1
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Sharma V, Sachan N, Sarkar B, Mutsuddi M, Mukherjee A. E3 ubiquitin ligase Deltex facilitates the expansion of Wingless gradient and antagonizes Wingless signaling through a conserved mechanism of transcriptional effector Armadillo/β-catenin degradation. eLife 2024; 12:RP88466. [PMID: 38900140 PMCID: PMC11189633 DOI: 10.7554/elife.88466] [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] [Indexed: 06/21/2024] Open
Abstract
The Wnt/Wg pathway controls myriads of biological phenomena throughout the development and adult life of all organisms across the phyla. Thus, an aberrant Wnt signaling is associated with a wide range of pathologies in humans. Tight regulation of Wnt/Wg signaling is required to maintain proper cellular homeostasis. Here, we report a novel role of E3 ubiquitin ligase Deltex in Wg signaling regulation. Drosophila dx genetically interacts with wg and its pathway components. Furthermore, Dx LOF results in a reduced spreading of Wg while its over-expression expands the diffusion gradient of the morphogen. We attribute this change in Wg gradient to the endocytosis of Wg through Dx which directly affects the short- and long-range Wg targets. We also demonstrate the role of Dx in regulating Wg effector Armadillo where Dx down-regulates Arm through proteasomal degradation. We also showed the conservation of Dx function in the mammalian system where DTX1 is shown to bind with β-catenin and facilitates its proteolytic degradation, spotlighting a novel step that potentially modulates Wnt/Wg signaling cascade.
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Affiliation(s)
- Vartika Sharma
- Department of Molecular and Human Genetics, Institute of Science, Banaras Hindu UniversityVaranasiIndia
- Department of Integrative Biology and Physiology, University of California Los AngelesLos AngelesUnited States
| | - Nalani Sachan
- Department of Cell Biology, NYU Langone Medical CenterNew YorkUnited States
| | - Bappi Sarkar
- Department of Molecular and Human Genetics, Institute of Science, Banaras Hindu UniversityVaranasiIndia
| | - Mousumi Mutsuddi
- Department of Molecular and Human Genetics, Institute of Science, Banaras Hindu UniversityVaranasiIndia
| | - Ashim Mukherjee
- Department of Molecular and Human Genetics, Institute of Science, Banaras Hindu UniversityVaranasiIndia
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2
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Akiyama T, Raftery LA, Wharton KA. Bone morphogenetic protein signaling: the pathway and its regulation. Genetics 2024; 226:iyad200. [PMID: 38124338 PMCID: PMC10847725 DOI: 10.1093/genetics/iyad200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 10/27/2023] [Indexed: 12/23/2023] Open
Abstract
In the mid-1960s, bone morphogenetic proteins (BMPs) were first identified in the extracts of bone to have the remarkable ability to induce heterotopic bone. When the Drosophila gene decapentaplegic (dpp) was first identified to share sequence similarity with mammalian BMP2/BMP4 in the late-1980s, it became clear that secreted BMP ligands can mediate processes other than bone formation. Following this discovery, collaborative efforts between Drosophila geneticists and mammalian biochemists made use of the strengths of their respective model systems to identify BMP signaling components and delineate the pathway. The ability to conduct genetic modifier screens in Drosophila with relative ease was critical in identifying the intracellular signal transducers for BMP signaling and the related transforming growth factor-beta/activin signaling pathway. Such screens also revealed a host of genes that encode other core signaling components and regulators of the pathway. In this review, we provide a historical account of this exciting time of gene discovery and discuss how the field has advanced over the past 30 years. We have learned that while the core BMP pathway is quite simple, composed of 3 components (ligand, receptor, and signal transducer), behind the versatility of this pathway lies multiple layers of regulation that ensures precise tissue-specific signaling output. We provide a sampling of these discoveries and highlight many questions that remain to be answered to fully understand the complexity of BMP signaling.
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Affiliation(s)
- Takuya Akiyama
- Department of Biology, Rich and Robin Porter Cancer Research Center, The Center for Genomic Advocacy, Indiana State University, Terre Haute, IN 47809, USA
| | - Laurel A Raftery
- School of Life Sciences, University of Nevada, 4505 S. Maryland Parkway, Las Vegas, NV 89154, USA
| | - Kristi A Wharton
- Department of Molecular Biology, Cell Biology, and Biochemistry, Carney Institute for Brain Science, Brown University, Providence, RI 02912, USA
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3
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Simon N, Safyan A, Pyrowolakis G, Matsuda S. Dally is not essential for Dpp spreading or internalization but for Dpp stability by antagonizing Tkv-mediated Dpp internalization. eLife 2024; 12:RP86663. [PMID: 38265865 PMCID: PMC10945656 DOI: 10.7554/elife.86663] [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] [Indexed: 01/25/2024] Open
Abstract
Dpp/BMP acts as a morphogen to provide positional information in the Drosophila wing disc. Key cell-surface molecules to control Dpp morphogen gradient formation and signaling are heparan sulfate proteoglycans (HSPGs). In the wing disc, two HSPGs, the glypicans Division abnormally delayed (Dally) and Dally-like (Dlp) have been suggested to act redundantly to control these processes through direct interaction of their heparan sulfate (HS) chains with Dpp. Based on this assumption, a number of models on how glypicans control Dpp gradient formation and signaling have been proposed, including facilitating or hindering Dpp spreading, stabilizing Dpp on the cell surface, or recycling Dpp. However, how distinct HSPGs act remains largely unknown. Here, we generate genome-engineering platforms for the two glypicans and find that only Dally is critical for Dpp gradient formation and signaling through interaction of its core protein with Dpp. We also find that this interaction is not sufficient and that the HS chains of Dally are essential for these functions largely without interacting with Dpp. We provide evidence that the HS chains of Dally are not essential for spreading or recycling of Dpp but for stabilizing Dpp on the cell surface by antagonizing receptor-mediated Dpp internalization. These results provide new insights into how distinct HSPGs control morphogen gradient formation and signaling during development.
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Affiliation(s)
- Niklas Simon
- Growth & Development, Biozentrum, Spitalstrasse, University of BaselBaselSwitzerland
| | - Abu Safyan
- International Max Planck Research School for Immunobiology, Epigenetics, and MetabolismFreiburdGermany
- Institute for Biology I, Faculty of Biology, University of FreiburgFreiburgGermany
- CIBSS – Centre for Integrative Biological Signalling Studies, University of FreiburgFreiburgGermany
- BIOSS – Centre for Biological Signalling Studies, University of FreiburgFreiburgGermany
- Hilde Mangold Haus, University of FreiburgFreiburgGermany
| | - George Pyrowolakis
- Institute for Biology I, Faculty of Biology, University of FreiburgFreiburgGermany
- CIBSS – Centre for Integrative Biological Signalling Studies, University of FreiburgFreiburgGermany
- BIOSS – Centre for Biological Signalling Studies, University of FreiburgFreiburgGermany
- Hilde Mangold Haus, University of FreiburgFreiburgGermany
| | - Shinya Matsuda
- Growth & Development, Biozentrum, Spitalstrasse, University of BaselBaselSwitzerland
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4
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Mim MS, Knight C, Zartman JJ. Quantitative insights in tissue growth and morphogenesis with optogenetics. Phys Biol 2023; 20:061001. [PMID: 37678266 PMCID: PMC10594237 DOI: 10.1088/1478-3975/acf7a1] [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: 01/20/2023] [Revised: 08/15/2023] [Accepted: 09/07/2023] [Indexed: 09/09/2023]
Abstract
Cells communicate with each other to jointly regulate cellular processes during cellular differentiation and tissue morphogenesis. This multiscale coordination arises through the spatiotemporal activity of morphogens to pattern cell signaling and transcriptional factor activity. This coded information controls cell mechanics, proliferation, and differentiation to shape the growth and morphogenesis of organs. While many of the molecular components and physical interactions have been identified in key model developmental systems, there are still many unresolved questions related to the dynamics involved due to challenges in precisely perturbing and quantitatively measuring signaling dynamics. Recently, a broad range of synthetic optogenetic tools have been developed and employed to quantitatively define relationships between signal transduction and downstream cellular responses. These optogenetic tools can control intracellular activities at the single cell or whole tissue scale to direct subsequent biological processes. In this brief review, we highlight a selected set of studies that develop and implement optogenetic tools to unravel quantitative biophysical mechanisms for tissue growth and morphogenesis across a broad range of biological systems through the manipulation of morphogens, signal transduction cascades, and cell mechanics. More generally, we discuss how optogenetic tools have emerged as a powerful platform for probing and controlling multicellular development.
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Affiliation(s)
- Mayesha Sahir Mim
- Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, United States of America
| | - Caroline Knight
- Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, United States of America
| | - Jeremiah J Zartman
- Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, United States of America
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5
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Matsuda S, Schaefer JV, Mii Y, Hori Y, Bieli D, Taira M, Plückthun A, Affolter M. Asymmetric requirement of Dpp/BMP morphogen dispersal in the Drosophila wing disc. Nat Commun 2021; 12:6435. [PMID: 34750371 PMCID: PMC8576045 DOI: 10.1038/s41467-021-26726-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 10/20/2021] [Indexed: 11/26/2022] Open
Abstract
How morphogen gradients control patterning and growth in developing tissues remains largely unknown due to lack of tools manipulating morphogen gradients. Here, we generate two membrane-tethered protein binders that manipulate different aspects of Decapentaplegic (Dpp), a morphogen required for overall patterning and growth of the Drosophila wing. One is "HA trap" based on a single-chain variable fragment (scFv) against the HA tag that traps HA-Dpp to mainly block its dispersal, the other is "Dpp trap" based on a Designed Ankyrin Repeat Protein (DARPin) against Dpp that traps Dpp to block both its dispersal and signaling. Using these tools, we found that, while posterior patterning and growth require Dpp dispersal, anterior patterning and growth largely proceed without Dpp dispersal. We show that dpp transcriptional refinement from an initially uniform to a localized expression and persistent signaling in transient dpp source cells render the anterior compartment robust against the absence of Dpp dispersal. Furthermore, despite a critical requirement of dpp for the overall wing growth, neither Dpp dispersal nor direct signaling is critical for lateral wing growth after wing pouch specification. These results challenge the long-standing dogma that Dpp dispersal is strictly required to control and coordinate overall wing patterning and growth.
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Affiliation(s)
| | - Jonas V Schaefer
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Yusuke Mii
- National Institute for Basic Biology and Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Aichi, Japan
- JST PRESTO, Kawaguchi, Saitama, Japan
| | - Yutaro Hori
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, Japan
| | | | - Masanori Taira
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
- Department of Biological Sciences, Faculty of Science and Engineering, Chuo University, Tokyo, Japan
| | - Andreas Plückthun
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
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6
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Montanari MP, Tran NV, Shimmi O. Regulation of spatial distribution of BMP ligands for pattern formation. Dev Dyn 2021; 251:198-212. [PMID: 34241935 DOI: 10.1002/dvdy.397] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 06/15/2021] [Accepted: 07/05/2021] [Indexed: 12/25/2022] Open
Abstract
Bone morphogenetic proteins (BMPs), members of the transforming growth factor-ß (TGF-ß) family, have been shown to contribute to embryogenesis and organogenesis during animal development. Relevant studies provide support for the following concepts: (a) BMP signals are evolutionarily highly conserved as a genetic toolkit; (b) spatiotemporal distributions of BMP signals are precisely controlled at the post-translational level; and (c) the BMP signaling network has been co-opted to adapt to diversified animal development. These concepts originated from the historical findings of the Spemann-Mangold organizer and the subsequent studies about how this organizer functions at the molecular level. In this Commentary, we focus on two topics. First, we review how the BMP morphogen gradient is formed to sustain larval wing imaginal disc and early embryo growth and patterning in Drosophila. Second, we discuss how BMP signal is tightly controlled in a context-dependent manner, and how the signal and tissue dynamics are coupled to facilitate complex tissue structure formation. Finally, we argue how these concepts might be developed in the future for further understanding the significance of BMP signaling in animal development.
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Affiliation(s)
| | - Ngan Vi Tran
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Osamu Shimmi
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland.,Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
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7
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Zhang S, Zhao J, Lv X, Fan J, Lu Y, Zeng T, Wu H, Chen L, Zhao Y. Analysis on gene modular network reveals morphogen-directed development robustness in Drosophila. Cell Discov 2020; 6:43. [PMID: 32637151 PMCID: PMC7324402 DOI: 10.1038/s41421-020-0173-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 04/27/2020] [Indexed: 12/21/2022] Open
Abstract
Genetic robustness is an important characteristic to tolerate genetic or nongenetic perturbations and ensure phenotypic stability. Morphogens, a type of evolutionarily conserved diffusible molecules, govern tissue patterns in a direction-dependent or concentration-dependent manner by differentially regulating downstream gene expression. However, whether the morphogen-directed gene regulatory network possesses genetic robustness remains elusive. In the present study, we collected 4217 morphogen-responsive genes along A-P axis of Drosophila wing discs from the RNA-seq data, and clustered them into 12 modules. By applying mathematical model to the measured data, we constructed a gene modular network (GMN) to decipher the module regulatory interactions and robustness in morphogen-directed development. The computational analyses on asymptotical dynamics of this GMN demonstrated that this morphogen-directed GMN is robust to tolerate a majority of genetic perturbations, which has been further validated by biological experiments. Furthermore, besides the genetic alterations, we further demonstrated that this morphogen-directed GMN can well tolerate nongenetic perturbations (Hh production changes) via computational analyses and experimental validation. Therefore, these findings clearly indicate that the morphogen-directed GMN is robust in response to perturbations and is important for Drosophila to ensure the proper tissue patterning in wing disc.
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Affiliation(s)
- Shuo Zhang
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 200031 Shanghai, China
- University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Juan Zhao
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 200031 Shanghai, China
- CAS Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, 650223 Yunnan China
| | - Xiangdong Lv
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 200031 Shanghai, China
- University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Jialin Fan
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 200031 Shanghai, China
- University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Yi Lu
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 200031 Shanghai, China
| | - Tao Zeng
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 200031 Shanghai, China
- CAS Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, 650223 Yunnan China
| | - Hailong Wu
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 200031 Shanghai, China
| | - Luonan Chen
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 200031 Shanghai, China
- CAS Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, 650223 Yunnan China
- School of Life Science and Technology, ShanghaiTech University, 201210 Shanghai, China
- Key Laboratory of Systems Biology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Hangzhou, 310024 Zhejiang China
| | - Yun Zhao
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 200031 Shanghai, China
- School of Life Science and Technology, ShanghaiTech University, 201210 Shanghai, China
- School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024 Zhejiang China
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8
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Gordon NK, Chen Z, Gordon R, Zou Y. French flag gradients and Turing reaction-diffusion versus differentiation waves as models of morphogenesis. Biosystems 2020; 196:104169. [PMID: 32485350 DOI: 10.1016/j.biosystems.2020.104169] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 05/11/2020] [Accepted: 05/11/2020] [Indexed: 01/01/2023]
Abstract
The Turing reaction-diffusion model and the French Flag Model are widely accepted in the field of development as the best models for explaining embryogenesis. Virtually all current attempts to understand cell differentiation in embryos begin and end with the assumption that some combination of these two models works. The result may become a bias in embryogenesis in assuming the problem has been solved by these two-chemical substance-based models. Neither model is applied consistently. We review the differences between the French Flag, Turing reaction-diffusion model, and a mechanochemical model called the differentiation wave/cell state splitter model. The cytoskeletal cell state splitter and the embryonic differentiation waves was first proposed in 1987 as a combined physics and chemistry model for cell differentiation in embryos, based on empirical observations on urodele amphibian embryos. We hope that the development of theory can be advanced and observations relevant to distinguishing the embryonic differentiation wave model from the French Flag model and reaction-diffusion equations will be taken up by experimentalists. Experimentalists rely on mathematical biologists for theory, and therefore depend on them for what parameters they choose to measure and ignore. Therefore, mathematical biologists need to fully understand the distinctions between these three models.
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Affiliation(s)
| | - Zhan Chen
- Department of Mathematical Sciences, Georgia Southern University, Statesboro, GA, USA.
| | - Richard Gordon
- Gulf Specimen Marine Laboratory & Aquarium, 222 Clark Drive, Panacea, FL, 32346, USA; C.S. Mott Center for Human Growth & Development, Department of Obstetrics & Gynecology, Wayne State University, 275 E. Hancock, Detroit, MI, 48201, USA.
| | - Yuting Zou
- Department of Mathematical Sciences, Georgia Southern University, Statesboro, GA, USA.
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9
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Li Y, Zhang F, Jiang N, Liu T, Shen J, Zhang J. Decapentaplegic signaling regulates Wingless ligand production and target activation during
Drosophila
wing development. FEBS Lett 2020; 594:1176-1186. [DOI: 10.1002/1873-3468.13713] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 11/25/2019] [Accepted: 11/26/2019] [Indexed: 12/22/2022]
Affiliation(s)
- Yunlong Li
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management College of Plant Protection China Agricultural University Beijing China
| | - Fengchao Zhang
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management College of Plant Protection China Agricultural University Beijing China
| | - Na Jiang
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management College of Plant Protection China Agricultural University Beijing China
| | - Tong Liu
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management College of Plant Protection China Agricultural University Beijing China
| | - Jie Shen
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management College of Plant Protection China Agricultural University Beijing China
| | - Junzheng Zhang
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management College of Plant Protection China Agricultural University Beijing China
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10
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Marty F, Rago G, Smith DF, Gao X, Eijkel GB, MacAleese L, Bonn M, Brunner E, Basler K, Heeren RMA. Combining Time-of-Flight Secondary Ion Mass Spectrometry Imaging Mass Spectrometry and CARS Microspectroscopy Reveals Lipid Patterns Reminiscent of Gene Expression Patterns in the Wing Imaginal Disc of Drosophila melanogaster. Anal Chem 2017; 89:9664-9670. [PMID: 28727418 PMCID: PMC5607455 DOI: 10.1021/acs.analchem.7b00125] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
![]()
Using
label-free ToF-SIMS imaging mass spectrometry, we generated
a map of small molecules differentially expressed in the Drosophila wing imaginal disc. The distributions of these moieties were in
line with gene expression patterns observed during wing imaginal disc
development. Combining ToF-SIMS imaging and coherent anti-Stokes Raman
spectroscopy (CARS) microspectroscopy allowed us to locally identify
acylglycerols as the main constituents of the pattern differentiating
the future body wall tissue from the wing blade tissue. The findings
presented herein clearly demonstrate that lipid localization patterns
are strongly correlated with a developmental gene expression. From
this correlation, we hypothesize that lipids play a so far unrecognized
role in organ development.
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Affiliation(s)
- Florian Marty
- Institute of Molecular Life Sciences, University of Zürich , Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - Gianluca Rago
- FOM-Institute AMOLF , Science Park 104, 1098 XG Amsterdam, The Netherlands.,Max Planck Institute for Polymer Research , Ackermannweg 10, 55128 Mainz, Germany
| | - Donald F Smith
- FOM-Institute AMOLF , Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - Xiaoli Gao
- Institutional Mass Spectrometry Laboratory, The University of Texas Health Science Center at San Antonio , 8403 Floyd Curl Drive, MC-7760 San Antonio, Texas, United States
| | - Gert B Eijkel
- FOM-Institute AMOLF , Science Park 104, 1098 XG Amsterdam, The Netherlands.,The Maastricht Multimodal Molecular Imaging Institute, Maastricht University , Universiteitssingel 50, 6229 ER Maastricht, The Netherlands
| | - Luke MacAleese
- FOM-Institute AMOLF , Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - Mischa Bonn
- FOM-Institute AMOLF , Science Park 104, 1098 XG Amsterdam, The Netherlands.,Max Planck Institute for Polymer Research , Ackermannweg 10, 55128 Mainz, Germany
| | - Erich Brunner
- Institute of Molecular Life Sciences, University of Zürich , Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - Konrad Basler
- Institute of Molecular Life Sciences, University of Zürich , Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - Ron M A Heeren
- FOM-Institute AMOLF , Science Park 104, 1098 XG Amsterdam, The Netherlands.,The Maastricht Multimodal Molecular Imaging Institute, Maastricht University , Universiteitssingel 50, 6229 ER Maastricht, The Netherlands
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11
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Umetsu D, Kuranaga E. Planar polarized contractile actomyosin networks in dynamic tissue morphogenesis. Curr Opin Genet Dev 2017; 45:90-96. [PMID: 28419933 DOI: 10.1016/j.gde.2017.03.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 03/09/2017] [Accepted: 03/21/2017] [Indexed: 11/29/2022]
Abstract
The complex shapes of animal bodies are constructed through a sequence of simple physical interactions of constituent cells. Mechanical forces generated by cellular activities, such as division, death, shape change and rearrangement, drive tissue morphogenesis. By confining assembly or disassembly of actomyosin networks within the three-dimensional space of the cell, cells can localize forces to induce tissue deformation. Tissue-scale morphogenesis emerges from a collective behavior of cells that coordinates the force generation in space and time. Thus, the molecular mechanisms that govern the temporal and spatial regulation of forces in individual cells are elemental to organogenesis, and the tissue-scale coordination of forces generated by individual cells is key to determining the final shape of organs.
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Affiliation(s)
- Daiki Umetsu
- Laboratory of Histogenetic Dynamics, Graduate School of Life Sciences, Tohoku University, 6-3, Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Erina Kuranaga
- Laboratory of Histogenetic Dynamics, Graduate School of Life Sciences, Tohoku University, 6-3, Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan; Laboratory for Histogenetic Dynamics, RIKEN Center for Developmental Biology, 2-2-3, Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan.
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12
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Kiecker C, Graham A, Logan M. Differential Cellular Responses to Hedgehog Signalling in Vertebrates-What is the Role of Competence? J Dev Biol 2016; 4:jdb4040036. [PMID: 29615599 PMCID: PMC5831800 DOI: 10.3390/jdb4040036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Revised: 11/24/2016] [Accepted: 12/01/2016] [Indexed: 12/21/2022] Open
Abstract
A surprisingly small number of signalling pathways generate a plethora of cellular responses ranging from the acquisition of multiple cell fates to proliferation, differentiation, morphogenesis and cell death. These diverse responses may be due to the dose-dependent activities of signalling factors, or to intrinsic differences in the response of cells to a given signal—a phenomenon called differential cellular competence. In this review, we focus on temporal and spatial differences in competence for Hedgehog (HH) signalling, a signalling pathway that is reiteratively employed in embryos and adult organisms. We discuss the upstream signals and mechanisms that may establish differential competence for HHs in a range of different tissues. We argue that the changing competence for HH signalling provides a four-dimensional framework for the interpretation of the signal that is essential for the emergence of functional anatomy. A number of diseases—including several types of cancer—are caused by malfunctions of the HH pathway. A better understanding of what provides differential competence for this signal may reveal HH-related disease mechanisms and equip us with more specific tools to manipulate HH signalling in the clinic.
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Affiliation(s)
- Clemens Kiecker
- Department of Developmental Neurobiology, King's College London, Hodgkin Building, Guy's Hospital Campus, London SE1 1UL, UK.
| | - Anthony Graham
- Department of Developmental Neurobiology, King's College London, Hodgkin Building, Guy's Hospital Campus, London SE1 1UL, UK.
| | - Malcolm Logan
- Randall Division of Cell & Molecular Biophysics, King's College London, Hodgkin Building, Guy's Hospital Campus, London SE1 1UL, UK.
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13
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Darnell D, Gilbert SF. Neuroembryology. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2016; 6. [PMID: 27906497 DOI: 10.1002/wdev.215] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 08/25/2015] [Accepted: 09/03/2015] [Indexed: 11/10/2022]
Abstract
How is it that some cells become neurons? And how is it that neurons become organized in the spinal cord and brain to allow us to walk and talk, to see, recall events in our lives, feel pain, keep our balance, and think? The cells that are specified to form the brain and spinal cord are originally located on the outside surface of the embryo. They loop inward to form the neural tube in a process called neurulation. Structures that are nearby send signals to the posterior neural tube to form and pattern the spinal cord so that the dorsal side receives sensory input and the ventral side sends motor signals from neurons to muscles. In the brain, stem cells near the center of the neural tube migrate out to form a mantel zone, and a set of dividing cells from the mantle zone migrate further to produce a second set of neurons at the outer surface of the brain. These neurons will form the cerebral cortex, which contains six discrete layers. Each layer has different connections and different functions. WIREs Dev Biol 2017, 6:e215. doi: 10.1002/wdev.215 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Diana Darnell
- College of Medicine, University of Arizona, Tucson, AZ, USA
| | - Scott F Gilbert
- Swarthmore College, Swarthmore, PA, USA.,University of Helsinki, Helsinki, Finland
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14
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Abstract
The study of Drosophila imaginal discs has contributed to a number of discoveries in developmental and cellular biology. In addition to the elucidation of the role of tissue compartments and organ-specific master regulator genes during development, imaginal discs have also become well established as models for studying cellular interactions and complex genetic pathways. Here, we review key discoveries resulting from investigations of these epithelial precursor organs, ranging from cell fate determination and transdetermination to tissue patterning. Furthermore, the design of increasingly sophisticated genetic tools over the last decades has added value to the use of imaginal discs as model systems. As a result of tissue-specific genetic screens, several components of developmentally regulated signaling pathways were identified and epistasis revealed the levels at which they function. Discs have been widely used to assess cellular interactions in their natural tissue context, contributing to a better understanding of growth regulation, tissue regeneration, and cancer. With the continuous implementation of novel tools, imaginal discs retain significant potential as model systems to address emerging questions in biology and medicine.
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15
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16
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Control of organ growth by patterning and hippo signaling in Drosophila. Cold Spring Harb Perspect Biol 2015; 7:7/6/a019224. [PMID: 26032720 DOI: 10.1101/cshperspect.a019224] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Control of organ size is of fundamental importance and is controlled by genetic, environmental, and mechanical factors. Studies in many species have pointed to the existence of both organ-extrinsic and -intrinsic size-control mechanisms, which ultimately must coordinate to regulate organ size. Here, we discuss organ size control by organ patterning and the Hippo pathway, which both act in an organ-intrinsic fashion. The influence of morphogens and other patterning molecules couples growth and patterning, whereas emerging evidence suggests that the Hippo pathway controls growth in response to mechanical stimuli and signals emanating from cell-cell interactions. Several points of cross talk have been reported between signaling pathways that control organ patterning and the Hippo pathway, both at the level of membrane receptors and transcriptional regulators. However, despite substantial progress in the past decade, key questions in the growth-control field remain, including precisely how and when organ patterning and the Hippo pathway communicate to control size, and whether these communication mechanisms are organ specific or general. In addition, elucidating mechanisms by which organ-intrinsic cues, such as patterning factors and the Hippo pathway, interface with extrinsic cues, such as hormones to control organ size, remain unresolved.
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17
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Cell-intrinsic adaptation of lipid composition to local crowding drives social behaviour. Nature 2015; 523:88-91. [DOI: 10.1038/nature14429] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 03/25/2015] [Indexed: 12/20/2022]
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18
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The bHLH-PAS transcription factor dysfusion regulates tarsal joint formation in response to Notch activity during drosophila leg development. PLoS Genet 2014; 10:e1004621. [PMID: 25329825 PMCID: PMC4199481 DOI: 10.1371/journal.pgen.1004621] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 07/19/2014] [Indexed: 01/22/2023] Open
Abstract
A characteristic of all arthropods is the presence of flexible structures called joints that connect all leg segments. Drosophila legs include two types of joints: the proximal or "true" joints that are motile due to the presence of muscle attachment and the distal joints that lack musculature. These joints are not only morphologically, functionally and evolutionarily different, but also the morphogenetic program that forms them is distinct. Development of both proximal and distal joints requires Notch activity; however, it is still unknown how this pathway can control the development of such homologous although distinct structures. Here we show that the bHLH-PAS transcription factor encoded by the gene dysfusion (dys), is expressed and absolutely required for tarsal joint development while it is dispensable for proximal joints. In the presumptive tarsal joints, Dys regulates the expression of the pro-apoptotic genes reaper and head involution defective and the expression of the RhoGTPases modulators, RhoGEf2 and RhoGap71E, thus directing key morphogenetic events required for tarsal joint development. When ectopically expressed, dys is able to induce some aspects of the morphogenetic program necessary for distal joint development such as fold formation and programmed cell death. This novel Dys function depends on its obligated partner Tango to activate the transcription of target genes. We also identified a dedicated dys cis-regulatory module that regulates dys expression in the tarsal presumptive leg joints through direct Su(H) binding. All these data place dys as a key player downstream of Notch, directing distal versus proximal joint morphogenesis.
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19
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Yin H, Xiao X, Wen X, Zhou T. Mathematical analysis on a multidimensional model of morphogen transport with receptor synthesis. INT J BIOMATH 2014. [DOI: 10.1142/s179352451450051x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In biological development, morphogens are locally produced and spread to other regions in organs, forming gradients that control the inter-related pattern and growth of developing organs. Mechanisms of morphogen transport were built and investigated by numerical simulations in [A. D. Lander, Q. Nie and F. Y. M. Wan, Do morphogen gradients arise by diffusion? Developmental Cell2 (2002) 785–796]. In that paper, model C, which considers endocytosis, exocytosis and receptor synthesis and degradation, is in a one-dimensional spatial region and couples a partial differential equation with ordinary differential equations. Here, this model is promoted to an arbitrary dimension bounded region. We prove existence, uniqueness and non-negativity of a global solution for this advanced model, of its steady-state solution and linear stability of steady state by operator semigroup, the Schauder theorem and local perturbation method. Our results improve previous results for this model in a one dimension region.
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Affiliation(s)
- Hongwei Yin
- School of Science, Nanchang University, Nanchang 330031, P. R. China
| | - Xiaoyong Xiao
- School of Science, Nanchang University, Nanchang 330031, P. R. China
| | - Xiaoqing Wen
- School of Science, Nanchang University, Nanchang 330031, P. R. China
| | - Tianshou Zhou
- School of Mathematics and Computational Science, Sun Yat-Sen University, Guangzhou 510275, P. R. China
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Abstract
Autophagy is a highly conserved cytoplasmic degradation pathway that has an impact on many physiological and disease states, including immunity, tumorigenesis and neurodegeneration. Recent studies suggest that autophagy may also have important functions in embryogenesis and development. Many autophagy gene-knockout mice have embryonic lethality at different stages of development. Furthermore, interactions of autophagy with crucial developmental pathways such as Wnt, Shh (Sonic Hedgehog), TGFβ (transforming growth factor β) and FGF (fibroblast growth factor) have been reported. This suggests that autophagy may regulate cell fate decisions, such as differentiation and proliferation. In the present article, we discuss how mammalian autophagy may affect phenotypes associated with development.
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Yin H, Wen X, Zhou T. Local accumulation time for the formation of morphogen gradients from a Lévy diffusion process. Phys Biol 2013; 10:056012. [DOI: 10.1088/1478-3975/10/5/056012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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22
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The embryonic transcription factor Zelda of Drosophila melanogaster is also expressed in larvae and may regulate developmentally important genes. Biochem Biophys Res Commun 2013; 438:329-33. [PMID: 23891688 DOI: 10.1016/j.bbrc.2013.07.071] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2013] [Accepted: 07/17/2013] [Indexed: 11/20/2022]
Abstract
The transcription factor Zelda plays a pivotal role in promoting the maternal to zygotic transition during embryogenesis in Drosophila melanogaster. However, little is known about its role later in development. Here we are showing that Zelda is essential for proper wing development through gain and loss of function experiments. Zelda's transcript variants RB, RC and RD are present in imaginal wing discs of third instar larvae and the production of 2 protein isoforms of ∼180 and ∼70kD was detected in the same tissue. In ChIP experiments using larval wing discs, Zelda was found to bind to a region of the optomotor-blind gene, suggesting an interaction with a Dpp target that promotes wing growth and patterning.
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23
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Hadar N, Yaron S, Oren Z, Elly O, Itamar W, Johnathan G, Tama D, Offer G. A screen identifying genes responsive to Dpp and Wg signaling in the Drosophila developing wing. Gene 2012; 494:65-72. [DOI: 10.1016/j.gene.2011.11.047] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Accepted: 11/21/2011] [Indexed: 10/14/2022]
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24
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Raftery LA, Umulis DM. Regulation of BMP activity and range in Drosophila wing development. Curr Opin Cell Biol 2011; 24:158-65. [PMID: 22152945 DOI: 10.1016/j.ceb.2011.11.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 11/10/2011] [Accepted: 11/14/2011] [Indexed: 01/01/2023]
Abstract
Bone morphogenetic protein (BMP) signaling controls development and maintenance of many tissues. Genetic and quantitative approaches in Drosophila reveal that ligand isoforms show distinct function in wing development. Spatiotemporal control of BMP patterning depends on a network of extracellular proteins Pent, Ltl and Dally that regulate BMP signaling strength and morphogen range. BMP-mediated feedback regulation of Pent, Ltl, and Dally expression provides a system where cells actively respond to, and modify, the extracellular morphogen landscape to form a gradient that exhibits remarkable properties, including proportional scaling of BMP patterning with tissue size and the modulation of uniform tissue growth. This system provides valuable insights into mechanisms that mitigate the influence of variability to regulate cell-cell interactions and maintain organ function.
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Affiliation(s)
- Laurel A Raftery
- School of Life Sciences, University of Nevada, Las Vegas, NV 89154-4004, USA.
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25
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Drosophila IAP1-mediated ubiquitylation controls activation of the initiator caspase DRONC independent of protein degradation. PLoS Genet 2011; 7:e1002261. [PMID: 21909282 PMCID: PMC3164697 DOI: 10.1371/journal.pgen.1002261] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Accepted: 07/06/2011] [Indexed: 02/07/2023] Open
Abstract
Ubiquitylation targets proteins for proteasome-mediated degradation and plays important roles in many biological processes including apoptosis. However, non-proteolytic functions of ubiquitylation are also known. In Drosophila, the inhibitor of apoptosis protein 1 (DIAP1) is known to ubiquitylate the initiator caspase DRONC in vitro. Because DRONC protein accumulates in diap1 mutant cells that are kept alive by caspase inhibition (“undead” cells), it is thought that DIAP1-mediated ubiquitylation causes proteasomal degradation of DRONC, protecting cells from apoptosis. However, contrary to this model, we show here that DIAP1-mediated ubiquitylation does not trigger proteasomal degradation of full-length DRONC, but serves a non-proteolytic function. Our data suggest that DIAP1-mediated ubiquitylation blocks processing and activation of DRONC. Interestingly, while full-length DRONC is not subject to DIAP1-induced degradation, once it is processed and activated it has reduced protein stability. Finally, we show that DRONC protein accumulates in “undead” cells due to increased transcription of dronc in these cells. These data refine current models of caspase regulation by IAPs. The Drosophila inhibitor of apoptosis 1 (DIAP1) readily promotes ubiquitylation of the CASPASE-9–like initiator caspase DRONC in vitro and in vivo. Because DRONC protein accumulates in diap1 mutant cells that are kept alive by effector caspase inhibition—producing so-called “undead” cells—it has been proposed that DIAP1-mediated ubiquitylation would target full-length DRONC for proteasomal degradation, ensuring survival of normal cells. However, this has never been tested rigorously in vivo. By examining loss and gain of diap1 function, we show that DIAP1-mediated ubiquitylation does not trigger degradation of full-length DRONC. Our analysis demonstrates that DIAP1-mediated ubiquitylation controls DRONC processing and activation in a non-proteolytic manner. Interestingly, once DRONC is processed and activated, it has reduced protein stability. We also demonstrate that “undead” cells induce transcription of dronc, explaining increased protein levels of DRONC in these cells. This study re-defines the mechanism by which IAP-mediated ubiquitylation regulates caspase activity.
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26
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Flores-Otero J, Davis RL. Synaptic proteins are tonotopically graded in postnatal and adult type I and type II spiral ganglion neurons. J Comp Neurol 2011; 519:1455-75. [PMID: 21452215 DOI: 10.1002/cne.22576] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Inherent in the design of the mammalian auditory system is the precision necessary to transduce complex sounds and transmit the resulting electrical signals to higher neural centers. Unique specializations in the organ of Corti are required to make this conversion, such that mechanical and electrical properties of hair cell receptors are tailored to their specific role in signal coding. Electrophysiological and immunocytochemical characterizations have shown that this principle also applies to neurons of the spiral ganglion, as evidenced by distinctly different firing features and synaptic protein distributions of neurons that innervate high- and low-frequency regions of the cochlea. However, understanding the fine structure of how these properties are distributed along the cochlear partition and within the type I and type II classes of spiral ganglion neurons is necessary to appreciate their functional significance fully. To address this issue, we assessed the localization of the postsynaptic AMPA receptor subunits GluR2 and GluR3 and the presynaptic protein synaptophysin by using immunocytochemical labeling in both postnatal and adult tissue. We report that these presynaptic and postsynaptic proteins are distributed oppositely in relation to the tonotopic map and that they are equally distributed in each neuronal class, thus having an overall gradation from one end of the cochlea to the other. For synaptophysin, an additional layer of heterogeneity was superimposed orthogonal to the tonotopic axis. The highest anti-synaptophysin antibody levels were observed within neurons located close to the scala tympani compared with those located close to the scala vestibuli. Furthermore, we noted that the protein distribution patterns observed in postnatal preparations were largely retained in adult tissue sections, indicating that these features characterize spiral ganglion neurons in the fully developed ear.
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Affiliation(s)
- Jacqueline Flores-Otero
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, New Jersey 08854, USA
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27
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Berezhkovskii AM, Sample C, Shvartsman SY. Formation of morphogen gradients: local accumulation time. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 83:051906. [PMID: 21728570 PMCID: PMC4957404 DOI: 10.1103/physreve.83.051906] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 10/12/2010] [Indexed: 05/31/2023]
Abstract
Spatial regulation of cell differentiation in embryos can be provided by morphogen gradients, which are defined as the concentration fields of molecules that control gene expression. For example, a cell can use its surface receptors to measure the local concentration of an extracellular ligand and convert this information into a corresponding change in its transcriptional state. We characterize the time needed to establish a steady-state gradient in problems with diffusion and degradation of locally produced chemical signals. A relaxation function is introduced to describe how the morphogen concentration profile approaches its steady state. This function is used to obtain a local accumulation time that provides a time scale that characterizes relaxation to steady state at an arbitrary position within the patterned field. To illustrate the approach we derive local accumulation times for a number of commonly used models of morphogen gradient formation.
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Affiliation(s)
- Alexander M Berezhkovskii
- Mathematical and Statistical Computing Laboratory, Division of Computational Bioscience, Center for Information Technology, National Institutes of Health, Bethesda, Maryland 20892, USA
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28
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Schilling S, Willecke M, Aegerter-Wilmsen T, Cirpka OA, Basler K, von Mering C. Cell-sorting at the A/P boundary in the Drosophila wing primordium: a computational model to consolidate observed non-local effects of Hh signaling. PLoS Comput Biol 2011; 7:e1002025. [PMID: 21490725 PMCID: PMC3072364 DOI: 10.1371/journal.pcbi.1002025] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Accepted: 02/16/2011] [Indexed: 12/31/2022] Open
Abstract
Non-intermingling, adjacent populations of cells define compartment boundaries;
such boundaries are often essential for the positioning and the maintenance of
tissue-organizers during growth. In the developing wing primordium of
Drosophila melanogaster, signaling by the secreted protein
Hedgehog (Hh) is required for compartment boundary maintenance. However, the
precise mechanism of Hh input remains poorly understood. Here, we combine
experimental observations of perturbed Hh signaling with computer simulations of
cellular behavior, and connect physical properties of cells to their Hh
signaling status. We find that experimental disruption of Hh signaling has
observable effects on cell sorting surprisingly far from the compartment
boundary, which is in contrast to a previous model that confines Hh influence to
the compartment boundary itself. We have recapitulated our experimental
observations by simulations of Hh diffusion and transduction coupled to
mechanical tension along cell-to-cell contact surfaces. Intriguingly, the best
results were obtained under the assumption that Hh signaling cannot alter the
overall tension force of the cell, but will merely re-distribute it locally
inside the cell, relative to the signaling status of neighboring cells. Our
results suggest a scenario in which homotypic interactions of a putative Hh
target molecule at the cell surface are converted into a mechanical force. Such
a scenario could explain why the mechanical output of Hh signaling appears to be
confined to the compartment boundary, despite the longer range of the Hh
molecule itself. Our study is the first to couple a cellular vertex model
describing mechanical properties of cells in a growing tissue, to an explicit
model of an entire signaling pathway, including a freely diffusible component.
We discuss potential applications and challenges of such an approach. In developing animal tissues, cells can often re-arrange locally and mix
relatively freely. However, in some stereotypic and crucially important
instances during body development, cells will strictly not intermingle, and
instead form sharp boundaries along which they will sort out from each other.
This mechanism helps organisms to establish signaling centers and to maintain
distinct cellular identities. Often, cells at such boundaries will remain in
close physical contact and are morphologically alike. Thus, the boundary itself
can be difficult to observe unless the expression status of specific marker
genes is monitored experimentally. How are these ‘compartment
boundaries’ established? Here we devise a computational model that aims to
describe one such boundary in a well-studied animal tissue: the developing wing
primordium of Drosophila melanogaster. We model the production,
diffusion and local sensing of an essential signaling molecule, the
Hedgehog protein. We reveal one possible mechanism by which
Hedgehog sensing can influence the mechanical properties of cells, and compare
the simulated outcome to observations in experimentally perturbed, actual wing
discs. Our relatively simple model suffices to establish a straight and stable
compartment boundary.
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Affiliation(s)
- Sabine Schilling
- Institute of Molecular Life Sciences, University of Zurich, Zurich,
Switzerland
- Swiss Institute of Bioinformatics, University of Zurich, Zurich,
Switzerland
| | - Maria Willecke
- Institute of Molecular Life Sciences, University of Zurich, Zurich,
Switzerland
| | | | - Olaf A. Cirpka
- Center for Applied Geoscience, University of Tuebingen, Tuebingen,
Germany
| | - Konrad Basler
- Institute of Molecular Life Sciences, University of Zurich, Zurich,
Switzerland
| | - Christian von Mering
- Institute of Molecular Life Sciences, University of Zurich, Zurich,
Switzerland
- Swiss Institute of Bioinformatics, University of Zurich, Zurich,
Switzerland
- * E-mail:
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29
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Tortoriello G, de Celis JF, Furia M. Linking pseudouridine synthases to growth, development and cell competition. FEBS J 2010; 277:3249-63. [DOI: 10.1111/j.1742-4658.2010.07731.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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30
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Vicidomini R, Tortoriello G, Furia M, Polese G. Laser microdissection applied to gene expression profiling of subset of cells from the Drosophila wing disc. J Vis Exp 2010:1895. [PMID: 20436400 DOI: 10.3791/1895] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Heterogeneous nature of tissues has proven to be a limiting factor in the amount of information that can be generated from biological samples, compromising downstream analyses. Considering the complex and dynamic cellular associations existing within many tissues, in order to recapitulate the in vivo interactions thorough molecular analysis one must be able to analyze specific cell populations within their native context. Laser-mediated microdissection can achieve this goal, allowing unambiguous identification and successful harvest of cells of interest under direct microscopic visualization while maintaining molecular integrity. We have applied this technology to analyse gene expression within defined areas of the developing Drosophila wing disc, which represents an advantageous model system to study growth control, cell differentiation and organogenesis. Larval imaginal discs are precociously subdivided into anterior and posterior, dorsal and ventral compartments by lineage restriction boundaries. Making use of the inducible GAL4-UAS binary expression system, each of these compartments can be specifically labelled in transgenic flies expressing an UAS-GFP transgene under the control of the appropriate GAL4-driver construct. In the transgenic discs, gene expression profiling of discrete subsets of cells can precisely be determined after laser-mediated microdissection, using the fluorescent GFP signal to guide laser cut. Among the variety of downstream applications, we focused on RNA transcript profiling after localised RNA interference (RNAi). With the advent of RNAi technology, GFP labelling can be coupled with localised knockdown of a given gene, allowing to determinate the transcriptional response of a discrete cell population to the specific gene silencing. To validate this approach, we dissected equivalent areas of the disc from the posterior (labelled by GFP expression), and the anterior (unlabelled) compartment upon regional silencing in the P compartment of an otherwise ubiquitously expressed gene. RNA was extracted from microdissected silenced and unsilenced areas and comparative gene expression profiling determined by quantitative real-time RT-PCR. We show that this method can effectively be applied for accurate transcriptomics of subsets of cells within the Drosophila imaginal discs. Indeed, while massive disc preparation as source of RNA generally assumes cell homogeneity, it is well known that transcriptional expression can vary greatly within these structures in consequence of positional information. Using localized fluorescent GFP signal to guide laser cut, more accurate transcriptional analyses can be performed and profitably applied to disparate applications, including transcript profiling of distinct cell lineages within their native context.
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Affiliation(s)
- Rosario Vicidomini
- Dipartimento di Biologia Strutturale e Funzionale, Università di Napoli Federico II, Naples, Italy
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31
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Akiyama-Oda Y, Oda H. Cell migration that orients the dorsoventral axis is coordinated with anteroposterior patterning mediated by Hedgehog signaling in the early spider embryo. Development 2010; 137:1263-73. [PMID: 20332148 DOI: 10.1242/dev.045625] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The early embryo of the spider Achaearanea tepidariorum is emerging as a model for the simultaneous study of cell migration and pattern formation. A cell cluster internalized at the center of the radially symmetric germ disc expresses the evolutionarily conserved dorsal signal Decapentaplegic. This cell cluster migrates away from the germ disc center along the basal side of the epithelium to the germ disc rim. This cell migration is thought to be the symmetry-breaking event that establishes the orientation of the dorsoventral axis. In this study, knockdown of a patched homolog, At-ptc, that encodes a putative negative regulator of Hedgehog (Hh) signaling, prevented initiation of the symmetry-breaking cell migration. Knockdown of a smoothened homolog, At-smo, showed that Hh signaling inactivation also arrested the cells at the germ disc center, whereas moderate inactivation resulted in sporadic failure of cell migration termination at the germ disc rim. hh transcript expression patterns indicated that the rim and outside of the germ disc were the source of the Hh ligand. Analyses of patterning events suggested that in the germ disc, short-range Hh signal promotes anterior specification and long-range Hh signal represses caudal specification. Moreover, negative regulation of Hh signaling by At-ptc appears to be required for progressive derepression of caudal specification from the germ disc center. Cell migration defects caused by At-ptc and At-smo knockdown correlated with patterning defects in the germ disc epithelium. We propose that the cell migration crucial for dorsoventral axis orientation in Achaearanea is coordinated with anteroposterior patterning mediated by Hh signaling.
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32
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Mathematical Model of the Formation of Morphogen Gradients Through Membrane-Associated Non-receptors. Bull Math Biol 2009; 72:805-29. [DOI: 10.1007/s11538-009-9470-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Accepted: 10/12/2009] [Indexed: 10/20/2022]
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33
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Hamaratoglu F, Basler K, Affolter M. Confronting Morphogen Gradients: How Important Are They for Growth? Sci Signal 2009; 2:pe67. [DOI: 10.1126/scisignal.294pe67] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Fisun Hamaratoglu
- Biozentrum der Universität Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland
| | - Konrad Basler
- Institute of Molecular Biology, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - Markus Affolter
- Biozentrum der Universität Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland
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34
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Use of Gel-Assembly to Fabricate Multi-Component Molecular Gradient Layers and the Investigation of Structure and Electron Transport Therein. Chemphyschem 2009; 10:2212-6. [DOI: 10.1002/cphc.200900304] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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35
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Dpp of posterior origin patterns the proximal region of the wing. Mech Dev 2009; 126:99-106. [DOI: 10.1016/j.mod.2008.12.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2008] [Revised: 11/13/2008] [Accepted: 12/04/2008] [Indexed: 11/21/2022]
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36
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Hartmann B, Castelo R, Blanchette M, Boue S, Rio DC, Valcárcel J. Global analysis of alternative splicing regulation by insulin and wingless signaling in Drosophila cells. Genome Biol 2009; 10:R11. [PMID: 19178699 PMCID: PMC2687788 DOI: 10.1186/gb-2009-10-1-r11] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2008] [Revised: 12/23/2008] [Accepted: 01/29/2009] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Despite the prevalence and biological relevance of both signaling pathways and alternative pre-mRNA splicing, our knowledge of how intracellular signaling impacts on alternative splicing regulation remains fragmentary. We report a genome-wide analysis using splicing-sensitive microarrays of changes in alternative splicing induced by activation of two distinct signaling pathways, insulin and wingless, in Drosophila cells in culture. RESULTS Alternative splicing changes induced by insulin affect more than 150 genes and more than 50 genes are regulated by wingless activation. About 40% of the genes showing changes in alternative splicing also show regulation of mRNA levels, suggesting distinct but also significantly overlapping programs of transcriptional and post-transcriptional regulation. Distinct functional sets of genes are regulated by each pathway and, remarkably, a significant overlap is observed between functional categories of genes regulated transcriptionally and at the level of alternative splicing. Functions related to carbohydrate metabolism and cellular signaling are enriched among genes regulated by insulin and wingless, respectively. Computational searches identify pathway-specific sequence motifs enriched near regulated 5' splice sites. CONCLUSIONS Taken together, our data indicate that signaling cascades trigger pathway-specific and biologically coherent regulatory programs of alternative splicing regulation. They also reveal that alternative splicing can provide a novel molecular mechanism for crosstalk between different signaling pathways.
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Affiliation(s)
- Britta Hartmann
- Centre de Regulació Genòmica, Parc de Recerca Biomèdica de Barcelona, Dr Aiguader 88, Barcelona, Spain.
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37
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Geometric control of tissue morphogenesis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1793:903-10. [PMID: 19167433 DOI: 10.1016/j.bbamcr.2008.12.014] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2008] [Revised: 11/29/2008] [Accepted: 12/19/2008] [Indexed: 01/16/2023]
Abstract
Morphogenesis is the dynamic and regulated change in tissue form that leads to creation of the body plan and development of mature organs. Research over the past several decades has uncovered a multitude of genetic factors required for morphogenesis in animals. The behaviors of individual cells within a developing tissue are determined by combining these genetic signals with information from the surrounding microenvironment. At any point in time, the local microenvironment is influenced by macroscale tissue geometry, which sculpts long range signals by affecting gradients of morphogens and mechanical stresses. The geometry of a tissue thus acts as both a template and instructive cue for further morphogenesis.
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38
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Kataoka A, Shimogori T. Fgf8 controls regional identity in the developing thalamus. Development 2008; 135:2873-81. [DOI: 10.1242/dev.021618] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The vertebrate thalamus contains multiple sensory nuclei and serves as a relay station to receive sensory information and project to corresponding cortical areas. During development, the progenitor region of the diencephalon is divided into three parts, p1, p2 (presumptive thalamus) and p3, along its longitudinal axis. Besides the local expression of signaling molecules such as sonic hedgehog (Shh), Wnt proteins and Fgf8, the patterning mechanisms of the thalamic nuclei are largely unknown. Using mouse in utero electroporation to overexpress or inhibit endogenous Fgf8 at the diencephalic p2/p3 border, we revealed that it affected gene expression only in the p2 region without altering overall diencephalic size or the expression of other signaling molecules. We demonstrated that two distinctive populations in p2,which can be distinguished by Ngn2 and Mash1 in early embryonic diencephalon, are controlled by Fgf8 activity in complementary manner. Furthermore, we found that FGF activity shifts thalamic sensory nuclei on the A/P axis in postnatal brain. Moreover, gene expression analysis demonstrated that FGF signaling shifts prethalamic nuclei in complementary manner to the thalamic shift. These findings suggest conserved roles of FGF signaling in patterning along the A/P axis in CNS, and reveal mechanisms of nucleogenesis in the developing thalamus.
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Affiliation(s)
- Ayane Kataoka
- RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-Shi, Saitama 351-0198,Japan
| | - Tomomi Shimogori
- RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-Shi, Saitama 351-0198,Japan
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Liu YI, Chang MV, Li HE, Barolo S, Chang JL, Blauwkamp TA, Cadigan KM. The chromatin remodelers ISWI and ACF1 directly repress Wingless transcriptional targets. Dev Biol 2008; 323:41-52. [PMID: 18786525 DOI: 10.1016/j.ydbio.2008.08.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2008] [Revised: 08/01/2008] [Accepted: 08/09/2008] [Indexed: 02/05/2023]
Abstract
The highly conserved Wingless/Wnt signaling pathway controls many developmental processes by regulating the expression of target genes, most often through members of the TCF family of DNA-binding proteins. In the absence of signaling, many of these targets are silenced, by mechanisms involving TCFs that are not fully understood. Here we report that the chromatin remodeling proteins ISWI and ACF1 are required for basal repression of WG target genes in Drosophila. This regulation is not due to global repression by ISWI and ACF1 and is distinct from their previously reported role in chromatin assembly. While ISWI is localized to the same regions of Wingless target gene chromatin as TCF, we find that ACF1 binds much more broadly to target loci. This broad distribution of ACF1 is dependent on ISWI. ISWI and ACF1 are required for TCF binding to chromatin, while a TCF-independent role of ISWI-ACF1 in repression of Wingless targets is also observed. Finally, we show that Wingless signaling reduces ACF1 binding to WG targets, and ISWI and ACF1 regulate repression by antagonizing histone H4 acetylation. Our results argue that WG signaling activates target gene expression partly by overcoming the chromatin barrier maintained by ISWI and ACF1.
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Affiliation(s)
- Yan I Liu
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109-1048, USA
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40
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Nahmad M, Glass L, Abouheif E. The dynamics of developmental system drift in the gene network underlying wing polyphenism in ants: a mathematical model. Evol Dev 2008; 10:360-74. [DOI: 10.1111/j.1525-142x.2008.00244.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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41
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Ibañes M, Belmonte JCI. Theoretical and experimental approaches to understand morphogen gradients. Mol Syst Biol 2008; 4:176. [PMID: 18364710 PMCID: PMC2290935 DOI: 10.1038/msb.2008.14] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2007] [Accepted: 02/06/2008] [Indexed: 12/31/2022] Open
Abstract
Morphogen gradients, which specify different fates for cells in a direct concentration-dependent manner, are a highly influential framework in which pattern formation processes in developmental biology can be characterized. A common analysis approach is combining experimental and theoretical strategies, thereby fostering relevant data on the dynamics and transduction of gradients. The mechanisms of morphogen transport and conversion from graded information to binary responses are some of the topics on which these combined strategies have shed light. Herein, we review these data, emphasizing, on the one hand, how theoretical approaches have been helpful and, on the other hand, how these have been combined with experimental strategies. In addition, we discuss those cases in which gradient formation and gradient interpretation at the molecular and/or cellular level may influence each other within a mutual feedback loop. To understand this interplay and the features it yields, it becomes essential to take system-level approaches that combine experimental and theoretical strategies.
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Affiliation(s)
- Marta Ibañes
- Department of Estructura i Constituents de la Matèria, University of Barcelona, Barcelona, Spain
| | - Juan Carlos Izpisúa Belmonte
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
- Centre of Regenerative Medicine in Barcelona, Barcelona, Spain
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42
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Furrer MP, Vasenkova I, Kamiyama D, Rosado Y, Chiba A. Slit and Robo control the development of dendrites in Drosophila CNS. Development 2007; 134:3795-804. [PMID: 17933790 DOI: 10.1242/dev.02882] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The molecular mechanisms that generate dendrites in the CNS are poorly understood. The diffusible signal molecule Slit and the neuronally expressed receptor Robo mediate growth cone collapse in vivo. However, in cultured neurons, these molecules promote dendritic development. Here we examine the aCC motoneuron, one of the first CNS neurons to generate dendrites in Drosophila. Slit displays a dynamic concentration topography that prefigures aCC dendrogenesis. Genetic deletion of Slit leads to complete loss of aCC dendrites. Robo is cell-autonomously required in aCC motoneurons to develop dendrites. Our results demonstrate that Slit and Robo control the development of dendrites in the embryonic CNS.
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Affiliation(s)
- Marie-Pierre Furrer
- Department of Cell and Developmental Biology, University of Illinois, Urbana, IL 61801, USA
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43
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Abstract
Morphogenetic fields organize tissue morphology in the embryo. By analogy, morphostatic fields maintain normal cell behaviour and normal tissue microarchitecture in the adult. The most prominent feature of cancer is the disruption of tissue microarchitecture. Cancer occurs much more frequently when morphostatic influences fail (metaplasia) or at the junction of two different morphostatic fields. This Review will describe what we know about morphostats and morphostasis, discuss the evidence for the role of disruption of morphostasis in malignancy, and address some testable hypotheses.
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Affiliation(s)
- John D Potter
- Fred Hutchinson Cancer Research Center, P.O. Box 19024, M4-B814, Seattle, Washington 98109-1024, USA.
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44
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Singh A, Shi X, Choi KW. Lobe and Serrate are required for cell survival during early eye development in Drosophila. Development 2007; 133:4771-81. [PMID: 17090721 DOI: 10.1242/dev.02686] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Organogenesis involves an initial surge of cell proliferation, leading to differentiation. This is followed by cell death in order to remove extra cells. During early development, there is little or no cell death. However, there is a lack of information concerning the genes required for survival during the early cell-proliferation phase. Here, we show that Lobe (L) and the Notch (N) ligand Serrate (Ser), which are both involved in ventral eye growth, are required for cell survival in the early eye disc. We observed that the loss-of-ventral-eye phenotype in L or Ser mutants is due to the induction of cell death and the upregulation of secreted Wingless (Wg). This loss-of-ventral-eye phenotype can be rescued by (i) increasing the levels of cell death inhibitors, (ii) reducing the levels of Hid-Reaper-Grim complex, or (iii) reducing canonical Wg signaling components. Blocking Jun-N-terminal kinase (JNK) signaling, which can induce caspase-independent cell death, significantly rescued ventral eye loss in L or Ser mutants. However, blocking both caspase-dependent cell death and JNK signaling together showed stronger rescues of the L- or Ser-mutant eye at a 1.5-fold higher frequency. This suggests that L or Ser loss-of-function triggers both caspase-dependent and -independent cell death. Our studies thus identify a mechanism responsible for cell survival in the early eye.
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Affiliation(s)
- Amit Singh
- Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA.
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45
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Smith JD, Melhem ME, Magge KT, Waggoner AS, Campbell PG. Improved growth factor directed vascularization into fibrin constructs through inclusion of additional extracellular molecules. Microvasc Res 2007; 73:84-94. [PMID: 17223139 PMCID: PMC3013344 DOI: 10.1016/j.mvr.2006.10.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2006] [Revised: 09/08/2006] [Accepted: 10/05/2006] [Indexed: 11/18/2022]
Abstract
Using the chick chorioallantoic membrane assay (CAM) and a novel histological technique, we investigated the ability of blood vessels to directly invade fibrin-based scaffolds. In our initial experiments utilizing vascular endothelial growth factor (VEGF(165)), we found no direct invasion. Instead, the fibrin was completely degraded and replaced with highly vascularized new tissue. Addition of fibroblast growth factor-2 (FGF-2), bone morphogenic protein-2 (BMP-2), or platelet-derived growth factor-BB (PDGF-BB) to the fibrin construct also did not result in construct vascularization. Because natural and regenerating tissues exhibit complex extracellular matrices (ECMs), we hypothesized that a more complex scaffold may improve blood vessel invasion. Addition of fibronectin, hyaluronic acid, and collagen type I within 20 mg/mL fibrin constructs resulted in no significant improvement. However, the same additive concentrations within 10 mg/mL fibrin constructs resulted in dramatic improvements, specifically with hyaluronic acid. Overall, we believe that these results indicate the importance of structural and functional cues of not only in the initial scaffold but also as the construct is degraded and remodeled. Furthermore, the CAM assay may represent a useful model for understanding ECM interactions as well as for screening and designing tissue-engineered scaffolds.
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Affiliation(s)
- JD Smith
- Institute for Complex Engineered Systems, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, PA 15213
- Molecular Biosensor and Imaging Center Carnegie Mellon University, 4400 Fifth Ave., Pittsburgh, PA 15213
| | - ME Melhem
- Institute for Complex Engineered Systems, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, PA 15213
| | - KT Magge
- Institute for Complex Engineered Systems, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, PA 15213
| | - AS Waggoner
- Molecular Biosensor and Imaging Center Carnegie Mellon University, 4400 Fifth Ave., Pittsburgh, PA 15213
| | - PG Campbell
- Institute for Complex Engineered Systems, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, PA 15213
- Molecular Biosensor and Imaging Center Carnegie Mellon University, 4400 Fifth Ave., Pittsburgh, PA 15213
- Correspondence should be addressed to: Phil Campbell, Ph.D., 1212 Hamburg Hall, Institute for Complex Engineered Systems, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, PA, PA 15213, Phone: (412) 268-4126, Fax: (412) 268-5229,
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46
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Baker RE, Maini PK. A mechanism for morphogen-controlled domain growth. J Math Biol 2006; 54:597-622. [PMID: 17180375 DOI: 10.1007/s00285-006-0060-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2006] [Revised: 10/31/2006] [Indexed: 12/31/2022]
Abstract
Many developmental systems are organised via the action of graded distributions of morphogens. In the Drosophila wing disc, for example, recent experimental evidence has shown that graded expression of the morphogen Dpp controls cell proliferation and hence disc growth. Our goal is to explore a simple model for regulation of wing growth via the Dpp gradient: we use a system of reaction-diffusion equations to model the dynamics of Dpp and its receptor Tkv, with advection arising as a result of the flow generated by cell proliferation. We analyse the model both numerically and analytically, showing that uniform domain growth across the disc produces an exponentially growing wing disc.
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Affiliation(s)
- R E Baker
- Centre for Mathematical Biology, Mathematical Institute, 24-29 St Giles', Oxford, OX1 3LB, UK.
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47
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Nelson CM, VanDuijn MM, Inman JL, Fletcher DA, Bissell MJ. Tissue geometry determines sites of mammary branching morphogenesis in organotypic cultures. Science 2006; 314:298-300. [PMID: 17038622 PMCID: PMC2933179 DOI: 10.1126/science.1131000] [Citation(s) in RCA: 446] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The treelike structures of many organs, including the mammary gland, are generated by branching morphogenesis, a reiterative process of branch initiation and invasion from a preexisting epithelium. Using a micropatterning approach to control the initial three-dimensional structure of mouse mammary epithelial tubules in culture, combined with an algorithm to quantify the extent of branching, we found that the geometry of tubules dictates the position of branches. We predicted numerically and confirm experimentally that branches initiate at sites with a local minimum in the concentration of autocrine inhibitory morphogens, such as transforming growth factor-beta. These results reveal that tissue geometry can control organ morphogenesis by defining the local cellular microenvironment, a finding that has relevance to control of invasion and metastasis.
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Affiliation(s)
- Celeste M. Nelson
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- To whom correspondence should be addressed. (M.J.B.); (C.M.N.)
| | - Martijn M. VanDuijn
- Department of Bioengineering, University of California, Berkeley, CA 94720, USA
| | - Jamie L. Inman
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Daniel A. Fletcher
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Bioengineering, University of California, Berkeley, CA 94720, USA
| | - Mina J. Bissell
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- To whom correspondence should be addressed. (M.J.B.); (C.M.N.)
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48
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de Navas LF, Garaulet DL, Sánchez-Herrero E. The ultrabithorax Hox gene of Drosophila controls haltere size by regulating the Dpp pathway. Development 2006; 133:4495-506. [PMID: 17050628 DOI: 10.1242/dev.02609] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The halteres and wings of Drosophila are homologous thoracic appendages, which share common positional information provided by signaling pathways. The activity in the haltere discs of the Ultrabithorax (Ubx) Hox gene establishes the differences between these structures, their different size being an obvious one. We show here that Ubx regulates the activity of the Decapentaplegic (Dpp) signaling pathway at different levels, and that this regulation is instrumental in establishing the size difference. Ubx downregulates dpp transcription and reduces Dpp diffusion by repressing the expression of master of thick veins and division abnormally delayed and by increasing the levels of thick veins, one of the Dpp receptors. Our results suggest that modulation in Dpp expression and spread accounts, in part, for the different size of halteres and wings.
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Affiliation(s)
- Luis F de Navas
- Centro de Biología Molecular Severo Ochoa (C.S.I.C.-U.A.M.) Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
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49
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Ibañes M, Kawakami Y, Rasskin-Gutman D, Belmonte JCI. Cell lineage transport: a mechanism for molecular gradient formation. Mol Syst Biol 2006; 2:57. [PMID: 17047664 PMCID: PMC1682021 DOI: 10.1038/msb4100098] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2006] [Accepted: 08/18/2006] [Indexed: 12/02/2022] Open
Abstract
Gradient formation is a fundamental patterning mechanism during embryo development, commonly related to secreted proteins that move along an existing field of cells. Here, we mathematically address the feasibility of gradients of mRNAs and non-secreted proteins. We show that these gradients can arise in growing tissues whereby cells dilute and transport their molecular content as they divide and grow, a mechanism we termed ‘cell lineage transport.' We provide an experimental test by unveiling a distal-to-proximal gradient of Hoxd13 in the vertebrate developing limb bud driven by cell lineage transport, corroborating our model. Our study indicates that gradients of non-secreted molecules exhibit a power-law profile and can arise for a wide range of biologically relevant parameter values. Dilution and nonlinear growth confer robustness to the spatial gradient under changes in the cell cycle period, but at the expense of sensitivity in the timing of gradient formation. We expect that gradient formation driven by cell lineage transport will provide future insights into understanding the coordination between growth and patterning during embryonic development.
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Affiliation(s)
- Marta Ibañes
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Yasuhiko Kawakami
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Diego Rasskin-Gutman
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Juan Carlos Izpisúa Belmonte
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
- Center of Regenerative Medicine in Barcelona, Barcelona, Spain
- Gene Expression Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Rd, La Jolla, CA 92037, USA. Tel.: +1 8584534100x1130; Fax: +1 8584532573;
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50
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Joshi M, Buchanan KT, Shroff S, Orenic TV. Delta and Hairy establish a periodic prepattern that positions sensory bristles in Drosophila legs. Dev Biol 2006; 293:64-76. [PMID: 16542648 DOI: 10.1016/j.ydbio.2006.01.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2005] [Revised: 12/05/2005] [Accepted: 01/04/2006] [Indexed: 10/24/2022]
Abstract
In vertebrates and invertebrates, spatially defined proneural gene expression is an early and essential event in neuronal patterning. In this study, we investigate the mechanisms involved in establishing proneural gene expression in the primordia of a group of small mechanosensory bristles (microchaetae), which on the legs of the Drosophila adult are arranged in a series of longitudinal rows along the leg circumference. In prepupal legs, the proneural gene achaete (ac) is expressed in longitudinal stripes, which comprise the leg microchaete primordia. We have previously shown that periodic ac expression is partially established by the prepattern gene, hairy, which represses ac expression in four of eight interstripe domains. Here, we identify Delta (Dl), which encodes a Notch (N) ligand, as a second leg prepattern gene. We show that Hairy and Dl function concertedly and nonredundantly to define periodic ac expression. We also explore the regulation of periodic hairy expression. In prior studies, we have found that expression of two hairy stripes along the D/V axis is induced in response to the Hedgehog (Hh), Decapentaplegic (Dpp) and Wingless (Wg) morphogens. Here, we show that expression of two other hairy stripes along the orthogonal A/P axis is established through a distinct mechanism which involves uniform activation combined with repressive influences from Dpp and Wg. Our findings allow us to formulate a general model for generation of periodic pattern in the adult leg. This process involves broad and late activation of ac expression combined with refinement in response to a prepattern of repression, established by Hairy and Dl, which unfolds progressively during larval and early prepupal stages.
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Affiliation(s)
- Meghana Joshi
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
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