1
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Garg N, Štibler UK, Eismann B, Mercker M, Bergheim BG, Linn A, Tuchscherer P, Engel U, Redl S, Marciniak-Czochra A, Holstein TW, Hess MW, Özbek S. Non-muscle myosin II drives critical steps of nematocyst morphogenesis. iScience 2023; 26:106291. [PMID: 36936784 PMCID: PMC10014300 DOI: 10.1016/j.isci.2023.106291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 10/04/2022] [Accepted: 02/20/2023] [Indexed: 03/02/2023] Open
Abstract
Nematocysts are generated by secretion of proteins into a post-Golgi compartment. They consist of a capsule that elongates into a long tube, which is coiled inside the capsule matrix and expelled during its nano-second discharge deployed for prey capture. The driving force for discharge is an extreme osmotic pressure of 150 bar. The complex processes of tube elongation and invagination under these biomechanical constraints have so far been elusive. Here, we show that a non-muscle myosin II homolog (HyNMII) is essential for nematocyst formation in Hydra. In early nematocysts, HyNMII assembles to a collar around the neck of the protruding tube. HyNMII then facilitates tube outgrowth by compressing it along the longitudinal axis as evidenced by inhibitor treatment and genetic knockdown. In addition, live imaging of a NOWA::NOWA-GFP transgenic line, which re-defined NOWA as a tube component facilitating invagination, allowed us to analyze the impact of HyNMII on tube maturation.
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Affiliation(s)
- Niharika Garg
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Urška Knez Štibler
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Björn Eismann
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Moritz Mercker
- Institute for Applied Mathematics, Interdisciplinary Center for Scientific Computing, Heidelberg University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Bruno Gideon Bergheim
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Anna Linn
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Patrizia Tuchscherer
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Ulrike Engel
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
- Nikon Imaging Center at the University of Heidelberg, Bioquant, Heidelberg University, 69120 Heidelberg, Germany
| | - Stefan Redl
- Institute of Neuroanatomy, Medical University of Innsbruck, Müllerstrasse 59, 6020 Innsbruck, Austria
- Institute of Zoology, University of Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
| | - Anna Marciniak-Czochra
- Institute for Applied Mathematics, Interdisciplinary Center for Scientific Computing, Heidelberg University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Thomas W. Holstein
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Michael W. Hess
- Institute of Histology and Embryology, Medical University of Innsbruck, Müllerstrasse 59, 6020 Innsbruck, Austria
| | - Suat Özbek
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
- Corresponding author
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2
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Kyslík J, Vancová M, Bartošová-Sojková P, Lövy A, Holzer AS, Fiala I. Expression profiling and cellular localization of myxozoan minicollagens during nematocyst formation and sporogenesis. Int J Parasitol 2022:S0020-7519(22)00104-7. [PMID: 35970383 DOI: 10.1016/j.ijpara.2022.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 07/14/2022] [Accepted: 07/19/2022] [Indexed: 11/20/2022]
Abstract
In free-living cnidarians, minicollagens are major structural components in the biogenesis of nematocysts. Recent sequence mining and proteomic analysis demonstrate that minicollagens are also expressed by myxozoans, a group of evolutionarily ancient cnidarian endoparasites. Nonetheless, the presence and abundance of nematocyst-associated genes/proteins in nematocyst morphogenesis have never been studied in Myxozoa. Here, we report the gene expression profiles of three myxozoan minicollagens, ncol-1, ncol-3, and the recently identified noncanonical ncol-5, during the intrapiscine development of Myxidium lieberkuehni, the myxozoan parasite of the northern pike, Esox lucius. Moreover, we localized the myxozoan-specific minicollagen Ncol-5 in the developing myxosporean stages by Western blotting, immunofluorescence, and immunogold electron microscopy. We found that expression of minicollagens was spatiotemporally restricted to developing nematocysts within the myxospores during sporogenesis. Intriguingly, Ncol-5 is localized in the walls of nematocysts and predominantly in nematocyst tubules. Overall, we demonstrate that despite being significantly reduced in morphology, myxozoans retain structural components associated with nematocyst development in free-living cnidarians. Furthermore, our findings have practical implications for future functional and comparative studies as minicollagens are useful markers of the developmental phase of myxozoan parasites.
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3
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Karabulut A, McClain M, Rubinstein B, Sabin KZ, McKinney SA, Gibson MC. The architecture and operating mechanism of a cnidarian stinging organelle. Nat Commun 2022; 13:3494. [PMID: 35715400 DOI: 10.1038/s41467-022-31090-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 06/02/2022] [Indexed: 11/29/2022] Open
Abstract
The stinging organelles of jellyfish, sea anemones, and other cnidarians, known as nematocysts, are remarkable cellular weapons used for both predation and defense. Nematocysts consist of a pressurized capsule containing a coiled harpoon-like thread. These structures are in turn built within specialized cells known as nematocytes. When triggered, the capsule explosively discharges, ejecting the coiled thread which punctures the target and rapidly elongates by turning inside out in a process called eversion. Due to the structural complexity of the thread and the extreme speed of discharge, the precise mechanics of nematocyst firing have remained elusive7. Here, using a combination of live and super-resolution imaging, 3D electron microscopy, and genetic perturbations, we define the step-by-step sequence of nematocyst operation in the model sea anemone Nematostella vectensis. This analysis reveals the complex biomechanical transformations underpinning the operating mechanism of nematocysts, one of nature’s most exquisite biological micro-machines. Further, this study will provide insight into the form and function of related cnidarian organelles and serve as a template for the design of bioinspired microdevices. The venomous stinging cells of jellyfish, anemones, and corals contain an organelle, the nematocyst, which explosively discharges a venom-laden thread. Here, the authors describe the nematocyst thread and its sub-structures in the sea anemone N. vectensis, revealing a complexity and sophistication underpinning this cellular weapon.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Kyslík J, Kosakyan A, Nenarokov S, Holzer AS, Fiala I. The myxozoan minicollagen gene repertoire was not simplified by the parasitic lifestyle: computational identification of a novel myxozoan minicollagen gene. BMC Genomics 2021; 22:198. [PMID: 33743585 PMCID: PMC7981951 DOI: 10.1186/s12864-021-07515-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 03/08/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Lineage-specific gene expansions represent one of the driving forces in the evolutionary dynamics of unique phylum traits. Myxozoa, a cnidarian subphylum of obligate parasites, are evolutionarily altered and highly reduced organisms with a simple body plan including cnidarian-specific organelles and polar capsules (a type of nematocyst). Minicollagens, a group of structural proteins, are prominent constituents of nematocysts linking Myxozoa and Cnidaria. Despite recent advances in the identification of minicollagens in Myxozoa, the evolutionary history and diversity of minicollagens in Myxozoa and Cnidaria remain elusive. RESULTS We generated new transcriptomes of two myxozoan species using a novel pipeline for filtering of closely related contaminant species in RNA-seq data. Mining of our transcriptomes and published omics data confirmed the existence of myxozoan Ncol-4, reported only once previously, and revealed a novel noncanonical minicollagen, Ncol-5, which is exclusive to Myxozoa. Phylogenetic analyses support a close relationship between myxozoan Ncol-1-3 with minicollagens of Polypodium hydriforme, but suggest independent evolution in the case of the myxozoan minicollagens Ncol-4 and Ncol-5. Additional genome- and transcriptome-wide searches of cnidarian minicollagens expanded the dataset to better clarify the evolutionary trajectories of minicollagen. CONCLUSIONS The development of a new approach for the handling of next-generation data contaminated by closely related species represents a useful tool for future applications beyond the field of myxozoan research. This data processing pipeline allowed us to expand the dataset and study the evolution and diversity of minicollagen genes in Myxozoa and Cnidaria. We identified a novel type of minicollagen in Myxozoa (Ncol-5). We suggest that the large number of minicollagen paralogs in some cnidarians is a result of several recent large gene multiplication events. We revealed close juxtaposition of minicollagens Ncol-1 and Ncol-4 in myxozoan genomes, suggesting their common evolutionary history. The unique gene structure of myxozoan Ncol-5 suggests a specific function in the myxozoan polar capsule or tubule. Despite the fact that myxozoans possess only one type of nematocyst, their gene repertoire is similar to those of other cnidarians.
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Affiliation(s)
- Jiří Kyslík
- Institute of Parasitology, Biology Centre, Academy of Sciences of the Czech Republic, Ceske Budejovice, Czech Republic
- Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Anush Kosakyan
- Institute of Parasitology, Biology Centre, Academy of Sciences of the Czech Republic, Ceske Budejovice, Czech Republic
| | - Serafim Nenarokov
- Institute of Parasitology, Biology Centre, Academy of Sciences of the Czech Republic, Ceske Budejovice, Czech Republic
| | - Astrid S Holzer
- Institute of Parasitology, Biology Centre, Academy of Sciences of the Czech Republic, Ceske Budejovice, Czech Republic
| | - Ivan Fiala
- Institute of Parasitology, Biology Centre, Academy of Sciences of the Czech Republic, Ceske Budejovice, Czech Republic.
- Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic.
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6
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Americus B, Lotan T, Bartholomew JL, Atkinson SD. A comparison of the structure and function of nematocysts in free-living and parasitic cnidarians (Myxozoa). Int J Parasitol 2020; 50:763-769. [PMID: 32707121 DOI: 10.1016/j.ijpara.2020.04.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 04/23/2020] [Accepted: 04/28/2020] [Indexed: 11/30/2022]
Abstract
Myxozoans are obligate parasites that have complex life cycles requiring alternate vertebrate and invertebrate hosts, with transmission via microscopic waterborne spores. Unusually for parasites, they belong to the phylum Cnidaria, alongside thousands of free-living corals, sea anemones, jellyfish and hydrozoans. Their cnidarian affinity is affirmed by genetic relatedness and the presence of nematocysts, historically called "polar capsules" in myxozoan research. Free-living cnidarians utilise this cellular weaponry for defence, predation and adhesion, whereas myxozoans use it to anchor to their hosts as the first step in infection. Despite the ~650 million years of divergence between free-living cnidarians and myxozoans, their nematocysts retain many shared morphological and molecular characters. Both are intra-cellular capsules with a single opening, and contain a coiled, evertable tubule. They are composed of unique nematocyst proteins, nematogalectin and minicollagen, and both likely contain an internal matrix of metal cations covalently bound to the anionic polymer poly-gamma glutamate. The rapid dissociation of this matrix and the resulting increase in internal osmotic potential is the driving force behind tubule elongation during discharge. In this review, we compare the structure and function of nematocysts in Myxozoa and free-living Cnidaria, incorporating recent molecular characterizations. We propose that terminology for homologous myxozoan structures be synonymized with those from other Cnidaria, hence, "polar capsule" as a taxon-specific nematocyst morphotype and "polar filament" as "tubule." Despite taxonomic divergence, genome reduction and an evolution to parasitism, myxozoans maintain nematocysts that are structurally and functionally homologous to those of their free-living cnidarian relatives.
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Affiliation(s)
- Benjamin Americus
- Department of Microbiology, Oregon State University, Corvallis, OR, USA
| | - Tamar Lotan
- Department of Marine Biology, The Leon H.Charney School of Marine Sciences, University of Haifa, Haifa, Israel
| | | | - Stephen D Atkinson
- Department of Microbiology, Oregon State University, Corvallis, OR, USA.
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Farajollahi S, Dennis PB, Crosby MG, Slocik JM, Pelton AT, Hampton CM, Drummy LF, Yang SJ, Silberstein MN, Gupta MK, Naik RR. Disulfide Crosslinked Hydrogels Made From the Hydra Stinging Cell Protein, Minicollagen-1. Front Chem 2020; 7:950. [PMID: 32039158 PMCID: PMC6989532 DOI: 10.3389/fchem.2019.00950] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 12/31/2019] [Indexed: 11/28/2022] Open
Abstract
Minicollagens from cnidarian nematocysts are attractive potential building blocks for the creation of strong, lightweight and tough polymeric materials with the potential for dynamic and reconfigurable crosslinking to modulate functionality. In this study, the Hydra magnipapillata minicollagen-1 isoform was recombinantly expressed in bacteria, and a high throughput purification protocol was developed to generate milligram levels of pure protein without column chromatography. The resulting minicollagen-1 preparation demonstrated spectral properties similar to those observed with collagen and polyproline sequences as well as the ability to self-assemble into oriented fibers and bundles. Photo-crosslinking with Ru(II)( bpy ) 3 2 + was used to create robust hydrogels that were analyzed by mechanical testing. Interestingly, the minicollagen-1 hydrogels could be dissolved with reducing agents, indicating that ruthenium-mediated photo-crosslinking was able to induce disulfide metathesis to create the hydrogels. Together, this work is an important first step in creating minicollagen-based materials whose properties can be manipulated through static and reconfigurable post-translational modifications.
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Affiliation(s)
- Sanaz Farajollahi
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, United States
- UES Inc., Dayton, OH, United States
| | - Patrick B. Dennis
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, United States
| | - Marquise G. Crosby
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, United States
| | - Joseph M. Slocik
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, United States
- UES Inc., Dayton, OH, United States
| | - Anthony T. Pelton
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, United States
- UES Inc., Dayton, OH, United States
| | - Cheri M. Hampton
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, United States
- UES Inc., Dayton, OH, United States
| | - Lawrence F. Drummy
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, United States
| | - Steven J. Yang
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, United States
| | - Meredith N. Silberstein
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, United States
| | - Maneesh K. Gupta
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, United States
| | - Rajesh R. Naik
- 711th Human Performance Wing, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, United States
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8
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Abstract
The nervous system is produced and maintained in adult Hydra through the continuous production of nerve cells and mechanosensory cells (nematocytes or cnidocytes). De novo neurogenesis occurs slowly in intact animals that replace their dying nerve cells, at a faster rate in animals regenerating their head as a complete apical nervous system is built in few days. To dissect the molecular mechanisms that underlie these properties, a precise monitoring of the markers of neurogenesis and nematogenesis is required. Here we describe the conditions for an efficient BrdU-labeling coupled to an immunodetection of neuronal markers, either regulators of neurogenesis, here the homeoprotein prdl-a, or neuropeptides such as RFamide or Hym-355. This method can be performed on whole-mount animals as well as on macerated tissues when cells retain their morphology. Moreover, when antibodies are not available, BrdU-labeling can be combined with the analysis of gene expression by whole-mount in situ hybridization. This co-immunodetection procedure is well adapted to visualize and quantify the dynamics of de novo neurogenesis. Upon continuous BrdU labeling, the repeated measurements of BrdU-labeling indexes in specific cellular populations provide a precise monitoring of nematogenesis as well as neurogenesis, in homeostatic or developmental conditions.
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Affiliation(s)
- Wanda Buzgariu
- Department of Genetics and Evolution, iGE3, Faculty of Sciences, University of Geneva, Geneva, Switzerland
| | - Marie-Laure Curchod
- Department of Genetics and Evolution, iGE3, Faculty of Sciences, University of Geneva, Geneva, Switzerland
| | - Chrystelle Perruchoud
- Department of Genetics and Evolution, iGE3, Faculty of Sciences, University of Geneva, Geneva, Switzerland
| | - Brigitte Galliot
- Department of Genetics and Evolution, iGE3, Faculty of Sciences, University of Geneva, Geneva, Switzerland.
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Bentele T, Amadei F, Kimmle E, Veschgini M, Linke P, Sontag-González M, Tennigkeit J, Ho AD, Özbek S, Tanaka M. New Class of Crosslinker-Free Nanofiber Biomaterials from Hydra Nematocyst Proteins. Sci Rep 2019; 9:19116. [PMID: 31836799 PMCID: PMC6910907 DOI: 10.1038/s41598-019-55655-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 10/30/2019] [Indexed: 11/10/2022] Open
Abstract
Nematocysts, the stinging organelles of cnidarians, have remarkable mechanical properties. Hydra nematocyst capsules undergo volume changes of 50% during their explosive exocytosis and withstand osmotic pressures of beyond 100 bar. Recently, two novel protein components building up the nematocyst capsule wall in Hydra were identified. The cnidarian proline-rich protein 1 (CPP-1) characterized by a "rigid" polyproline motif and the elastic Cnidoin possessing a silk-like domain were shown to be part of the capsule structure via short cysteine-rich domains that spontaneously crosslink the proteins via disulfide bonds. In this study, recombinant Cnidoin and CPP-1 are expressed in E. coli and the elastic modulus of spontaneously crosslinked bulk proteins is compared with that of isolated nematocysts. For the fabrication of uniform protein nanofibers by electrospinning, the preparative conditions are systematically optimized. Both fibers remain stable even after rigorous washing and immersion into bulk water owing to the simultaneous crosslinking of cysteine-rich domains. This makes our nanofibers clearly different from other protein nanofibers that are not stable without chemical crosslinkers. Following the quantitative assessment of mechanical properties, the potential of Cnidoin and CPP-1 nanofibers is examined towards the maintenance of human mesenchymal stem cells.
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Affiliation(s)
- Theresa Bentele
- Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Heidelberg University, 69120, Heidelberg, Germany
| | - Federico Amadei
- Physical Chemistry of Biosystems, Institute of Physical Chemistry, Heidelberg University, 69120, Heidelberg, Germany
| | - Esther Kimmle
- Physical Chemistry of Biosystems, Institute of Physical Chemistry, Heidelberg University, 69120, Heidelberg, Germany
| | - Mariam Veschgini
- Physical Chemistry of Biosystems, Institute of Physical Chemistry, Heidelberg University, 69120, Heidelberg, Germany
| | - Philipp Linke
- Physical Chemistry of Biosystems, Institute of Physical Chemistry, Heidelberg University, 69120, Heidelberg, Germany
| | - Mariana Sontag-González
- Physical Chemistry of Biosystems, Institute of Physical Chemistry, Heidelberg University, 69120, Heidelberg, Germany
- School of Earth and Environmental Sciences, Science Medicine and Health, University of Wollongong, NSW 2522, Wollongong, Australia
| | - Jutta Tennigkeit
- Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Heidelberg University, 69120, Heidelberg, Germany
| | - Anthony D Ho
- Department of Medicine V, University of Heidelberg, 69120, Heidelberg, Germany
- Center for Integrative Medicine and Physics, Institute for Advanced Study, Kyoto University, 606-8501, Kyoto, Japan
| | - Suat Özbek
- Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Heidelberg University, 69120, Heidelberg, Germany.
| | - Motomu Tanaka
- Physical Chemistry of Biosystems, Institute of Physical Chemistry, Heidelberg University, 69120, Heidelberg, Germany.
- Center for Integrative Medicine and Physics, Institute for Advanced Study, Kyoto University, 606-8501, Kyoto, Japan.
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10
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Strömberg SM, Östman C, Larsson AI. The cnidome and ultrastructural morphology of late planulae in
Lophelia pertusa
(Linnaeus, 1758)—With implications for settling competency. ACTA ZOOL-STOCKHOLM 2019. [DOI: 10.1111/azo.12296] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Susanna M. Strömberg
- Department of Marine Sciences, Tjärnö Marine Laboratory University of Gothenburg Strömstad Sweden
| | - Carina Östman
- Evolutionary Biology Centre Uppsala University Uppsala Sweden
| | - Ann I. Larsson
- Department of Marine Sciences, Tjärnö Marine Laboratory University of Gothenburg Strömstad Sweden
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11
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Sunagar K, Columbus-Shenkar YY, Fridrich A, Gutkovich N, Aharoni R, Moran Y. Cell type-specific expression profiling unravels the development and evolution of stinging cells in sea anemone. BMC Biol 2018; 16:108. [PMID: 30261880 PMCID: PMC6161364 DOI: 10.1186/s12915-018-0578-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 09/18/2018] [Indexed: 12/21/2022] Open
Abstract
Background Cnidocytes are specialized cells that define the phylum Cnidaria. They possess an “explosive” organelle called cnidocyst that is important for prey capture and anti-predator defense. An extraordinary morphological and functional complexity of the cnidocysts has inspired numerous studies to investigate their structure and development. However, the transcriptomes of the cells bearing these unique organelles are yet to be characterized, impeding our understanding of the genetic basis of their biogenesis. Results In this study, we generated a nematocyte reporter transgenic line of the sea anemone Nematostella vectensis using the CRISPR/Cas9 system. By using a fluorescence-activated cell sorter (FACS), we have characterized cell type-specific transcriptomic profiles of various stages of cnidocyte maturation and showed that nematogenesis (the formation of functional cnidocysts) is underpinned by dramatic shifts in the spatiotemporal gene expression. Among the genes identified as upregulated in cnidocytes were Cnido-Jun and Cnido-Fos1—cnidarian-specific paralogs of the highly conserved c-Jun and c-Fos proteins of the stress-induced AP-1 transcriptional complex. The knockdown of the cnidocyte-specific c-Jun homolog by microinjection of morpholino antisense oligomer results in disruption of normal nematogenesis. Conclusions Here, we show that the majority of upregulated genes and enriched biochemical pathways specific to cnidocytes are uncharacterized, emphasizing the need for further functional research on nematogenesis. The recruitment of the metazoan stress-related transcription factor c-Fos/c-Jun complex into nematogenesis highlights the evolutionary ingenuity and novelty associated with the formation of these highly complex, enigmatic, and phyletically unique organelles. Thus, we provide novel insights into the biology, development, and evolution of cnidocytes. Electronic supplementary material The online version of this article (10.1186/s12915-018-0578-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kartik Sunagar
- Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, 9190401, Jerusalem, Israel. .,Evolutionary Venomics Lab, Centre for Ecological Sciences, Indian Institute of Science, Bangalore, 560012, India.
| | - Yaara Y Columbus-Shenkar
- Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, 9190401, Jerusalem, Israel
| | - Arie Fridrich
- Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, 9190401, Jerusalem, Israel
| | - Nadya Gutkovich
- Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, 9190401, Jerusalem, Israel
| | - Reuven Aharoni
- Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, 9190401, Jerusalem, Israel
| | - Yehu Moran
- Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, 9190401, Jerusalem, Israel.
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12
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Shpirer E, Diamant A, Cartwright P, Huchon D. A genome wide survey reveals multiple nematocyst-specific genes in Myxozoa. BMC Evol Biol 2018; 18:138. [PMID: 30208843 PMCID: PMC6134521 DOI: 10.1186/s12862-018-1253-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 08/22/2018] [Indexed: 12/02/2022] Open
Abstract
Background Myxozoa represents a diverse group of microscopic endoparasites whose life cycle involves two hosts: a vertebrate (usually a fish) and an invertebrate (usually an annelid worm). Despite lacking nearly all distinguishing animal characteristics, given that each life cycle stage consists of no more than a few cells, molecular phylogenetic studies have revealed that myxozoans belong to the phylum Cnidaria, which includes corals, sea anemones, and jellyfish. Myxozoa, however, do possess a polar capsule; an organelle that is homologous to the stinging structure unique to Cnidaria: the nematocyst. Previous studies have identified in Myxozoa a number of protein-coding genes that are specific to nematocytes (the cells producing nematocysts) and thus restricted to Cnidaria. Determining which other genes are also homologous with the myxozoan polar capsule genes could provide insight into both the conservation and changes that occurred during nematocyst evolution in the transition to endoparasitism. Results Previous studies have examined the phylogeny of two cnidarian-restricted gene families: minicollagens and nematogalectins. Here we identify and characterize seven additional cnidarian-restricted genes in myxozoan genomes using a phylogenetic approach. Four of the seven had never previously been identified as cnidarian-specific and none have been studied in a phylogenetic context. A majority of the proteins appear to be involved in the structure of the nematocyst capsule and tubule. No venom proteins were identified among the cnidarian-restricted genes shared by myxozoans. Conclusions Given the highly divergent forms that comprise Cnidaria, obtaining insight into the processes underlying their ancient diversification remains challenging. In their evolutionary transition to microscopic endoparasites, myxozoans lost nearly all traces of their cnidarian ancestry, with the one prominent exception being their nematocysts (or polar capsules). Thus nematocysts, and the genes that code for their structure, serve as rich sources of information to support the cnidarian origin of Myxozoa. Electronic supplementary material The online version of this article (10.1186/s12862-018-1253-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Erez Shpirer
- School of Zoology, Tel Aviv University, Tel Aviv, Israel
| | - Arik Diamant
- National Center for Mariculture, Israel Oceanographic and Limnological Research, Eilat, Israel
| | - Paulyn Cartwright
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, USA.
| | - Dorothée Huchon
- School of Zoology, Tel Aviv University, Tel Aviv, Israel. .,The Steinhardt Museum of Natural History and National Research Center, Tel Aviv University, Tel Aviv, Israel.
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13
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Babonis LS, Martindale MQ. PaxA, but not PaxC, is required for cnidocyte development in the sea anemone Nematostella vectensis. EvoDevo 2017; 8:14. [PMID: 28878874 PMCID: PMC5584322 DOI: 10.1186/s13227-017-0077-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 08/16/2017] [Indexed: 12/25/2022] Open
Abstract
Background Pax genes are a family of conserved transcription factors that regulate many aspects of developmental morphogenesis, notably the development of ectodermal sensory structures including eyes. Nematostella vectensis, the starlet sea anemone, has numerous Pax orthologs, many of which are expressed early during embryogenesis. The function of Pax genes in this eyeless cnidarian is unknown. Results Here, we show that PaxA, but not PaxC, plays a critical role in the development of cnidocytes in N. vectensis. Knockdown of PaxA results in a loss of developing cnidocytes and downregulation of numerous cnidocyte-specific genes, including a variant of the transcription factor Mef2. We also demonstrate that the co-expression of Mef2 in a subset of the PaxA-expressing cells is associated with the development with a second lineage of cnidocytes and show that knockdown of the neural progenitor gene SoxB2 results in downregulation of expression of PaxA, Mef2, and several cnidocyte-specific genes. Because PaxA is not co-expressed with SoxB2 at any time during cnidocyte development, we propose a simple model for cnidogenesis whereby a SoxB2-expressing progenitor cell population undergoes division to give rise to PaxA-expressing cnidocytes, some of which also express Mef2. Discussion The role of PaxA in cnidocyte development among hydrozoans has not been studied, but the conserved role of SoxB2 in regulating the fate of a progenitor cell that gives rise to neurons and cnidocytes in Nematostella and Hydractinia echinata suggests that this SoxB2/PaxA pathway may well be conserved across cnidarians.
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Affiliation(s)
- Leslie S Babonis
- Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Blvd, St. Augustine, FL 32080 USA
| | - Mark Q Martindale
- Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Blvd, St. Augustine, FL 32080 USA.,Department of Biology, University of Florida, Gainesville, FL 32611 USA
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14
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Gavelis GS, Wakeman KC, Tillmann U, Ripken C, Mitarai S, Herranz M, Özbek S, Holstein T, Keeling PJ, Leander BS. Microbial arms race: Ballistic "nematocysts" in dinoflagellates represent a new extreme in organelle complexity. Sci Adv 2017; 3:e1602552. [PMID: 28435864 PMCID: PMC5375639 DOI: 10.1126/sciadv.1602552] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 02/10/2017] [Indexed: 05/07/2023]
Abstract
We examine the origin of harpoon-like secretory organelles (nematocysts) in dinoflagellate protists. These ballistic organelles have been hypothesized to be homologous to similarly complex structures in animals (cnidarians); but we show, using structural, functional, and phylogenomic data, that nematocysts evolved independently in both lineages. We also recorded the first high-resolution videos of nematocyst discharge in dinoflagellates. Unexpectedly, our data suggest that different types of dinoflagellate nematocysts use two fundamentally different types of ballistic mechanisms: one type relies on a single pressurized capsule for propulsion, whereas the other type launches 11 to 15 projectiles from an arrangement similar to a Gatling gun. Despite their radical structural differences, these nematocysts share a single origin within dinoflagellates and both potentially use a contraction-based mechanism to generate ballistic force. The diversity of traits in dinoflagellate nematocysts demonstrates a stepwise route by which simple secretory structures diversified to yield elaborate subcellular weaponry.
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Affiliation(s)
- Gregory S. Gavelis
- Department of Botany, University of British Columbia, Vancouver, Canada
- Department of Zoology, University of British Columbia, Vancouver, Canada
- Corresponding author.
| | - Kevin C. Wakeman
- Office of International Affairs, Hokkaido University, Kita 10, Nishi 8, Sapporo 060-0810, Japan
- Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany
| | - Urban Tillmann
- Faculty of Science, Hokkaido University, Kita 10, Nishi 8, Sapporo 060-0810, Japan
| | - Christina Ripken
- Marine Biophysics Unit, Okinawa Institute of Science and Technology, Okinawa, Japan
| | - Satoshi Mitarai
- Marine Biophysics Unit, Okinawa Institute of Science and Technology, Okinawa, Japan
| | - Maria Herranz
- Department of Botany, University of British Columbia, Vancouver, Canada
| | - Suat Özbek
- Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Thomas Holstein
- Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | | | - Brian S. Leander
- Department of Botany, University of British Columbia, Vancouver, Canada
- Department of Zoology, University of British Columbia, Vancouver, Canada
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15
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Tursch A, Mercadante D, Tennigkeit J, Gräter F, Özbek S. Minicollagen cysteine-rich domains encode distinct modes of polymerization to form stable nematocyst capsules. Sci Rep 2016; 6:25709. [PMID: 27166560 DOI: 10.1038/srep25709] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 04/21/2016] [Indexed: 12/04/2022] Open
Abstract
The stinging capsules of cnidarians, nematocysts, function as harpoon-like organelles with unusual biomechanical properties. The nanosecond discharge of the nematocyst requires a dense protein network of the capsule structure withstanding an internal pressure of up to 150 bar. Main components of the capsule are short collagens, so-called minicollagens, that form extended polymers by disulfide reshuffling of their cysteine-rich domains (CRDs). Although CRDs have identical cysteine patterns, they exhibit different structures and disulfide connectivity at minicollagen N and C-termini. We show that the structurally divergent CRDs have different cross-linking potentials in vitro and in vivo. While the C-CRD can participate in several simultaneous intermolecular disulfides and functions as a cystine knot after minicollagen synthesis, the N-CRD is monovalent. Our combined experimental and computational analyses reveal the cysteines in the C-CRD fold to exhibit a higher structural propensity for disulfide bonding and a faster kinetics of polymerization. During nematocyst maturation, the highly reactive C-CRD is instrumental in efficient cross-linking of minicollagens to form pressure resistant capsules. The higher ratio of C-CRD folding types evidenced in the medusozoan lineage might have fostered the evolution of novel, predatory nematocyst types in cnidarians with a free-swimming medusa stage.
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16
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Chang ES, Neuhof M, Rubinstein ND, Diamant A, Philippe H, Huchon D, Cartwright P. Genomic insights into the evolutionary origin of Myxozoa within Cnidaria. Proc Natl Acad Sci U S A 2015; 112:14912-7. [PMID: 26627241 DOI: 10.1073/pnas.1511468112] [Citation(s) in RCA: 146] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Myxozoa comprise over 2,000 species of microscopic obligate parasites that use both invertebrate and vertebrate hosts as part of their life cycle. Although the evolutionary origin of myxozoans has been elusive, a close relationship with cnidarians, a group that includes corals, sea anemones, jellyfish, and hydroids, is supported by some phylogenetic studies and the observation that the distinctive myxozoan structure, the polar capsule, is remarkably similar to the stinging structures (nematocysts) in cnidarians. To gain insight into the extreme evolutionary transition from a free-living cnidarian to a microscopic endoparasite, we analyzed genomic and transcriptomic assemblies from two distantly related myxozoan species, Kudoa iwatai and Myxobolus cerebralis, and compared these to the transcriptome and genome of the less reduced cnidarian parasite, Polypodium hydriforme. A phylogenomic analysis, using for the first time to our knowledge, a taxonomic sampling that represents the breadth of myxozoan diversity, including four newly generated myxozoan assemblies, confirms that myxozoans are cnidarians and are a sister taxon to P. hydriforme. Estimations of genome size reveal that myxozoans have one of the smallest reported animal genomes. Gene enrichment analyses show depletion of expressed genes in categories related to development, cell differentiation, and cell-cell communication. In addition, a search for candidate genes indicates that myxozoans lack key elements of signaling pathways and transcriptional factors important for multicellular development. Our results suggest that the degeneration of the myxozoan body plan from a free-living cnidarian to a microscopic parasitic cnidarian was accompanied by extreme reduction in genome size and gene content.
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Beckmann A, Xiao S, Müller JP, Mercadante D, Nüchter T, Kröger N, Langhojer F, Petrich W, Holstein TW, Benoit M, Gräter F, Özbek S. A fast recoiling silk-like elastomer facilitates nanosecond nematocyst discharge. BMC Biol 2015; 13:3. [PMID: 25592740 PMCID: PMC4321713 DOI: 10.1186/s12915-014-0113-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 12/24/2014] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND The discharge of the Cnidarian stinging organelle, the nematocyst, is one of the fastest processes in biology and involves volume changes of the highly pressurised (150 bar) capsule of up to 50%. Hitherto, the molecular basis for the unusual biomechanical properties of nematocysts has been elusive, as their structure was mainly defined as a stress-resistant collagenous matrix. RESULTS Here, we characterise Cnidoin, a novel elastic protein identified as a structural component of Hydra nematocysts. Cnidoin is expressed in nematocytes of all types and immunostainings revealed incorporation into capsule walls and tubules concomitant with minicollagens. Similar to spider silk proteins, to which it is related at sequence level, Cnidoin possesses high elasticity and fast coiling propensity as predicted by molecular dynamics simulations and quantified by force spectroscopy. Recombinant Cnidoin showed a high tendency for spontaneous aggregation to bundles of fibrillar structures. CONCLUSIONS Cnidoin represents the molecular factor involved in kinetic energy storage and release during the ultra-fast nematocyst discharge. Furthermore, it implies an early evolutionary origin of protein elastomers in basal metazoans.
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Affiliation(s)
- Anna Beckmann
- Department of Molecular Evolution and Genomics, University of Heidelberg, Centre for Organismal Studies, Im Neuenheimer Feld 329, 69120, Heidelberg, Germany.
| | - Senbo Xiao
- Heidelberg Institute for Theoretical Studies, Schloss-Wolfsbrunnenweg 35, 69118, Heidelberg, Germany.
| | - Jochen P Müller
- Applied Physics and Center for NanoScience, Ludwig Maximilian University, Amalienstr. 54, 80799, München, Germany.
| | - Davide Mercadante
- Heidelberg Institute for Theoretical Studies, Schloss-Wolfsbrunnenweg 35, 69118, Heidelberg, Germany.
| | - Timm Nüchter
- Department of Molecular Evolution and Genomics, University of Heidelberg, Centre for Organismal Studies, Im Neuenheimer Feld 329, 69120, Heidelberg, Germany.
| | - Niels Kröger
- Kirchhoff Institute for Physics, Heidelberg University, Im Neuenheimer Feld 227, 69210, Heidelberg, Germany.
| | | | - Wolfgang Petrich
- Kirchhoff Institute for Physics, Heidelberg University, Im Neuenheimer Feld 227, 69210, Heidelberg, Germany.
| | - Thomas W Holstein
- Department of Molecular Evolution and Genomics, University of Heidelberg, Centre for Organismal Studies, Im Neuenheimer Feld 329, 69120, Heidelberg, Germany.
| | - Martin Benoit
- Applied Physics and Center for NanoScience, Ludwig Maximilian University, Amalienstr. 54, 80799, München, Germany.
| | - Frauke Gräter
- Heidelberg Institute for Theoretical Studies, Schloss-Wolfsbrunnenweg 35, 69118, Heidelberg, Germany.
| | - Suat Özbek
- Department of Molecular Evolution and Genomics, University of Heidelberg, Centre for Organismal Studies, Im Neuenheimer Feld 329, 69120, Heidelberg, Germany.
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18
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Shpirer E, Chang ES, Diamant A, Rubinstein N, Cartwright P, Huchon D. Diversity and evolution of myxozoan minicollagens and nematogalectins. BMC Evol Biol 2014; 14:205. [PMID: 25262812 PMCID: PMC4195985 DOI: 10.1186/s12862-014-0205-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 09/19/2014] [Indexed: 11/10/2022] Open
Abstract
Background Myxozoa are a diverse group of metazoan parasites with a very simple organization, which has for decades eluded their evolutionary origin. Their most prominent and characteristic feature is the polar capsule: a complex intracellular structure of the myxozoan spore, which plays a role in host infection. Striking morphological similarities have been found between myxozoan polar capsules and nematocysts, the stinging structures of cnidarians (corals, sea anemones and jellyfish) leading to the suggestion that Myxozoa and Cnidaria share a more recent common ancestry. This hypothesis has recently been supported by phylogenomic evidence and by the identification of a nematocyst specific minicollagen gene in the myxozoan Tetracapsuloides bryosalmonae. Here we searched genomes and transcriptomes of several myxozoan taxa for the presence of additional cnidarian specific genes and characterized these genes within a phylogenetic context. Results Illumina assemblies of transcriptome or genome data of three myxozoan species (Enteromyxum leei, Kudoa iwatai, and Sphaeromyxa zaharoni) and of the enigmatic cnidarian parasite Polypodium hydriforme (Polypodiozoa) were mined using tBlastn searches with nematocyst-specific proteins as queries. Several orthologs of nematogalectins and minicollagens were identified. Our phylogenetic analyses indicate that myxozoans possess three distinct minicollagens. We found that the cnidarian repertoire of nematogalectins is more complex than previously thought and we identified additional members of the nematogalectin family. Cnidarians were found to possess four nematogalectin/ nematogalectin-related genes, while in myxozoans only three genes could be identified. Conclusions Our results demonstrate that myxozoans possess a diverse array of genes that are taxonomically restricted to Cnidaria. Characterization of these genes provide compelling evidence that polar capsules and nematocysts are homologous structures and that myxozoans are highly degenerate cnidarians. The diversity of minicollagens was higher than previously thought, with the presence of three minicollagen genes in myxozoans. Our phylogenetic results suggest that the different myxozoan sequences are the results of ancient divergences within Cnidaria and not of recent specializations of the polar capsule. For both minicollagen and nematogalectin, our results show that myxozoans possess less gene copies than their cnidarian counter parts, suggesting that the polar capsule gene repertoire was simplified with their reduced body plan. Electronic supplementary material The online version of this article (doi:10.1186/s12862-014-0205-0) contains supplementary material, which is available to authorized users.
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19
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Boehm AM, Khalturin K, Anton-Erxleben F, Hemmrich G, Klostermeier UC, Lopez-Quintero JA, Oberg HH, Puchert M, Rosenstiel P, Wittlieb J, Bosch TC. FoxO is a critical regulator of stem cell maintenance in immortal Hydra. Proc Natl Acad Sci U S A 2012; 109:19697-702. [PMID: 23150562 DOI: 10.1073/pnas.1209714109] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Hydra's unlimited life span has long attracted attention from natural scientists. The reason for that phenomenon is the indefinite self-renewal capacity of its stem cells. The underlying molecular mechanisms have yet to be explored. Here, by comparing the transcriptomes of Hydra's stem cells followed by functional analysis using transgenic polyps, we identified the transcription factor forkhead box O (FoxO) as one of the critical drivers of this continuous self-renewal. foxO overexpression increased interstitial stem cell and progenitor cell proliferation and activated stem cell genes in terminally differentiated somatic cells. foxO down-regulation led to an increase in the number of terminally differentiated cells, resulting in a drastically reduced population growth rate. In addition, it caused down-regulation of stem cell genes and antimicrobial peptide (AMP) expression. These findings contribute to a molecular understanding of Hydra's immortality, indicate an evolutionarily conserved role of FoxO in controlling longevity from Hydra to humans, and have implications for understanding cellular aging.
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20
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Yoffe C, Lotan T, Benayhau Y. A modified view on octocorals: Heteroxenia fuscescens nematocysts are diverse, featuring both an ancestral and a novel type. PLoS One 2012; 7:e31902. [PMID: 22348137 PMCID: PMC3279420 DOI: 10.1371/journal.pone.0031902] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 01/14/2012] [Indexed: 01/08/2023] Open
Abstract
Cnidarians are characterized by the presence of stinging cells containing nematocysts, a sophisticated injection system targeted mainly at prey-capture and defense. In the anthozoan subclass Octocorallia nematocytes have been considered to exist only in low numbers, to be small, and all of the ancestral atrichous-isorhiza type. This study, in contrast, revealed numerous nematocytes in the octocoral Heteroxenia fuscescens. The study demonstrates the applicability of cresyl-violet dye for differential staining and stimulating discharge of the nematocysts. In addition to the atrichous isorhiza-type of nematocysts, a novel type of macrobasic-mastigophore nematocysts was found, featuring a shaft, uniquely comprised of three loops and densely packed arrow-like spines. In contrast to the view that octocorals possess a single type of nematocyst, Heteroxenia fuscescens features two distinct types, indicating for the first time the diversification and complexity of nematocysts for Octocorallia.
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Affiliation(s)
- Chen Yoffe
- Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel
| | - Tamar Lotan
- Marine Biology Department, The Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel
| | - Yehuda Benayhau
- Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel
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21
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Ozbek S. The cnidarian nematocyst: a miniature extracellular matrix within a secretory vesicle. Protoplasma 2011; 248:635-640. [PMID: 20957500 DOI: 10.1007/s00709-010-0219-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Accepted: 10/05/2010] [Indexed: 05/30/2023]
Abstract
Nematocysts are the taxon-defining features of all cnidarians including jellyfish, sea anemones, and corals. They are highly sophisticated organelles used for the capture of prey and defense. The nematocyst capsule is produced within a giant post-Golgi vesicle, which is continuously fed by proteins from the secretory pathway. Mature nematocysts consist of a hollow capsule body in which a long tubule is coiled up that, upon discharge, is expelled in a harpoon-like fashion. This is accompanied by the release of a toxin cocktail stored in the capsule matrix. Nematocyst discharge, which is one of the fastest processes in biology, is driven by an extreme osmotic pressure of about 150 bar. The molecular analysis of the nematocyst has from the beginning indicated a collagenous nature of the capsule structure. In particular, a large family of unusual minicollagens has been demonstrated to form the highly resistant scaffold of the capsule. Recent findings on the molecular composition of Hydra nematocysts have confirmed the notion of a specialized extracellular matrix, which is assembled during an intracellular secretion process to form the most complex predatory apparatus at the cellular level.
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Affiliation(s)
- Suat Ozbek
- Institute of Zoology, Department of Molecular Evolution and Genomics, University of Heidelberg, Im Neuenheimer Feld 230, 69120, Heidelberg, Germany.
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22
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Abstract
The starlet sea anemone Nematostella vectensis is an emerging model organism for developmental and evolutionary biology. Due to the availability of genome data and its amenability to genetic manipulation Nematostella serves as a source for comparative molecular and phylogenetic studies. Despite this fact, the characterization of the nematocyst inventory and of nematocyst-specific genes is still fragmentary and sometimes misleading in this cnidarian species. Here, we present a thorough qualitative and quantitative analysis of nematocysts in Nematostella vectensis. In addition, we have cloned major nematocyst components, Nematostella minicollagens 1, 3 and 4, and show their expression patterns by in situ hybridization and immunocytochemistry using specific antibodies. Our data provides tools and insights for further studies on nematocyst morphogenesis in Nematostella and comparative evolution in cnidarians.
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Affiliation(s)
- Claudia Zenkert
- Department for Molecular Evolution and Genomics, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Toshio Takahashi
- Suntory Foundation for Life Sciences, Bioorganic Research Institute, Osaka, Japan
| | - Mark-Oliver Diesner
- Department for Molecular Evolution and Genomics, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Suat Özbek
- Department for Molecular Evolution and Genomics, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
- * E-mail:
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Steele RE, David CN, Technau U. A genomic view of 500 million years of cnidarian evolution. Trends Genet 2010; 27:7-13. [PMID: 21047698 DOI: 10.1016/j.tig.2010.10.002] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 09/23/2010] [Accepted: 10/08/2010] [Indexed: 01/29/2023]
Abstract
Cnidarians (corals, anemones, jellyfish and hydras) are a diverse group of animals of interest to evolutionary biologists, ecologists and developmental biologists. With the publication of the genome sequences of Hydra and Nematostella, whose last common ancestor was the stem cnidarian, researchers are beginning to see the genomic underpinnings of cnidarian biology. Cnidarians are known for the remarkable plasticity of their morphology and life cycles. This plasticity is reflected in the Hydra and Nematostella genomes, which differ to an exceptional degree in size, base composition, transposable element content and gene conservation. It is now known what cnidarian genomes, given 500 million years, are capable of; as we discuss here, the next challenge is to understand how this genomic history has led to the striking diversity seen in this group.
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Affiliation(s)
- Robert E Steele
- Department of Biological Chemistry and the Developmental Biology Center, University of California, Irvine, CA 92697, USA.
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Hwang JS, Takaku Y, Momose T, Adamczyk P, Özbek S, Ikeo K, Khalturin K, Hemmrich G, Bosch TCG, Holstein TW, David CN, Gojobori T. Nematogalectin, a nematocyst protein with GlyXY and galectin domains, demonstrates nematocyte-specific alternative splicing in Hydra. Proc Natl Acad Sci U S A 2010; 107:18539-44. [PMID: 20937891 PMCID: PMC2972925 DOI: 10.1073/pnas.1003256107] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Taxonomically restricted genes or lineage-specific genes contribute to morphological diversification in metazoans and provide unique functions for particular taxa in adapting to specific environments. To understand how such genes arise and participate in morphological evolution, we have investigated a gene called nematogalectin in Hydra, which has a structural role in the formation of nematocysts, stinging organelles that are unique to the phylum Cnidaria. Nematogalectin is a 28-kDa protein with an N-terminal GlyXY domain (glycine followed by two hydrophobic amino acids), which can form a collagen triple helix, followed by a galactose-binding lectin domain. Alternative splicing of the nematogalectin transcript allows the gene to encode two proteins, nematogalectin A and nematogalectin B. We demonstrate that expression of nematogalectin A and B is mutually exclusive in different nematocyst types: Desmonemes express nematogalectin B, whereas stenoteles and isorhizas express nematogalectin B early in differentiation, followed by nematogalectin A. Like Hydra, the marine hydrozoan Clytia also has two nematogalectin transcripts, which are expressed in different nematocyte types. By comparison, anthozoans have only one nematogalectin gene. Gene phylogeny indicates that tandem duplication of nematogalectin B exons gave rise to nematogalectin A before the divergence of Anthozoa and Medusozoa and that nematogalectin A was subsequently lost in Anthozoa. The emergence of nematogalectin A may have played a role in the morphological diversification of nematocysts in the medusozoan lineage.
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Affiliation(s)
- Jung Shan Hwang
- Center for Information Biology and DNA Data Base in Japan, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | - Yasuharu Takaku
- Center for Information Biology and DNA Data Base in Japan, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | - Tsuyoshi Momose
- UMR7009 Laboratory of Developmental Biology, Centre National de la Recherche Scientifique and Université Pierre et Marie Curie (Paris 6), Observatoire Océanologique, F-06234 Villefranche-sur-Mer, France
| | - Patrizia Adamczyk
- Institute of Zoology, Department of Molecular Evolution and Genomics, Heidelberg University, 69120 Heidelberg, Germany
| | - Suat Özbek
- Institute of Zoology, Department of Molecular Evolution and Genomics, Heidelberg University, 69120 Heidelberg, Germany
| | - Kazuho Ikeo
- Center for Information Biology and DNA Data Base in Japan, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | | | - Georg Hemmrich
- Zoological Institute, Christian-Albrechts University, 24118 Kiel, Germany; and
| | - Thomas C. G. Bosch
- Zoological Institute, Christian-Albrechts University, 24118 Kiel, Germany; and
| | - Thomas W. Holstein
- Institute of Zoology, Department of Molecular Evolution and Genomics, Heidelberg University, 69120 Heidelberg, Germany
| | - Charles N. David
- Department Biologie II, Ludwig-Maximilians University, D-82152 Planegg-Martinsried, Germany
| | - Takashi Gojobori
- Center for Information Biology and DNA Data Base in Japan, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
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Abstract
Myxozoans are enigmatic endoparasitic organisms sharing morphological features with bilateria, protists and cnidarians. This, coupled with their highly divergent gene sequences, has greatly obscured their phylogenetic affinities. Here we report the sequencing and characterization of a minicollagen homologue (designated Tb-Ncol-1) in the myxozoan Tetracapsuloides bryosalmonae. Minicollagens are phylum-specific genes encoding cnidarian nematocyst proteins. Sequence analysis revealed a cysteine-rich domain (CRD) architecture and genomic organization similar to group 1 minicollagens. Homology modelling predicted similar three-dimensional structures to Hydra CRDs despite deviations from the canonical pattern of group 1 minicollagens. The discovery of this minicollagen gene strongly supports myxozoans as cnidarians that have radiated as endoparasites of freshwater, marine and terrestrial hosts. It also reveals novel protein sequence variation of relevance to understanding the evolution of nematocyst complexity, and indicates a molecular/morphological link between myxozoan polar capsules and cnidarian nematocysts. Our study is the first to illustrate the power of using genes related to a taxon-specific novelty for phylogenetic inference within the Metazoa, and it exemplifies how the evolutionary relationships of other metazoans characterized by extreme sequence divergence could be similarly resolved.
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Affiliation(s)
- Jason W Holland
- Scottish Fish Immunology Research Centre, Aberdeen University, , Aberdeen AB24 2TZ, UK.
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Adamczyk P, Zenkert C, Balasubramanian PG, Yamada S, Murakoshi S, Sugahara K, Hwang JS, Gojobori T, Holstein TW, Ozbek S. A non-sulfated chondroitin stabilizes membrane tubulation in cnidarian organelles. J Biol Chem 2010; 285:25613-23. [PMID: 20538610 DOI: 10.1074/jbc.m110.107904] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Membrane tubulation is generally associated with rearrangements of the cytoskeleton and other cytoplasmic factors. Little is known about the contribution of extracellular matrix components to this process. Here, we demonstrate an essential role of proteoglycans in the tubulation of the cnidarian nematocyst vesicle. The morphogenesis of this extrusive organelle takes place inside a giant post-Golgi vesicle, which topologically represents extracellular space. This process includes the formation of a complex collagenous capsule structure that elongates into a long tubule, which invaginates after its completion. We show that a non-sulfated chondroitin appears as a scaffold in early morphogenesis of all nematocyst types in Hydra and Nematostella. It accompanies the tubulation of the vesicle membrane forming a provisional tubule structure, which after invagination matures by collagen incorporation. Inhibition of chondroitin synthesis by beta-xylosides arrests nematocyst morphogenesis at different stages of tubule outgrowth resulting in retention of tubule material and a depletion of mature capsules in the tentacles of hydra. Our data suggest a conserved role of proteoglycans in the stabilization of a membrane protrusion as an essential step in organelle morphogenesis.
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Affiliation(s)
- Patrizia Adamczyk
- Department of Molecular Evolution and Genomics, Institute of Zoology, Heidelberg University, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
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28
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Affiliation(s)
- Ulrike Engel
- Nikon Imaging Center at University of Heidelberg, Bioquant, University of Heidelberg, Heidelberg, Germany.
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Abstract
Using scanning and transmission electron microscopy, we studied formation of the structure at the apical end of sea anemone nematocysts through which the tubule everts at discharge. In anemones of the genus Metridium, we found that each of the three solid triangular apical flaps comprises two layers that are continuous with those of the capsule wall: the electron-lucent inner layer is bound to the electron-dense outer layer. The two-layer structure is obvious in some discharged capsules in which, perhaps due to fixation, the layers part at the flap's periphery. Before the nematocyst discharges, a channel leads from a pore at the tip of the joined flaps into the lumen of the inverted tubule. The thin laminate layer that coats each flap lines the channel. The base of the nematocyst tubule adheres to the capsule wall near the capsule's apical end, and a branch of the tubule underlies part of the laminate layer that coats the flaps. Thus the tubule is not continuous with the capsule wall but structurally separate from it. This helps reconcile differences in understanding of the number of layers constituting the capsule wall, and makes clear that the tubule should be considered part of the capsule contents.
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Affiliation(s)
- Abigail J Reft
- Department of Ecology and Evolutionary Biology, and Division of Invertebrate Zoology, Natural History Museum, University of Kansas, Lawrence, Kansas 66045
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Milde S, Hemmrich G, Anton-Erxleben F, Khalturin K, Wittlieb J, Bosch TCG. Characterization of taxonomically restricted genes in a phylum-restricted cell type. Genome Biol 2009; 10:R8. [PMID: 19161630 PMCID: PMC2687796 DOI: 10.1186/gb-2009-10-1-r8] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2008] [Revised: 12/11/2008] [Accepted: 01/22/2009] [Indexed: 12/04/2022] Open
Abstract
Computational and functional genomic analyses in Hydra magnipapillata suggest that taxonomically-restricted genes are involved in the evolution of morphological novelties such as the cnidarian nematocyte Background Despite decades of research, the molecular mechanisms responsible for the evolution of morphological diversity remain poorly understood. While current models assume that species-specific morphologies are governed by differential use of conserved genetic regulatory circuits, it is debated whether non-conserved taxonomically restricted genes are also involved in making taxonomically relevant structures. The genomic resources available in Hydra, a member of the early branching animal phylum Cnidaria, provide a unique opportunity to study the molecular evolution of morphological novelties such as the nematocyte, a cell type characteristic of, and unique to, Cnidaria. Results We have identified nematocyte-specific genes by suppression subtractive hybridization and find that a considerable portion has no homologues to any sequences in animals outside Hydra. By analyzing the transcripts of these taxonomically restricted genes and mining of the Hydra magnipapillata genome, we find unexpected complexity in gene structure and transcript processing. Transgenic Hydra expressing the green fluorescent protein reporter under control of one of the taxonomically restricted gene promoters recapitulate faithfully the described expression pattern, indicating that promoters of taxonomically restricted genes contain all elements essential for spatial and temporal control mechanisms. Surprisingly, phylogenetic footprinting of this promoter did not reveal any conserved cis-regulatory elements. Conclusions Our findings suggest that taxonomically restricted genes are involved in the evolution of morphological novelties such as the cnidarian nematocyte. The transcriptional regulatory network controlling taxonomically restricted gene expression may contain not yet characterized transcription factors or cis-regulatory elements.
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Affiliation(s)
- Sabine Milde
- Zoological Institute, Christian-Albrechts-University Kiel, Kiel, Germany.
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David CN, Özbek S, Adamczyk P, Meier S, Pauly B, Chapman J, Hwang JS, Gojobori T, Holstein TW. Evolution of complex structures: minicollagens shape the cnidarian nematocyst. Trends Genet 2008; 24:431-8. [DOI: 10.1016/j.tig.2008.07.001] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2008] [Revised: 06/27/2008] [Accepted: 07/04/2008] [Indexed: 01/03/2023]
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