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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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Tommasini G, Dufil G, Fardella F, Strakosas X, Fergola E, Abrahamsson T, Bliman D, Olsson R, Berggren M, Tino A, Stavrinidou E, Tortiglione C. Seamless integration of bioelectronic interface in an animal model via in vivo polymerization of conjugated oligomers. Bioact Mater 2021; 10:107-116. [PMID: 34901533 PMCID: PMC8637319 DOI: 10.1016/j.bioactmat.2021.08.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 08/05/2021] [Accepted: 08/23/2021] [Indexed: 12/26/2022] Open
Abstract
Leveraging the biocatalytic machinery of living organisms for fabricating functional bioelectronic interfaces, in vivo, defines a new class of micro-biohybrids enabling the seamless integration of technology with living biological systems. Previously, we have demonstrated the in vivo polymerization of conjugated oligomers forming conductors within the structures of plants. Here, we expand this concept by reporting that Hydra, an invertebrate animal, polymerizes the conjugated oligomer ETE-S both within cells that expresses peroxidase activity and within the adhesive material that is secreted to promote underwater surface adhesion. The resulting conjugated polymer forms electronically conducting and electrochemically active μm-sized domains, which are inter-connected resulting in percolative conduction pathways extending beyond 100 μm, that are fully integrated within the Hydra tissue and the secreted mucus. Furthermore, the introduction and in vivo polymerization of ETE-S can be used as a biochemical marker to follow the dynamics of Hydra budding (reproduction) and regeneration. This work paves the way for well-defined self-organized electronics in animal tissue to modulate biological functions and in vivo biofabrication of hybrid functional materials and devices.
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Affiliation(s)
- Giuseppina Tommasini
- Istituto di Scienze Applicate e Sistemi Intelligenti "E. Caianiello", Consiglio Nazionale delle Ricerche, Via Campi Flegrei 34, 80078, Pozzuoli, Italy
| | - Gwennaël Dufil
- Laboratory of Organic Electronics, Department of Science and Technology, Linkoping University, SE-60174, Norrkoping, Sweden
| | - Federica Fardella
- Istituto di Scienze Applicate e Sistemi Intelligenti "E. Caianiello", Consiglio Nazionale delle Ricerche, Via Campi Flegrei 34, 80078, Pozzuoli, Italy
| | - Xenofon Strakosas
- Laboratory of Organic Electronics, Department of Science and Technology, Linkoping University, SE-60174, Norrkoping, Sweden
| | - Eugenio Fergola
- Istituto di Scienze Applicate e Sistemi Intelligenti "E. Caianiello", Consiglio Nazionale delle Ricerche, Via Campi Flegrei 34, 80078, Pozzuoli, Italy
| | - Tobias Abrahamsson
- Laboratory of Organic Electronics, Department of Science and Technology, Linkoping University, SE-60174, Norrkoping, Sweden
| | - David Bliman
- Department of Chemistry and Molecular Biology, University of Gothenburg, SE-405 30, Gothenburg, Sweden
| | - Roger Olsson
- Department of Chemistry and Molecular Biology, University of Gothenburg, SE-405 30, Gothenburg, Sweden.,Chemical Biology & Therapeutics, Department of Experimental Medical Science, Lund University, SE-221 84, Lund, Sweden
| | - Magnus Berggren
- Laboratory of Organic Electronics, Department of Science and Technology, Linkoping University, SE-60174, Norrkoping, Sweden
| | - Angela Tino
- Istituto di Scienze Applicate e Sistemi Intelligenti "E. Caianiello", Consiglio Nazionale delle Ricerche, Via Campi Flegrei 34, 80078, Pozzuoli, Italy
| | - Eleni Stavrinidou
- Laboratory of Organic Electronics, Department of Science and Technology, Linkoping University, SE-60174, Norrkoping, Sweden
| | - Claudia Tortiglione
- Istituto di Scienze Applicate e Sistemi Intelligenti "E. Caianiello", Consiglio Nazionale delle Ricerche, Via Campi Flegrei 34, 80078, Pozzuoli, Italy
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Rodrigues M, Ostermann T, Kremeser L, Lindner H, Beisel C, Berezikov E, Hobmayer B, Ladurner P. Profiling of adhesive-related genes in the freshwater cnidarian Hydra magnipapillata by transcriptomics and proteomics. BIOFOULING 2016; 32:1115-1129. [PMID: 27661452 PMCID: PMC5080974 DOI: 10.1080/08927014.2016.1233325] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 09/01/2016] [Indexed: 06/06/2023]
Abstract
The differentiated ectodermal basal disc cells of the freshwater cnidarian Hydra secrete proteinaceous glue to temporarily attach themselves to underwater surfaces. Using transcriptome sequencing and a basal disc-specific RNA-seq combined with in situ hybridisation a highly specific set of candidate adhesive genes was identified. A de novo transcriptome assembly of 55,849 transcripts (>200 bp) was generated using paired-end and single reads from Illumina libraries constructed from different polyp conditions. Differential transcriptomics and spatial gene expression analysis by in situ hybridisation allowed the identification of 40 transcripts exclusively expressed in the ectodermal basal disc cells. Comparisons after mass spectrometry analysis of the adhesive secretion showed a total of 21 transcripts to be basal disc specific and eventually secreted through basal disc cells. This is the first study to survey adhesion-related genes in Hydra. The candidate list presented in this study provides a platform for unravelling the molecular mechanism of underwater adhesion of Hydra.
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Affiliation(s)
- Marcelo Rodrigues
- Institute of Zoology and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria
| | - Thomas Ostermann
- Institute of Zoology and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria
| | - Leopold Kremeser
- Division of Clinical Biochemistry, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Herbert Lindner
- Division of Clinical Biochemistry, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | | | - Eugene Berezikov
- ERIBA, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Bert Hobmayer
- Institute of Zoology and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria
| | - Peter Ladurner
- Institute of Zoology and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria
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Buzgariu W, Al Haddad S, Tomczyk S, Wenger Y, Galliot B. Multi-functionality and plasticity characterize epithelial cells in Hydra. Tissue Barriers 2015; 3:e1068908. [PMID: 26716072 PMCID: PMC4681288 DOI: 10.1080/21688370.2015.1068908] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 06/23/2015] [Accepted: 06/27/2015] [Indexed: 01/09/2023] Open
Abstract
Epithelial sheets, a synapomorphy of all metazoans but porifers, are present as 2 layers in cnidarians, ectoderm and endoderm, joined at their basal side by an extra-cellular matrix named mesoglea. In the Hydra polyp, epithelial cells of the body column are unipotent stem cells that continuously self-renew and concomitantly express their epitheliomuscular features. These multifunctional contractile cells maintain homeostasis by providing a protective physical barrier, by digesting nutrients, by selecting a stable microbiota, and by rapidly closing wounds. In addition, epithelial cells are highly plastic, supporting the adaptation of Hydra to physiological and environmental changes, such as long starvation periods where survival relies on a highly dynamic autophagy flux. Epithelial cells also play key roles in developmental processes as evidenced by the organizer activity they develop to promote budding and regeneration. We propose here an integrative view of the homeostatic and developmental aspects of epithelial plasticity in Hydra.
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Affiliation(s)
- W Buzgariu
- Department of Genetics and Evolution; Institute of Genetics and Genomics in Geneva (IGe3); Faculty of Sciences; University of Geneva; Geneva, Switzerland
| | - S Al Haddad
- Department of Genetics and Evolution; Institute of Genetics and Genomics in Geneva (IGe3); Faculty of Sciences; University of Geneva; Geneva, Switzerland
| | - S Tomczyk
- Department of Genetics and Evolution; Institute of Genetics and Genomics in Geneva (IGe3); Faculty of Sciences; University of Geneva; Geneva, Switzerland
| | - Y Wenger
- Department of Genetics and Evolution; Institute of Genetics and Genomics in Geneva (IGe3); Faculty of Sciences; University of Geneva; Geneva, Switzerland
| | - B Galliot
- Department of Genetics and Evolution; Institute of Genetics and Genomics in Geneva (IGe3); Faculty of Sciences; University of Geneva; Geneva, Switzerland
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6
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Böttger A, Doxey AC, Hess MW, Pfaller K, Salvenmoser W, Deutzmann R, Geissner A, Pauly B, Altstätter J, Münder S, Heim A, Gabius HJ, McConkey BJ, David CN. Horizontal gene transfer contributed to the evolution of extracellular surface structures: the freshwater polyp Hydra is covered by a complex fibrous cuticle containing glycosaminoglycans and proteins of the PPOD and SWT (sweet tooth) families. PLoS One 2012; 7:e52278. [PMID: 23300632 PMCID: PMC3531485 DOI: 10.1371/journal.pone.0052278] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 11/12/2012] [Indexed: 01/11/2023] Open
Abstract
The single-cell layered ectoderm of the fresh water polyp Hydra fulfills the function of an epidermis by protecting the animals from the surrounding medium. Its outer surface is covered by a fibrous structure termed the cuticle layer, with similarity to the extracellular surface coats of mammalian epithelia. In this paper we have identified molecular components of the cuticle. We show that its outermost layer contains glycoproteins and glycosaminoglycans and we have identified chondroitin and chondroitin-6-sulfate chains. In a search for proteins that could be involved in organising this structure we found PPOD proteins and several members of a protein family containing only SWT (sweet tooth) domains. Structural analyses indicate that PPODs consist of two tandem β-trefoil domains with similarity to carbohydrate-binding sites found in lectins. Experimental evidence confirmed that PPODs can bind sulfated glycans and are secreted into the cuticle layer from granules localized under the apical surface of the ectodermal epithelial cells. PPODs are taxon-specific proteins which appear to have entered the Hydra genome by horizontal gene transfer from bacteria. Their acquisition at the time Hydra evolved from a marine ancestor may have been critical for the transition to the freshwater environment.
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Affiliation(s)
- Angelika Böttger
- Department Biologie II, Ludwig-Maximilians-University, Munich, Germany.
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Dash B, Phillips TD. Molecular characterization of a catalase from Hydra vulgaris. Gene 2012; 501:144-52. [PMID: 22521743 DOI: 10.1016/j.gene.2012.04.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Revised: 04/03/2012] [Accepted: 04/05/2012] [Indexed: 01/06/2023]
Abstract
Catalase, an antioxidant and hydroperoxidase enzyme protects the cellular environment from harmful effects of hydrogen peroxide by facilitating its degradation to oxygen and water. Molecular information on a cnidarian catalase and/or peroxidase is, however, limited. In this work an apparent full length cDNA sequence coding for a catalase (HvCatalase) was isolated from Hydra vulgaris using 3'- and 5'- (RLM) RACE approaches. The 1859 bp HvCatalase cDNA included an open reading frame of 1518 bp encoding a putative protein of 505 amino acids with a predicted molecular mass of 57.44 kDa. The deduced amino acid sequence of HvCatalase contained several highly conserved motifs including the heme-ligand signature sequence RLFSYGDTH and the active site signature FXRERIPERVVHAKGXGA. A comparative analysis showed the presence of conserved catalytic amino acids [His(71), Asn(145), and Tyr(354)] in HvCatalase as well. Homology modeling indicated the presence of the conserved features of mammalian catalase fold. Hydrae exposed to thermal, starvation, metal and oxidative stress responded by regulating its catalase mRNA transcription. These results indicated that the HvCatalase gene is involved in the cellular stress response and (anti)oxidative processes triggered by stressor and contaminant exposure.
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Affiliation(s)
- Bhagirathi Dash
- Faculty of Toxicology, Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA
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Notch signalling defines critical boundary during budding in Hydra. Dev Biol 2010; 344:331-45. [DOI: 10.1016/j.ydbio.2010.05.517] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 05/04/2010] [Accepted: 05/28/2010] [Indexed: 11/19/2022]
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Proteomic screen in the simple metazoan Hydra identifies 14-3-3 binding proteins implicated in cellular metabolism, cytoskeletal organisation and Ca2+ signalling. BMC Cell Biol 2007; 8:31. [PMID: 17651497 PMCID: PMC1964759 DOI: 10.1186/1471-2121-8-31] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2006] [Accepted: 07/25/2007] [Indexed: 12/22/2022] Open
Abstract
Background 14-3-3 proteins have been implicated in many signalling mechanisms due to their interaction with Ser/Thr phosphorylated target proteins. They are evolutionarily well conserved in eukaryotic organisms from single celled protozoans and unicellular algae to plants and humans. A diverse array of target proteins has been found in higher plants and in human cell lines including proteins involved in cellular metabolism, apoptosis, cytoskeletal organisation, secretion and Ca2+ signalling. Results We found that the simple metazoan Hydra has four 14-3-3 isoforms. In order to investigate whether the diversity of 14-3-3 target proteins is also conserved over the whole animal kingdom we isolated 14-3-3 binding proteins from Hydra vulgaris using a 14-3-3-affinity column. We identified 23 proteins that covered most of the above-mentioned groups. We also isolated several novel 14-3-3 binding proteins and the Hydra specific secreted fascin-domain-containing protein PPOD. In addition, we demonstrated that one of the 14-3-3 isoforms, 14-3-3 HyA, interacts with one Hydra-Bcl-2 like protein in vitro. Conclusion Our results indicate that 14-3-3 proteins have been ubiquitous signalling components since the start of metazoan evolution. We also discuss the possibility that they are involved in the regulation of cell numbers in response to food supply in Hydra.
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Dash B, Metz R, Huebner HJ, Porter W, Phillips TD. Molecular characterization of phospholipid hydroperoxide glutathione peroxidases from Hydra vulgaris. Gene 2006; 381:1-12. [PMID: 16919897 DOI: 10.1016/j.gene.2006.04.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2005] [Revised: 04/11/2006] [Accepted: 04/13/2006] [Indexed: 11/21/2022]
Abstract
Apparent full-length cDNA sequences coding respectively for mitochondrial (HvGPx41) and nuclear (HvGPx42) phospholipid hydroperoxide glutathione peroxidase were isolated from Hydra vulgaris. The cDNA sequences share total identity in their 3'-end and differ in their 5'-end. The protein-coding regions of the HvGPx41 and HvGPx42 cDNA encode polypeptides of 190 and 168 amino acids, including a TGA-encoded selenocysteine, respectively. Phylogenetic analysis showed that the HvGPx41 and HvGPx42 are clustered together along with other phospholipid hydroperoxide glutathione peroxidases (PHGPx) from several organisms. A tertiary structure model generated for the H. vulgaris PHGPx displayed the thioredoxin fold. Hydrae exposed to starvation, metal and oxidative stress responded by regulating their PHGPx mRNA transcription. These results indicated that the PHGPx gene is affected by the cellular stress response and (anti)oxidative processes triggered by stressor and contaminant exposure. Hence the expression of PHGPx mRNA in hydra may have potential use as molecular biomarkers for assessing stress, toxicity and pro-oxidant quality of chemicals and aquatic environmental quality.
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Affiliation(s)
- Bhagirathi Dash
- Faculty of Toxicology, Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA
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Galliot B, Miljkovic-Licina M, de Rosa R, Chera S. Hydra, a niche for cell and developmental plasticity. Semin Cell Dev Biol 2006; 17:492-502. [PMID: 16807002 DOI: 10.1016/j.semcdb.2006.05.005] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The silencing of genes whose expression is restricted to specific cell types and/or specific regeneration stages opens avenues to decipher the molecular control of the cellular plasticity underlying head regeneration in hydra. In this review, we highlight recent studies that identified genes involved in the immediate cytoprotective function played by gland cells after amputation; the early dedifferentiation of digestive cells into blastema-like cells during head regeneration, and the early late proliferation of neuronal progenitors required for head patterning. Hence, developmental plasticity in hydra relies on spatially restricted and timely orchestrated cellular modifications, where the functions played by stem cells remain to be characterized.
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Affiliation(s)
- Brigitte Galliot
- Department of Zoology and Animal Biology, University of Geneva, Sciences III, 30 Quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland.
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Thomsen S, Bosch TCG. Foot differentiation and genomic plasticity in Hydra: lessons from the PPOD gene family. Dev Genes Evol 2006; 216:57-68. [PMID: 16402271 DOI: 10.1007/s00427-005-0032-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2005] [Accepted: 09/21/2005] [Indexed: 10/25/2022]
Abstract
In Hydra, developmental processes are permanently active to maintain a simple body plan consisting of a two-layered, radially symmetrical tube with two differentiated structures, head and foot. Foot formation is a dynamic process and includes terminal differentiation of gastric epithelial cells into mucous secreting basal disc cells. A well-established marker for this highly specialized cell type is a locally expressed peroxidase (Hoffmeister et al. 1985). Based on the foot-specific peroxidase activity, the gene PPOD1 has been identified (Hoffmeister-Ullerich et al. 2002). Unexpectedly, this approach led to the identification of a second gene, PPOD2, with high sequence similarity to PPOD1 but a strikingly different expression pattern. Here, we characterize PPOD2 in more detail and show that both genes, PPOD1 and PPOD2, are members of a gene family with differential complexity and expression patterns in different Hydra species. At the genomic level, differences in gene number and structure within the PPOD gene family, even among closely related species, support a recently proposed phylogeny of the genus Hydra and point to unexpected genomic plasticity within closely related species of this ancient metazoan taxon.
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Affiliation(s)
- Stefan Thomsen
- Zoological Institute, Christian-Albrechts-University, Kiel, Germany.
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13
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Siebert S, Thomsen S, Reimer MM, Bosch TCG. Control of foot differentiation in Hydra: Phylogenetic footprinting indicates interaction of head, bud and foot patterning systems. Mech Dev 2005; 122:998-1007. [PMID: 15922570 DOI: 10.1016/j.mod.2005.04.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2004] [Revised: 04/27/2005] [Accepted: 04/27/2005] [Indexed: 10/25/2022]
Abstract
Homeodomain transcription factor CnNK-2 seems to play a major role in foot formation in Hydra. Recently, we reported in vitro evidence indicating that CnNK-2 has autoregulatory features and regulates expression of the morphogenetic peptide pedibin. We proposed that CnNK-2 and pedibin synergistically orchestrate foot differentiation processes. Here, we further analyzed the regulatory network controlling foot formation in Hydra. By phylogenetic footprinting we compared the CnNK-2 5'-flanking sequence from two closely related species, Hydra vulgaris and Hydra oligactis. Unexpectedly, we detected a highly conserved binding site for HNF-3beta, a vertebrate Forkhead transcription factor, in the CnNK-2 5'-flanking region. The Hydra HNF-3beta homolog budhead is predominantly expressed in the apical region of the body column and early during budding. Budhead is absent from tissue expressing CnNK-2 and thought to be involved in determining tissue for head differentiation. By electrophoretic mobility shift assays we demonstrate an in vitro interaction between recombinant budhead protein and the interspecific conserved HNF-3beta binding motif in the CnNK-2 5'-flanking region. Our results strengthen the view of CnNK-2 as an important regulator during foot patterning processes. Furtheron, they point to budhead as a candidate for a transcriptional regulator of CnNK-2 and to an interaction of foot and head patterning processes in Hydra on the molecular level.
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Affiliation(s)
- S Siebert
- Zoological Institute, Christian-Albrechts University of Kiel, Am Botanischen Garten 1-9, 24118 Kiel, Germany
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14
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Blackstone NW, Bivins MJ, Cherry KS, Fletcher RE, Geddes GC. Redox signaling in colonial hydroids: many pathways for peroxide. J Exp Biol 2005; 208:383-90. [PMID: 15634856 DOI: 10.1242/jeb.01394] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Studies of mitochondrial redox signaling predict that the colonial hydroids Eirene viridula and Podocoryna carnea should respond to manipulations of reactive oxygen species (ROS). Both species encrust surfaces with feeding polyps connected by networks of stolons; P. carnea is more `sheet-like' with closely spaced polyps and short stolons, while E. viridula is more `runner-like' with widely spaced polyps and long stolons. Treatment with the chemical antioxidant vitamin C diminishes ROS in mitochondrion-rich epitheliomuscular cells (EMCs) and produces phenotypic effects (sheet-like growth) similar to uncouplers of oxidative phosphorylation. In peripheral stolon tips, treatment with vitamin C triggers a dramatic increase of ROS that is followed by tissue death and stolon regression. The enzymatic anti-oxidant catalase is probably not taken up by the colony but, rather, converts hydrogen peroxide in the medium to water and oxygen. Exogenous catalase does not affect ROS in mitochondrion-rich EMCs, but does increase the amounts of ROS emitted from peripheral stolons, resulting in rapid, runner-like growth. Treatment with exogenous hydrogen peroxide increases ROS levels in stolon tips and results in somewhat faster colony growth. Finally, untreated colonies of E. viridula exhibit higher levels of ROS in stolon tips than untreated colonies of P. carnea. ROS may participate in a number of putative signaling pathways: (1) high levels of ROS may trigger cell and tissue death in peripheral stolon tips; (2)more moderate levels of ROS in stolon tips may trigger outward growth, inhibit branching and, possibly, mediate the redox signaling of mitochondrion-rich EMCs; and (3) ROS may have an extra-colony function, perhaps in suppressing the growth of bacteria.
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Affiliation(s)
- Neil W Blackstone
- Department of Biological Sciences, Northern Illinois University, DeKalb, IL 60115, USA.
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