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Pulido Companys P, Norris A, Bischoff M. Coordination of cytoskeletal dynamics and cell behaviour during Drosophila abdominal morphogenesis. J Cell Sci 2020; 133:jcs235325. [PMID: 32229579 PMCID: PMC7132776 DOI: 10.1242/jcs.235325] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 01/20/2020] [Indexed: 12/20/2022] Open
Abstract
During morphogenesis, cells exhibit various behaviours, such as migration and constriction, which need to be coordinated. How this is achieved remains elusive. During morphogenesis of the Drosophila adult abdominal epidermis, larval epithelial cells (LECs) migrate directedly before constricting apically and undergoing apoptosis. Here, we study the mechanisms underlying the transition from migration to constriction. We show that LECs possess a pulsatile apical actomyosin network, and that a change in network polarity correlates with behavioural change. Exploring the properties of the contractile network, we find that cell contractility, as determined by myosin activity, has an impact on the behaviour of the network, as well as on cytoskeletal architecture and cell behaviour. Pulsed contractions occur only in cells with intermediate levels of contractility. Furthermore, increasing levels of the small Rho GTPase Rho1 disrupts pulsing, leading to cells that cycle between two states, characterised by a junctional cortical and an apicomedial actin network. Our results highlight that behavioural change relies on tightly controlled cellular contractility. Moreover, we show that constriction can occur without pulsing, raising questions why constricting cells pulse in some contexts but not in others.
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Affiliation(s)
- Pau Pulido Companys
- Biomedical Sciences Research Complex, University of St Andrews, North Haugh, St Andrews KY16 9ST, UK
| | - Anneliese Norris
- Biomedical Sciences Research Complex, University of St Andrews, North Haugh, St Andrews KY16 9ST, UK
| | - Marcus Bischoff
- Biomedical Sciences Research Complex, University of St Andrews, North Haugh, St Andrews KY16 9ST, UK
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52
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Kanca O, Bellen HJ. La CaSSA da Drosophila: A Versatile Expansion of the Tool Box. Neuron 2020; 104:177-179. [PMID: 31647888 DOI: 10.1016/j.neuron.2019.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In this issue of Neuron, Garcia-Marques et al. (2019) describe a new set of elegant tools based on the single strand annealing DNA repair system and CRISPR technology that provide many avenues for genetic and cellular manipulations.
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Affiliation(s)
- Oguz Kanca
- Department of Molecular and Human Genetics, BCM, Houston, TX, USA; Neurological Research Institute, TCH, Houston, TX, USA
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, BCM, Houston, TX, USA; Neurological Research Institute, TCH, Houston, TX, USA; Department of Neuroscience, BCM, Houston, TX, USA; Howard Hughes Medical Institute, BCM, Houston, TX, USA.
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53
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Bernasek SM, Peláez N, Carthew RW, Bagheri N, Amaral LAN. Fly-QMA: Automated analysis of mosaic imaginal discs in Drosophila. PLoS Comput Biol 2020; 16:e1007406. [PMID: 32126077 PMCID: PMC7100978 DOI: 10.1371/journal.pcbi.1007406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 03/27/2020] [Accepted: 01/27/2020] [Indexed: 12/01/2022] Open
Abstract
Mosaic analysis provides a means to probe developmental processes in situ by generating loss-of-function mutants within otherwise wildtype tissues. Combining these techniques with quantitative microscopy enables researchers to rigorously compare RNA or protein expression across the resultant clones. However, visual inspection of mosaic tissues remains common in the literature because quantification demands considerable labor and computational expertise. Practitioners must segment cell membranes or cell nuclei from a tissue and annotate the clones before their data are suitable for analysis. Here, we introduce Fly-QMA, a computational framework that automates each of these tasks for confocal microscopy images of Drosophila imaginal discs. The framework includes an unsupervised annotation algorithm that incorporates spatial context to inform the genetic identity of each cell. We use a combination of real and synthetic validation data to survey the performance of the annotation algorithm across a broad range of conditions. By contributing our framework to the open-source software ecosystem, we aim to contribute to the current move toward automated quantitative analysis among developmental biologists.
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Affiliation(s)
- Sebastian M. Bernasek
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, United States of America
- NSF-Simons Center for Quantitative Biology, Northwestern University, Evanston, Illinois, United States of America
| | - Nicolás Peláez
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Richard W. Carthew
- NSF-Simons Center for Quantitative Biology, Northwestern University, Evanston, Illinois, United States of America
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
- Department of Biochemistry and Molecular Genetics, Northwestern University, Evanston, Illinois, United States of America
| | - Neda Bagheri
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, United States of America
- NSF-Simons Center for Quantitative Biology, Northwestern University, Evanston, Illinois, United States of America
- Department of Biology, University of Washington, Seattle, Washington, United States of America
- Department of Chemical Engineering, University of Washington, Seattle, Washington, United States of America
- Northwestern Institute on Complex Systems, Northwestern University, Evanston, Illinois, United States of America
| | - Luís A. N. Amaral
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, United States of America
- NSF-Simons Center for Quantitative Biology, Northwestern University, Evanston, Illinois, United States of America
- Northwestern Institute on Complex Systems, Northwestern University, Evanston, Illinois, United States of America
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois, United States of America
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54
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tpHusion: An efficient tool for clonal pH determination in Drosophila. PLoS One 2020; 15:e0228995. [PMID: 32059043 PMCID: PMC7021318 DOI: 10.1371/journal.pone.0228995] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 01/27/2020] [Indexed: 02/04/2023] Open
Abstract
Genetically encoded pH indicators (GEpHI) have emerged as important tools for investigating intracellular pH (pHi) dynamics in Drosophila. However, most of the indicators are based on the Gal4/UAS binary expression system. Here, we report the generation of a ubiquitously-expressed GEpHI. The fusion protein of super ecliptic pHluorin and FusionRed was cloned under the tubulin promoter (tpHusion) to drive it independently of the Gal4/UAS system. The function of tpHusion was validated in various tissues from different developmental stages of Drosophila. Differences in pHi were also indicated correctly in fixed tissues. Finally, we describe the use of tpHusion for comparative analysis of pHi in manipulated clones and the surrounding cells in epithelial tissues. Our findings establish tpHusion as a robust tool for studying pHi in Drosophila.
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55
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Li Z, Guo X, Huang H, Wang C, Yang F, Zhang Y, Wang J, Han L, Jin Z, Cai T, Xi R. A Switch in Tissue Stem Cell Identity Causes Neuroendocrine Tumors in Drosophila Gut. Cell Rep 2020; 30:1724-1734.e4. [DOI: 10.1016/j.celrep.2020.01.041] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 11/15/2019] [Accepted: 01/13/2020] [Indexed: 12/12/2022] Open
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56
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Role of Notch Signaling in Leg Development in Drosophila melanogaster. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1218:103-127. [PMID: 32060874 DOI: 10.1007/978-3-030-34436-8_7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Notch pathway plays diverse and fundamental roles during animal development. One of the most relevant, which arises directly from its unique mode of activation, is the specification of cell fates and tissue boundaries. The development of the leg of Drosophila melanogaster is a fine example of this Notch function, as it is required to specify the fate of the cells that will eventually form the leg joints, the flexible structures that separate the different segments of the adult leg. Notch activity is accurately activated and maintained at the distal end of each segment in response to the proximo-distal patterning gene network of the developing leg. Region-specific downstream targets of Notch in turn regulate the formation of the different types of joints. We discuss recent findings that shed light on the molecular and cellular mechanisms that are ultimately governed by Notch to achieve epithelial fold and joint morphogenesis. Finally, we briefly summarize the role that Notch plays in inducing the nonautonomous growth of the leg. Overall, this book chapter aims to highlight leg development as a useful model to study how patterning information is translated into specific cell behaviors that shape the final form of an adult organ.
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57
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Heingård M, Turetzek N, Prpic NM, Janssen R. FoxB, a new and highly conserved key factor in arthropod dorsal-ventral (DV) limb patterning. EvoDevo 2019; 10:28. [PMID: 31728178 PMCID: PMC6842170 DOI: 10.1186/s13227-019-0141-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 10/16/2019] [Indexed: 12/25/2022] Open
Abstract
Forkhead box (Fox) transcription factors evolved early in animal evolution and represent important components of conserved gene regulatory networks (GRNs) during animal development. Most of the researches concerning Fox genes, however, are on vertebrates and only a relatively low number of studies investigate Fox gene function in invertebrates. In addition to this shortcoming, the focus of attention is often restricted to a few well-characterized Fox genes such as FoxA (forkhead), FoxC (crocodile) and FoxQ2. Although arthropods represent the largest and most diverse animal group, most other Fox genes have not been investigated in detail, not even in the arthropod model species Drosophila melanogaster. In a general gene expression pattern screen for panarthropod Fox genes including the red flour beetle Tribolium castaneum, the pill millipede Glomeris marginata, the common house spider Parasteatoda tepidariorum, and the velvet worm Euperipatoides kanangrensis, we identified a Fox gene with a highly conserved expression pattern along the ventral ectoderm of arthropod and onychophoran limbs. Functional investigation of FoxB in Parasteatoda reveals a hitherto unrecognized important function of FoxB upstream of wingless (wg) and decapentaplegic (dpp) in the GRN orchestrating dorsal–ventral limb patterning.
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Affiliation(s)
- Miriam Heingård
- 1Department of Earth Sciences, Palaeobiology, Uppsala University, Villavägen 16, Uppsala, Sweden.,4Present Address: Department of Geology, Faculty of Science, Lund University, Sölvegatan 12, Lund, Sweden
| | - Natascha Turetzek
- 2Abteilung für Entwicklungsbiologie, Johann-Friedrich-Blumenbach-Institut für Zoologie und Anthropologie, Georg-August-Universität, Göttingen, Germany.,Present Address: Göttingen Center for Molecular Biosciences (GZMB), Ernst-Caspari-Haus, Göttingen, Germany
| | - Nikola-Michael Prpic
- 2Abteilung für Entwicklungsbiologie, Johann-Friedrich-Blumenbach-Institut für Zoologie und Anthropologie, Georg-August-Universität, Göttingen, Germany.,5Present Address: Bereich Allgemeine Zoologie und Entwicklungsbiologie, Institut für Allgemeine und Spezielle Zoologie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 38, 35392 Gießen, Germany
| | - Ralf Janssen
- 1Department of Earth Sciences, Palaeobiology, Uppsala University, Villavägen 16, Uppsala, Sweden
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58
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Expression-Based Cell Lineage Analysis in Drosophila Through a Course-Based Research Experience for Early Undergraduates. G3-GENES GENOMES GENETICS 2019; 9:3791-3800. [PMID: 31690598 PMCID: PMC6829132 DOI: 10.1534/g3.119.400541] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A variety of genetic techniques have been devised to determine cell lineage relationships during tissue development. Some of these systems monitor cell lineages spatially and/or temporally without regard to gene expression by the cells, whereas others correlate gene expression with the lineage under study. The GAL4 Technique for Real-time and Clonal Expression (G-TRACE) system allows for rapid, fluorescent protein-based visualization of both current and past GAL4 expression patterns and is therefore amenable to genome-wide expression-based lineage screens. Here we describe the results from such a screen, performed by undergraduate students of the University of California, Los Angeles (UCLA) Undergraduate Research Consortium for Functional Genomics (URCFG) and high school summer scholars as part of a discovery-based education program. The results of the screen, which reveal novel expression-based lineage patterns within the brain, the imaginal disc epithelia, and the hematopoietic lymph gland, have been compiled into the G-TRACE Expression Database (GED), an online resource for use by the Drosophila research community. The impact of this discovery-based research experience on student learning gains was assessed independently and shown to be greater than that of similar programs conducted elsewhere. Furthermore, students participating in the URCFG showed considerably higher STEM retention rates than UCLA STEM students that did not participate in the URCFG, as well as STEM students nationwide.
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59
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Transgenic Analyses in Drosophila Reveal That mCORL1 Is Functionally Distinct from mCORL2 and dCORL. G3-GENES GENOMES GENETICS 2019; 9:3781-3789. [PMID: 31530634 PMCID: PMC6829133 DOI: 10.1534/g3.119.400647] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Uncovering how new members of multigene families acquire new functions is an important topic in evolutionary and developmental genetics. CORL proteins (SKOR in mice, Fussel in humans and fussel in Flybase) are a family of CNS specific proteins related to mammalian Sno/Ski oncogenes. Drosophila CORL (dCORL) participates in TGF-β and insulin signaling during development and in adult homeostasis but roles for the two mouse CORL proteins (mCORL) are essentially unknown. A series of studies were conducted to test the hypothesis based on previous results that mCORL1 is more similar to dCORL than mCORL2. Neither an updated alignment nor ectopic expression in adult wings were able to distinguish mCORL1 or mCORL2 from dCORL. Transgene experiments employing a dCORL endogenous function in mushroom body neurons showed that mCORL1 is distinct from mCORL2 and dCORL. mCORL1 and mCORL2 are also distinct in biochemical assays of Smad-binding and BMP signaling. Taken together, the data suggests testable new hypotheses for mCORL2 function in mammalian TGF-β and insulin signaling based on known roles for dCORL. Overall, the study reiterates the value of transgenic methods in Drosophila to provide new information on multigene family evolution and the function of family members in other species.
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60
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Garcia-Marques J, Yang CP, Espinosa-Medina I, Mok K, Koyama M, Lee T. Unlimited Genetic Switches for Cell-Type-Specific Manipulation. Neuron 2019; 104:227-238.e7. [PMID: 31395429 DOI: 10.1016/j.neuron.2019.07.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 06/11/2019] [Accepted: 07/03/2019] [Indexed: 01/23/2023]
Abstract
Gaining independent genetic access to discrete cell types is critical to interrogate their biological functions as well as to deliver precise gene therapy. Transcriptomics has allowed us to profile cell populations with extraordinary precision, revealing that cell types are typically defined by a unique combination of genetic markers. Given the lack of adequate tools to target cell types based on multiple markers, most cell types remain inaccessible to genetic manipulation. Here we present CaSSA, a platform to create unlimited genetic switches based on CRISPR/Cas9 (Ca) and the DNA repair mechanism known as single-strand annealing (SSA). CaSSA allows engineering of independent genetic switches, each responding to a specific gRNA. Expressing multiple gRNAs in specific patterns enables multiplex cell-type-specific manipulations and combinatorial genetic targeting. CaSSA is a new genetic tool that conceptually works as an unlimited number of recombinases and will facilitate genetic access to cell types in diverse organisms.
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Affiliation(s)
- Jorge Garcia-Marques
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Ching-Po Yang
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | | | - Kent Mok
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Minoru Koyama
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Tzumin Lee
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA.
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61
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Held LI, Sessions SK. Reflections on Bateson's rule: Solving an old riddle about why extra legs are mirror‐symmetric. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2019; 332:219-237. [DOI: 10.1002/jez.b.22910] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 08/18/2019] [Accepted: 09/26/2019] [Indexed: 12/17/2022]
Affiliation(s)
- Lewis I. Held
- Department of Biological SciencesTexas Tech University Lubbock Texas
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62
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Exocyst-mediated apical Wg secretion activates signaling in the Drosophila wing epithelium. PLoS Genet 2019; 15:e1008351. [PMID: 31527874 PMCID: PMC6764796 DOI: 10.1371/journal.pgen.1008351] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 09/27/2019] [Accepted: 08/07/2019] [Indexed: 01/19/2023] Open
Abstract
Wnt proteins are secreted signaling factors that regulate cell fate specification and patterning decisions throughout the animal kingdom. In the Drosophila wing epithelium, Wingless (Wg, the homolog of Wnt1) is secreted from a narrow strip of cells at the dorsal-ventral boundary. However, the route of Wg secretion in polarized epithelial cells remains poorly understood and key proteins involved in this process are still unknown. Here, we performed an in vivo RNAi screen and identified members of the exocyst complex to be required for apical but not basolateral Wg secretion. Specifically blocking the apical Wg secretion leads to reduced downstream signaling. Using an in vivo ‘temporal-rescue’ assay, our results further indicate that apically secreted Wg activates target genes that require high signaling activity. In conclusion, our results demonstrate that the exocyst is required for an apical route of Wg secretion from polarized wing epithelial cells. Regulation of Wnt signaling and the production of Wnt ligands is crucial for proper development and homeostasis, as dysregulation leads to developmental defects and diseases such as cancer. This study addresses the question of how functional Wnt ligands are secreted by epithelial cells. By using the polarized epithelium of the developing Drosophila wing as a model system to study Wnt/Wg secretion, the authors performed a large-scale RNAi screen and identified proteins of the exocyst complex to be required for Wnt signaling. The study shows that exocyst complex preferentially regulates apical secretion of Wg proteins. Taken together, this study identifies routes and regulators for secretion of signaling-active Wnt proteins from polarized epithelial cells.
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63
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Thuveson M, Gaengel K, Collu GM, Chin ML, Singh J, Mlodzik M. Integrins are required for synchronous ommatidial rotation in the Drosophila eye linking planar cell polarity signalling to the extracellular matrix. Open Biol 2019; 9:190148. [PMID: 31409231 PMCID: PMC6731590 DOI: 10.1098/rsob.190148] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Integrins mediate the anchorage between cells and their environment, the extracellular matrix (ECM), and form transmembrane links between the ECM and the cytoskeleton, a conserved feature throughout development and morphogenesis of epithelial organs. Here, we demonstrate that integrins and components of the ECM are required during the planar cell polarity (PCP) signalling-regulated cell movement of ommatidial rotation in the Drosophila eye. The loss-of-function mutations of integrins or ECM components cause defects in rotation, with mutant clusters rotating asynchronously compared to wild-type clusters. Initially, mutant clusters tend to rotate faster, and at later stages they fail to be synchronous with their neighbours, leading to aberrant rotation angles and resulting in a disorganized ommatidial arrangement in adult eyes. We further demonstrate that integrin localization changes dynamically during the rotation process. Our data suggest that core Frizzled/PCP factors, acting through RhoA and Rho kinase, regulate the function/activity of integrins and that integrins thus contribute to the complex interaction network of PCP signalling, cell adhesion and cytoskeletal elements required for a precise and synchronous 90° rotation movement.
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Affiliation(s)
- Maria Thuveson
- Department of Cell, Developmental and Regenerative Biology and Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, Annenberg Building 18-92, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Konstantin Gaengel
- Department of Cell, Developmental and Regenerative Biology and Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, Annenberg Building 18-92, One Gustave L. Levy Place, New York, NY 10029, USA.,Department of Immunology, Genetics and Pathology, Uppsala University, Rudbeck Laboratory C11, Dag Hammarskjölds Väg 20, 751 85 Uppsala, Sweden
| | - Giovanna M Collu
- Department of Cell, Developmental and Regenerative Biology and Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, Annenberg Building 18-92, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Mei-Ling Chin
- Department of Cell, Developmental and Regenerative Biology and Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, Annenberg Building 18-92, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Jaskirat Singh
- Department of Cell, Developmental and Regenerative Biology and Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, Annenberg Building 18-92, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Marek Mlodzik
- Department of Cell, Developmental and Regenerative Biology and Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, Annenberg Building 18-92, One Gustave L. Levy Place, New York, NY 10029, USA
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64
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Chaudhary V, Hingole S, Frei J, Port F, Strutt D, Boutros M. Robust Wnt signaling is maintained by a Wg protein gradient and Fz2 receptor activity in the developing Drosophila wing. Development 2019; 146:dev174789. [PMID: 31399474 PMCID: PMC6703709 DOI: 10.1242/dev.174789] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Accepted: 07/10/2019] [Indexed: 12/19/2022]
Abstract
Wnts are secreted proteins that regulate cell fate during development of all metazoans. Wnt proteins were proposed to spread over several cells to activate signaling directly at a distance. In the Drosophila wing epithelium, an extracellular gradient of the Wnt1 homolog Wingless (Wg) was observed extending over several cells away from producing cells. Surprisingly, however, it was also shown that a membrane-tethered Neurotactin-Wg fusion protein (NRT-Wg) can largely replace endogenous Wg, leading to proper patterning of the wing. Therefore, the functional range of Wg and whether Wg spreading is required for correct tissue patterning remains controversial. Here, by capturing secreted Wg on cells away from the source, we show that Wg acts over a distance of up to 11 cell diameters to induce signaling. Furthermore, cells located outside the reach of extracellular Wg depend on the Frizzled2 receptor to maintain signaling. Frizzled2 expression is increased in the absence of Wg secretion and is required to maintain signaling and cell survival in NRT-wg wing discs. Together, these results provide insight into the mechanisms by which robust Wnt signaling is achieved in proliferating tissues.
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Affiliation(s)
- Varun Chaudhary
- German Cancer Research Center (DKFZ), Division Signaling and Functional Genomics and Department of Cell and Molecular Biology, Medical Faculty Mannheim, Heidelberg University, Im Neuenheimer Feld 580, 69120 Heidelberg, Germany
- Department of Biological Science, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462066, India
| | - Swapnil Hingole
- Department of Biological Science, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462066, India
| | - Jana Frei
- German Cancer Research Center (DKFZ), Division Signaling and Functional Genomics and Department of Cell and Molecular Biology, Medical Faculty Mannheim, Heidelberg University, Im Neuenheimer Feld 580, 69120 Heidelberg, Germany
| | - Fillip Port
- German Cancer Research Center (DKFZ), Division Signaling and Functional Genomics and Department of Cell and Molecular Biology, Medical Faculty Mannheim, Heidelberg University, Im Neuenheimer Feld 580, 69120 Heidelberg, Germany
| | - David Strutt
- Department of Biomedical Science, University of Sheffield, Sheffield S10 2TN, UK
| | - Michael Boutros
- German Cancer Research Center (DKFZ), Division Signaling and Functional Genomics and Department of Cell and Molecular Biology, Medical Faculty Mannheim, Heidelberg University, Im Neuenheimer Feld 580, 69120 Heidelberg, Germany
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65
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Lybrand DB, Naiman M, Laumann JM, Boardman M, Petshow S, Hansen K, Scott G, Wehrli M. Destruction complex dynamics: Wnt/β-catenin signaling alters Axin-GSK3β interactions in vivo. Development 2019; 146:dev164145. [PMID: 31189665 PMCID: PMC6633605 DOI: 10.1242/dev.164145] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 06/05/2019] [Indexed: 01/20/2023]
Abstract
The central regulator of the Wnt/β-catenin pathway is the Axin/APC/GSK3β destruction complex (DC), which, under unstimulated conditions, targets cytoplasmic β-catenin for degradation. How Wnt activation inhibits the DC to permit β-catenin-dependent signaling remains controversial, in part because the DC and its regulation have never been observed in vivo Using bimolecular fluorescence complementation (BiFC) methods, we have now analyzed the activity of the DC under near-physiological conditions in Drosophila By focusing on well-established patterns of Wnt/Wg signaling in the developing Drosophila wing, we have defined the sequence of events by which activated Wnt receptors induce a conformational change within the DC, resulting in modified Axin-GSK3β interactions that prevent β-catenin degradation. Surprisingly, the nucleus is surrounded by active DCs, which principally control the degradation of β-catenin and thereby nuclear access. These DCs are inactivated and removed upon Wnt signal transduction. These results suggest a novel mechanistic model for dynamic Wnt signal transduction in vivo.
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Affiliation(s)
- Daniel B Lybrand
- Dept. of Integrative Biosciences, School of Dentistry, Oregon Health and Science University, Portland, OR 97239, USA
- Reed College, Portland, OR 97202, USA
| | - Misha Naiman
- Dept. of Integrative Biosciences, School of Dentistry, Oregon Health and Science University, Portland, OR 97239, USA
- Reed College, Portland, OR 97202, USA
| | - Jessie May Laumann
- Dept. of Integrative Biosciences, School of Dentistry, Oregon Health and Science University, Portland, OR 97239, USA
| | - Mitzi Boardman
- Dept. of Integrative Biosciences, School of Dentistry, Oregon Health and Science University, Portland, OR 97239, USA
| | - Samuel Petshow
- Dept. of Integrative Biosciences, School of Dentistry, Oregon Health and Science University, Portland, OR 97239, USA
| | - Kevin Hansen
- Dept. of Integrative Biosciences, School of Dentistry, Oregon Health and Science University, Portland, OR 97239, USA
| | - Gregory Scott
- Dept. of Integrative Biosciences, School of Dentistry, Oregon Health and Science University, Portland, OR 97239, USA
| | - Marcel Wehrli
- Dept. of Integrative Biosciences, School of Dentistry, Oregon Health and Science University, Portland, OR 97239, USA
- Knight Cancer Institute, Portland, OR 97239, USA
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66
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Morata G, Calleja M. Cell competition and tumorigenesis in the imaginal discs of Drosophila. Semin Cancer Biol 2019; 63:19-26. [PMID: 31255773 DOI: 10.1016/j.semcancer.2019.06.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 06/14/2019] [Accepted: 06/19/2019] [Indexed: 12/20/2022]
Abstract
Cancer is a major health issue and the object of investigations in thousands of laboratories all over the world. Most of cancer research is being carried out in in vitro systems or in animal models, generally mice or rats. However, the discovery of the high degree of genetic identity among metazoans has prompted investigation in organisms like Drosophila, on the idea that the genetic basis of cancer in flies and humans may have many aspects in common. Moreover, the sophisticated genetic methodology of Drosophila offers operational advantages and allows experimental approaches inaccessible in other species. Cell competition is a cell-quality control process that aims to identifying and subsequently removing cells within animal tissues that are unfit, abnormal or aberrant, and that may compromise the fitness or the viability of the organism. It was originally described in Drosophila imaginal discs but later work has shown it occurs in mammalian tissues where it fulfils similar roles. One aspect of the surveillance role of cell competition is to eliminate oncogenic cells that may appear during development or the life of an organism. In this review we have focussed on the work on Drosophila imaginal discs relating cell competition and tumorigenic processes. We briefly discuss related work in mammalian tissues.
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Affiliation(s)
- Ginés Morata
- Centro de Biología Molecular, CSIC-UAM, Nicolas Cabrera 1, Madrid, 28049, Spain.
| | - Manuel Calleja
- Centro de Biología Molecular, CSIC-UAM, Nicolas Cabrera 1, Madrid, 28049, Spain
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67
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Sánchez-Aragón M, Cantisán-Gómez J, Luque CM, Brás-Pereira C, Lopes CS, Lemos MC, Casares F. A Toggle-Switch and a Feed-Forward Loop Engage in the Control of the Drosophila Retinal Determination Gene Network. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
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68
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Tian A, Duwadi D, Benchabane H, Ahmed Y. Essential long-range action of Wingless/Wnt in adult intestinal compartmentalization. PLoS Genet 2019; 15:e1008111. [PMID: 31194729 PMCID: PMC6563961 DOI: 10.1371/journal.pgen.1008111] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 03/26/2019] [Indexed: 12/13/2022] Open
Abstract
Signal transduction activated by Wingless/Wnt ligands directs cell proliferation and fate specification in metazoans, and its overactivation underlies the development of the vast majority of colorectal cancers. In the conventional model, the secretion and movement of Wingless to cells distant from its source of synthesis are essential for long-range signaling in tissue patterning. However, this model was upended recently by an unanticipated finding: replacement of wild-type Drosophila Wingless with a membrane-tethered form produced viable adults with largely normal external morphology, which suggested that Wingless secretion and movement are dispensable for tissue patterning. Herein, we tested this foundational principle in the adult intestine, where Wingless signaling gradients coincide with all major boundaries between compartments. We find that the critical roles of Wingless during adult intestinal development, which include regulation of target gene activation, boundary formation, stem cell proliferation, epithelial cell fate specification, muscle differentiation, gut folding, and signaling crosstalk with the Decapentaplegic pathway, are all disrupted by Wingless tethering. These findings provide new evidence that supports the requirement for the direct, long-range action of Wingless in tissue patterning, with relevance for animal development, tissue homeostasis and Wnt-driven disease.
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Affiliation(s)
- Ai Tian
- Department of Molecular and Systems Biology and the Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, Hanover, NH, United States of America
| | - Deepesh Duwadi
- Department of Molecular and Systems Biology and the Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, Hanover, NH, United States of America
| | - Hassina Benchabane
- Department of Molecular and Systems Biology and the Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, Hanover, NH, United States of America
| | - Yashi Ahmed
- Department of Molecular and Systems Biology and the Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, Hanover, NH, United States of America
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69
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Brunner E, Yagi R, Debrunner M, Beck-Schneider D, Burger A, Escher E, Mosimann C, Hausmann G, Basler K. CRISPR-induced double-strand breaks trigger recombination between homologous chromosome arms. Life Sci Alliance 2019; 2:e201800267. [PMID: 31196871 PMCID: PMC6587125 DOI: 10.26508/lsa.201800267] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 05/29/2019] [Accepted: 05/29/2019] [Indexed: 12/27/2022] Open
Abstract
CRISPR-Cas9-based genome editing has transformed the life sciences, enabling virtually unlimited genetic manipulation of genomes: The RNA-guided Cas9 endonuclease cuts DNA at a specific target sequence and the resulting double-strand breaks are mended by one of the intrinsic cellular repair pathways. Imprecise double-strand repair will introduce random mutations such as indels or point mutations, whereas precise editing will restore or specifically edit the locus as mandated by an endogenous or exogenously provided template. Recent studies indicate that CRISPR-induced DNA cuts may also result in the exchange of genetic information between homologous chromosome arms. However, conclusive data of such recombination events in higher eukaryotes are lacking. Here, we show that in Drosophila, the detected Cas9-mediated editing events frequently resulted in germline-transmitted exchange of chromosome arms-often without indels. These findings demonstrate the feasibility of using the system for generating recombinants and also highlight an unforeseen risk of using CRISPR-Cas9 for therapeutic intervention.
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Affiliation(s)
- Erich Brunner
- Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Ryohei Yagi
- Institute of Molecular Systems Biology, Eidgenössische Technische Hochschule Zurich, Zurich, Switzerland
| | - Marc Debrunner
- Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | | | - Alexa Burger
- Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Eliane Escher
- Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Christian Mosimann
- Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - George Hausmann
- Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Konrad Basler
- Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
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70
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Guo X, Huang H, Yang Z, Cai T, Xi R. Division of Labor: Roles of Groucho and CtBP in Notch-Mediated Lateral Inhibition that Controls Intestinal Stem Cell Differentiation in Drosophila. Stem Cell Reports 2019; 12:1007-1023. [PMID: 30982741 PMCID: PMC6523041 DOI: 10.1016/j.stemcr.2019.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 03/15/2019] [Accepted: 03/15/2019] [Indexed: 01/12/2023] Open
Abstract
Intestinal stem cell (ISC) differentiation in the Drosophila midgut requires Delta/Notch-mediated lateral inhibition, which separates the fate of ISCs from differentiating enteroblasts (EBs). Although a canonical Notch signaling cascade is involved in the lateral inhibition, its regulation at the transcriptional level is still unclear. Here we show that the establishment of lateral inhibition between ISC-EB requires two evolutionarily conserved transcriptional co-repressors Groucho (Gro) and C-terminal binding protein (CtBP) that act differently. Gro functions in EBs with E(spl)-C proteins to suppress Delta expression, inhibit cell-cycle re-entry, and promote cell differentiation, whereas CtBP functions specifically in ISCs to mediate transcriptional repression of Su(H) targets and maintain ISC fate. Interestingly, several E(spl)-C genes are also expressed in ISCs that cooperate with Gro to inhibit cell proliferation. Collectively, our study demonstrates separable and cell-type-specific functions of Gro and CtBP in a lateral inhibition process that controls the proliferation and differentiation of tissue stem cells. Gro and CtBP are required for lateral inhibition between ISC and EB in fly midgut Gro cooperates with E(spl)-C factors in EBs to promote differentiation CtBP cooperates with Hairless in ISCs to maintain stem cell fate Gro and E(spl)-C mediate baseline Notch activity and thereby restrict ISC division
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Affiliation(s)
- Xingting Guo
- College of Life Sciences, Beijing Normal University, Beijing 100875, China; National Institute of Biological Sciences, No. 7 Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China
| | - Huanwei Huang
- National Institute of Biological Sciences, No. 7 Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China
| | - Ziqing Yang
- National Institute of Biological Sciences, No. 7 Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China
| | - Tao Cai
- National Institute of Biological Sciences, No. 7 Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China
| | - Rongwen Xi
- National Institute of Biological Sciences, No. 7 Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 102206, China.
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71
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Neitzel LR, Spencer ZT, Nayak A, Cselenyi CS, Benchabane H, Youngblood CQ, Zouaoui A, Ng V, Stephens L, Hann T, Patton JG, Robbins D, Ahmed Y, Lee E. Developmental regulation of Wnt signaling by Nagk and the UDP-GlcNAc salvage pathway. Mech Dev 2019; 156:20-31. [PMID: 30904594 DOI: 10.1016/j.mod.2019.03.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 03/15/2019] [Accepted: 03/18/2019] [Indexed: 11/19/2022]
Abstract
In a screen for human kinases that regulate Xenopus laevis embryogenesis, we identified Nagk and other components of the UDP-GlcNAc glycosylation salvage pathway as regulators of anteroposterior patterning and Wnt signaling. We find that the salvage pathway does not affect other major embryonic signaling pathways (Fgf, TGFβ, Notch, or Shh), thereby demonstrating specificity for Wnt signaling. We show that the role of the salvage pathway in Wnt signaling is evolutionarily conserved in zebrafish and Drosophila. Finally, we show that GlcNAc is essential for the growth of intestinal enteroids, which are highly dependent on Wnt signaling for growth and maintenance. We propose that the Wnt pathway is sensitive to alterations in the glycosylation state of a cell and acts as a nutritional sensor in order to couple growth/proliferation with its metabolic status. We also propose that the clinical manifestations observed in congenital disorders of glycosylation (CDG) in humans may be due, in part, to their effects on Wnt signaling during development.
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Affiliation(s)
- Leif R Neitzel
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA; Program in Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Zachary T Spencer
- Department of Molecular and Systems Biology, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, Hanover, NH 03755, USA
| | - Anmada Nayak
- Sylvester Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Christopher S Cselenyi
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA; Department of Psychiatry, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Hassina Benchabane
- Department of Molecular and Systems Biology, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, Hanover, NH 03755, USA
| | - CheyAnne Q Youngblood
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA; Department of Natural Science, Northeastern State University, Tahlequah, OK 74464, USA
| | - Alya Zouaoui
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Victoria Ng
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Leah Stephens
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Trevor Hann
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - James G Patton
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA
| | - David Robbins
- Sylvester Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Yashi Ahmed
- Department of Molecular and Systems Biology, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, Hanover, NH 03755, USA
| | - Ethan Lee
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA; Program in Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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72
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Sugime Y, Oguchi K, Gotoh H, Hayashi Y, Matsunami M, Shigenobu S, Koshikawa S, Miura T. Termite soldier mandibles are elongated by dachshund under hormonal and Hox gene controls. Development 2019; 146:dev.171942. [PMID: 30833380 DOI: 10.1242/dev.171942] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 02/12/2019] [Indexed: 11/20/2022]
Abstract
In social insects, interactions among colony members trigger caste differentiation with morphological modifications. In termite soldier differentiation, the mandible size considerably increases through two moltings (via the presoldier stage) under the control of juvenile hormone (JH). Regulatory genes are predicted to provide patterning information that induces the mandible-specific cell proliferation. To identify factors responsible for the mandibular enlargement, expression analyses of 18 candidate genes were carried out in the termite Hodotermopsis sjostedti Among those, dachshund (dac), which identifies the intermediate domain along the proximodistal appendage axis, showed mandible-specific upregulation prior to the molt into presoldiers, which can explain the pattern of cell proliferation for the mandibular elongation. Knockdown of dac by RNAi reduced the mandibular length and distorted its morphology. Furthermore, the epistatic relationships among Methoprene tolerant, Insulin receptor, Deformed (Dfd) and dac were revealed by combined RNAi and qRT-PCR analyses, suggesting that dac is regulated by Dfd, downstream of the JH and insulin signaling pathways. Thus, caste-specific morphogenesis is controlled by interactions between the factors that provide spatial information and physiological status.
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Affiliation(s)
- Yasuhiro Sugime
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido, 060-0810, Japan
| | - Kohei Oguchi
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido, 060-0810, Japan.,Misaki Marine Biological Station, Graduate School of Science, The University of Tokyo, Miura, Kanagawa, 238-0225, Japan
| | - Hiroki Gotoh
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido, 060-0810, Japan.,Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan
| | - Yoshinobu Hayashi
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido, 060-0810, Japan.,Department of Biology, Keio University, Yokohama, Kanagawa, 223-8521, Japan
| | - Masatoshi Matsunami
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido, 060-0810, Japan.,Graduate School of Medicine, University of the Ryukyus, Nishihara, Okinawa, 903-0215, Japan
| | - Shuji Shigenobu
- NIBB Core Research Facilities, National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, 444-8585, Japan
| | - Shigeyuki Koshikawa
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido, 060-0810, Japan
| | - Toru Miura
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido, 060-0810, Japan .,Misaki Marine Biological Station, Graduate School of Science, The University of Tokyo, Miura, Kanagawa, 238-0225, Japan
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73
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Chai A, Mateus AM, Oozeer F, Sousa-Nunes R. Spatiotemporally controlled genetic perturbation for efficient large-scale studies of cell non-autonomous effects. eLife 2018; 7:e38393. [PMID: 30479273 PMCID: PMC6320068 DOI: 10.7554/elife.38393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 11/26/2018] [Indexed: 11/13/2022] Open
Abstract
Studies in genetic model organisms have revealed much about the development and pathology of complex tissues. Most have focused on cell-intrinsic gene functions and mechanisms. Much less is known about how transformed, or otherwise functionally disrupted, cells interact with healthy ones toward a favorable or pathological outcome. This is largely due to technical limitations. We developed new genetic tools in Drosophila melanogaster that permit efficient multiplexed gain- and loss-of-function genetic perturbations with separable spatial and temporal control. Importantly, our novel tool-set is independent of the commonly used GAL4/UAS system, freeing the latter for additional, non-autonomous, genetic manipulations; and is built into a single strain, allowing one-generation interrogation of non-autonomous effects. Altogether, our design opens up efficient genome-wide screens on any deleterious phenotype, once plasmid or genome engineering is used to place the desired miRNA(s) or ORF(s) into our genotype. Specifically, we developed tools to study extrinsic effects on neural tumor growth but the strategy presented has endless applications within and beyond neurobiology, and in other model organisms.
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Affiliation(s)
- Andrea Chai
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and NeuroscienceKing’s College LondonLondonUnited Kingdom
| | - Ana M Mateus
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and NeuroscienceKing’s College LondonLondonUnited Kingdom
| | - Fazal Oozeer
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and NeuroscienceKing’s College LondonLondonUnited Kingdom
| | - Rita Sousa-Nunes
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and NeuroscienceKing’s College LondonLondonUnited Kingdom
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74
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Wolff T, Rubin GM. Neuroarchitecture of the Drosophila central complex: A catalog of nodulus and asymmetrical body neurons and a revision of the protocerebral bridge catalog. J Comp Neurol 2018; 526:2585-2611. [PMID: 30084503 PMCID: PMC6283239 DOI: 10.1002/cne.24512] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 06/28/2018] [Accepted: 06/29/2018] [Indexed: 12/17/2022]
Abstract
The central complex, a set of neuropils in the center of the insect brain, plays a crucial role in spatial aspects of sensory integration and motor control. Stereotyped neurons interconnect these neuropils with one another and with accessory structures. We screened over 5,000 Drosophila melanogaster GAL4 lines for expression in two neuropils, the noduli (NO) of the central complex and the asymmetrical body (AB), and used multicolor stochastic labeling to analyze the morphology, polarity, and organization of individual cells in a subset of the GAL4 lines that showed expression in these neuropils. We identified nine NO and three AB cell types and describe them here. The morphology of the NO neurons suggests that they receive input primarily in the lateral accessory lobe and send output to each of the six paired noduli. We demonstrate that the AB is a bilateral structure which exhibits asymmetry in size between the left and right bodies. We show that the AB neurons directly connect the AB to the central complex and accessory neuropils, that they target both the left and right ABs, and that one cell type preferentially innervates the right AB. We propose that the AB be considered a central complex neuropil in Drosophila. Finally, we present highly restricted GAL4 lines for most identified protocerebral bridge, NO, and AB cell types. These lines, generated using the split-GAL4 method, will facilitate anatomical studies, behavioral assays, and physiological experiments.
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Affiliation(s)
- Tanya Wolff
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia
| | - Gerald M Rubin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia
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75
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Wingless Signaling: A Genetic Journey from Morphogenesis to Metastasis. Genetics 2018; 208:1311-1336. [PMID: 29618590 DOI: 10.1534/genetics.117.300157] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 12/13/2017] [Indexed: 12/15/2022] Open
Abstract
This FlyBook chapter summarizes the history and the current state of our understanding of the Wingless signaling pathway. Wingless, the fly homolog of the mammalian Wnt oncoproteins, plays a central role in pattern generation during development. Much of what we know about the pathway was learned from genetic and molecular experiments in Drosophila melanogaster, and the core pathway works the same way in vertebrates. Like most growth factor pathways, extracellular Wingless/Wnt binds to a cell surface complex to transduce signal across the plasma membrane, triggering a series of intracellular events that lead to transcriptional changes in the nucleus. Unlike most growth factor pathways, the intracellular events regulate the protein stability of a key effector molecule, in this case Armadillo/β-catenin. A number of mysteries remain about how the "destruction complex" destabilizes β-catenin and how this process is inactivated by the ligand-bound receptor complex, so this review of the field can only serve as a snapshot of the work in progress.
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76
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Abstract
Since the founding of Drosophila genetics by Thomas Hunt Morgan and his colleagues over 100 years ago, the experimental induction of mosaicism has featured prominently in its recognition as an unsurpassed genetic model organism. The use of genetic mosaics has facilitated the discovery of a wide variety of developmental processes, identified specific cell lineages, allowed the study of recessive embryonic lethal mutations, and demonstrated the existence of cell competition. Here, we discuss how genetic mosaicism in Drosophila became an invaluable research tool that revolutionized developmental biology. We describe the prevailing methods used to produce mosaic animals, and highlight advantages and disadvantages of each genetic system. We cover methods ranging from simple "twin-spot" analysis to more sophisticated systems of multicolor labeling.
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77
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Courgeon M, He DQ, Liu HH, Legent K, Treisman JE. The Drosophila Epidermal Growth Factor Receptor does not act in the nucleus. J Cell Sci 2018; 131:jcs.220251. [PMID: 30158176 DOI: 10.1242/jcs.220251] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 08/16/2018] [Indexed: 12/15/2022] Open
Abstract
Mammalian members of the ErbB family, including the epidermal growth factor receptor (EGFR), can regulate transcription, DNA replication and repair through nuclear entry of either the full-length proteins or their cleaved cytoplasmic domains. In cancer cells, these nuclear functions contribute to tumor progression and drug resistance. Here, we examined whether the single Drosophila EGFR can also localize to the nucleus. A chimeric EGFR protein fused at its cytoplasmic C-terminus to DNA-binding and transcriptional activation domains strongly activated transcriptional reporters when overexpressed in cultured cells or in vivo However, this activity was independent of cleavage and endocytosis. Without an exogenous activation domain, EGFR fused to a DNA-binding domain did not activate or repress transcription. Addition of the same DNA-binding and transcriptional activation domains to the endogenous Egfr locus through genome editing led to no detectable reporter expression in wild-type or oncogenic contexts. These results show that, when expressed at physiological levels, the cytoplasmic domain of the Drosophila EGFR does not have access to the nucleus. Therefore, nuclear EGFR functions are likely to have evolved after vertebrates and invertebrates diverged.
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Affiliation(s)
- Maximilien Courgeon
- Skirball Institute for Biomolecular Medicine and Department of Cell Biology, NYU School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | - Dan Qing He
- Skirball Institute for Biomolecular Medicine and Department of Cell Biology, NYU School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | - Hui Hua Liu
- Skirball Institute for Biomolecular Medicine and Department of Cell Biology, NYU School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | - Kevin Legent
- Skirball Institute for Biomolecular Medicine and Department of Cell Biology, NYU School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | - Jessica E Treisman
- Skirball Institute for Biomolecular Medicine and Department of Cell Biology, NYU School of Medicine, 540 First Avenue, New York, NY 10016, USA
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78
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Newcomb S, Voutev R, Jory A, Delker RK, Slattery M, Mann RS. cis-regulatory architecture of a short-range EGFR organizing center in the Drosophila melanogaster leg. PLoS Genet 2018; 14:e1007568. [PMID: 30142157 PMCID: PMC6147608 DOI: 10.1371/journal.pgen.1007568] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 09/20/2018] [Accepted: 07/16/2018] [Indexed: 12/19/2022] Open
Abstract
We characterized the establishment of an Epidermal Growth Factor Receptor (EGFR) organizing center (EOC) during leg development in Drosophila melanogaster. Initial EGFR activation occurs in the center of leg discs by expression of the EGFR ligand Vn and the EGFR ligand-processing protease Rho, each through single enhancers, vnE and rhoE, that integrate inputs from Wg, Dpp, Dll and Sp1. Deletion of vnE and rhoE eliminates vn and rho expression in the center of the leg imaginal discs, respectively. Animals with deletions of both vnE and rhoE (but not individually) show distal but not medial leg truncations, suggesting that the distal source of EGFR ligands acts at short-range to only specify distal-most fates, and that multiple additional ‘ring’ enhancers are responsible for medial fates. Further, based on the cis-regulatory logic of vnE and rhoE we identified many additional leg enhancers, suggesting that this logic is broadly used by many genes during Drosophila limb development. The EGFR signaling pathway plays a major role in innumerable developmental processes in all animals and its deregulation leads to different types of cancer, as well as many other developmental diseases in humans. Here we explored the integration of inputs from the Wnt- and TGF-beta signaling pathways and the leg-specifying transcription factors Distal-less and Sp1 at enhancer elements of EGFR ligands. These enhancers trigger a specific EGFR-dependent developmental output in the fly leg that is limited to specifying distal-most fates. Our findings suggest that activation of the EGFR pathway during fly leg development occurs through the activation of multiple EGFR ligand enhancers that are active at different positions along the proximo-distal axis. Similar enhancer elements are likely to control EGFR activation in humans as well. Such DNA elements might be ‘hot spots’ that cause formation of EGFR-dependent tumors if mutations in them occur. Thus, understanding the molecular characteristics of such DNA elements could facilitate the detection and treatment of cancer.
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Affiliation(s)
- Susan Newcomb
- Department of Biological Sciences, Columbia University, New York, NY, United States of America
| | - Roumen Voutev
- Department of Biochemistry and Molecular Biophysics and Department of Systems Biology, Columbia University, New York, NY, United States of America
- * E-mail: (RV); (RSM)
| | - Aurelie Jory
- Department of Biochemistry and Molecular Biophysics and Department of Systems Biology, Columbia University, New York, NY, United States of America
| | - Rebecca K. Delker
- Department of Biochemistry and Molecular Biophysics and Department of Systems Biology, Columbia University, New York, NY, United States of America
| | - Matthew Slattery
- Department of Biochemistry and Molecular Biophysics and Department of Systems Biology, Columbia University, New York, NY, United States of America
| | - Richard S. Mann
- Department of Biochemistry and Molecular Biophysics and Department of Systems Biology, Columbia University, New York, NY, United States of America
- * E-mail: (RV); (RSM)
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79
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Beaven R, Denholm B. Release and spread of Wingless is required to pattern the proximo-distal axis of Drosophila renal tubules. eLife 2018; 7:e35373. [PMID: 30095068 PMCID: PMC6086663 DOI: 10.7554/elife.35373] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 08/01/2018] [Indexed: 01/06/2023] Open
Abstract
Wingless/Wnts are signalling molecules, traditionally considered to pattern tissues as long-range morphogens. However, more recently the spread of Wingless was shown to be dispensable in diverse developmental contexts in Drosophila and vertebrates. Here we demonstrate that release and spread of Wingless is required to pattern the proximo-distal (P-D) axis of Drosophila Malpighian tubules. Wingless signalling, emanating from the midgut, directly activates odd skipped expression several cells distant in the proximal tubule. Replacing Wingless with a membrane-tethered version that is unable to diffuse from the Wingless producing cells results in aberrant patterning of the Malpighian tubule P-D axis and development of short, deformed ureters. This work directly demonstrates a patterning role for a released Wingless signal. As well as extending our understanding about the functional modes by which Wnts shape animal development, we anticipate this mechanism to be relevant to patterning epithelial tubes in other organs, such as the vertebrate kidney.
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Affiliation(s)
- Robin Beaven
- Deanery of Biomedical SciencesUniversity of EdinburghEdinburghUnited Kingdom
| | - Barry Denholm
- Deanery of Biomedical SciencesUniversity of EdinburghEdinburghUnited Kingdom
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80
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Katanaev VL, Egger-Adam D, Tomlinson A. Antagonistic PCP Signaling Pathways in the developing Drosophila eye. Sci Rep 2018; 8:5741. [PMID: 29636485 PMCID: PMC5893544 DOI: 10.1038/s41598-018-24053-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 03/26/2018] [Indexed: 01/23/2023] Open
Abstract
In Planar cell polarity (PCP), cells coordinately polarize their cytoskeletons within the plane of the epithelium in which they lie. In most insect epithelia this is indicated by the coordinated projections of the hairs secreted by the ectodermal cells. PCP of this form has been effectively studied in Drosophila, but it has proven difficult to achieve an integrated description of the roles played by the various proteins. In the insect eye, PCP is not evident as the polarization of individual cells, but as the asymmetric arrangements of the cells of the ommatidia. This different form of PCP allows different studies to be performed, and using this system we have detected the action of two antagonistic signaling pathways. Even though antagonistic, the two pathways synergize and cooperate to ensure that the correct arrangement of the cells is achieved. The cooperative use of antagonistic signaling pathways occurs in the polarization of chemotacting cells, and we discuss the possibility that a similar molecular principle may underlie PCP.
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Affiliation(s)
- Vladimir L Katanaev
- Department of Genetics and Development, College of Physicians and Surgeons, Columbia University, 701 West 168th St #1120, New York, NY, 10032, USA.,Department of Biology, University of Konstanz, Universitätsstrasse, 10, Box M643, 78467, Konstanz, Germany.,Department of Pharmacology and Toxicology, University of Lausanne, Rue du Bugnon 27, CH-1005, Lausanne, Switzerland
| | - Diane Egger-Adam
- Department of Biology, University of Konstanz, Universitätsstrasse, 10, Box M643, 78467, Konstanz, Germany
| | - Andrew Tomlinson
- Department of Genetics and Development, College of Physicians and Surgeons, Columbia University, 701 West 168th St #1120, New York, NY, 10032, USA. .,Department of Genetics and Development, College of Physicians and Surgeons, Columbia University, Jerome L. Greene Science Center, MC9892, Level 9 Room 028, 3227 Broadway, New York, NY, 10027, USA.
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81
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Wingless/Wnt Signaling in Intestinal Development, Homeostasis, Regeneration and Tumorigenesis: A Drosophila Perspective. J Dev Biol 2018; 6:jdb6020008. [PMID: 29615557 PMCID: PMC6026893 DOI: 10.3390/jdb6020008] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 03/23/2018] [Accepted: 03/24/2018] [Indexed: 02/06/2023] Open
Abstract
In mammals, the Wnt/β-catenin signal transduction pathway regulates intestinal stem cell maintenance and proliferation, whereas Wnt pathway hyperactivation, resulting primarily from the inactivation of the tumor suppressor Adenomatous polyposis coli (APC), triggers the development of the vast majority of colorectal cancers. The Drosophila adult gut has recently emerged as a powerful model to elucidate the mechanisms by which Wingless/Wnt signaling regulates intestinal development, homeostasis, regeneration, and tumorigenesis. Herein, we review recent insights on the roles of Wnt signaling in Drosophila intestinal physiology and pathology.
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82
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Abstract
Organizers, which comprise groups of cells with the ability to instruct adjacent cells into specific states, represent a key principle in developmental biology. The concept was first introduced by Spemann and Mangold, who showed that there is a cellular population in the newt embryo that elicits the development of a secondary axis from adjacent cells. Similar experiments in chicken and rabbit embryos subsequently revealed groups of cells with similar instructive potential. In birds and mammals, organizer activity is often associated with a structure known as the node, which has thus been considered a functional homologue of Spemann's organizer. Here, we take an in-depth look at the structure and function of organizers across species and note that, whereas the amphibian organizer is a contingent collection of elements, each performing a specific function, the elements of organizers in other species are dispersed in time and space. This observation urges us to reconsider the universality and meaning of the organizer concept. Summary: This Review re-evaluates the notion of Spemann's organizer as identified in amphibians, highlighting the spatiotemporal dispersion of equivalent elements in mouse and the key influence of responsiveness to organizer signals.
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Affiliation(s)
| | - Ben Steventon
- Department of Genetics, University of Cambridge, Cambridge CB2 3EH, UK
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83
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Chen J, Xu N, Wang C, Huang P, Huang H, Jin Z, Yu Z, Cai T, Jiao R, Xi R. Transient Scute activation via a self-stimulatory loop directs enteroendocrine cell pair specification from self-renewing intestinal stem cells. Nat Cell Biol 2018; 20:152-161. [PMID: 29335529 DOI: 10.1038/s41556-017-0020-0] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 12/01/2017] [Indexed: 01/26/2023]
Abstract
The process through which multiple types of cell-lineage-restricted progenitor cells are specified from multipotent stem cells is unclear. Here we show that, in intestinal stem cell lineages in adult Drosophila, in which the Delta-Notch-signalling-guided progenitor cell differentiation into enterocytes is the default mode, the specification of enteroendocrine cells (EEs) is initiated by transient Scute activation in a process driven by transcriptional self-stimulation combined with a negative feedback regulation between Scute and Notch targets. Scute activation induces asymmetric intestinal stem cell divisions that generate EE progenitor cells. The mitosis-inducing and fate-inducing activities of Scute guide each EE progenitor cell to divide exactly once prior to its terminal differentiation, yielding a pair of EEs. The transient expression of a fate inducer therefore specifies both type and numbers of committed progenitor cells originating from stem cells, which could represent a general mechanism used for diversifying committed progenitor cells from multipotent stem cells.
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Affiliation(s)
- Jun Chen
- Graduate School of Peking Union Medical College, Beijing, China.,National Institute of Biological Sciences, Beijing, China
| | - Na Xu
- National Institute of Biological Sciences, Beijing, China
| | - Chenhui Wang
- National Institute of Biological Sciences, Beijing, China
| | - Pin Huang
- National Institute of Biological Sciences, Beijing, China
| | - Huanwei Huang
- National Institute of Biological Sciences, Beijing, China
| | - Zhen Jin
- National Institute of Biological Sciences, Beijing, China
| | - Zhongsheng Yu
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Tao Cai
- National Institute of Biological Sciences, Beijing, China
| | - Renjie Jiao
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,Sino-French Hoffmann Institute, Guangzhou Medical University, Guangzhou, China
| | - Rongwen Xi
- Graduate School of Peking Union Medical College, Beijing, China. .,National Institute of Biological Sciences, Beijing, China. .,Institute for Regenerative Medicine, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China.
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84
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Yin C, Xi R. A Phyllopod-Mediated Feedback Loop Promotes Intestinal Stem Cell Enteroendocrine Commitment in Drosophila. Stem Cell Reports 2017; 10:43-57. [PMID: 29276156 PMCID: PMC5768918 DOI: 10.1016/j.stemcr.2017.11.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 11/15/2017] [Accepted: 11/16/2017] [Indexed: 01/17/2023] Open
Abstract
The intestinal epithelium in the Drosophila midgut is maintained by intestinal stem cells (ISCs), which are capable of generating both enterocytes and enteroendocrine cells (EEs) via alternative cell fate specification. Activation of Delta-Notch signaling directs ISCs for enterocyte generation, but how EEs are generated from ISCs remains poorly understood. Here, we identified Phyllopod (Phyl) as a key regulator that drives EE generation from ISCs. Phyl, which is normally suppressed by Notch, functions as an adaptor protein that bridges Tramtrack 69 (Ttk69) and E3 ubiquitin ligase Sina for degradation. Degradation of Ttk69 allows the activation of the Achaete-Scute Complex (AS-C)-Pros regulatory axis, which promotes EE specification. Interestingly, expression of AS-C genes in turn further induces Phyl expression, thereby establishing a positive feedback loop for continuous EE fate specification and commitment. This positive feedback circuit-driven regulatory mechanism could represent a common strategy for reliable and irreversible cell fate determination from progenitor cells.
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Affiliation(s)
- Chang Yin
- Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China; National Institute of Biological Sciences, No. 7 Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China
| | - Rongwen Xi
- Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China; National Institute of Biological Sciences, No. 7 Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China; Institute for Regenerative Medicine, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China.
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85
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Requena D, Álvarez JA, Gabilondo H, Loker R, Mann RS, Estella C. Origins and Specification of the Drosophila Wing. Curr Biol 2017; 27:3826-3836.e5. [PMID: 29225023 DOI: 10.1016/j.cub.2017.11.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 10/11/2017] [Accepted: 11/08/2017] [Indexed: 01/18/2023]
Abstract
The insect wing is a key evolutionary innovation that was essential for insect diversification. Yet despite its importance, there is still debate about its evolutionary origins. Two main hypotheses have been proposed: the paranotal hypothesis, which suggests that wings evolved as an extension of the dorsal thorax, and the gill-exite hypothesis, which proposes that wings were derived from a modification of a pre-existing branch at the dorsal base (subcoxa) of the leg. Here, we address this question by studying how wing fates are initially specified during Drosophila embryogenesis, by characterizing a cis-regulatory module (CRM) from the snail (sna) gene, sna-DP (for dorsal primordia). sna-DP specifically marks the early primordia for both the wing and haltere, collectively referred to as the DP. We found that the inputs that activate sna-DP are distinct from those that activate Distalless, a marker for leg fates. Further, in genetic backgrounds in which the leg primordia are absent, the DP are still partially specified. However, lineage-tracing experiments demonstrate that cells from the early leg primordia contribute to both ventral and dorsal appendage fates. Together, these results suggest that the wings of Drosophila have a dual developmental origin: two groups of cells, one ventral and one more dorsal, give rise to the mature wing. We suggest that the dual developmental origins of the wing may be a molecular remnant of the evolutionary history of this appendage, in which cells of the subcoxa of the leg coalesced with dorsal outgrowths to evolve a dorsal appendage with motor control.
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Affiliation(s)
- David Requena
- Departamento de Biología Molecular and Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Nicolás Cabrera 1, 28049 Madrid, Spain
| | - Jose Andres Álvarez
- Departamento de Biología and Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Nicolás Cabrera 1, 28049 Madrid, Spain
| | - Hugo Gabilondo
- Departamento de Biología Molecular and Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Nicolás Cabrera 1, 28049 Madrid, Spain
| | - Ryan Loker
- Departments of Biochemistry and Molecular Biophysics and Systems Biology, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, 701 W. 168th St., HHSC 1104, New York, NY 10032, USA
| | - Richard S Mann
- Departments of Biochemistry and Molecular Biophysics and Systems Biology, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, 701 W. 168th St., HHSC 1104, New York, NY 10032, USA.
| | - Carlos Estella
- Departamento de Biología Molecular and Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Nicolás Cabrera 1, 28049 Madrid, Spain.
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86
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Ren S, Huang Z, Jiang Y, Wang T. dTBC1D7 regulates systemic growth independently of TSC through insulin signaling. J Cell Biol 2017; 217:517-526. [PMID: 29187524 PMCID: PMC5800808 DOI: 10.1083/jcb.201706027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 10/10/2017] [Accepted: 11/08/2017] [Indexed: 12/31/2022] Open
Abstract
The insulin signaling pathway plays key roles in systemic growth. TBC1D7 has recently been identified as the third subunit of the tuberous sclerosis complex (TSC), a negative regulator of cell growth. Here, we used Drosophila as a model system to dissect the physiological function of TBC1D7 in vivo. In mutants lacking TBC1D7, cell and organ growth were promoted, and TBC1D7 limited cell growth in a cell-nonautonomous and TSC-independent manner. TBC1D7 is specifically expressed in insulin-producing cells in the fly brain and regulated biosynthesis and release of insulin-like peptide 2, leading to systemic growth. Furthermore, animals carrying the dTBC1D7 mutation were hypoglycemic, short-lived, and sensitive to oxidative stress. Our findings provide new insights into the physiological function of TBC1D7 in the systemic control of growth, as well as insights into human disorders caused by TBC1D7 mutation.
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Affiliation(s)
- Suxia Ren
- College of Biological Sciences, China Agricultural University, Beijing, China.,National Institute of Biological Sciences, Beijing, China
| | - Zengyi Huang
- National Institute of Biological Sciences, Beijing, China.,State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Yuqiang Jiang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Tao Wang
- National Institute of Biological Sciences, Beijing, China
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87
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Gupta RP, Bajpai A, Sinha P. Selector genes display tumor cooperation and inhibition in Drosophila epithelium in a developmental context-dependent manner. Biol Open 2017; 6:1581-1591. [PMID: 29141951 PMCID: PMC5703612 DOI: 10.1242/bio.027821] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
During animal development, selector genes determine identities of body segments and those of individual organs. Selector genes are also misexpressed in cancers, although their contributions to tumor progression per se remain poorly understood. Using a model of cooperative tumorigenesis, we show that gain of selector genes results in tumor cooperation, but in only select developmental domains of the wing, haltere and eye-antennal imaginal discs of Drosophila larva. Thus, the field selector, Eyeless (Ey), and the segment selector, Ultrabithorax (Ubx), readily cooperate to bring about neoplastic transformation of cells displaying somatic loss of the tumor suppressor, Lgl, but in only those developmental domains that express the homeo-box protein, Homothorax (Hth), and/or the Zinc-finger protein, Teashirt (Tsh). In non-Hth/Tsh-expressing domains of these imaginal discs, however, gain of Ey in lgl- somatic clones induces neoplastic transformation in the distal wing disc and haltere, but not in the eye imaginal disc. Likewise, gain of Ubx in lgl- somatic clones induces transformation in the eye imaginal disc but not in its endogenous domain, namely, the haltere imaginal disc. Our results reveal that selector genes could behave as tumor drivers or inhibitors depending on the tissue contexts of their gains.
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Affiliation(s)
- Ram Prakash Gupta
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Anjali Bajpai
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Pradip Sinha
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur 208016, India
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88
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Boiko N, Medrano G, Montano E, Jiang N, Williams CR, Madungwe NB, Bopassa JC, Kim CC, Parrish JZ, Hargreaves KM, Stockand JD, Eaton BA. TrpA1 activation in peripheral sensory neurons underlies the ionic basis of pain hypersensitivity in response to vinca alkaloids. PLoS One 2017; 12:e0186888. [PMID: 29084244 PMCID: PMC5662086 DOI: 10.1371/journal.pone.0186888] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 10/09/2017] [Indexed: 12/30/2022] Open
Abstract
Chemotherapy induced peripheral neuropathy (CIPN), a side effect of many anti-cancer drugs including the vinca alkaloids, is characterized by a severe pain syndrome that compromises treatment in many patients. Currently there are no effective treatments for this pain syndrome except for the reduction of anti-cancer drug dose. Existing data supports the model that the pain associated with CIPN is the result of anti-cancer drugs augmenting the function of the peripheral sensory nociceptors but the cellular mechanisms underlying the effects of anti-cancer drugs on sensory neuron function are not well described. Studies from animal models have suggested a number of disease etiologies including mitotoxicity, axonal degeneration, immune signaling, and reduced sensory innervations but these outcomes are the result of prolonged treatment paradigms and do not necessarily represent the early formative events associated with CIPN. Here we show that acute exposure to vinca alkaloids results in an immediate pain syndrome in both flies and mice. Furthermore, we demonstrate that exposure of isolated sensory neurons to vinca alkaloids results in the generation of an inward sodium current capable of depolarizing these neurons to threshold resulting in neuronal firing. These neuronal effects of vinca alkaloids require the transient receptor potential ankyrin-1 (TrpA1) channel, and the hypersensitization to painful stimuli in response to the acute exposure to vinca alkaloids is reduced in TrpA1 mutant flies and mice. These findings demonstrate the direct excitation of sensory neurons by CIPN-causing chemotherapy drugs, and identify TrpA1 as an important target during the pathogenesis of CIPN.
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Affiliation(s)
- Nina Boiko
- Department of Cellular and Integrative Physiology, University of Texas Health Sciences Center at San Antonio, San Antonio, Texas, United States of America
| | - Geraldo Medrano
- Department of Cellular and Integrative Physiology, University of Texas Health Sciences Center at San Antonio, San Antonio, Texas, United States of America
| | - Elizabeth Montano
- Department of Cellular and Integrative Physiology, University of Texas Health Sciences Center at San Antonio, San Antonio, Texas, United States of America
| | - Nan Jiang
- Department of Biology, University of Washington, Seattle, Washington, United States of America
| | - Claire R. Williams
- Department of Biology, University of Washington, Seattle, Washington, United States of America
| | - Ngonidzashe B. Madungwe
- Department of Cellular and Integrative Physiology, University of Texas Health Sciences Center at San Antonio, San Antonio, Texas, United States of America
| | - Jean C. Bopassa
- Department of Cellular and Integrative Physiology, University of Texas Health Sciences Center at San Antonio, San Antonio, Texas, United States of America
| | - Charles C. Kim
- Verily, South San Francisco, California, United States of America
| | - Jay Z. Parrish
- Department of Biology, University of Washington, Seattle, Washington, United States of America
| | - Kenneth M. Hargreaves
- Department of Endodontics, University of Texas Health Sciences Center at San Antonio, San Antonio, Texas, United States of America
| | - James D. Stockand
- Department of Cellular and Integrative Physiology, University of Texas Health Sciences Center at San Antonio, San Antonio, Texas, United States of America
| | - Benjamin A. Eaton
- Department of Cellular and Integrative Physiology, University of Texas Health Sciences Center at San Antonio, San Antonio, Texas, United States of America
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89
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Bower DV, Lansdale N, Navarro S, Truong TV, Bower DJ, Featherstone NC, Connell MG, Al Alam D, Frey MR, Trinh LA, Fernandez GE, Warburton D, Fraser SE, Bennett D, Jesudason EC. SERCA directs cell migration and branching across species and germ layers. Biol Open 2017; 6:1458-1471. [PMID: 28821490 PMCID: PMC5665464 DOI: 10.1242/bio.026039] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 08/14/2017] [Indexed: 12/24/2022] Open
Abstract
Branching morphogenesis underlies organogenesis in vertebrates and invertebrates, yet is incompletely understood. Here, we show that the sarco-endoplasmic reticulum Ca2+ reuptake pump (SERCA) directs budding across germ layers and species. Clonal knockdown demonstrated a cell-autonomous role for SERCA in Drosophila air sac budding. Live imaging of Drosophila tracheogenesis revealed elevated Ca2+ levels in migratory tip cells as they form branches. SERCA blockade abolished this Ca2+ differential, aborting both cell migration and new branching. Activating protein kinase C (PKC) rescued Ca2+ in tip cells and restored cell migration and branching. Likewise, inhibiting SERCA abolished mammalian epithelial budding, PKC activation rescued budding, while morphogens did not. Mesoderm (zebrafish angiogenesis) and ectoderm (Drosophila nervous system) behaved similarly, suggesting a conserved requirement for cell-autonomous Ca2+ signaling, established by SERCA, in iterative budding.
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Affiliation(s)
- Danielle V Bower
- Division of Biological Sciences, California Institute of Technology, Pasadena, CA 91125, USA
- The Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA
- Department of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Bern University Hospital, University of Bern, 3010 Bern, Switzerland, and the Department of Biomedical Research, University of Bern, 3008 Bern, Switzerland
| | - Nick Lansdale
- Department of Biochemistry & Centre for Cell Imaging, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
- Division of Child Health, Institute of Translational Medicine, University of Liverpool, Liverpool L12 2AP, UK
| | - Sonia Navarro
- The Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA
- Craniofacial Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Thai V Truong
- Division of Biological Sciences, California Institute of Technology, Pasadena, CA 91125, USA
- Biological Sciences and Molecular and Computational Biology, Translational Imaging Center, University of Southern California, Los Angeles, CA 90089, USA
| | - Dan J Bower
- Center for Space and Habitability, University of Bern, 3012 Bern, Switzerland
| | - Neil C Featherstone
- Department of Biochemistry & Centre for Cell Imaging, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Marilyn G Connell
- Department of Biochemistry & Centre for Cell Imaging, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Denise Al Alam
- The Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA
| | - Mark R Frey
- The Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA
| | - Le A Trinh
- Division of Biological Sciences, California Institute of Technology, Pasadena, CA 91125, USA
- Biological Sciences and Molecular and Computational Biology, Translational Imaging Center, University of Southern California, Los Angeles, CA 90089, USA
| | - G Esteban Fernandez
- The Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA
| | - David Warburton
- The Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA
| | - Scott E Fraser
- Division of Biological Sciences, California Institute of Technology, Pasadena, CA 91125, USA
- Biological Sciences and Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Biological Sciences and Molecular and Computational Biology, Translational Imaging Center, University of Southern California, Los Angeles, CA 90089, USA
| | - Daimark Bennett
- Department of Biochemistry & Centre for Cell Imaging, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Edwin C Jesudason
- Division of Biological Sciences, California Institute of Technology, Pasadena, CA 91125, USA
- The Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA
- NHS Lothian, Edinburgh, EH14 1TY, UK
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90
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Dendritic space-filling requires a neuronal type-specific extracellular permissive signal in Drosophila. Proc Natl Acad Sci U S A 2017; 114:E8062-E8071. [PMID: 28874572 DOI: 10.1073/pnas.1707467114] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Neurons sometimes completely fill available space in their receptive fields with evenly spaced dendrites to uniformly sample sensory or synaptic information. The mechanisms that enable neurons to sense and innervate all space in their target tissues are poorly understood. Using Drosophila somatosensory neurons as a model, we show that heparan sulfate proteoglycans (HSPGs) Dally and Syndecan on the surface of epidermal cells act as local permissive signals for the dendritic growth and maintenance of space-filling nociceptive C4da neurons, allowing them to innervate the entire skin. Using long-term time-lapse imaging with intact Drosophila larvae, we found that dendrites grow into HSPG-deficient areas but fail to stay there. HSPGs are necessary to stabilize microtubules in newly formed high-order dendrites. In contrast to C4da neurons, non-space-filling sensory neurons that develop in the same microenvironment do not rely on HSPGs for their dendritic growth. Furthermore, HSPGs do not act by transporting extracellular diffusible ligands or require leukocyte antigen-related (Lar), a receptor protein tyrosine phosphatase (RPTP) and the only known Drosophila HSPG receptor, for promoting dendritic growth of space-filling neurons. Interestingly, another RPTP, Ptp69D, promotes dendritic growth of C4da neurons in parallel to HSPGs. Together, our data reveal an HSPG-dependent pathway that specifically allows dendrites of space-filling neurons to innervate all target tissues in Drosophila.
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91
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Apitz H, Salecker I. Retinal determination genes coordinate neuroepithelial specification and neurogenesis modes in the Drosophila optic lobe. Development 2017; 143:2431-42. [PMID: 27381228 PMCID: PMC4958324 DOI: 10.1242/dev.135004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 05/18/2016] [Indexed: 12/15/2022]
Abstract
Differences in neuroepithelial patterning and neurogenesis modes contribute to area-specific diversifications of neural circuits. In the Drosophila visual system, two neuroepithelia, the outer (OPC) and inner (IPC) proliferation centers, generate neuron subtypes for four ganglia in several ways. Whereas neuroepithelial cells in the medial OPC directly convert into neuroblasts, in an IPC subdomain they generate migratory progenitors by epithelial-mesenchymal transition that mature into neuroblasts in a second proliferative zone. The molecular mechanisms that regulate the identity of these neuroepithelia, including their neurogenesis modes, remain poorly understood. Analysis of Polycomblike revealed that loss of Polycomb group-mediated repression of the Hox gene Abdominal-B (Abd-B) caused the transformation of OPC to IPC neuroepithelial identity. This suggests that the neuroepithelial default state is IPC-like, whereas OPC identity is derived. Ectopic Abd-B blocks expression of the highly conserved retinal determination gene network members Eyes absent (Eya), Sine oculis (So) and Homothorax (Hth). These factors are essential for OPC specification and neurogenesis control. Finally, eya and so are also sufficient to confer OPC-like identity, and, in parallel with hth, the OPC-specific neurogenesis mode on the IPC. Summary: Polycomb-mediated repression of the Abd-B Hox gene controls expression of retinal determination genes and hence identity of the Drosophila optic lobe neuroepithelia.
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Affiliation(s)
- Holger Apitz
- The Francis Crick Institute, Mill Hill Laboratory, London NW7 1AA, UK
| | - Iris Salecker
- The Francis Crick Institute, Mill Hill Laboratory, London NW7 1AA, UK
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92
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Ding ZY, Wang YH, Huang YC, Lee MC, Tseng MJ, Chi YH, Huang ML. Outer nuclear membrane protein Kuduk modulates the LINC complex and nuclear envelope architecture. J Cell Biol 2017; 216:2827-2841. [PMID: 28716842 PMCID: PMC5584142 DOI: 10.1083/jcb.201606043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 05/25/2017] [Accepted: 06/15/2017] [Indexed: 11/25/2022] Open
Abstract
LINC complexes connect the inner and outer nuclear membrane (ONM) to transduce nucleocytoskeletal force. Ding et al. identify an ONM protein, Kuduk/TMEM258, which modulates the quality of LINC complexes and regulates the nuclear envelope architecture, nuclear positioning, and the development of ovarian follicles. Linker of nucleoskeleton and cytoskeleton (LINC) complexes spanning the nuclear envelope (NE) contribute to nucleocytoskeletal force transduction. A few NE proteins have been found to regulate the LINC complex. In this study, we identify one, Kuduk (Kud), which can reside at the outer nuclear membrane and is required for the development of Drosophila melanogaster ovarian follicles and NE morphology of myonuclei. Kud associates with LINC complex components in an evolutionarily conserved manner. Loss of Kud increases the level but impairs functioning of the LINC complex. Overexpression of Kud suppresses NE targeting of cytoskeleton-free LINC complexes. Thus, Kud acts as a quality control mechanism for LINC-mediated nucleocytoskeletal connections. Genetic data indicate that Kud also functions independently of the LINC complex. Overexpression of the human orthologue TMEM258 in Drosophila proved functional conservation. These findings expand our understanding of the regulation of LINC complexes and NE architecture.
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Affiliation(s)
- Zhao-Ying Ding
- Department of Life Science, National Chung-Cheng University, Chiayi, Taiwan
| | - Ying-Hsuan Wang
- Department of Life Science, National Chung-Cheng University, Chiayi, Taiwan
| | - Yu-Cheng Huang
- Department of Life Science, National Chung-Cheng University, Chiayi, Taiwan
| | - Myong-Chol Lee
- Department of Life Science, National Chung-Cheng University, Chiayi, Taiwan
| | - Min-Jen Tseng
- Department of Life Science, National Chung-Cheng University, Chiayi, Taiwan
| | - Ya-Hui Chi
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Miaoli, Taiwan
| | - Min-Lang Huang
- Department of Life Science, National Chung-Cheng University, Chiayi, Taiwan
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93
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Morimoto K, Tamori Y. Induction and Diagnosis of Tumors in Drosophila Imaginal Disc Epithelia. J Vis Exp 2017. [PMID: 28784954 DOI: 10.3791/55901] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
In the early stages of cancer, transformed mutant cells show cytological abnormalities, begin uncontrolled overgrowth, and progressively disrupt tissue organization. Drosophila melanogaster has emerged as a popular experimental model system in cancer biology to study the genetic and cellular mechanisms of tumorigenesis. In particular, genetic tools for Drosophila imaginal discs (developing epithelia in larvae) enable the creation of transformed pro-tumor cells within a normal epithelial tissue, a situation similar to the initial stages of human cancer. A recent study of tumorigenesis in Drosophila wing imaginal discs, however, showed that tumor initiation depends on the tissue-intrinsic cytoarchitecture and the local microenvironment, suggesting that it is important to consider the region-specific susceptibility to tumorigenic stimuli in evaluating tumor phenotypes in imaginal discs. To facilitate phenotypic analysis of tumor progression in imaginal discs, here we describe a protocol for genetic experiments using the GAL4-UAS system to induce neoplastic tumors in wing imaginal discs. We further introduce a diagnosis method to classify the phenotypes of clonal lesions induced in imaginal epithelia, as a clear classification method to discriminate various stages of tumor progression (such as hyperplasia, dysplasia, or neoplasia) had not been described before. These methods might be broadly applicable to the clonal analysis of tumor phenotypes in various organs in Drosophila.
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Affiliation(s)
- Kenta Morimoto
- Structural Biology Center, National Institute of Genetics and Department of Genetics, School of Life Science, SOKENDAI; Graduate School of Media and Governance, Keio University
| | - Yoichiro Tamori
- Structural Biology Center, National Institute of Genetics and Department of Genetics, School of Life Science, SOKENDAI;
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94
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Serotonergic Modulation Enables Pathway-Specific Plasticity in a Developing Sensory Circuit in Drosophila. Neuron 2017; 95:623-638.e4. [PMID: 28712652 DOI: 10.1016/j.neuron.2017.06.034] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 05/06/2017] [Accepted: 06/19/2017] [Indexed: 11/23/2022]
Abstract
How experiences during development cause long-lasting changes in sensory circuits and affect behavior in mature animals are poorly understood. Here we establish a novel system for mechanistic analysis of the plasticity of developing neural circuits by showing that sensory experience during development alters nociceptive behavior and circuit physiology in Drosophila larvae. Despite the convergence of nociceptive and mechanosensory inputs on common second-order neurons (SONs), developmental noxious input modifies transmission from nociceptors to their SONs, but not from mechanosensors to the same SONs, which suggests striking sensory pathway specificity. These SONs activate serotonergic neurons to inhibit nociceptor-to-SON transmission; stimulation of nociceptors during development sensitizes nociceptor presynapses to this feedback inhibition. Our results demonstrate that, unlike associative learning, which involves inputs from two sensory pathways, sensory pathway-specific plasticity in the Drosophila nociceptive circuit is in part established through feedback modulation. This study elucidates a novel mechanism that enables pathway-specific plasticity in sensory systems. VIDEO ABSTRACT.
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95
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Neto M, Naval-Sánchez M, Potier D, Pereira PS, Geerts D, Aerts S, Casares F. Nuclear receptors connect progenitor transcription factors to cell cycle control. Sci Rep 2017; 7:4845. [PMID: 28687780 PMCID: PMC5501803 DOI: 10.1038/s41598-017-04936-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 05/23/2017] [Indexed: 01/31/2023] Open
Abstract
The specification and growth of organs is controlled simultaneously by networks of transcription factors. While the connection between these transcription factors with fate determinants is increasingly clear, how they establish the link with the cell cycle is far less understood. Here we investigate this link in the developing Drosophila eye, where two transcription factors, the MEIS1 homologue hth and the Zn-finger tsh, synergize to stimulate the proliferation of naïve eye progenitors. Experiments combining transcriptomics, open-chromatin profiling, motif analysis and functional assays indicate that these progenitor transcription factors exert a global regulation of the proliferation program. Rather than directly regulating cell cycle genes, they control proliferation through an intermediary layer of nuclear receptors of the ecdysone/estrogen-signaling pathway. This regulatory subnetwork between hth, tsh and nuclear receptors might be conserved from Drosophila to mammals, as we find a significant co-overexpression of their human homologues in specific cancer types.
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Affiliation(s)
- Marta Neto
- CABD, Andalusian Centre for Developmental Biology, CSIC-UPO-JA, 41013, Seville, Spain.,i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal.,IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal
| | | | - Delphine Potier
- School of Medicine, University of Leuven, box 602 3000, Leuven, Belgium
| | - Paulo S Pereira
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal.,IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal
| | - Dirk Geerts
- Department of Medical Biology L2-109, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Stein Aerts
- School of Medicine, University of Leuven, box 602 3000, Leuven, Belgium.
| | - Fernando Casares
- CABD, Andalusian Centre for Developmental Biology, CSIC-UPO-JA, 41013, Seville, Spain.
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96
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Li Y, Pang Z, Huang H, Wang C, Cai T, Xi R. Transcription Factor Antagonism Controls Enteroendocrine Cell Specification from Intestinal Stem Cells. Sci Rep 2017; 7:988. [PMID: 28428611 PMCID: PMC5430544 DOI: 10.1038/s41598-017-01138-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 03/23/2017] [Indexed: 01/28/2023] Open
Abstract
The balanced maintenance and differentiation of local stem cells is required for Homeostatic renewal of tissues. In the Drosophila midgut, the transcription factor Escargot (Esg) maintains undifferentiated states in intestinal stem cells, whereas the transcription factors Scute (Sc) and Prospero (Pros) promote enteroendocrine cell specification. However, the mechanism through which Esg and Sc/Pros coordinately regulate stem cell differentiation is unknown. Here, by combining chromatin immunoprecipitation analysis with genetic studies, we show that both Esg and Sc bind to a common promoter region of pros. Moreover, antagonistic activity between Esg and Sc controls the expression status of Pros in stem cells, thereby, specifying whether stem cells remain undifferentiated or commit to enteroendocrine cell differentiation. Our study therefore reveals transcription factor antagonism between Esg and Sc as a novel mechanism that underlies fate specification from intestinal stem cells in Drosophila.
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Affiliation(s)
- Yumei Li
- School of Life Science, Tsinghua University, Beijing, 100084, China. .,National Institute of Biological Sciences, Zhongguancun Life Science Park 7 Science Park Road, Beijing, 102206, China.
| | - Zhimin Pang
- National Institute of Biological Sciences, Zhongguancun Life Science Park 7 Science Park Road, Beijing, 102206, China
| | - Huanwei Huang
- National Institute of Biological Sciences, Zhongguancun Life Science Park 7 Science Park Road, Beijing, 102206, China
| | - Chenhui Wang
- National Institute of Biological Sciences, Zhongguancun Life Science Park 7 Science Park Road, Beijing, 102206, China
| | - Tao Cai
- National Institute of Biological Sciences, Zhongguancun Life Science Park 7 Science Park Road, Beijing, 102206, China
| | - Rongwen Xi
- National Institute of Biological Sciences, Zhongguancun Life Science Park 7 Science Park Road, Beijing, 102206, China.
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97
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Coleman RT, Struhl G. Causal role for inheritance of H3K27me3 in maintaining the OFF state of a Drosophila HOX gene. Science 2017; 356:eaai8236. [PMID: 28302795 PMCID: PMC5595140 DOI: 10.1126/science.aai8236] [Citation(s) in RCA: 140] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 02/03/2017] [Indexed: 12/20/2022]
Abstract
Many eukaryotic cells can respond to transient environmental or developmental stimuli with heritable changes in gene expression that are associated with nucleosome modifications. However, it remains uncertain whether modified nucleosomes play a causal role in transmitting such epigenetic memories, as opposed to controlling or merely reflecting transcriptional states inherited by other means. Here, we provide in vivo evidence that H3K27 trimethylated nucleosomes, once established at a repressed Drosophila HOX gene, remain heritably associated with that gene and can carry the memory of the silenced state through multiple rounds of replication, even when the capacity to copy the H3K27me3 mark to newly incorporated nucleosomes is diminished or abolished. Hence, in this context, the inheritance of H3K27 trimethylation conveys epigenetic memory.
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Affiliation(s)
- Rory T Coleman
- Department of Genetics and Development, Columbia University College of Physicians and Surgeons, 701 West 168th Street, New York, NY 10032, USA
| | - Gary Struhl
- Department of Genetics and Development, Columbia University College of Physicians and Surgeons, 701 West 168th Street, New York, NY 10032, USA.
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98
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Facilitating Neuron-Specific Genetic Manipulations in Drosophila melanogaster Using a Split GAL4 Repressor. Genetics 2017; 206:775-784. [PMID: 28363977 PMCID: PMC5499185 DOI: 10.1534/genetics.116.199687] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Accepted: 03/28/2017] [Indexed: 12/22/2022] Open
Abstract
Efforts to map neural circuits have been galvanized by the development of genetic technologies that permit the manipulation of targeted sets of neurons in the brains of freely behaving animals. The success of these efforts relies on the experimenter’s ability to target arbitrarily small subsets of neurons for manipulation, but such specificity of targeting cannot routinely be achieved using existing methods. In Drosophila melanogaster, a widely-used technique for refined cell type-specific manipulation is the Split GAL4 system, which augments the targeting specificity of the binary GAL4-UAS (Upstream Activating Sequence) system by making GAL4 transcriptional activity contingent upon two enhancers, rather than one. To permit more refined targeting, we introduce here the “Killer Zipper” (KZip+), a suppressor that makes Split GAL4 targeting contingent upon a third enhancer. KZip+ acts by disrupting both the formation and activity of Split GAL4 heterodimers, and we show how this added layer of control can be used to selectively remove unwanted cells from a Split GAL4 expression pattern or to subtract neurons of interest from a pattern to determine their requirement in generating a given phenotype. To facilitate application of the KZip+ technology, we have developed a versatile set of LexAop-KZip+ fly lines that can be used directly with the large number of LexA driver lines with known expression patterns. KZip+ significantly sharpens the precision of neuronal genetic control available in Drosophila and may be extended to other organisms where Split GAL4-like systems are used.
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99
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Drosophila dyskerin is required for somatic stem cell homeostasis. Sci Rep 2017; 7:347. [PMID: 28337032 PMCID: PMC5428438 DOI: 10.1038/s41598-017-00446-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 02/27/2017] [Indexed: 02/07/2023] Open
Abstract
Drosophila represents an excellent model to dissect the roles played by the evolutionary conserved family of eukaryotic dyskerins. These multifunctional proteins are involved in the formation of H/ACA snoRNP and telomerase complexes, both involved in essential cellular tasks. Since fly telomere integrity is guaranteed by a different mechanism, we used this organism to investigate the specific role played by dyskerin in somatic stem cell maintenance. To this aim, we focussed on Drosophila midgut, a hierarchically organized and well characterized model for stemness analysis. Surprisingly, the ubiquitous loss of the protein uniquely affects the formation of the larval stem cell niches, without altering other midgut cell types. The number of adult midgut precursor stem cells is dramatically reduced, and this effect is not caused by premature differentiation and is cell-autonomous. Moreover, a few dispersed precursors found in the depleted midguts can maintain stem identity and the ability to divide asymmetrically, nor show cell-growth defects or undergo apoptosis. Instead, their loss is mainly specifically dependent on defective amplification. These studies establish a strict link between dyskerin and somatic stem cell maintenance in a telomerase-lacking organism, indicating that loss of stemness can be regarded as a conserved, telomerase-independent effect of dyskerin dysfunction.
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100
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Abstract
The fruit fly, Drosophila melanogaster, has been a favorite experimental system of developmental biologists for more than a century. One of the most attractive features of this model system is the clarity by which one can analyze mutant phenotypes. Most genes are found in single copies, and loss-of-function mutants often have obvious phenotypes that can be analyzed during development and in adulthood. As with all metazoans, a significant fraction of Drosophila genes are used during both embryonic and postembryonic development, and null mutants often die during embryogenesis thereby precluding the analysis of postembryonic tissues. For several decades researchers worked around this problem by either studying gynandromorphs or irradiating chromosomes carrying mutations in the hope of inducing mitotic recombination which would then allow for the analysis of mutant phenotypes in smaller populations of cells. The former method suffers from the fact that mutations in the gene of interest are often lethal when generated in large sectors, which is a hallmark of gynandromorphs. Clonal induction with the latter method occurs at relatively low frequencies making this method laborious. The introduction of the yeast FRT System/FRT site-directed recombination system to Drosophila has made generating loss-of-function mosaic clones simple and easy. Over the years several variants of this method have allowed developmental biologists to remove genes, overexpress genes, and even express one gene in patches of cells that are mutant for a second gene. In this review we will briefly discuss some of various FRT System/FRT-based approaches that are being used to manipulate gene expression in Drosophila. The individual FRT System/FRT-based methods are described in the papers that are cited herein. We will outline the procedure that our lab uses to prepare and analyze mosaic clones in Drosophila eye-antennal imaginal discs.
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