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Raymond MJ, McCusker CD. Making a new limb out of old cells: exploring endogenous cell reprogramming and its role during limb regeneration. Am J Physiol Cell Physiol 2024; 326:C505-C512. [PMID: 38105753 PMCID: PMC11192473 DOI: 10.1152/ajpcell.00233.2023] [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: 05/30/2023] [Revised: 12/13/2023] [Accepted: 12/14/2023] [Indexed: 12/19/2023]
Abstract
Cellular reprogramming is characterized by the induced dedifferentiation of mature cells into a more plastic and potent state. This process can occur through artificial reprogramming manipulations in the laboratory such as nuclear reprogramming and induced pluripotent stem cell (iPSC) generation, and endogenously in vivo during amphibian limb regeneration. In amphibians such as the Mexican axolotl, a regeneration permissive environment is formed by nerve-dependent signaling in the wounded limb tissue. When exposed to these signals, limb connective tissue cells dedifferentiate into a limb progenitor-like state. This state allows the cells to acquire new pattern information, a property called positional plasticity. Here, we review our current understanding of endogenous reprogramming and why it is important for successful regeneration. We will also explore how naturally induced dedifferentiation and plasticity were leveraged to study how the missing pattern is established in the regenerating limb tissue.
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Affiliation(s)
- Michael J Raymond
- Department of Biology, University of Massachusetts Boston, Boston, Massachusetts, United States
| | - Catherine D McCusker
- Department of Biology, University of Massachusetts Boston, Boston, Massachusetts, United States
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2
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Storer MA, Mahmud N, Karamboulas K, Borrett MJ, Yuzwa SA, Gont A, Androschuk A, Sefton MV, Kaplan DR, Miller FD. Acquisition of a Unique Mesenchymal Precursor-like Blastema State Underlies Successful Adult Mammalian Digit Tip Regeneration. Dev Cell 2020; 52:509-524.e9. [PMID: 31902657 DOI: 10.1016/j.devcel.2019.12.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 11/11/2019] [Accepted: 12/09/2019] [Indexed: 12/11/2022]
Abstract
Here, we investigate the origin and nature of blastema cells that regenerate the adult murine digit tip. We show that Pdgfra-expressing mesenchymal cells in uninjured digits establish the regenerative blastema and are essential for regeneration. Single-cell profiling shows that the mesenchymal blastema cells are distinct from both uninjured digit and embryonic limb or digit Pdgfra-positive cells. This unique blastema state is environmentally determined; dermal fibroblasts transplanted into the regenerative, but not non-regenerative, digit express blastema-state genes and contribute to bone regeneration. Moreover, lineage tracing with single-cell profiling indicates that endogenous osteoblasts or osteocytes acquire a blastema mesenchymal transcriptional state and contribute to both dermis and bone regeneration. Thus, mammalian digit tip regeneration occurs via a distinct adult mechanism where the regenerative environment promotes acquisition of a blastema state that enables cells from tissues such as bone to contribute to the regeneration of other mesenchymal tissues such as the dermis.
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Affiliation(s)
- Mekayla A Storer
- Program in Neurosciences and Mental Health, Hospital for Sick Children, Toronto M5G 1L7, Canada
| | - Neemat Mahmud
- Program in Neurosciences and Mental Health, Hospital for Sick Children, Toronto M5G 1L7, Canada; Department of Physiology, University of Toronto, Toronto M5G 1A8, Canada
| | - Konstantina Karamboulas
- Program in Neurosciences and Mental Health, Hospital for Sick Children, Toronto M5G 1L7, Canada
| | - Michael J Borrett
- Program in Neurosciences and Mental Health, Hospital for Sick Children, Toronto M5G 1L7, Canada; Institute of Medical Sciences, University of Toronto, Toronto M5G 1A8, Canada
| | - Scott A Yuzwa
- Program in Neurosciences and Mental Health, Hospital for Sick Children, Toronto M5G 1L7, Canada
| | - Alexander Gont
- Program in Neurosciences and Mental Health, Hospital for Sick Children, Toronto M5G 1L7, Canada
| | - Alaura Androschuk
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto M5G 1A8, Canada
| | - Michael V Sefton
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto M5G 1A8, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto M5G 1A8, Canada
| | - David R Kaplan
- Program in Neurosciences and Mental Health, Hospital for Sick Children, Toronto M5G 1L7, Canada; Department of Molecular Genetics, University of Toronto, Toronto M5G 1A8, Canada; Institute of Medical Sciences, University of Toronto, Toronto M5G 1A8, Canada
| | - Freda D Miller
- Program in Neurosciences and Mental Health, Hospital for Sick Children, Toronto M5G 1L7, Canada; Department of Molecular Genetics, University of Toronto, Toronto M5G 1A8, Canada; Department of Physiology, University of Toronto, Toronto M5G 1A8, Canada; Institute of Medical Sciences, University of Toronto, Toronto M5G 1A8, Canada.
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3
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Oscillatory cortical forces promote three dimensional cell intercalations that shape the murine mandibular arch. Nat Commun 2019; 10:1703. [PMID: 30979871 PMCID: PMC6461694 DOI: 10.1038/s41467-019-09540-z] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Accepted: 03/15/2019] [Indexed: 01/10/2023] Open
Abstract
Multiple vertebrate embryonic structures such as organ primordia are composed of confluent cells. Although mechanisms that shape tissue sheets are increasingly understood, those which shape a volume of cells remain obscure. Here we show that 3D mesenchymal cell intercalations are essential to shape the mandibular arch of the mouse embryo. Using a genetically encoded vinculin tension sensor that we knock-in to the mouse genome, we show that cortical force oscillations promote these intercalations. Genetic loss- and gain-of-function approaches show that Wnt5a functions as a spatial cue to coordinate cell polarity and cytoskeletal oscillation. These processes diminish tissue rigidity and help cells to overcome the energy barrier to intercalation. YAP/TAZ and PIEZO1 serve as downstream effectors of Wnt5a-mediated actomyosin polarity and cytosolic calcium transients that orient and drive mesenchymal cell intercalations. These findings advance our understanding of how developmental pathways regulate biophysical properties and forces to shape a solid organ primordium.
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Tao H, Kawakami Y, Hui CC, Hopyan S. The two domain hypothesis of limb prepattern and its relevance to congenital limb anomalies. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2017; 6. [PMID: 28319333 DOI: 10.1002/wdev.270] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 02/03/2017] [Accepted: 02/07/2017] [Indexed: 11/06/2022]
Abstract
Functional annotation of mutations that cause human limb anomalies is enabled by basic developmental studies. In this study, we focus on the prepatterning stage of limb development and discuss a recent model that proposes anterior and posterior domains of the early limb bud generate two halves of the future skeleton. By comparing phenotypes in humans with those in model organisms, we evaluate whether this prepatterning concept helps to annotate human disease alleles. WIREs Dev Biol 2017, 6:e270. doi: 10.1002/wdev.270 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Hirotaka Tao
- Program in Developmental and Stem Cell Biology, Research Institute, The Hospital for Sick Children, Toronto, Canada
| | - Yasuhiko Kawakami
- Department of Genetics, Cell Biology and Development, Stem Cell Institute, University of Minnesota, Minneapolis, MN, USA
| | - Chi-Chung Hui
- Program in Developmental and Stem Cell Biology, Research Institute, The Hospital for Sick Children, Toronto, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Sevan Hopyan
- Program in Developmental and Stem Cell Biology, Research Institute, The Hospital for Sick Children, Toronto, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Canada.,Division of Orthopaedic Surgery, Hospital for Sick Children and University of Toronto, Toronto, Canada
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5
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Pelttari K, Pippenger B, Mumme M, Feliciano S, Scotti C, Mainil-Varlet P, Procino A, von Rechenberg B, Schwamborn T, Jakob M, Cillo C, Barbero A, Martin I. Adult human neural crest-derived cells for articular cartilage repair. Sci Transl Med 2015; 6:251ra119. [PMID: 25163479 DOI: 10.1126/scitranslmed.3009688] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In embryonic models and stem cell systems, mesenchymal cells derived from the neuroectoderm can be distinguished from mesoderm-derived cells by their Hox-negative profile--a phenotype associated with enhanced capacity of tissue regeneration. We investigated whether developmental origin and Hox negativity correlated with self-renewal and environmental plasticity also in differentiated cells from adults. Using hyaline cartilage as a model, we showed that adult human neuroectoderm-derived nasal chondrocytes (NCs) can be constitutively distinguished from mesoderm-derived articular chondrocytes (ACs) by lack of expression of specific HOX genes, including HOXC4 and HOXD8. In contrast to ACs, serially cloned NCs could be continuously reverted from differentiated to dedifferentiated states, conserving the ability to form cartilage tissue in vitro and in vivo. NCs could also be reprogrammed to stably express Hox genes typical of ACs upon implantation into goat articular cartilage defects, directly contributing to cartilage repair. Our findings identify previously unrecognized regenerative properties of HOX-negative differentiated neuroectoderm cells in adults, implying a role for NCs in the unmet clinical challenge of articular cartilage repair. An ongoing phase 1 clinical trial preliminarily indicated the safety and feasibility of autologous NC-based engineered tissues for the treatment of traumatic articular cartilage lesions.
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Affiliation(s)
- Karoliina Pelttari
- Departments of Surgery and of Biomedicine, University Hospital Basel, University of Basel, Hebelstrasse 20, 4031 Basel, Switzerland
| | - Benjamin Pippenger
- Departments of Surgery and of Biomedicine, University Hospital Basel, University of Basel, Hebelstrasse 20, 4031 Basel, Switzerland
| | - Marcus Mumme
- Departments of Surgery and of Biomedicine, University Hospital Basel, University of Basel, Hebelstrasse 20, 4031 Basel, Switzerland
| | - Sandra Feliciano
- Departments of Surgery and of Biomedicine, University Hospital Basel, University of Basel, Hebelstrasse 20, 4031 Basel, Switzerland
| | - Celeste Scotti
- Istituto Di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Ortopedico Galeazzi, Via R. Galeazzi 4, 20161 Milano, Italy
| | - Pierre Mainil-Varlet
- AGINKO Research AG, Route de l'ancienne Papeterie, P. O. Box 30, 1723 Marly, Switzerland
| | - Alfredo Procino
- Department of Medicine and Surgery, Federico II Medical School, Via S. Pansini 5, 80131 Napoli, Italy
| | - Brigitte von Rechenberg
- Musculoskeletal Research Unit, Equine Hospital, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland
| | | | - Marcel Jakob
- Departments of Surgery and of Biomedicine, University Hospital Basel, University of Basel, Hebelstrasse 20, 4031 Basel, Switzerland
| | - Clemente Cillo
- Department of Medicine and Surgery, Federico II Medical School, Via S. Pansini 5, 80131 Napoli, Italy
| | - Andrea Barbero
- Departments of Surgery and of Biomedicine, University Hospital Basel, University of Basel, Hebelstrasse 20, 4031 Basel, Switzerland
| | - Ivan Martin
- Departments of Surgery and of Biomedicine, University Hospital Basel, University of Basel, Hebelstrasse 20, 4031 Basel, Switzerland.
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6
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Lau K, Tao H, Liu H, Wen J, Sturgeon K, Sorfazlian N, Lazic S, Burrows JTA, Wong MD, Li D, Deimling S, Ciruna B, Scott I, Simmons C, Henkelman RM, Williams T, Hadjantonakis AK, Fernandez-Gonzalez R, Sun Y, Hopyan S. Anisotropic stress orients remodelling of mammalian limb bud ectoderm. Nat Cell Biol 2015; 17:569-79. [PMID: 25893915 PMCID: PMC4955842 DOI: 10.1038/ncb3156] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 03/11/2015] [Indexed: 02/08/2023]
Abstract
The physical forces that drive morphogenesis are not well characterized in vivo, especially among vertebrates. In the early limb bud, dorsal and ventral ectoderm converge to form the apical ectodermal ridge (AER), although the underlying mechanisms are unclear. By live imaging mouse embryos, we show that prospective AER progenitors intercalate at the dorsoventral boundary and that ectoderm remodels by concomitant cell division and neighbour exchange. Mesodermal expansion and ectodermal tension together generate a dorsoventrally biased stress pattern that orients ectodermal remodelling. Polarized distribution of cortical actin reflects this stress pattern in a β-catenin- and Fgfr2-dependent manner. Intercalation of AER progenitors generates a tensile gradient that reorients resolution of multicellular rosettes on adjacent surfaces, a process facilitated by β-catenin-dependent attachment of cortex to membrane. Therefore, feedback between tissue stress pattern and cell intercalations remodels mammalian ectoderm.
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MESH Headings
- Actins/metabolism
- Animals
- Anisotropy
- Cell Communication
- Cell Division
- Cell Polarity
- Ectoderm/metabolism
- Ectoderm/physiology
- Embryo Culture Techniques
- Embryonic Stem Cells/physiology
- Feedback
- Gene Expression Regulation, Developmental
- Genotype
- Limb Buds/metabolism
- Limb Buds/physiology
- Mechanotransduction, Cellular
- Mice, Inbred C57BL
- Mice, Transgenic
- Microscopy, Video
- Models, Biological
- Morphogenesis
- Phenotype
- Receptor, Fibroblast Growth Factor, Type 2/genetics
- Receptor, Fibroblast Growth Factor, Type 2/metabolism
- Stress, Mechanical
- Time Factors
- beta Catenin/genetics
- beta Catenin/metabolism
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Affiliation(s)
- Kimberly Lau
- Program in Developmental and Stem Cell Biology, Research Institute, The Hospital for Sick Children, Toronto M5G 1X8, Canada
| | - Hirotaka Tao
- Program in Developmental and Stem Cell Biology, Research Institute, The Hospital for Sick Children, Toronto M5G 1X8, Canada
| | - Haijiao Liu
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto M5S 3G8, Canada
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto M5S 3G9, Canada
| | - Jun Wen
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto M5S 3G8, Canada
| | - Kendra Sturgeon
- Program in Developmental and Stem Cell Biology, Research Institute, The Hospital for Sick Children, Toronto M5G 1X8, Canada
| | - Natalie Sorfazlian
- Program in Developmental and Stem Cell Biology, Research Institute, The Hospital for Sick Children, Toronto M5G 1X8, Canada
| | - Savo Lazic
- Program in Developmental and Stem Cell Biology, Research Institute, The Hospital for Sick Children, Toronto M5G 1X8, Canada
- Department of Molecular Genetics, University of Toronto, Toronto M5S 1A8, Canada
| | - Jeffrey T. A. Burrows
- Program in Developmental and Stem Cell Biology, Research Institute, The Hospital for Sick Children, Toronto M5G 1X8, Canada
| | - Michael D. Wong
- Mouse Imaging Centre, Hospital for Sick Children, Toronto Centre for Phenogenomics, Toronto M5T 3H7, Canada
- Department of Medical Biophysics, University of Toronto, Toronto M5T 3H7, Canada
| | - Danyi Li
- Program in Developmental and Stem Cell Biology, Research Institute, The Hospital for Sick Children, Toronto M5G 1X8, Canada
- Department of Molecular Genetics, University of Toronto, Toronto M5S 1A8, Canada
| | - Steven Deimling
- Program in Developmental and Stem Cell Biology, Research Institute, The Hospital for Sick Children, Toronto M5G 1X8, Canada
| | - Brian Ciruna
- Program in Developmental and Stem Cell Biology, Research Institute, The Hospital for Sick Children, Toronto M5G 1X8, Canada
- Department of Molecular Genetics, University of Toronto, Toronto M5S 1A8, Canada
| | - Ian Scott
- Program in Developmental and Stem Cell Biology, Research Institute, The Hospital for Sick Children, Toronto M5G 1X8, Canada
- Department of Molecular Genetics, University of Toronto, Toronto M5S 1A8, Canada
| | - Craig Simmons
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto M5S 3G8, Canada
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto M5S 3G9, Canada
| | - R. Mark Henkelman
- Mouse Imaging Centre, Hospital for Sick Children, Toronto Centre for Phenogenomics, Toronto M5T 3H7, Canada
- Department of Medical Biophysics, University of Toronto, Toronto M5T 3H7, Canada
| | - Trevor Williams
- Program in Molecular Biology, School of Medicine, University of Colorado, Aurora, Colorado 80045, USA
| | | | - Rodrigo Fernandez-Gonzalez
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto M5S 3G9, Canada
- Cell and Systems Biology, University of Toronto, Toronto M5G 3G5, Canada
| | - Yu Sun
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto M5S 3G8, Canada
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto M5S 3G9, Canada
| | - Sevan Hopyan
- Program in Developmental and Stem Cell Biology, Research Institute, The Hospital for Sick Children, Toronto M5G 1X8, Canada
- Department of Molecular Genetics, University of Toronto, Toronto M5S 1A8, Canada
- Division of Orthopaedic Surgery, Hospital for Sick Children and University of Toronto, Toronto M5G 1X8, Canada
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7
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Liang L, Shen YY, Pan XW, Zhou TC, Yang C, Irwin DM, Zhang YP. Adaptive evolution of the Hox gene family for development in bats and dolphins. PLoS One 2013; 8:e65944. [PMID: 23825528 PMCID: PMC3692524 DOI: 10.1371/journal.pone.0065944] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2013] [Accepted: 05/01/2013] [Indexed: 12/20/2022] Open
Abstract
Bats and cetaceans (i.e., whales, dolphins, porpoises) are two kinds of mammals with unique locomotive styles and occupy novel niches. Bats are the only mammals capable of sustained flight in the sky, while cetaceans have returned to the aquatic environment and are specialized for swimming. Associated with these novel adaptations to their environment, various development changes have occurred to their body plans and associated structures. Given the importance of Hox genes in many aspects of embryonic development, we conducted an analysis of the coding regions of all Hox gene family members from bats (represented by Pteropus vampyrus, Pteropus alecto, Myotis lucifugus and Myotis davidii) and cetaceans (represented by Tursiops truncatus) for adaptive evolution using the available draft genome sequences. Differences in the selective pressures acting on many Hox genes in bats and cetaceans were found compared to other mammals. Positive selection, however, was not found to act on any of the Hox genes in the common ancestor of bats and only upon Hoxb9 in cetaceans. PCR amplification data from additional bat and cetacean species, and application of the branch-site test 2, showed that the Hoxb2 gene within bats had significant evidence of positive selection. Thus, our study, with genomic and newly sequenced Hox genes, identifies two candidate Hox genes that may be closely linked with developmental changes in bats and cetaceans, such as those associated with the pancreatic, neuronal, thymus shape and forelimb. In addition, the difference in our results from the genome-wide scan and newly sequenced data reveals that great care must be taken in interpreting results from draft genome data from a limited number of species, and deep genetic sampling of a particular clade is a powerful tool for generating complementary data to address this limitation.
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Affiliation(s)
- Lu Liang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- Graduate School of the Chinese Academy of Sciences, Beijing, China
| | - Yong-Yi Shen
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
- * E-mail: (Y-PZ); (Y-YS)
| | - Xiao-Wei Pan
- Laboratory for Conservation and Utilization of Bio-resources, Yunnan University, Kunming, China
| | - Tai-Cheng Zhou
- Laboratory for Conservation and Utilization of Bio-resources, Yunnan University, Kunming, China
| | - Chao Yang
- Laboratory for Conservation and Utilization of Bio-resources, Yunnan University, Kunming, China
| | - David M. Irwin
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Banting and Best Diabetes Centre, University of Toronto, Toronto, ON, Canada
| | - Ya-Ping Zhang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- Laboratory for Conservation and Utilization of Bio-resources, Yunnan University, Kunming, China
- * E-mail: (Y-PZ); (Y-YS)
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8
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Mahony C, Vargesson N. Molecular analysis of regulative events in the developing chick limb. J Anat 2013; 223:1-13. [PMID: 23678942 DOI: 10.1111/joa.12060] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/12/2013] [Indexed: 12/01/2022] Open
Abstract
The developing chick limb has the remarkable ability to regulate for the loss of large amounts of mesenchyme and maintain a normal limb pattern in early (Hamburger and Hamilton Stage 19; E3) limbs. How the limb can regulate for tissue loss and why this ability is lost as development proceeds (after Hamburger and Hamilton Stage 21; E3.5) is unclear. We have investigated the origins of cells involved in regulative processes and, for the first time, the molecular changes occurring, and find striking differences between developmental time points just 0.5 days apart. We demonstrate that subtle changes in cell dispersal and cell proliferation occur in HH St21 limbs but not in HH St19 limbs and also demonstrate that there is no net replacement of removed tissue at either HH St21 or St19. We further show that changes in the Fgf8/Shh/Bmp4/Gremlin signaling pathway together with the appearance of distal Hox gene activation coincide with the limbs' ability to regulate for large tissue loss. We also demonstrate that following small tissue loss, limbs can regulate for missing tissue to produce normal pattern with no net replacement of missing tissue, as seen in limbs following large tissue loss. Our results indicate the regulative ability of the limb is not due to changes in cell proliferation, cell lineage nor replacement of the missing tissue - regulative ability is reliant upon the signaling environment remaining.
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Affiliation(s)
- Chris Mahony
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, UK
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9
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Roselló-Díez A, Torres M. Regulative patterning in limb bud transplants is induced by distalizing activity of apical ectodermal ridge signals on host limb cells. Dev Dyn 2011; 240:1203-11. [PMID: 21509894 DOI: 10.1002/dvdy.22635] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
We have used the chick limb as a model to gain insight into the longstanding question of regulative vs. mosaic development. To test the influence of signals on limb proximodistal development, distal limb bud tips of several stages were grafted to regions of the embryo known to provide different signaling environments. Of interest, thin grafts (100-micron thick) formed elements more proximal in character when grafted to the proximal limb region than when grafted to other regions. The extra elements were derived from host tissue, presumably distalized and recruited by the graft's apical ectodermal ridge signals. The results of classic and recent experiments have been reinterpreted in light of our conclusions.
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Affiliation(s)
- Alberto Roselló-Díez
- Departamento de Desarrollo y Reparación Cardiovascular, Centro Nacional de Investigaciones Cardiovasculares, Instituto de Salud Carlos III, Melchor Fernández Almagro, Madrid, Spain
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10
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Wyngaarden LA, Delgado-Olguin P, Su IH, Bruneau BG, Hopyan S. Ezh2 regulates anteroposterior axis specification and proximodistal axis elongation in the developing limb. Development 2011; 138:3759-67. [PMID: 21795281 DOI: 10.1242/dev.063180] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Specification and determination (commitment) of positional identities precedes overt pattern formation during development. In the limb bud, it is clear that the anteroposterior axis is specified at a very early stage and is prepatterned by the mutually antagonistic interaction between Gli3 and Hand2. There is also evidence that the proximodistal axis is specified early and determined progressively. Little is known about upstream regulators of these processes or how epigenetic modifiers influence axis formation. Using conditional mutagenesis at different time points, we show that the histone methyltransferase Ezh2 is an upstream regulator of anteroposterior prepattern at an early stage. Mutants exhibit posteriorised limb bud identity. During later limb bud stages, Ezh2 is essential for cell survival and proximodistal segment elongation. Ezh2 maintains the late phase of Hox gene expression and cell transposition experiments suggest that it regulates the plasticity with which cells respond to instructive positional cues.
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Affiliation(s)
- Laurie A Wyngaarden
- Developmental and Stem Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
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11
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Marcon L, Arqués CG, Torres MS, Sharpe J. A computational clonal analysis of the developing mouse limb bud. PLoS Comput Biol 2011; 7:e1001071. [PMID: 21347315 PMCID: PMC3037386 DOI: 10.1371/journal.pcbi.1001071] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2010] [Accepted: 12/29/2010] [Indexed: 01/29/2023] Open
Abstract
A comprehensive spatio-temporal description of the tissue movements underlying organogenesis would be an extremely useful resource to developmental biology. Clonal analysis and fate mappings are popular experiments to study tissue movement during morphogenesis. Such experiments allow cell populations to be labeled at an early stage of development and to follow their spatial evolution over time. However, disentangling the cumulative effects of the multiple events responsible for the expansion of the labeled cell population is not always straightforward. To overcome this problem, we develop a novel computational method that combines accurate quantification of 2D limb bud morphologies and growth modeling to analyze mouse clonal data of early limb development. Firstly, we explore various tissue movements that match experimental limb bud shape changes. Secondly, by comparing computational clones with newly generated mouse clonal data we are able to choose and characterize the tissue movement map that better matches experimental data. Our computational analysis produces for the first time a two dimensional model of limb growth based on experimental data that can be used to better characterize limb tissue movement in space and time. The model shows that the distribution and shapes of clones can be described as a combination of anisotropic growth with isotropic cell mixing, without the need for lineage compartmentalization along the AP and PD axis. Lastly, we show that this comprehensive description can be used to reassess spatio-temporal gene regulations taking tissue movement into account and to investigate PD patterning hypothesis. A comprehensive mathematical description of the growth of an organ can be given by the velocity vectors defining the displacement of each tissue point in a fixed coordinate system plus a description of the degree of mixing between the cells. As an alternative to live imaging, a way to estimate the collection of such velocity vectors, known as velocity vector field, is to use cell-labeling experiments. However, this approach can be applied only when the labeled populations have been grown for small periods of time and the tensors of the velocity vector field can be estimated directly from the shape of the labeled population. Unfortunately, most of the available cell-labeling experiments of developmental systems have been generated considering a long clone expansion time that is more suitable for lineaging studies than for estimating velocity vector fields. In this study we present a new computational method that allows us to estimate the velocity vector field of limb tissue movement by using clonal data with long harvesting time and a sequence of experimental limb morphologies. The method results in the first realistic 2D model of limb outgrowth and establishes a powerful framework for numerical simulations of limb development.
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Affiliation(s)
- Luciano Marcon
- EMBL-CRG Systems Biology Research Unit, Center for Genomic Regulation (CRG), Universitat Pompeu Fabra, Barcelona, Spain
- * E-mail: (LM); (JS)
| | - Carlos G. Arqués
- Departamento de Biología del Desarrollo Cardiovascular, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Instituto de Salud Carlos III, Madrid, Spain
| | - Miguel S. Torres
- Departamento de Biología del Desarrollo Cardiovascular, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Instituto de Salud Carlos III, Madrid, Spain
| | - James Sharpe
- EMBL-CRG Systems Biology Research Unit, Center for Genomic Regulation (CRG), Universitat Pompeu Fabra, Barcelona, Spain
- ICREA Professor, Centre for Genomic Regulation (CRG), Universitat Pompeu Fabra, Barcelona, Spain
- * E-mail: (LM); (JS)
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