10.1021/acsnano.6b01142] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Cellular force regulates many types of cell mechanics and the associated physiological behaviors. Recent evidence suggested that cell motion with left-right (LR) bias may be the origin of LR asymmetry in tissue architecture. As actomyosin activity was found essential in the process, it predicts a type of cellular force that coordinates the development of LR asymmetry in tissue formation. However, due to the lack of appropriate platform, cellular force with LR bias has not yet been found. Here we report a nanowire magnetoscope that reveals a rotating force-torque-exerted by cells. Ferromagnetic nanowires were deposited and internalized by micropatterned cells. Within a uniform, horizontal magnetic field, the nanowires that initially aligned with the magnetic field were subsequently rotated due to the cellular torque. We found that the torque is LR-biased depending on cell types. While NIH 3T3 fibroblasts and human vascular endothelial cells exhibited counterclockwise torque, C2C12 myoblasts showed torque with slight clockwise bias. Moreover, an actin ring composed of transverse arcs and radial fibers was identified as a major factor determining the LR bias of cellular torque, since the disruption of actin ring by biochemical inhibitors or elongated cell shape abrogated the counterclockwise bias of NIH 3T3 fibroblasts. Our finding reveals a LR-biased torque of single cells and a fundamental origin of cytoskeletal chirality. More broadly, we anticipate that our method will provide a different perspective on mechanics-related cell physiology and force transmission necessary for LR propagation in tissue formation.
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Affiliation(s)
| | | | - Miu Ling Lam
- CityU Shenzhen Research Institute , Shenzhen, 518057, China
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Bao Y, Huang Y, Lam ML, Xu T, Zhu N, Guo Z, Cui X, Lam RHW, Chen TH. Substrate Stiffness Regulates the Development of Left-Right Asymmetry in Cell Orientation. ACS APPLIED MATERIALS & INTERFACES 2016; 8:17976-17986. [PMID: 27359036 DOI: 10.1021/acsami.6b06789] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Left-right (LR) asymmetry of tissue/organ structure is a morphological feature essential for many tissue functions. The ability to incorporate the LR formation in constructing tissue/organ replacement is important for recapturing the inherent tissue structure and functions. However, how LR asymmetry is formed remains largely underdetermined, which creates significant hurdles to reproduce and regulate the formation of LR asymmetry in an engineering context. Here, we report substrate rigidity functioning as an effective switch that turns on the development of LR asymmetry. Using micropatterned cell-adherent stripes on rigid substrates, we found that cells collectively oriented at a LR-biased angle relative to the stripe boundary. This LR asymmetry was initiated by a LR-biased migration of cells at stripe boundary, which later generated a velocity gradient propagating from stripe boundary to the center. After a series of cell translocations and rotations, ultimately, an LR-biased cell orientation within the micropatterned stripe was formed. Importantly, this initiation and propagation of LR asymmetry was observed only on rigid but not on soft substrates, suggesting that the LR asymmetry was regulated by rigid substrate probably through the organization of actin cytoskeleton. Together, we demonstrated substrate rigidity as a determinant factor that mediates the self-organizing LR asymmetry being unfolded from single cells to multicellular organization. More broadly, we anticipate that our findings would pave the way for rebuilding artificial tissue constructs with inherent LR asymmetry in the future.
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Affiliation(s)
| | | | - Miu Ling Lam
- CityU Shenzhen Research Institute , Shenzhen 518057, China
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32
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Sullivan KG, Emmons-Bell M, Levin M. Physiological inputs regulate species-specific anatomy during embryogenesis and regeneration. Commun Integr Biol 2016; 9:e1192733. [PMID: 27574538 PMCID: PMC4988443 DOI: 10.1080/19420889.2016.1192733] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 05/13/2016] [Accepted: 05/16/2016] [Indexed: 12/12/2022] Open
Abstract
A key problem in evolutionary developmental biology is identifying the sources of instructive information that determine species-specific anatomical pattern. Understanding the inputs to large-scale morphology is also crucial for efforts to manipulate pattern formation in regenerative medicine and synthetic bioengineering. Recent studies have revealed a physiological system of communication among cells that regulates pattern during embryogenesis and regeneration in vertebrate and invertebrate models. Somatic tissues form networks using the same ion channels, electrical synapses, and neurotransmitter mechanisms exploited by the brain for information-processing. Experimental manipulation of these circuits was recently shown to override genome default patterning outcomes, resulting in head shapes resembling those of other species in planaria and Xenopus. The ability to drastically alter macroscopic anatomy to that of other extant species, despite a wild-type genomic sequence, suggests exciting new approaches to the understanding and control of patterning. Here, we review these results and discuss hypotheses regarding non-genomic systems of instructive information that determine biological growth and form.
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Affiliation(s)
- Kelly G Sullivan
- Allen Discovery Center at Tufts University, Tufts University , Medford, MA, USA
| | - Maya Emmons-Bell
- Allen Discovery Center at Tufts University, Tufts University , Medford, MA, USA
| | - Michael Levin
- Allen Discovery Center at Tufts University, Tufts University , Medford, MA, USA
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Davison A, McDowell GS, Holden JM, Johnson HF, Koutsovoulos GD, Liu MM, Hulpiau P, Van Roy F, Wade CM, Banerjee R, Yang F, Chiba S, Davey JW, Jackson DJ, Levin M, Blaxter ML. Formin Is Associated with Left-Right Asymmetry in the Pond Snail and the Frog. Curr Biol 2016; 26:654-60. [PMID: 26923788 PMCID: PMC4791482 DOI: 10.1016/j.cub.2015.12.071] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 12/01/2015] [Accepted: 12/29/2015] [Indexed: 01/29/2023]
Abstract
While components of the pathway that establishes left-right asymmetry have been identified in diverse animals, from vertebrates to flies, it is striking that the genes involved in the first symmetry-breaking step remain wholly unknown in the most obviously chiral animals, the gastropod snails. Previously, research on snails was used to show that left-right signaling of Nodal, downstream of symmetry breaking, may be an ancestral feature of the Bilateria [1 and 2]. Here, we report that a disabling mutation in one copy of a tandemly duplicated, diaphanous-related formin is perfectly associated with symmetry breaking in the pond snail. This is supported by the observation that an anti-formin drug treatment converts dextral snail embryos to a sinistral phenocopy, and in frogs, drug inhibition or overexpression by microinjection of formin has a chirality-randomizing effect in early (pre-cilia) embryos. Contrary to expectations based on existing models [3, 4 and 5], we discovered asymmetric gene expression in 2- and 4-cell snail embryos, preceding morphological asymmetry. As the formin-actin filament has been shown to be part of an asymmetry-breaking switch in vitro [6 and 7], together these results are consistent with the view that animals with diverse body plans may derive their asymmetries from the same intracellular chiral elements [8].
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Affiliation(s)
- Angus Davison
- School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK.
| | - Gary S McDowell
- Center for Regenerative and Developmental Biology, and Department of Biology, Tufts University, Medford, MA 02155, USA
| | - Jennifer M Holden
- School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK
| | - Harriet F Johnson
- School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK
| | | | - M Maureen Liu
- School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK
| | - Paco Hulpiau
- Department for Biomedical Molecular Biology, Ghent University, and Inflammation Research Center (IRC), VIB, 9052 Ghent, Belgium
| | - Frans Van Roy
- Department for Biomedical Molecular Biology, Ghent University, and Inflammation Research Center (IRC), VIB, 9052 Ghent, Belgium
| | - Christopher M Wade
- School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK
| | - Ruby Banerjee
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Fengtang Yang
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Satoshi Chiba
- Community and Ecosystem Ecology, Division of Ecology and Evolutionary Biology, Graduate School of Life Sciences, Tohoku University, Aobayama, Sendai 980-8578, Japan
| | - John W Davey
- Department for Biomedical Molecular Biology, Ghent University, and Inflammation Research Center (IRC), VIB, 9052 Ghent, Belgium
| | - Daniel J Jackson
- Department of Geobiology, University of Göttingen, Göttingen 37077, Germany
| | - Michael Levin
- Center for Regenerative and Developmental Biology, and Department of Biology, Tufts University, Medford, MA 02155, USA
| | - Mark L Blaxter
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh EH9 3JT, UK; Edinburgh Genomics, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JT, UK
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Dimonte A, Adamatzky A, Erokhin V, Levin M. On chirality of slime mould. Biosystems 2015; 140:23-7. [PMID: 26747637 DOI: 10.1016/j.biosystems.2015.12.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 12/23/2015] [Accepted: 12/25/2015] [Indexed: 11/24/2022]
Abstract
Left-right patterning and lateralised behaviour is an ubiquitous aspect of plants and animals. The mechanisms linking cellular chirality to the large-scale asymmetry of multicellular structures are incompletely understood, and it has been suggested that the chirality of living cells is hardwired in their cytoskeleton. We examined the question of biased asymmetry in a unique organism: the slime mould Physarum polycephalum, which is unicellular yet possesses macroscopic, complex structure and behaviour. In laboratory experiment using a T-shape, we found that Physarum turns right in more than 74% of trials. The results are in agreement with previously published studies on asymmetric movement of muscle cells, neutrophils, liver cells and growing neural filaments, and for the first time reveal the presence of consistently-biased laterality in the fungi kingdom. Exact mechanisms of the slime mould's direction preference remain unknown.
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Cytoskeletal Symmetry Breaking and Chirality: From Reconstituted Systems to Animal Development. Symmetry (Basel) 2015. [DOI: 10.3390/sym7042062] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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Selective chromatid segregation mechanism proposed for the human split hand/foot malformation development by chromosome 2 translocations: A perspective. Dev Biol 2015; 408:7-13. [PMID: 26477560 DOI: 10.1016/j.ydbio.2015.10.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 10/08/2015] [Accepted: 10/08/2015] [Indexed: 11/20/2022]
Abstract
Three unrelated chromosome 2q14.1-14.2 region translocations caused the split hand/foot limb malformation development in humans by an unknown mechanism. Their etiology was described by the autosomal dominant inheritance with incomplete penetrance genetic model although authors stated, "the understanding of the genotype-to-phenotype relationship has been most challenging". The conundrums are that no mutation was found in known genes located at or near the translocation breakpoints, some limbs were malformed while others were not in the same patient and surprisingly breakpoints lie at relatively large distance of more than 2.5 million bases to have caused disorder-causing gene mutations in a single gene. To help understand translocations etiology for limb development, we invoke the selective DNA strand/chromatid-specific epigenetic imprinting and segregation mechanism employed by the two highly diverged fission yeasts to produce daughter cells of different cell types by mitosis. By this mechanism, an anterior- and posterior-limb-tissues-generating pair of daughter cells is produced by a single deterministic cell dividing in the anlagen of the limb bud. Accordingly, malformation develops simply because translocations hinder the proper distribution of chromatid-specific epialleles of a limb developmental gene during the deterministic cell's mitosis. It is tempting to speculate that such a mechanism might involve the HOXD-cluster genes situated centromere-distal to the translocation breakpoints many million bases away at the 2q31.1 region. Further genetic tests of the hypothesis are proposed for the human and mouse limb development. In sum, genetic analysis of translocations suggests that the sequence asymmetry of strands in the double-helical DNA structure of a developmental gene forms the physical basis of daughter cells' developmental asymmetry, thus opposing the morphogen-gradient research paradigm of limb development.
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37
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Lobikin M, Lobo D, Blackiston DJ, Martyniuk CJ, Tkachenko E, Levin M. Serotonergic regulation of melanocyte conversion: A bioelectrically regulated network for stochastic all-or-none hyperpigmentation. Sci Signal 2015; 8:ra99. [PMID: 26443706 DOI: 10.1126/scisignal.aac6609] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Experimentally induced depolarization of resting membrane potential in "instructor cells" in Xenopus laevis embryos causes hyperpigmentation in an all-or-none fashion in some tadpoles due to excess proliferation and migration of melanocytes. We showed that this stochastic process involved serotonin signaling, adenosine 3',5'-monophosphate (cAMP), and the transcription factors cAMP response element-binding protein (CREB), Sox10, and Slug. Transcriptional microarray analysis of embryos taken at stage 15 (early neurula) and stage 45 (free-swimming tadpole) revealed changes in the abundance of 45 and 517 transcripts, respectively, between control embryos and embryos exposed to the instructor cell-depolarizing agent ivermectin. Bioinformatic analysis revealed that the human homologs of some of the differentially regulated genes were associated with cancer, consistent with the induced arborization and invasive behavior of converted melanocytes. We identified a physiological circuit that uses serotonergic signaling between instructor cells, melanotrope cells of the pituitary, and melanocytes to control the proliferation, cell shape, and migration properties of the pigment cell pool. To understand the stochasticity and properties of this multiscale signaling system, we applied a computational machine-learning method that iteratively explored network models to reverse-engineer a stochastic dynamic model that recapitulated the frequency of the all-or-none hyperpigmentation phenotype produced in response to various pharmacological and molecular genetic manipulations. This computational approach may provide insight into stochastic cellular decision-making that occurs during normal development and pathological conditions, such as cancer.
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Affiliation(s)
- Maria Lobikin
- Biology Department and Center for Regenerative and Developmental Biology, Tufts University, Medford, MA 02155, USA
| | - Daniel Lobo
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
| | - Douglas J Blackiston
- Biology Department and Center for Regenerative and Developmental Biology, Tufts University, Medford, MA 02155, USA
| | - Christopher J Martyniuk
- Center for Environmental and Human Toxicology and Department of Physiological Sciences, UF Genetics Institute, University of Florida, Gainesville, FL 32611, USA
| | - Elizabeth Tkachenko
- Biology Department and Center for Regenerative and Developmental Biology, Tufts University, Medford, MA 02155, USA
| | - Michael Levin
- Biology Department and Center for Regenerative and Developmental Biology, Tufts University, Medford, MA 02155, USA.
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Levin M. Molecular bioelectricity: how endogenous voltage potentials control cell behavior and instruct pattern regulation in vivo. Mol Biol Cell 2015; 25:3835-50. [PMID: 25425556 PMCID: PMC4244194 DOI: 10.1091/mbc.e13-12-0708] [Citation(s) in RCA: 221] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In addition to biochemical gradients and transcriptional networks, cell behavior is regulated by endogenous bioelectrical cues originating in the activity of ion channels and pumps, operating in a wide variety of cell types. Instructive signals mediated by changes in resting potential control proliferation, differentiation, cell shape, and apoptosis of stem, progenitor, and somatic cells. Of importance, however, cells are regulated not only by their own Vmem but also by the Vmem of their neighbors, forming networks via electrical synapses known as gap junctions. Spatiotemporal changes in Vmem distribution among nonneural somatic tissues regulate pattern formation and serve as signals that trigger limb regeneration, induce eye formation, set polarity of whole-body anatomical axes, and orchestrate craniofacial patterning. New tools for tracking and functionally altering Vmem gradients in vivo have identified novel roles for bioelectrical signaling and revealed the molecular pathways by which Vmem changes are transduced into cascades of downstream gene expression. Because channels and gap junctions are gated posttranslationally, bioelectrical networks have their own characteristic dynamics that do not reduce to molecular profiling of channel expression (although they couple functionally to transcriptional networks). The recent data provide an exciting opportunity to crack the bioelectric code, and learn to program cellular activity at the level of organs, not only cell types. The understanding of how patterning information is encoded in bioelectrical networks, which may require concepts from computational neuroscience, will have transformative implications for embryogenesis, regeneration, cancer, and synthetic bioengineering.
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Affiliation(s)
- Michael Levin
- Biology Department, Center for Regenerative and Developmental Biology, Tufts University, Medford, MA 02155-4243
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39
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Blum M, Schweickert A, Vick P, Wright CVE, Danilchik MV. Symmetry breakage in the vertebrate embryo: when does it happen and how does it work? Dev Biol 2014; 393:109-23. [PMID: 24972089 PMCID: PMC4481729 DOI: 10.1016/j.ydbio.2014.06.014] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 06/08/2014] [Accepted: 06/17/2014] [Indexed: 10/25/2022]
Abstract
Asymmetric development of the vertebrate embryo has fascinated embryologists for over a century. Much has been learned since the asymmetric Nodal signaling cascade in the left lateral plate mesoderm was detected, and began to be unraveled over the past decade or two. When and how symmetry is initially broken, however, has remained a matter of debate. Two essentially mutually exclusive models prevail. Cilia-driven leftward flow of extracellular fluids occurs in mammalian, fish and amphibian embryos. A great deal of experimental evidence indicates that this flow is indeed required for symmetry breaking. An alternative model has argued, however, that flow simply acts as an amplification step for early asymmetric cues generated by ion flux during the first cleavage divisions. In this review we critically evaluate the experimental basis of both models. Although a number of open questions persist, the available evidence is best compatible with flow-based symmetry breakage as the archetypical mode of symmetry breakage.
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Affiliation(s)
- Martin Blum
- University of Hohenheim, Institute of Zoology (220), Garbenstrasse 30, D-70593 Stuttgart, Germany.
| | - Axel Schweickert
- University of Hohenheim, Institute of Zoology (220), Garbenstrasse 30, D-70593 Stuttgart, Germany
| | - Philipp Vick
- University of Hohenheim, Institute of Zoology (220), Garbenstrasse 30, D-70593 Stuttgart, Germany
| | - Christopher V E Wright
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232-0494, USA
| | - Michael V Danilchik
- Department of Integrative Biosciences, Oregon Health & Science University, Portland, OR 97239-3098, USA
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40
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Muñoz-Nortes T, Wilson-Sánchez D, Candela H, Micol JL. Symmetry, asymmetry, and the cell cycle in plants: known knowns and some known unknowns. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:2645-55. [PMID: 24474806 DOI: 10.1093/jxb/ert476] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The body architectures of most multicellular organisms consistently display both symmetry and asymmetry. Here, we discuss some of the available knowledge and open questions on how symmetry and asymmetry appear in several conspicuous plant cells and tissues. We focus, where possible, on the role of genes that participate in the maintenance or the breaking of symmetry and that are directly or indirectly related to the cell cycle, under an organ-centric point of view and with an emphasis on the leaf.
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Affiliation(s)
- Tamara Muñoz-Nortes
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202 Elche, Spain
| | - David Wilson-Sánchez
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202 Elche, Spain
| | - Héctor Candela
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202 Elche, Spain
| | - José Luis Micol
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202 Elche, Spain
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41
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Tingler M, Ott T, Tözser J, Kurz S, Getwan M, Tisler M, Schweickert A, Blum M. Symmetry breakage in the frog Xenopus
: Role of Rab11 and the ventral-right blastomere. Genesis 2014; 52:588-99. [DOI: 10.1002/dvg.22766] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 02/12/2014] [Accepted: 02/25/2014] [Indexed: 02/04/2023]
Affiliation(s)
- Melanie Tingler
- Institute of Zoology, University of Hohenheim; Stuttgart D-70593 Germany
| | - Tim Ott
- Institute of Zoology, University of Hohenheim; Stuttgart D-70593 Germany
| | - Janos Tözser
- Institute of Zoology, University of Hohenheim; Stuttgart D-70593 Germany
| | - Sabrina Kurz
- Institute of Zoology, University of Hohenheim; Stuttgart D-70593 Germany
| | - Maike Getwan
- Institute of Zoology, University of Hohenheim; Stuttgart D-70593 Germany
| | - Matthias Tisler
- Institute of Zoology, University of Hohenheim; Stuttgart D-70593 Germany
| | - Axel Schweickert
- Institute of Zoology, University of Hohenheim; Stuttgart D-70593 Germany
| | - Martin Blum
- Institute of Zoology, University of Hohenheim; Stuttgart D-70593 Germany
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42
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Namigai EK, Kenny NJ, Shimeld SM. Right across the tree of life: The evolution of left-right asymmetry in the Bilateria. Genesis 2014; 52:458-70. [DOI: 10.1002/dvg.22748] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 01/27/2014] [Accepted: 01/29/2014] [Indexed: 02/02/2023]
Affiliation(s)
- Erica K.O. Namigai
- Department of Zoology; University of Oxford; South Parks Road Oxford United Kingdom
| | - Nathan J. Kenny
- Department of Zoology; University of Oxford; South Parks Road Oxford United Kingdom
| | - Sebastian M. Shimeld
- Department of Zoology; University of Oxford; South Parks Road Oxford United Kingdom
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Srivastava D, Chakrabarti O. Mahogunin-mediated α-tubulin ubiquitination via noncanonical K6 linkage regulates microtubule stability and mitotic spindle orientation. Cell Death Dis 2014; 5:e1064. [PMID: 24556679 PMCID: PMC3944237 DOI: 10.1038/cddis.2014.1] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 12/19/2013] [Accepted: 12/19/2013] [Indexed: 12/26/2022]
Abstract
Mahogunin ring finger-1 (MGRN1) is a cytosolic ubiquitin ligase whose disruption or interaction with some isoforms of cytosolically exposed prion protein leads to spongiform neurodegeneration and also lack of which results in reduced embryonic viability due to mispatterning of the left–right (LR) axis during development. Here we demonstrate an interaction between the cytoskeletal protein α-tubulin and MGRN1. In cultured cell systems, loss of the ubiquitin E3 ligase activity of MGRN1 results in spindle misorientation and decreased α-tubulin polymerization, an effect also seen in primary cells. α-Tubulin was post-translationally modified by MGRN1 via noncanonical K6-linked polyubiquitination. This was significant because expression of catalytically inactive MGRN1 and/or ubiquitin mutant capable of only monoubiquitination resulted in similar mitotic spindle misorientation. The modulatory effect of MGRN1 was specific for α-tubulin and similar changes could not be detected in β- or γ-tubulin. However, catalytic inactivation of MGRN1 did not abrogate monoubiquitination of α-tubulin, thus unraveling a unique dual mode of ubiquitination by an unknown E3 ligase and MGRN1. MGRN1-mediated α-tubulin modification, and hence its stability, may highlight a key event in the LR patterning during embryogenesis.
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Affiliation(s)
- D Srivastava
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata, India
| | - O Chakrabarti
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata, India
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44
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VANDENBERG LAURAN, BLACKISTON DOUGLASJ, REA ADAMC, DORE TIMOTHYM, LEVIN MICHAEL. Left-right patterning in Xenopus conjoined twin embryos requires serotonin signaling and gap junctions. THE INTERNATIONAL JOURNAL OF DEVELOPMENTAL BIOLOGY 2014; 58:799-809. [PMID: 25896280 PMCID: PMC10471180 DOI: 10.1387/ijdb.140215ml] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
A number of processes operating during the first cell cleavages enable the left-right (LR) axis to be consistently oriented during Xenopus laevis development. Prior work showed that secondary organizers induced in frog embryos after cleavage stages (i.e. conjoined twins arising from ectopic induced primary axes) correctly pattern their own LR axis only when a primary (early) organizer is also present. This instructive effect confirms the unique LR patterning functions that occur during early embryogenesis, but leaves open the question: which mechanisms that operate during early stages are also involved in the orientation of later-induced organizers? We sought to distinguish the two phases of LR patterning in secondary organizers (LR patterning of the primary twin and the later transfer of this information to the secondary twin) by perturbing only the latter process. Here, we used reagents that do not affect primary LR patterning at the time secondary organizers form to inhibit each of 4 mechanisms in the induced twin. Using pharmacological, molecular-genetic, and photo-chemical tools, we show that serotonergic and gap-junctional signaling, but not proton or potassium flows, are required for the secondary organizer to appropriately pattern its LR axis in a multicellular context. We also show that consistently-asymmetric gene expression begins prior to ciliary flow. Together, our data highlight the importance of physiological signaling in the propagation of cleavage-derived LR orientation to multicellular cell fields.
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Affiliation(s)
- LAURA N. VANDENBERG
- Biology Department, Center for Regenerative and Developmental Biology, Tufts University, Medford, MA, USA
- Department of Public Health, Division of Environmental Health Sciences, University of Massachusetts – Amherst, Amherst, MA, USA
| | - DOUGLAS J. BLACKISTON
- Biology Department, Center for Regenerative and Developmental Biology, Tufts University, Medford, MA, USA
| | - ADAM C. REA
- Department of Chemistry, University of Georgia, Athens, GA, USA and
| | - TIMOTHY M. DORE
- Department of Chemistry, University of Georgia, Athens, GA, USA and
- New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - MICHAEL LEVIN
- Biology Department, Center for Regenerative and Developmental Biology, Tufts University, Medford, MA, USA
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45
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Vandenberg LN, Lemire JM, Levin M. It's never too early to get it Right: A conserved role for the cytoskeleton in left-right asymmetry. Commun Integr Biol 2013; 6:e27155. [PMID: 24505508 PMCID: PMC3912007 DOI: 10.4161/cib.27155] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 11/08/2013] [Accepted: 11/11/2013] [Indexed: 01/08/2023] Open
Abstract
For centuries, scientists and physicians have been captivated by the consistent left-right (LR) asymmetry of the heart, viscera, and brain. A recent study implicated tubulin proteins in establishing laterality in several experimental models, including asymmetric chemosensory receptor expression in C. elegans neurons, polarization of HL-60 human neutrophil-like cells in culture, and asymmetric organ placement in Xenopus. The same mutations that randomized asymmetry in these diverse systems also affect chirality in Arabidopsis, revealing a remarkable conservation of symmetry-breaking mechanisms among kingdoms. In Xenopus, tubulin mutants only affected LR patterning very early, suggesting that this axis is established shortly after fertilization. This addendum summarizes and extends the knowledge of the cytoskeleton's role in the patterning of the LR axis. Results from many species suggest a conserved role for the cytoskeleton as the initiator of asymmetry, and indicate that symmetry is first broken during early embryogenesis by an intracellular process.
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Affiliation(s)
- Laura N Vandenberg
- Biology Department; Center for Regenerative and Developmental Biology; Tufts University; Medford, MA USA ; Current affiliation: Department of Public Health; Division of Environmental Health Sciences; University of Massachusetts, Amherst; Amherst, MA USA
| | - Joan M Lemire
- Biology Department; Center for Regenerative and Developmental Biology; Tufts University; Medford, MA USA
| | - Michael Levin
- Biology Department; Center for Regenerative and Developmental Biology; Tufts University; Medford, MA USA
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Schlueter J, Brand T. Subpopulation of proepicardial cells is derived from the somatic mesoderm in the chick embryo. Circ Res 2013; 113:1128-37. [PMID: 24019406 DOI: 10.1161/circresaha.113.301347] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
RATIONALE The proepicardium (PE) is a transient structure forming at the venous pole of the heart and gives rise to the epicardium, fibroblasts, and smooth muscle cells. The embryological origin of the PE is presently unclear. Asymmetrical formation of the PE on the right inflow tract is a conserved feature of many vertebrate embryos, and in the chicken is under the control of fibroblast growth factor 8 and snail homolog 1. OBJECTIVE To gain further insight into the process of asymmetrical PE formation, we studied the role of TWIST1 during PE formation in the chick embryo. METHODS AND RESULTS TWIST1 is asymmetrically expressed on the right side in the somatic mesoderm under the control of snail homolog 1. Fate mapping experiments revealed a contribution of the somatic mesoderm to the PE. After colonization of the heart, this cell lineage gives rise to the epicardium, smooth muscle cells, and potentially fibroblast. Suppression of TWIST1 function in the right coelomic cavity caused a severe disruption of the villous protrusions of the PE and Wilms tumor 1 and transcription factor 21 expression. Rescue with the corresponding mouse cDNA normalized gene expression and PE morphology. Forced expression of TWIST1 on the left side induced ectopic expression domains of Wilms tumor 1 and transcription factor 21. CONCLUSIONS A significant proportion of the PE has its origin outside of the currently proposed domain in the splanchnic layer of the lateral plate mesoderm. The phenotype in embryos subjected to TWIST1 loss- or gain-of-function suggests an important contribution of somatic mesoderm to the mesothelial cell layer of the PE.
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Affiliation(s)
- Jan Schlueter
- From the Heart Science Centre, National Heart and Lung Institute, Imperial College London, United Kingdom
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Vandenberg LN, Levin M. A unified model for left-right asymmetry? Comparison and synthesis of molecular models of embryonic laterality. Dev Biol 2013; 379:1-15. [PMID: 23583583 PMCID: PMC3698617 DOI: 10.1016/j.ydbio.2013.03.021] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Revised: 03/15/2013] [Accepted: 03/22/2013] [Indexed: 12/31/2022]
Abstract
Understanding how and when the left-right (LR) axis is first established is a fundamental question in developmental biology. A popular model is that the LR axis is established relatively late in embryogenesis, due to the movement of motile cilia and the resultant directed fluid flow during late gastrulation/early neurulation. Yet, a large body of evidence suggests that biophysical, molecular, and bioelectrical asymmetries exist much earlier in development, some as early as the first cell cleavage after fertilization. Alternative models of LR asymmetry have been proposed that accommodate these data, postulating that asymmetry is established due to a chiral cytoskeleton and/or the asymmetric segregation of chromatids. There are some similarities, and many differences, in how these various models postulate the origin and timing of symmetry breaking and amplification, and these events' linkage to the well-conserved subsequent asymmetric transcriptional cascades. This review examines experimental data that lend strong support to an early origin of LR asymmetry, yet are also consistent with later roles for cilia in the amplification of LR pathways. In this way, we propose that the various models of asymmetry can be unified: early events are needed to initiate LR asymmetry, and later events could be utilized by some species to maintain LR-biases. We also present an alternative hypothesis, which proposes that individual embryos stochastically choose one of several possible pathways with which to establish their LR axis. These two hypotheses are both tractable in appropriate model species; testing them to resolve open questions in the field of LR patterning will reveal interesting new biology of wide relevance to developmental, cell, and evolutionary biology.
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Affiliation(s)
- Laura N. Vandenberg
- Center for Regenerative and Developmental Biology, and Biology Department, Tufts University, Medford, MA 02155
| | - Michael Levin
- Center for Regenerative and Developmental Biology, and Biology Department, Tufts University, Medford, MA 02155
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Breviario D, Gianì S, Morello L. Multiple tubulins: evolutionary aspects and biological implications. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2013; 75:202-18. [PMID: 23662651 DOI: 10.1111/tpj.12243] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 05/03/2013] [Accepted: 05/09/2013] [Indexed: 05/05/2023]
Abstract
Plant tubulin is a dimeric protein that contributes to formation of microtubules, major intracellular structures that are involved in the control of fundamental processes such as cell division, polarity of growth, cell-wall deposition, intracellular trafficking and communications. Because it is a structural protein whose function is confined to the role of microtubule formation, tubulin may be perceived as an uninteresting gene product, but such a perception is incorrect. In fact, tubulin represents a key molecule for studying fundamental biological issues such as (i) microtubule evolution (also with reference to prokaryotic precursors and the formation of cytomotive filaments), (ii) protein structure with reference to the various biochemical features of members of the FstZ/tubulin superfamily, (iii) isoform variations contributed by the existence of multi-gene families and various kinds of post-translational modifications, (iv) anti-mitotic drug interactions and mode of action, (v) plant and cell symmetry, as determined using a series of tubulin mutants, (vi) multiple and sophisticated mechanisms of gene regulation, and (vii) intron molecular evolution. In this review, we present and discuss many of these issues, and offer an updated interpretation of the multi-tubulin hypothesis.
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Affiliation(s)
- Diego Breviario
- Istituto Biologia e Biotecnologia Agraria, Via Bassini 15, 20133 Milano, Italy.
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Wan LQ, Ronaldson K, Guirguis M, Vunjak-Novakovic G. Micropatterning of cells reveals chiral morphogenesis. Stem Cell Res Ther 2013; 4:24. [PMID: 23672821 PMCID: PMC3706915 DOI: 10.1186/scrt172] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Invariant left-right (LR) patterning or chirality is critical for embryonic development. The loss or reversal of LR asymmetry is often associated with malformations and disease. Although several theories have been proposed, the exact mechanism of the initiation of the LR symmetry has not yet been fully elucidated. Recently, chirality has been detected within single cells as well as multicellular structures using several in vitro approaches. These studies demonstrated the universality of cell chirality, its dependence on cell phenotype, and the role of physical boundaries. In this review, we discuss the theories for developmental LR asymmetry, compare various in vitro cell chirality model systems, and highlight possible roles of cell chirality in stem cell differentiation. We emphasize that the in vitro cell chirality systems have great promise for helping unveil the nature of chiral morphogenesis in development.
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