1
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Perween N, Pekhale K, Haval G, Sirkar G, Bose GS, Mittal SPK, Ghaskadbi S, Ghaskadbi SS. Identification and characterization of multidomain monothiol glutaredoxin 3 from diploblastic Hydra. Comp Biochem Physiol B Biochem Mol Biol 2024; 273:110986. [PMID: 38703881 DOI: 10.1016/j.cbpb.2024.110986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 04/30/2024] [Accepted: 04/30/2024] [Indexed: 05/06/2024]
Abstract
Intracellular antioxidant glutaredoxin controls cell proliferation and survival. Based on the active site, structure, and conserved domain motifs, it is classified into two classes. Class I contains dithiol Grxs with two cysteines in the consensus active site sequence CXXC, while class II has monothiol Grxs with one cysteine residue in the active site. Monothiol Grxs can also have an additional N-terminal thioredoxin (Trx)-like domain. Previously, we reported the characterization of Grx1 from Hydra vulgaris (HvGrx1), which is a dithiol isoform. Here, we report the molecular cloning, expression, analysis, and characterization of another isoform of Grx, which is the multidomain monothiol glutaredoxin-3 from Hydra vulgaris (HvGrx3). It encodes a protein with 303 amino acids and is significantly larger and more divergent than HvGrx1. In-silico analysis revealed that Grx1 and Grx3 have 22.5% and 9.9% identical nucleotide and amino acid sequences, respectively. HvGrx3 has two glutaredoxin domains and a thioredoxin-like domain at its amino terminus, unlike HvGrx1, which has a single glutaredoxin domain. Like other monothiol glutaredoxins, HvGrx3 failed to reduce glutathione-hydroxyethyl disulfide. In the whole Hydra, HvGrx3 was found to be expressed all over the body column, and treatment with H2O2 led to a significant upregulation of HvGrx3. When transfected in HCT116 (human colon cancer cells) cells, HvGrx3 enhanced cell proliferation and migration, indicating that this isoform could be involved in these cellular functions. These transfected cells also tolerate oxidative stress better.
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Affiliation(s)
- Nusrat Perween
- Department of Zoology, Savitribai Phule Pune University, Pune 411007, India; Department of Zoology, M.C.E. Society's Abeda Inamdar Senior College, Pune 411001, India. https://twitter.com/nusratperween13
| | - Komal Pekhale
- Department of Zoology, Savitribai Phule Pune University, Pune 411007, India
| | - Gauri Haval
- Department of Zoology, Savitribai Phule Pune University, Pune 411007, India; Department of Zoology, Abasaheb Garware College, Pune 411004, India
| | - Gargi Sirkar
- Department of Zoology, Savitribai Phule Pune University, Pune 411007, India
| | - Ganesh S Bose
- Department of Biotechnology, Savitribai Phule Pune University, Pune 411007, India
| | - Smriti P K Mittal
- Department of Biotechnology, Savitribai Phule Pune University, Pune 411007, India
| | - Surendra Ghaskadbi
- Developmental Biology Group, MACS-Agharkar Research Institute, Pune 411004, India
| | - Saroj S Ghaskadbi
- Department of Zoology, Savitribai Phule Pune University, Pune 411007, India.
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2
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Iglesias Ollé L, Perruchoud C, Sanchez PGL, Vogg MC, Galliot B. The Wnt/β-catenin/TCF/Sp5/Zic4 Gene Network That Regulates Head Organizer Activity in Hydra Is Differentially Regulated in Epidermis and Gastrodermis. Biomedicines 2024; 12:1274. [PMID: 38927481 PMCID: PMC11201823 DOI: 10.3390/biomedicines12061274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 06/02/2024] [Accepted: 06/03/2024] [Indexed: 06/28/2024] Open
Abstract
Hydra head formation depends on an organizing center in which Wnt/β-catenin signaling, that plays an inductive role, positively regulates Sp5 and Zic4, with Sp5 limiting Wnt3/β-catenin expression and Zic4 triggering tentacle formation. Using transgenic lines in which the HySp5 promoter drives eGFP expression in either the epidermis or gastrodermis, we show that Sp5 promoter activity is differentially regulated in each epithelial layer. In intact animals, epidermal HySp5:GFP activity is strong apically and weak along the body column, while in the gastrodermis, it is maximal in the tentacle ring region and maintained at a high level along the upper body column. During apical regeneration, HySp5:GFP is activated early in the gastrodermis and later in the epidermis. Alsterpaullone treatment induces a shift in apical HySp5:GFP expression towards the body column where it forms transient circular figures in the epidermis. Upon β-catenin(RNAi), HySp5:GFP activity is down-regulated in the epidermis while bud-like structures expressing HySp5:GFP in the gastrodermis develop. Sp5(RNAi) reveals a negative Sp5 autoregulation in the epidermis, but not in the gastrodermis. These differential regulations in the epidermis and gastrodermis highlight the distinct architectures of the Wnt/β-catenin/TCF/Sp5/Zic4 network in the hypostome, tentacle base and body column of intact animals, as well as in the buds and apical and basal regenerating tips.
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Affiliation(s)
| | | | | | | | - Brigitte Galliot
- Department of Genetics and Evolution, Institute of Genetics and Genomics (iGE3), Faculty of Sciences, University of Geneva, 30 Quai Ernest Ansermet, 1205 Geneva, Switzerland (C.P.); (P.G.L.S.)
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3
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Pan Q, Mercker M, Klimovich A, Wittlieb J, Marciniak-Czochra A, Böttger A. Genetic interference with HvNotch provides new insights into the role of the Notch-signalling pathway for developmental pattern formation in Hydra. Sci Rep 2024; 14:8553. [PMID: 38609434 PMCID: PMC11014954 DOI: 10.1038/s41598-024-58837-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 04/03/2024] [Indexed: 04/14/2024] Open
Abstract
The Notch-signalling pathway plays an important role in pattern formation in Hydra. Using pharmacological Notch inhibitors (DAPT and SAHM1), it has been demonstrated that HvNotch is required for head regeneration and tentacle patterning in Hydra. HvNotch is also involved in establishing the parent-bud boundary and instructing buds to develop feet and detach from the parent. To further investigate the functions of HvNotch, we successfully constructed NICD (HvNotch intracellular domain)-overexpressing and HvNotch-knockdown transgenic Hydra strains. NICD-overexpressing transgenic Hydra showed a pronounced inhibition on the expression of predicted HvNotch-target genes, suggesting a dominant negative effect of ectopic NICD. This resulted in a "Y-shaped" phenotype, which arises from the parent-bud boundary defect seen in polyps treated with DAPT. Additionally, "multiple heads", "two-headed" and "ectopic tentacles" phenotypes were observed. The HvNotch-knockdown transgenic Hydra with reduced expression of HvNotch exhibited similar, but not identical phenotypes, with the addition of a "two feet" phenotype. Furthermore, we observed regeneration defects in both, overexpression and knockdown strains. We integrated these findings into a mathematical model based on long-range gradients of signalling molecules underlying sharply defined positions of HvNotch-signalling cells at the Hydra tentacle and bud boundaries.
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Affiliation(s)
- Qin Pan
- Biocenter, Ludwig-Maximilians-University Munich, Großhaderner Str. 2, 82152, Planegg-Martinsried, Germany.
| | - Moritz Mercker
- Institute of Applied Mathematics, Heidelberg University, Im Neuenheimer Feld 205, 69120, Heidelberg, Germany
| | - Alexander Klimovich
- Zoological Institute, Christian-Albrechts-University of Kiel, Am Botanischen Garten 1-9, 24118, Kiel, Germany
| | - Jörg Wittlieb
- Zoological Institute, Christian-Albrechts-University of Kiel, Am Botanischen Garten 1-9, 24118, Kiel, Germany
| | - Anna Marciniak-Czochra
- Institute of Applied Mathematics, Heidelberg University, Im Neuenheimer Feld 205, 69120, Heidelberg, Germany
| | - Angelika Böttger
- Biocenter, Ludwig-Maximilians-University Munich, Großhaderner Str. 2, 82152, Planegg-Martinsried, Germany.
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4
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Holstein TW. The Hydra stem cell system - Revisited. Cells Dev 2023; 174:203846. [PMID: 37121433 DOI: 10.1016/j.cdev.2023.203846] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 04/12/2023] [Accepted: 04/25/2023] [Indexed: 05/02/2023]
Abstract
Cnidarians are >600 million years old and are considered the sister group of Bilateria based on numerous molecular phylogenetic studies. Apart from Hydra, the genomes of all major clades of Cnidaria have been uncovered (e.g. Aurelia, Clytia, Nematostella and Acropora) and they reveal a remarkable completeness of the metazoan genomic toolbox. Of particular interest is Hydra, a model system of aging research, regenerative biology, and stem cell biology. With the knowledge gained from scRNA research, it is now possible to characterize the expression profiles of all cell types with great precision. In functional studies, our picture of the Hydra stem cell biology has changed, and we are in the process of obtaining a clear picture of the homeostasis and properties of the different stem cell populations. Even though Hydra is often compared to plant systems, the new data on germline and regeneration, but also on the dynamics and plasticity of the nervous system, show that Hydra with its simple body plan represents in a nutshell the prototype of an animal with stem cell lineages, whose properties correspond in many ways to Bilateria. This review provides an overview of the four stem cell lineages, the two epithelial lineages that constitute the ectoderm and the endoderm, as well as the multipotent somatic interstitial lineage (MPSC) and the germline stem cell lineage (GSC), also known as the interstitial cells of Hydra.
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Affiliation(s)
- Thomas W Holstein
- Heidelberg University, Centre for Organismal Studies (COS), Molecular Evolution and Genomics, Im Neuenheimer Feld 230, D-69120 Heidelberg, Germany.
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5
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Vogg MC, Ferenc J, Buzgariu WC, Perruchoud C, Sanchez PGL, Beccari L, Nuninger C, Le Cras Y, Delucinge-Vivier C, Papasaikas P, Vincent S, Galliot B, Tsiairis CD. The transcription factor Zic4 promotes tentacle formation and prevents epithelial transdifferentiation in Hydra. SCIENCE ADVANCES 2022; 8:eabo0694. [PMID: 36563144 PMCID: PMC9788771 DOI: 10.1126/sciadv.abo0694] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The molecular mechanisms that maintain cellular identities and prevent dedifferentiation or transdifferentiation remain mysterious. However, both processes are transiently used during animal regeneration. Therefore, organisms that regenerate their organs, appendages, or even their whole body offer a fruitful paradigm to investigate the regulation of cell fate stability. Here, we used Hydra as a model system and show that Zic4, whose expression is controlled by Wnt3/β-catenin signaling and the Sp5 transcription factor, plays a key role in tentacle formation and tentacle maintenance. Reducing Zic4 expression suffices to induce transdifferentiation of tentacle epithelial cells into foot epithelial cells. This switch requires the reentry of tentacle battery cells into the cell cycle without cell division and is accompanied by degeneration of nematocytes embedded in these cells. These results indicate that maintenance of cell fate by a Wnt-controlled mechanism is a key process both during homeostasis and during regeneration.
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Affiliation(s)
- Matthias Christian Vogg
- Department of Genetics and Evolution, Institute of Genetics and Genomics (iGE3), Faculty of Sciences, University of Geneva, 30 Quai Ernest Ansermet, Geneva 4 1211, Switzerland
| | - Jaroslav Ferenc
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, Basel 4058, Switzerland
- University of Basel, Petersplatz 1, Basel 4001, Switzerland
| | - Wanda Christa Buzgariu
- Department of Genetics and Evolution, Institute of Genetics and Genomics (iGE3), Faculty of Sciences, University of Geneva, 30 Quai Ernest Ansermet, Geneva 4 1211, Switzerland
| | - Chrystelle Perruchoud
- Department of Genetics and Evolution, Institute of Genetics and Genomics (iGE3), Faculty of Sciences, University of Geneva, 30 Quai Ernest Ansermet, Geneva 4 1211, Switzerland
| | - Paul Gerald Layague Sanchez
- Department of Genetics and Evolution, Institute of Genetics and Genomics (iGE3), Faculty of Sciences, University of Geneva, 30 Quai Ernest Ansermet, Geneva 4 1211, Switzerland
| | - Leonardo Beccari
- Institut NeuroMyoGène, CNRS UMR 5310, INSERM U1217, University Claude Bernard Lyon 1, Lyon, France
| | - Clara Nuninger
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, Basel 4058, Switzerland
- University of Basel, Petersplatz 1, Basel 4001, Switzerland
| | - Youn Le Cras
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, Basel 4058, Switzerland
| | - Céline Delucinge-Vivier
- iGE3 Genomics Platform, University of Geneva, 1 Rue Michel-Servet, Geneva 4 1211, Switzerland
| | - Panagiotis Papasaikas
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, Basel 4058, Switzerland
- SIB Swiss Institute of Bioinformatics, Basel 4058, Switzerland
| | - Stéphane Vincent
- Laboratoire de Biologie et Modélisation de la Cellule, Ecole Normale Supérieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Université Claude Bernard Lyon 1, 46 allée d’Italie, Lyon F-69364, France
| | - Brigitte Galliot
- Department of Genetics and Evolution, Institute of Genetics and Genomics (iGE3), Faculty of Sciences, University of Geneva, 30 Quai Ernest Ansermet, Geneva 4 1211, Switzerland
- Corresponding author. (B.G.); (C.D.T.)
| | - Charisios D. Tsiairis
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, Basel 4058, Switzerland
- Corresponding author. (B.G.); (C.D.T.)
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6
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Erofeeva TV, Grigorenko AP, Gusev FE, Kosevich IA, Rogaev EI. Studying of Molecular Regulation of Developmental Processes of Lower Metazoans Exemplified by Cnidaria Using High-Throughput Sequencing. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:269-293. [PMID: 35526848 DOI: 10.1134/s0006297922030075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 12/13/2021] [Accepted: 01/17/2022] [Indexed: 06/14/2023]
Abstract
A unique set of features and characteristics of species of the Cnidaria phylum is the one reason that makes them a model for a various studies. The plasticity of a life cycle and the processes of cell differentiation and development of an integral multicellular organism associated with it are of a specific scientific interest. A new stage of development of molecular genetic methods, including methods for high-throughput genome, transcriptome, and epigenome sequencing, both at the level of the whole organism and at the level of individual cells, makes it possible to obtain a detailed picture of the development of these animals. This review examines some modern approaches and advances in the reconstruction of the processes of ontogenesis of cnidarians by studying the regulatory signal transduction pathways and their interactions.
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Affiliation(s)
- Taisia V Erofeeva
- Department Research Center for Genetics and Life Sciences, Sirius University of Science and Technology, Sochi, Krasnodar Region, 354349, Russia
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia
| | - Anastasia P Grigorenko
- Department Research Center for Genetics and Life Sciences, Sirius University of Science and Technology, Sochi, Krasnodar Region, 354349, Russia.
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia
| | - Fedor E Gusev
- Department Research Center for Genetics and Life Sciences, Sirius University of Science and Technology, Sochi, Krasnodar Region, 354349, Russia
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia
| | - Igor A Kosevich
- Department Research Center for Genetics and Life Sciences, Sirius University of Science and Technology, Sochi, Krasnodar Region, 354349, Russia
- Lomonosov Moscow State University, Moscow, 119234, Russia
| | - Evgeny I Rogaev
- Department Research Center for Genetics and Life Sciences, Sirius University of Science and Technology, Sochi, Krasnodar Region, 354349, Russia
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia
- Lomonosov Moscow State University, Moscow, 119234, Russia
- Department of Psychiatry, UMass Chan Medical School, Shrewsbury, MA 01545, USA
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7
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Moros M, Fergola E, Marchesano V, Mutarelli M, Tommasini G, Miedziak B, Palumbo G, Ambrosone A, Tino A, Tortiglione C. The Aquatic Invertebrate Hydra vulgaris Releases Molecular Messages Through Extracellular Vesicles. Front Cell Dev Biol 2022; 9:788117. [PMID: 34988080 PMCID: PMC8721104 DOI: 10.3389/fcell.2021.788117] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 11/15/2021] [Indexed: 12/11/2022] Open
Abstract
Recent body of evidence demonstrates that extracellular vesicles (EVs) represent the first language of cell-cell communication emerged during evolution. In aquatic environments, transferring signals between cells by EVs offers protection against degradation, allowing delivering of chemical information in high local concentrations to the target cells. The packaging of multiple signals, including those of hydrophobic nature, ensures target cells to receive the same EV-conveyed messages, and the coordination of a variety of physiological processes across cells of a single organisms, or at the population level, i.e., mediating the population’s response to changing environmental conditions. Here, we purified EVs from the medium of the freshwater invertebrate Hydra vulgaris, and the molecular profiling by proteomic and transcriptomic analyses revealed multiple markers of the exosome EV subtype, from structural proteins to stress induced messages promoting cell survival. Moreover, positive and negative regulators of the Wnt/β-catenin signaling pathway, the major developmental pathway acting in body axial patterning, were identified. Functional analysis on amputated polyps revealed EV ability to modulate both head and foot regeneration, suggesting bioactivity of the EV cargo and opening new perspectives on the mechanisms of developmental signalling. Our results open the path to unravel EV biogenesis and function in all cnidarian species, tracing back the origin of the cell-cell, cross-species or cross-kingdom communication in aquatic ecosystems.
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Affiliation(s)
- Maria Moros
- Instituto de Nanociencia y Materiales de Aragón(INMA), CSIC-Universidad de Zaragoza, Zaragoza, Spain.,Istituto di Scienze Applicate e Sistemi Intelligenti "E. Caianiello", Consiglio Nazionale Delle Ricerche, Pozzuoli, Italy
| | - Eugenio Fergola
- Istituto di Scienze Applicate e Sistemi Intelligenti "E. Caianiello", Consiglio Nazionale Delle Ricerche, Pozzuoli, Italy
| | - Valentina Marchesano
- Istituto di Scienze Applicate e Sistemi Intelligenti "E. Caianiello", Consiglio Nazionale Delle Ricerche, Pozzuoli, Italy
| | - Margherita Mutarelli
- Istituto di Scienze Applicate e Sistemi Intelligenti "E. Caianiello", Consiglio Nazionale Delle Ricerche, Pozzuoli, Italy
| | - Giuseppina Tommasini
- Istituto di Scienze Applicate e Sistemi Intelligenti "E. Caianiello", Consiglio Nazionale Delle Ricerche, Pozzuoli, Italy
| | - Beata Miedziak
- Istituto di Scienze Applicate e Sistemi Intelligenti "E. Caianiello", Consiglio Nazionale Delle Ricerche, Pozzuoli, Italy
| | - Giuliana Palumbo
- Istituto di Scienze Applicate e Sistemi Intelligenti "E. Caianiello", Consiglio Nazionale Delle Ricerche, Pozzuoli, Italy
| | - Alfredo Ambrosone
- Istituto di Scienze Applicate e Sistemi Intelligenti "E. Caianiello", Consiglio Nazionale Delle Ricerche, Pozzuoli, Italy
| | - Angela Tino
- Istituto di Scienze Applicate e Sistemi Intelligenti "E. Caianiello", Consiglio Nazionale Delle Ricerche, Pozzuoli, Italy
| | - Claudia Tortiglione
- Istituto di Scienze Applicate e Sistemi Intelligenti "E. Caianiello", Consiglio Nazionale Delle Ricerche, Pozzuoli, Italy
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8
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Murad R, Macias-Muñoz A, Wong A, Ma X, Mortazavi A. Coordinated Gene Expression and Chromatin Regulation during Hydra Head Regeneration. Genome Biol Evol 2021; 13:evab221. [PMID: 34877597 PMCID: PMC8651858 DOI: 10.1093/gbe/evab221] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/20/2021] [Indexed: 12/13/2022] Open
Abstract
The cnidarian model organism Hydra has long been studied for its remarkable ability to regenerate its head, which is controlled by a head organizer located near the hypostome. The canonical Wnt pathway plays a central role in head organizer function during regeneration and during bud formation, which is the asexual mode of reproduction in Hydra. However, it is unclear how shared the developmental programs of head organizer genesis are in budding and regeneration. Time-series analysis of gene expression changes during head regeneration and budding revealed a set of 298 differentially expressed genes during the 48-h head regeneration and 72-h budding time courses. In order to understand the regulatory elements controlling Hydra head regeneration, we first identified 27,137 open-chromatin elements that are open in one or more sections of the organism body or regenerating tissue. We used histone modification ChIP-seq to identify 9,998 candidate proximal promoter and 3,018 candidate enhancer-like regions respectively. We show that a subset of these regulatory elements is dynamically remodeled during head regeneration and identify a set of transcription factor motifs that are enriched in the enhancer regions activated during head regeneration. Our results show that Hydra displays complex gene regulatory structures of developmentally dynamic enhancers, which suggests that the evolution of complex developmental enhancers predates the split of cnidarians and bilaterians.
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Affiliation(s)
- Rabi Murad
- Department of Developmental and Cell Biology, University of California Irvine, USA
- Center for Complex Biological Systems, University of California Irvine, USA
| | - Aide Macias-Muñoz
- Department of Developmental and Cell Biology, University of California Irvine, USA
- Center for Complex Biological Systems, University of California Irvine, USA
| | - Ashley Wong
- Department of Developmental and Cell Biology, University of California Irvine, USA
- Center for Complex Biological Systems, University of California Irvine, USA
| | - Xinyi Ma
- Department of Developmental and Cell Biology, University of California Irvine, USA
- Center for Complex Biological Systems, University of California Irvine, USA
| | - Ali Mortazavi
- Department of Developmental and Cell Biology, University of California Irvine, USA
- Center for Complex Biological Systems, University of California Irvine, USA
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9
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Unni M, Reddy PC, Pal M, Sagi I, Galande S. Identification of Components of the Hippo Pathway in Hydra and Potential Role of YAP in Cell Division and Differentiation. Front Genet 2021; 12:676182. [PMID: 34691138 PMCID: PMC8526868 DOI: 10.3389/fgene.2021.676182] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 09/15/2021] [Indexed: 11/22/2022] Open
Abstract
The Hippo signaling pathway has been shown to be involved in regulating cellular identity, cell/tissue size maintenance and mechanotransduction. The Hippo pathway consists of a kinase cascade which determines the nucleo-cytoplasmic localization of YAP in the cell. YAP is the effector protein in the Hippo pathway, which acts as a transcriptional cofactor for TEAD. Phosphorylation of YAP upon activation of the Hippo pathway prevents it from entering the nucleus and abrogates its function in the transcription of the target genes. In Cnidaria, the information on the regulatory roles of the Hippo pathway is virtually lacking. Here, we report the existence of a complete set of Hippo pathway core components in Hydra for the first time. By studying their phylogeny and domain organization, we report evolutionary conservation of the components of the Hippo pathway. Protein modelling suggested the conservation of YAP-TEAD interaction in Hydra. Further, we characterized the expression pattern of the homologs of yap, hippo, mob and sav in Hydra using whole-mount RNA in situ hybridization and report their possible role in stem cell maintenance. Immunofluorescence assay revealed that Hvul_YAP expressing cells occur in clusters in the body column and are excluded in the terminally differentiated regions. Actively proliferating cells marked by Ki67 exhibit YAP colocalization in their nuclei. Strikingly, a subset of these colocalized cells is actively recruited to the newly developing bud. Disruption of the YAP-TEAD interaction increased the budding rate indicating a critical role of YAP in regulating cell proliferation in Hydra. Collectively, we posit that the Hippo pathway is an essential signaling system in Hydra; its components are ubiquitously expressed in the Hydra body column and play a crucial role in Hydra tissue homeostasis.
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Affiliation(s)
- Manu Unni
- Centre of Excellence in Epigenetics, Department of Biology, Indian Institute of Science Education and Research, Pune, India
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Puli Chandramouli Reddy
- Centre of Excellence in Epigenetics, Department of Biology, Indian Institute of Science Education and Research, Pune, India
| | - Mrinmoy Pal
- Centre of Excellence in Epigenetics, Department of Biology, Indian Institute of Science Education and Research, Pune, India
| | - Irit Sagi
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Sanjeev Galande
- Centre of Excellence in Epigenetics, Department of Biology, Indian Institute of Science Education and Research, Pune, India
- Department of Life Sciences, Shiv Nadar University, Delhi-NCR, India
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10
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Moneer J, Siebert S, Krebs S, Cazet J, Prexl A, Pan Q, Juliano C, Böttger A. Differential gene regulation in DAPT-treated Hydra reveals candidate direct Notch signalling targets. J Cell Sci 2021; 134:jcs258768. [PMID: 34346482 PMCID: PMC8353520 DOI: 10.1242/jcs.258768] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 05/03/2021] [Indexed: 11/20/2022] Open
Abstract
In Hydra, Notch inhibition causes defects in head patterning and prevents differentiation of proliferating nematocyte progenitor cells into mature nematocytes. To understand the molecular mechanisms by which the Notch pathway regulates these processes, we performed RNA-seq and identified genes that are differentially regulated in response to 48 h of treating the animals with the Notch inhibitor DAPT. To identify candidate direct regulators of Notch signalling, we profiled gene expression changes that occur during subsequent restoration of Notch activity and performed promoter analyses to identify RBPJ transcription factor-binding sites in the regulatory regions of Notch-responsive genes. Interrogating the available single-cell sequencing data set revealed the gene expression patterns of Notch-regulated Hydra genes. Through these analyses, a comprehensive picture of the molecular pathways regulated by Notch signalling in head patterning and in interstitial cell differentiation in Hydra emerged. As prime candidates for direct Notch target genes, in addition to Hydra (Hy)Hes, we suggest Sp5 and HyAlx. They rapidly recovered their expression levels after DAPT removal and possess Notch-responsive RBPJ transcription factor-binding sites in their regulatory regions.
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Affiliation(s)
- Jasmin Moneer
- Ludwig Maximilians-University Munich, Germany, Biocenter, 82152 Planegg-Martinsried, Großhaderner Str. 2, Germany
| | - Stefan Siebert
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Stefan Krebs
- Ludwig-Maximilians-University Munich, Gene Center Munich, Feodor-Lynen-Str. 25 81377 Munich, Germany
| | - Jack Cazet
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Andrea Prexl
- Ludwig Maximilians-University Munich, Germany, Biocenter, 82152 Planegg-Martinsried, Großhaderner Str. 2, Germany
| | - Qin Pan
- Ludwig Maximilians-University Munich, Germany, Biocenter, 82152 Planegg-Martinsried, Großhaderner Str. 2, Germany
| | - Celina Juliano
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Angelika Böttger
- Ludwig Maximilians-University Munich, Germany, Biocenter, 82152 Planegg-Martinsried, Großhaderner Str. 2, Germany
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11
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Luz BLP, Miller DJ, Kitahara MV. High regenerative capacity is a general feature within colonial dendrophylliid corals (Anthozoa, Scleractinia). JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2021; 336:281-292. [PMID: 33503321 DOI: 10.1002/jez.b.23021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 12/03/2020] [Accepted: 12/09/2020] [Indexed: 12/21/2022]
Abstract
The regenerative capacity of cnidarians plays an essential role in the maintenance and restoration of coral reef ecosystems by allowing faster recovery from disturbances and more efficient small-scale dispersal. However, in the case of invasive species, this property may contribute to their dispersal and success in nonnative habitats. Given that four Indo-Pacific members of the coral genus Tubastraea have invaded the Atlantic, here we evaluated the ability of three of these species (Tubastraea coccinea, Tubastraea diaphana, and Tubastraea micranthus) to regenerate from fragments of undifferentiated coral tissue to fully functional polyps in response to differences in food supply and fragment size. For comparative purposes, another colonial dendrophylliid (Dendrophyllia sp.) was included in the analyses. All dendrophylliids displayed regenerative ability and high survival rates that were independent of whether or not food was supplied or fragment size. However, regeneration rates varied between species and were influenced by fragment size. Temporal expression of key genes of the regenerative process (Wnt and FGF) was profiled during whole-body regeneration of T. coccinea, suggesting a remarkable regenerative ability of T. coccinea that points to its potential use as a laboratory model for the investigation of regeneration in colonial calcified anthozoans.
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Affiliation(s)
- Bruna Louise Pereira Luz
- Coastal and Ocean Systems Graduate Program, Federal University of Paraná, Pontal do Sul, Pontal do Paraná, Paraná, Brazil.,Center for Marine Biology, University of São Paulo, Praia do Cabelo Gordo, São Sebastião, Brazil.,ARC Centre of Excellence for Coral Reef Studies and Centre for Tropical Bioinformatics and Molecular Biology, James Cook University, Townsville, Queensland, Australia
| | - David John Miller
- ARC Centre of Excellence for Coral Reef Studies and Centre for Tropical Bioinformatics and Molecular Biology, James Cook University, Townsville, Queensland, Australia
| | - Marcelo Visentini Kitahara
- Coastal and Ocean Systems Graduate Program, Federal University of Paraná, Pontal do Sul, Pontal do Paraná, Paraná, Brazil.,Center for Marine Biology, University of São Paulo, Praia do Cabelo Gordo, São Sebastião, Brazil.,Department of Marine Sciences, Federal University of São Paulo, Santos, São Paulo, Brazil
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12
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Reverse Genetic Approaches to Investigate the Neurobiology of the Cnidarian Sea Anemone Nematostella vectensis. Methods Mol Biol 2020; 2047:25-43. [PMID: 31552647 DOI: 10.1007/978-1-4939-9732-9_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The cnidarian sea anemone Nematostella vectensis has grown in popularity as a model system to complement the ongoing work in traditional bilaterian model species (e.g. Drosophila, C. elegans, vertebrate). The driving force behind developing cnidarian model systems is the potential of this group of animals to impact EvoDevo studies aimed at better determining the origin and evolution of bilaterian traits, such as centralized nervous systems. However, it is becoming apparent that cnidarians have the potential to impact our understanding of regenerative neurogenesis and systems neuroscience. Next-generation sequencing and the development of reverse genetic approaches led to functional genetics becoming routine in the Nematostella system. As a result, researchers are beginning to understand how cnidarian nerve nets are related to the bilaterian nervous systems. This chapter describes the methods for morpholino and mRNA injections to knockdown or overexpress genes of interest, respectively. Carrying out these techniques in Nematostella requires obtaining and preparing embryos for microinjection, designing and generating effective morpholino and mRNA molecules with controls for injection, and optimizing injection conditions.
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13
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Mashanov V, Akiona J, Khoury M, Ferrier J, Reid R, Machado DJ, Zueva O, Janies D. Active Notch signaling is required for arm regeneration in a brittle star. PLoS One 2020; 15:e0232981. [PMID: 32396580 PMCID: PMC7217437 DOI: 10.1371/journal.pone.0232981] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 04/24/2020] [Indexed: 12/15/2022] Open
Abstract
Cell signaling pathways play key roles in coordinating cellular events in development. The Notch signaling pathway is highly conserved across all multicellular animals and is known to coordinate a multitude of diverse cellular events, including proliferation, differentiation, fate specification, and cell death. Specific functions of the pathway are, however, highly context-dependent and are not well characterized in post-traumatic regeneration. Here, we use a small-molecule inhibitor of the pathway (DAPT) to demonstrate that Notch signaling is required for proper arm regeneration in the brittle star Ophioderma brevispina, a highly regenerative member of the phylum Echinodermata. We also employ a transcriptome-wide gene expression analysis (RNA-seq) to characterize the downstream genes controlled by the Notch pathway in the brittle star regeneration. We demonstrate that arm regeneration involves an extensive cross-talk between the Notch pathway and other cell signaling pathways. In the regrowing arm, Notch regulates the composition of the extracellular matrix, cell migration, proliferation, and apoptosis, as well as components of the innate immune response. We also show for the first time that Notch signaling regulates the activity of several transposable elements. Our data also suggests that one of the possible mechanisms through which Notch sustains its activity in the regenerating tissues is via suppression of Neuralized1.
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Affiliation(s)
- Vladimir Mashanov
- Department of Biology, University of North Florida, Jacksonville, FL, United states of America
- Wake Forest Institute for Regenerative Medicine, Winston Salem, NC, United states of America
- * E-mail:
| | - Jennifer Akiona
- Department of Biology, University of North Florida, Jacksonville, FL, United states of America
| | - Maleana Khoury
- Department of Biology, University of North Florida, Jacksonville, FL, United states of America
| | - Jacob Ferrier
- University of North Carolina at Charlotte, Charlotte, NC, United states of America
| | - Robert Reid
- University of North Carolina at Charlotte, Charlotte, NC, United states of America
| | - Denis Jacob Machado
- University of North Carolina at Charlotte, Charlotte, NC, United states of America
| | - Olga Zueva
- Department of Biology, University of North Florida, Jacksonville, FL, United states of America
| | - Daniel Janies
- University of North Carolina at Charlotte, Charlotte, NC, United states of America
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14
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Macias-Muñoz A, Murad R, Mortazavi A. Molecular evolution and expression of opsin genes in Hydra vulgaris. BMC Genomics 2019; 20:992. [PMID: 31847811 PMCID: PMC6918707 DOI: 10.1186/s12864-019-6349-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 11/28/2019] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND The evolution of opsin genes is of great interest because it can provide insight into the evolution of light detection and vision. An interesting group in which to study opsins is Cnidaria because it is a basal phylum sister to Bilateria with much visual diversity within the phylum. Hydra vulgaris (H. vulgaris) is a cnidarian with a plethora of genomic resources to characterize the opsin gene family. This eyeless cnidarian has a behavioral reaction to light, but it remains unknown which of its many opsins functions in light detection. Here, we used phylogenetics and RNA-seq to investigate the molecular evolution of opsin genes and their expression in H. vulgaris. We explored where opsin genes are located relative to each other in an improved genome assembly and where they belong in a cnidarian opsin phylogenetic tree. In addition, we used RNA-seq data from different tissues of the H. vulgaris adult body and different time points during regeneration and budding stages to gain insight into their potential functions. RESULTS We identified 45 opsin genes in H. vulgaris, many of which were located near each other suggesting evolution by tandem duplications. Our phylogenetic tree of cnidarian opsin genes supported previous claims that they are evolving by lineage-specific duplications. We identified two H. vulgaris genes (HvOpA1 and HvOpB1) that fall outside of the two commonly determined Hydra groups; these genes possibly have a function in nematocytes and mucous gland cells respectively. We also found opsin genes that have similar expression patterns to phototransduction genes in H. vulgaris. We propose a H. vulgaris phototransduction cascade that has components of both ciliary and rhabdomeric cascades. CONCLUSIONS This extensive study provides an in-depth look at the molecular evolution and expression of H. vulgaris opsin genes. The expression data that we have quantified can be used as a springboard for additional studies looking into the specific function of opsin genes in this species. Our phylogeny and expression data are valuable to investigations of opsin gene evolution and cnidarian biology.
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Affiliation(s)
- Aide Macias-Muñoz
- Department of Developmental and Cell Biology, University of California, Irvine, CA, 92697, USA.
| | - Rabi Murad
- Department of Developmental and Cell Biology, University of California, Irvine, CA, 92697, USA
| | - Ali Mortazavi
- Department of Developmental and Cell Biology, University of California, Irvine, CA, 92697, USA.
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15
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Epithelial and interstitial Notch1 activity contributes to the myofibroblastic phenotype and fibrosis. Cell Commun Signal 2019; 17:145. [PMID: 31718671 PMCID: PMC6849313 DOI: 10.1186/s12964-019-0455-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 10/10/2019] [Indexed: 12/13/2022] Open
Abstract
Background Notch1 signalling is a stem-cell-related pathway that is essential for embryonic development, tissue regeneration and organogenesis. However, the role of Notch1 in the formation of myofibroblasts and fibrosis in kidneys following injury remains unknown. Methods The activity of Notch1 signalling was evaluated in fibrotic kidneys in CKD patients and in ureteral obstructive models in vivo and in cultured fibroblasts and TECs in vitro. In addition, the crosstalk of Notch1 with TGF-β1/Smad2/3 signalling was also investigated. Results Notch1 activity was elevated in fibrotic kidneys of rat models and patients with chronic kidney disease (CKD). Further study revealed that epithelial and interstitial Notch1 activity correlated with an α-SMA-positive myofibroblastic phenotype. In vitro, injury stimulated epithelial Notch1 activation and epithelial-mesenchymal transition (EMT), resulting in matrix deposition in tubular epithelial cells (TECs). Additionally, interstitial Notch1 activation in association with fibroblast-myofibroblast differentiation (FMD) in fibroblasts mediated a myofibroblastic phenotype. These TGF-β1/Smad2/3-dependent phenotypic transitions were abolished by Notch1 knockdown or a specific antagonist, DAPT, and were exacerbated by Notch1 overexpression or an activator Jagged-1-Fc chimaera protein. Interestingly, as a major driving force behind the EMT and FMD, TGF-β1, also induced epithelial and interstitial Notch1 activity, indicating that TGF-β1 may engage in crosstalk with Notch1 signalling to trigger fibrogenesis. Conclusion These findings suggest that epithelial and interstitial Notch1 activation in kidneys following injury contributes to the myofibroblastic phenotype and fibrosis through the EMT in TECs and to the FMD in fibroblasts by targeting downstream TGF-β1/Smad2/3 signalling.
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16
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Goel T, Wang R, Martin S, Lanphear E, Collins EMS. Linalool acts as a fast and reversible anesthetic in Hydra. PLoS One 2019; 14:e0224221. [PMID: 31648269 PMCID: PMC6812832 DOI: 10.1371/journal.pone.0224221] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 10/08/2019] [Indexed: 01/23/2023] Open
Abstract
The ability to make transgenic Hydra lines has allowed for quantitative in vivo studies of Hydra regeneration and physiology. These studies commonly include excision, grafting and transplantation experiments along with high-resolution imaging of live animals, which can be challenging due to the animal’s response to touch and light stimuli. While various anesthetics have been used in Hydra studies, they tend to be toxic over the course of a few hours or their long-term effects on animal health are unknown. Here, we show that the monoterpenoid alcohol linalool is a useful anesthetic for Hydra. Linalool is easy to use, non-toxic, fast acting, and reversible. It has no detectable long-term effects on cell viability or cell proliferation. We demonstrate that the same animal can be immobilized in linalool multiple times at intervals of several hours for repeated imaging over 2–3 days. This uniquely allows for in vivo imaging of dynamic processes such as head regeneration. We directly compare linalool to currently used anesthetics and show its superior performance. Linalool will be a useful tool for tissue manipulation and imaging in Hydra research in both research and teaching contexts.
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Affiliation(s)
- Tapan Goel
- Department of Physics, University of California San Diego, La Jolla, CA, United States of America
- Department of Biology, Swarthmore College, Swarthmore, PA, United States of America
| | - Rui Wang
- Department of Biology, Swarthmore College, Swarthmore, PA, United States of America
- Department of Bioengineering, University of California San Diego, La Jolla, CA, United States of America
| | - Sara Martin
- Department of Biology, Swarthmore College, Swarthmore, PA, United States of America
| | - Elizabeth Lanphear
- Department of Biology, Swarthmore College, Swarthmore, PA, United States of America
| | - Eva-Maria S. Collins
- Department of Physics, University of California San Diego, La Jolla, CA, United States of America
- Department of Biology, Swarthmore College, Swarthmore, PA, United States of America
- * E-mail:
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17
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Mehta AS, Singh A. Insights into regeneration tool box: An animal model approach. Dev Biol 2019; 453:111-129. [PMID: 30986388 PMCID: PMC6684456 DOI: 10.1016/j.ydbio.2019.04.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 04/04/2019] [Accepted: 04/09/2019] [Indexed: 12/20/2022]
Abstract
For ages, regeneration has intrigued countless biologists, clinicians, and biomedical engineers. In recent years, significant progress made in identification and characterization of a regeneration tool kit has helped the scientific community to understand the mechanism(s) involved in regeneration across animal kingdom. These mechanistic insights revealed that evolutionarily conserved pathways like Wnt, Notch, Hedgehog, BMP, and JAK/STAT are involved in regeneration. Furthermore, advancement in high throughput screening approaches like transcriptomic analysis followed by proteomic validations have discovered many novel genes, and regeneration specific enhancers that are specific to highly regenerative species like Hydra, Planaria, Newts, and Zebrafish. Since genetic machinery is highly conserved across the animal kingdom, it is possible to engineer these genes and regeneration specific enhancers in species with limited regeneration properties like Drosophila, and mammals. Since these models are highly versatile and genetically tractable, cross-species comparative studies can generate mechanistic insights in regeneration for animals with long gestation periods e.g. Newts. In addition, it will allow extrapolation of regenerative capabilities from highly regenerative species to animals with low regeneration potential, e.g. mammals. In future, these studies, along with advancement in tissue engineering applications, can have strong implications in the field of regenerative medicine and stem cell biology.
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Affiliation(s)
- Abijeet S Mehta
- Department of Biology, University of Dayton, Dayton, OH, 45469, USA
| | - Amit Singh
- Department of Biology, University of Dayton, Dayton, OH, 45469, USA; Premedical Program, University of Dayton, Dayton, OH, 45469, USA; Center for Tissue Regeneration and Engineering at Dayton (TREND), University of Dayton, Dayton, OH, 45469, USA; The Integrative Science and Engineering Center, University of Dayton, Dayton, OH, 45469, USA; Center for Genomic Advocacy (TCGA), Indiana State University, Terre Haute, IN, USA.
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18
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He S, Grasis JA, Nicotra ML, Juliano CE, Schnitzler CE. Cnidofest 2018: the future is bright for cnidarian research. EvoDevo 2019; 10:20. [PMID: 31508195 PMCID: PMC6724248 DOI: 10.1186/s13227-019-0134-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 08/21/2019] [Indexed: 12/02/2022] Open
Abstract
The 2018 Cnidarian Model Systems Meeting (Cnidofest) was held September 6-9th at the University of Florida Whitney Laboratory for Marine Bioscience in St. Augustine, FL. Cnidofest 2018, which built upon the momentum of Hydroidfest 2016, brought together research communities working on a broad spectrum of cnidarian organisms from North America and around the world. Meeting talks covered diverse aspects of cnidarian biology, with sessions focused on genomics, development, neurobiology, immunology, symbiosis, ecology, and evolution. In addition to interesting biology, Cnidofest also emphasized the advancement of modern research techniques. Invited technology speakers showcased the power of microfluidics and single-cell transcriptomics and demonstrated their application in cnidarian models. In this report, we provide an overview of the exciting research that was presented at the meeting and discuss opportunities for future research.
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Affiliation(s)
- Shuonan He
- Stowers Institute for Medical Research, Kansas City, MO 64110 USA
| | - Juris A. Grasis
- School of Natural Sciences, University of California, Merced, CA 95343 USA
| | - Matthew L. Nicotra
- Department of Surgery, Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA 15261 USA
- Pittsburgh Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, PA USA
- Department of Immunology, University of Pittsburgh, Pittsburgh, PA USA
| | - Celina E. Juliano
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616 USA
| | - Christine E. Schnitzler
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL 32080 USA
- Department of Biology, University of Florida, Gainesville, FL 32611 USA
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19
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Regionalized nervous system in Hydra and the mechanism of its development. Gene Expr Patterns 2019; 31:42-59. [PMID: 30677493 DOI: 10.1016/j.gep.2019.01.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 01/15/2019] [Indexed: 12/15/2022]
Abstract
The last common ancestor of Bilateria and Cnidaria is considered to develop a nervous system over 500 million years ago. Despite the long course of evolution, many of the neuron-related genes, which are active in Bilateria, are also found in the cnidarian Hydra. Thus, Hydra is a good model to study the putative primitive nervous system in the last common ancestor that had the great potential to evolve to a more advanced one. Regionalization of the nervous system is one of the advanced features of bilaterian nervous system. Although a regionalized nervous system is already known to be present in Hydra, its developmental mechanisms are poorly understood. In this study we show how it is formed and maintained, focusing on the neuropeptide Hym-176 gene and its paralogs. First, we demonstrate that four axially localized neuron subsets that express different combination of the neuropeptide Hym-176 gene and its paralogs cover almost an entire body, forming a regionalized nervous system in Hydra. Second, we show that positional information governed by the Wnt signaling pathway plays a key role in determining the regional specificity of the neuron subsets as is the case in bilaterians. Finally, we demonstrated two basic mechanisms, regionally restricted new differentiation and phenotypic conversion, both of which are in part conserved in bilaterians, are involved in maintaining boundaries between the neuron subsets. Therefore, this study is the first comprehensive analysis of the anatomy and developmental regulation of the divergently evolved and axially regionalized peptidergic nervous system in Hydra, implicating an ancestral origin of neural regionalization.
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20
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Abstract
Regeneration of lost body parts is essential to regain the fitness of the organism for successful living. In the animal kingdom, organisms from different clades exhibit varied regeneration abilities. Hydra is one of the few organisms that possess tremendous regeneration potential, capable of regenerating complete organism from small tissue fragments or even from dissociated cells. This peculiar property has made this genus one of the most invaluable model organisms for understanding the process of regeneration. Multiple studies in Hydra led to the current understanding of gross morphological changes, basic cellular dynamics, and the role of molecular signalling such as the Wnt signalling pathway. However, cell-to-cell communication by cell adhesion, role of extracellular components such as extracellular matrix (ECM), and nature of cell types that contribute to the regeneration process need to be explored in depth. Additionally, roles of developmental signalling pathways need to be elucidated to enable more comprehensive understanding of regeneration in Hydra. Further research on cross communication among extracellular, cellular, and molecular signalling in Hydra will advance the field of regeneration biology. Here, we present a review of the existing literature on Hydra regeneration biology and outline the future perspectives.
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Affiliation(s)
- Puli Chandramouli Reddy
- Department of Biology, Indian Institute of Science Education and Research, Pune, Maharashtra, India.
| | - Akhila Gungi
- Department of Biology, Indian Institute of Science Education and Research, Pune, Maharashtra, India
| | - Manu Unni
- Department of Biology, Indian Institute of Science Education and Research, Pune, Maharashtra, India
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21
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Erkurt M. Emergence of form in embryogenesis. J R Soc Interface 2018; 15:20180454. [PMID: 30429261 PMCID: PMC6283983 DOI: 10.1098/rsif.2018.0454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 10/12/2018] [Indexed: 11/23/2022] Open
Abstract
The development of form in an embryo is the result of a series of topological and informational symmetry breakings. We introduce the vector-reaction-diffusion-drift (VRDD) system where the limit cycle of spatial dynamics is morphogen concentrations with Dirac delta-type distributions. This is fundamentally different from the Turing reaction-diffusion system, as VRDD generates system-wide broken symmetry. We developed 'fundamental forms' from spherical blastula with a single organizing axis (rotational symmetry), double axis (mirror symmetry) and triple axis (no symmetry operator in three dimensions). We then introduced dynamics for cell differentiation, where genetic regulatory states are modelled as a finite-state machine (FSM). The state switching of an FSM is based on local morphogen concentrations as epigenetic information that changes dynamically. We grow complicated forms hierarchically in spatial subdomains using the FSM model coupled with the VRDD system. Using our integrated simulation model with four layers (topological, physical, chemical and regulatory), we generated life-like forms such as hydra. Genotype-phenotype mapping was investigated with continuous and jump mutations. Our study can have applications in morphogenetic engineering, soft robotics and biomimetic design.
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Affiliation(s)
- Murat Erkurt
- Department of Mathematics, Centre for Complexity Science, Imperial College London, London SW7 2AZ, UK
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22
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Gazave E, Lemaître QIB, Balavoine G. The Notch pathway in the annelid Platynereis: insights into chaetogenesis and neurogenesis processes. Open Biol 2017; 7:rsob.160242. [PMID: 28148821 PMCID: PMC5356439 DOI: 10.1098/rsob.160242] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 01/03/2017] [Indexed: 01/13/2023] Open
Abstract
Notch is a key signalling pathway playing multiple and varied functions during development. Notch regulates the selection of cells with a neurogenic fate and maintains a pool of yet uncommitted precursors through lateral inhibition, both in insects and in vertebrates. Here, we explore the functions of Notch in the annelid Platynereis dumerilii (Lophotrochozoa). Conserved components of the pathway are identified and a scenario for their evolution in metazoans is proposed. Unexpectedly, neither Notch nor its ligands are expressed in the neurogenic epithelia of the larva at the time when massive neurogenesis begins. Using chemical inhibitors and neural markers, we demonstrate that Notch plays no major role in the general neurogenesis of larvae. Instead, we find Notch components expressed in nascent chaetal sacs, the organs that produce the annelid bristles. Impairing Notch signalling induces defects in chaetal sac formation, abnormalities in chaetae producing cells and a change of identity of chaeta growth accessory cells. This is the first bilaterian species in which the early neurogenesis processes appear to occur without a major involvement of the Notch pathway. Instead, Notch is co-opted to pattern annelid-specific organs, likely through a lateral inhibition process. These features reinforce the view that Notch signalling has been recruited multiple times in evolution due to its remarkable ‘toolkit’ nature.
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Affiliation(s)
- Eve Gazave
- Institut Jacques Monod, CNRS, UMR 7592, Univ Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France
| | - Quentin I B Lemaître
- Institut Jacques Monod, CNRS, UMR 7592, Univ Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France
| | - Guillaume Balavoine
- Institut Jacques Monod, CNRS, UMR 7592, Univ Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France
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23
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Gahan JM, Schnitzler CE, DuBuc TQ, Doonan LB, Kanska J, Gornik SG, Barreira S, Thompson K, Schiffer P, Baxevanis AD, Frank U. Functional studies on the role of Notch signaling in Hydractinia development. Dev Biol 2017; 428:224-231. [PMID: 28601529 DOI: 10.1016/j.ydbio.2017.06.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 06/06/2017] [Accepted: 06/06/2017] [Indexed: 11/19/2022]
Abstract
The function of Notch signaling was previously studied in two cnidarians, Hydra and Nematostella, representing the lineages Hydrozoa and Anthozoa, respectively. Using pharmacological inhibition in Hydra and a combination of pharmacological and genetic approaches in Nematostella, it was shown in both animals that Notch is required for tentacle morphogenesis and for late stages of stinging cell maturation. Surprisingly, a role for Notch in neural development, which is well documented in bilaterians, was evident in embryonic Nematostella but not in adult Hydra. Adult neurogenesis in the latter seemed to be unaffected by DAPT, a drug that inhibits Notch signaling. To address this apparent discrepancy, we studied the role of Notch in Hydractinia echinata, an additional hydrozoan, in all life stages. Using CRISPR-Cas9 mediated mutagenesis, transgenesis, and pharmacological interference we show that Notch is dispensable for Hydractinia normal neurogenesis in all life stages but is required for the maturation of stinging cells and for tentacle morphogenesis. Our results are consistent with a conserved role for Notch in morphogenesis and nematogenesis across Cnidaria, and a lineage-specific loss of Notch dependence in neurogenesis in hydrozoans.
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Affiliation(s)
- James M Gahan
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Christine E Schnitzler
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL 320803, USA; Department of Biology, University of Florida, Gainesville, FL 32611, USA; Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Timothy Q DuBuc
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Liam B Doonan
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Justyna Kanska
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Sebastian G Gornik
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Sofia Barreira
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Kerry Thompson
- Centre for Microscopy and Imaging, Discipline of Anatomy, School of Medicine, National University of Ireland, Galway, Galway, Ireland
| | - Philipp Schiffer
- Department for Genetics Environment and Evolution, University College London, London, UK
| | - Andreas D Baxevanis
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Uri Frank
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland.
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24
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Holz O, Apel D, Steinmetz P, Lange E, Hopfenmüller S, Ohler K, Sudhop S, Hassel M. Bud detachment in hydra requires activation of fibroblast growth factor receptor and a Rho-ROCK-myosin II signaling pathway to ensure formation of a basal constriction. Dev Dyn 2017; 246:502-516. [PMID: 28411398 PMCID: PMC5518445 DOI: 10.1002/dvdy.24508] [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: 09/14/2016] [Revised: 01/20/2017] [Accepted: 04/06/2017] [Indexed: 01/03/2023] Open
Abstract
Background:Hydra propagates asexually by exporting tissue into a bud, which detaches 4 days later as a fully differentiated young polyp. Prerequisite for detachment is activation of fibroblast growth factor receptor (FGFR) signaling. The mechanism which enables constriction and tissue separation within the monolayered ecto‐ and endodermal epithelia is unknown. Results: Histological sections and staining of F‐actin by phalloidin revealed conspicuous cell shape changes at the bud detachment site indicating a localized generation of mechanical forces and the potential enhancement of secretory functions in ectodermal cells. By gene expression analysis and pharmacological inhibition, we identified a candidate signaling pathway through Rho, ROCK, and myosin II, which controls bud base constriction and rearrangement of the actin cytoskeleton. Specific regional myosin phosphorylation suggests a crucial role of ectodermal cells at the detachment site. Inhibition of FGFR, Rho, ROCK, or myosin II kinase activity is permissive for budding, but represses myosin phosphorylation, rearrangement of F‐actin and constriction. The young polyp remains permanently connected to the parent by a broad tissue bridge. Conclusions: Our data suggest an essential role of FGFR and a Rho‐ROCK‐myosin II pathway in the control of cell shape changes required for bud detachment. Developmental Dynamics 246:502–516, 2017. © 2017 The Authors Developmental Dynamics published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists Hydra bud detachment involves the separation of two intact epithelia without cell death. Remarkable cell shape changes and multicellular rosettes at the bud base indicate functional specification and strong mechanical forces. mRNA colocalization, phospho‐myosin analysis and similar phenotypes obtained by pharmacological inhibition suggest a tight correlation between FGFR and a Rho‐ROCK‐Myosin II candidate signaling pathway.
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Affiliation(s)
- Oliver Holz
- Philipps-Universität Marburg, Faculty of Biology, Morphology and Evolution of Invertebrates, Marburg, Germany
| | - David Apel
- Philipps-Universität Marburg, Faculty of Biology, Morphology and Evolution of Invertebrates, Marburg, Germany
| | - Patrick Steinmetz
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway
| | - Ellen Lange
- Philipps-Universität Marburg, Faculty of Biology, Morphology and Evolution of Invertebrates, Marburg, Germany
| | - Simon Hopfenmüller
- Philipps-Universität Marburg, Faculty of Biology, Morphology and Evolution of Invertebrates, Marburg, Germany
| | - Kerstin Ohler
- Philipps-Universität Marburg, Faculty of Biology, Morphology and Evolution of Invertebrates, Marburg, Germany
| | - Stefanie Sudhop
- Center for Applied Tissue Engineering and Regenerative Medicine (CANTER), Munich University of Applied Sciences, Munich, Germany
| | - Monika Hassel
- Philipps-Universität Marburg, Faculty of Biology, Morphology and Evolution of Invertebrates, Marburg, Germany
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Kelava I, Rentzsch F, Technau U. Evolution of eumetazoan nervous systems: insights from cnidarians. Philos Trans R Soc Lond B Biol Sci 2016; 370:rstb.2015.0065. [PMID: 26554048 PMCID: PMC4650132 DOI: 10.1098/rstb.2015.0065] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Cnidarians, the sister group to bilaterians, have a simple diffuse nervous system. This morphological simplicity and their phylogenetic position make them a crucial group in the study of the evolution of the nervous system. The development of their nervous systems is of particular interest, as by uncovering the genetic programme that underlies it, and comparing it with the bilaterian developmental programme, it is possible to make assumptions about the genes and processes involved in the development of ancestral nervous systems. Recent advances in sequencing methods, genetic interference techniques and transgenic technology have enabled us to get a first glimpse into the molecular network underlying the development of a cnidarian nervous system—in particular the nervous system of the anthozoan Nematostella vectensis. It appears that much of the genetic network of the nervous system development is partly conserved between cnidarians and bilaterians, with Wnt and bone morphogenetic protein (BMP) signalling, and Sox genes playing a crucial part in the differentiation of neurons. However, cnidarians possess some specific characteristics, and further studies are necessary to elucidate the full regulatory network. The work on cnidarian neurogenesis further accentuates the need to study non-model organisms in order to gain insights into processes that shaped present-day lineages during the course of evolution.
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Affiliation(s)
- Iva Kelava
- Department of Molecular Evolution and Development, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Fabian Rentzsch
- Sars Centre, Sars International Centre for Marine Molecular Biology, Thormøhlensgt. 55, 5008 Bergen, Norway
| | - Ulrich Technau
- Department of Molecular Evolution and Development, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
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Reinardy HC, Emerson CE, Manley JM, Bodnar AG. Tissue regeneration and biomineralization in sea urchins: role of Notch signaling and presence of stem cell markers. PLoS One 2015; 10:e0133860. [PMID: 26267358 PMCID: PMC4534296 DOI: 10.1371/journal.pone.0133860] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 07/02/2015] [Indexed: 11/30/2022] Open
Abstract
Echinoderms represent a phylum with exceptional regenerative capabilities that can reconstruct both external appendages and internal organs. Mechanistic understanding of the cellular pathways involved in regeneration in these animals has been hampered by the limited genomic tools and limited ability to manipulate regenerative processes. We present a functional assay to investigate mechanisms of tissue regeneration and biomineralization by measuring the regrowth of amputated tube feet (sensory and motor appendages) and spines in the sea urchin, Lytechinus variegatus. The ability to manipulate regeneration was demonstrated by concentration-dependent inhibition of regrowth of spines and tube feet by treatment with the mitotic inhibitor, vincristine. Treatment with the gamma-secretase inhibitor DAPT resulted in a concentration-dependent inhibition of regrowth, indicating that both tube feet and spine regeneration require functional Notch signaling. Stem cell markers (Piwi and Vasa) were expressed in tube feet and spine tissue, and Vasa-positive cells were localized throughout the epidermis of tube feet by immunohistochemistry, suggesting the existence of multipotent progenitor cells in these highly regenerative appendages. The presence of Vasa protein in other somatic tissues (e.g. esophagus, radial nerve, and a sub-population of coelomocytes) suggests that multipotent cells are present throughout adult sea urchins and may contribute to normal homeostasis in addition to regeneration. Mechanistic insight into the cellular pathways governing the tremendous regenerative capacity of echinoderms may reveal processes that can be modulated for regenerative therapies, shed light on the evolution of regeneration, and enable the ability to predict how these processes will respond to changing environmental conditions.
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Affiliation(s)
- Helena C. Reinardy
- Molecular Discovery Laboratory, Bermuda Institute of Ocean Sciences, St. George’s GE 01, Bermuda
| | - Chloe E. Emerson
- Molecular Discovery Laboratory, Bermuda Institute of Ocean Sciences, St. George’s GE 01, Bermuda
| | - Jason M. Manley
- Molecular Discovery Laboratory, Bermuda Institute of Ocean Sciences, St. George’s GE 01, Bermuda
| | - Andrea G. Bodnar
- Molecular Discovery Laboratory, Bermuda Institute of Ocean Sciences, St. George’s GE 01, Bermuda
- * E-mail:
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Nödl MT, Fossati SM, Domingues P, Sánchez FJ, Zullo L. The making of an octopus arm. EvoDevo 2015; 6:19. [PMID: 26052417 PMCID: PMC4458049 DOI: 10.1186/s13227-015-0012-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 04/13/2015] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Most of our current findings on appendage formation and patterning stem from studies on chordate and ecdysozoan model organisms. However, in order to fully understand the evolution of animal appendages, it is essential to include information on appendage development from lophotrochozoan representatives. Here, we examined the basic dynamics of the Octopus vulgaris arm's formation and differentiation - as a highly evolved member of the lophotrochozoan super phylum - with a special focus on the formation of the arm's musculature. RESULTS The octopus arm forms during distinct phases, including an early outgrowth from an epithelial thickening, an elongation, and a late differentiation into mature tissue types. During early arm outgrowth, uniform proliferation leads to the formation of a rounded bulge, which subsequently elongates along its proximal-distal axis by means of actin-mediated epithelial cell changes. Further differentiation of all tissue layers is initiated but end-differentiation is postponed to post-hatching stages. Interestingly, muscle differentiation shows temporal differences in the formation of distinct muscle layers. Particularly, first myocytes appear in the area of the future transverse prior to the longitudinal muscle layer, even though the latter represents the more dominant muscle type at hatching stage. Sucker rudiments appear as small epithelial outgrowths with a mesodermal and ectodermal component on the oral part of the arm. During late differentiation stages, cell proliferation becomes localized to a distal arm region termed the growth zone of the arm. CONCLUSIONS O. vulgaris arm formation shows both, similarities to known model species as well as species-specific patterns of arm formation. Similarities include early uniform cell proliferation and actin-mediated cell dynamics, which lead to an elongation along the proximal-distal axis. Furthermore, the switch to an adult-like progressive distal growth mode during late differentiation stages is reminiscent of the vertebrate progress zone. However, tissue differentiation shows a species-specific delay, which is correlated to a paralarval pelagic phase after hatching and concomitant emerging behavioral modifications. By understanding the general dynamics of octopus arm formation, we established a basis for further studies on appendage patterning, growth, and differentiation in a representative of the lophotrochozoan super phylum.
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Affiliation(s)
- Marie-Therese Nödl
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - Sara M Fossati
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - Pedro Domingues
- Centro Oceanografico de Vigo, Instituto Español de Oceanografia, Subida Radio Faro, 50 36390 Vigo, Spain
| | - Francisco J Sánchez
- Centro Oceanografico de Vigo, Instituto Español de Oceanografia, Subida Radio Faro, 50 36390 Vigo, Spain
| | - Letizia Zullo
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
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Layden MJ, Martindale MQ. Non-canonical Notch signaling represents an ancestral mechanism to regulate neural differentiation. EvoDevo 2014; 5:30. [PMID: 25705370 PMCID: PMC4335385 DOI: 10.1186/2041-9139-5-30] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 08/12/2014] [Indexed: 01/22/2023] Open
Abstract
Background Cellular differentiation is a critical process during development of multicellular animals that must be tightly controlled in order to avoid precocious differentiation or failed generation of differentiated cell types. Research in flies, vertebrates, and nematodes has led to the identification of a conserved role for Notch signaling as a mechanism to regulate cellular differentiation regardless of tissue/cell type. Notch signaling can occur through a canonical pathway that results in the activation of hes gene expression by a complex consisting of the Notch intracellular domain, SuH, and the Mastermind co-activator. Alternatively, Notch signaling can occur via a non-canonical mechanism that does not require SuH or activation of hes gene expression. Regardless of which mechanism is being used, high Notch activity generally inhibits further differentiation, while low Notch activity promotes differentiation. Flies, vertebrates, and nematodes are all bilaterians, and it is therefore unclear if Notch regulation of differentiation is a bilaterian innovation, or if it represents a more ancient mechanism in animals. Results To reconstruct the ancestral function of Notch signaling we investigate Notch function in a non-bilaterian animal, the sea anemone Nematostella vectensis (Cnidaria). Morpholino or pharmacological knockdown of Nvnotch causes increased expression of the neural differentiation gene NvashA. Conversely, overactivation of Notch activity resulting from overexpression of the Nvnotch intracellular domain or by overexpression of the Notch ligand Nvdelta suppresses NvashA. We also knocked down or overactivated components of the canonical Notch signaling pathway. We disrupted NvsuH with morpholino or by overexpressing a dominant negative NvsuH construct. We saw no change in expression levels for Nvhes genes or NvashA. Overexpression of Nvhes genes did not alter NvashA expression levels. Lastly, we tested additional markers associated with neuronal differentiation and observed that non-canonical Notch signaling broadly suppresses neural differentiation in Nematostella. Conclusions We conclude that one ancestral role for Notch in metazoans was to regulate neural differentiation. Remarkably, we found no evidence for a functional canonical Notch pathway during Nematostella embryogenesis, suggesting that the non-canonical hes-independent Notch signaling mechanism may represent an ancestral Notch signaling pathway.
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Affiliation(s)
- Michael J Layden
- Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015, USA
| | - Mark Q Martindale
- Whitney Laboratory for Marine Bioscience, University of Florida, St Augustine, FL 32080, USA
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