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Tentacle Morphological Variation Coincides with Differential Expression of Toxins in Sea Anemones. Toxins (Basel) 2021; 13:toxins13070452. [PMID: 34209745 PMCID: PMC8310139 DOI: 10.3390/toxins13070452] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/25/2021] [Accepted: 06/26/2021] [Indexed: 02/08/2023] Open
Abstract
Phylum Cnidaria is an ancient venomous group defined by the presence of cnidae, specialised organelles that serve as venom delivery systems. The distribution of cnidae across the body plan is linked to regionalisation of venom production, with tissue-specific venom composition observed in multiple actiniarian species. In this study, we assess whether morphological variants of tentacles are associated with distinct toxin expression profiles and investigate the functional significance of specialised tentacular structures. Using five sea anemone species, we analysed differential expression of toxin-like transcripts and found that expression levels differ significantly across tentacular structures when substantial morphological variation is present. Therefore, the differential expression of toxin genes is associated with morphological variation of tentacular structures in a tissue-specific manner. Furthermore, the unique toxin profile of spherical tentacular structures in families Aliciidae and Thalassianthidae indicate that vesicles and nematospheres may function to protect branched structures that host a large number of photosynthetic symbionts. Thus, hosting zooxanthellae may account for the tentacle-specific toxin expression profiles observed in the current study. Overall, specialised tentacular structures serve unique ecological roles and, in order to fulfil their functions, they possess distinct venom cocktails.
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Ashwood LM, Norton RS, Undheim EAB, Hurwood DA, Prentis PJ. Characterising Functional Venom Profiles of Anthozoans and Medusozoans within Their Ecological Context. Mar Drugs 2020; 18:E202. [PMID: 32283847 PMCID: PMC7230708 DOI: 10.3390/md18040202] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 03/31/2020] [Accepted: 04/06/2020] [Indexed: 12/13/2022] Open
Abstract
This review examines the current state of knowledge regarding toxins from anthozoans (sea anemones, coral, zoanthids, corallimorphs, sea pens and tube anemones). We provide an overview of venom from phylum Cnidaria and review the diversity of venom composition between the two major clades (Medusozoa and Anthozoa). We highlight that the functional and ecological context of venom has implications for the temporal and spatial expression of protein and peptide toxins within class Anthozoa. Understanding the nuances in the regulation of venom arsenals has been made possible by recent advances in analytical technologies that allow characterisation of the spatial distributions of toxins. Furthermore, anthozoans are unique in that ecological roles can be assigned using tissue expression data, thereby circumventing some of the challenges related to pharmacological screening.
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Affiliation(s)
- Lauren M. Ashwood
- School of Biology and Environmental Science, Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Raymond S. Norton
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
- ARC Centre for Fragment-Based Design, Monash University, Parkville, Victoria 3052, Australia
| | - Eivind A. B. Undheim
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway
- Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, PO Box 1066 Blindern, 0316 Oslo, Norway
- Centre for Advanced Imaging, University of Queensland, St Lucia, QLD 4072, Australia
| | - David A. Hurwood
- School of Biology and Environmental Science, Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD 4000, Australia
- Institute of Future Environments, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Peter J. Prentis
- School of Biology and Environmental Science, Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD 4000, Australia
- Institute of Future Environments, Queensland University of Technology, Brisbane, QLD 4000, Australia
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Gold DA, Lau CLF, Fuong H, Kao G, Hartenstein V, Jacobs DK. Mechanisms of cnidocyte development in the moon jellyfish Aurelia. Evol Dev 2019; 21:72-81. [PMID: 30623570 DOI: 10.1111/ede.12278] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Stinging cells called cnidocytes are a defining trait of the cnidarians (sea anemones, corals, jellyfish, and their relatives). In hydrozoan cnidarians such as Hydra, cnidocytes develop from interstitial stem cells set aside in the ectoderm. It is less clear how cnidocytes develop outside the Hydrozoa, as other cnidarians appear to lack interstitial stem cells. We addressed this question by studying cnidogenesis in the moon jellyfish (Aurelia) through the visualization of minicollagen-a protein associated with cnidocyte development-as well as transmission electron microscopy. We discovered that developing cnidoblasts are rare or absent in feeding structures rich in mature cnidocytes, such as tentacles and lappets. Using transmission electron microscopy, we determined that the progenitors of cnidocytes have traits consistent with epitheliomuscular cells. Our data suggests a dynamic where cnidocytes develop at high concentrations in the epithelium of more proximal regions, and subsequently migrate to more distal regions where they exhibit high usage and turnover. Similar to some anthozoans, cnidocytes in Aurelia do not appear to be generated by interstitial stem cells; instead, epitheliomuscular cells appear to be the progenitor cell type. This observation polarizes the evolution of cnidogenesis, and raises the question of how interstitial stem cells came to regulate cnidogenesis in hydrozoans.
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Affiliation(s)
- David A Gold
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California.,Department of Earth and Planetary Sciences, University of California, Davis, California
| | - Clive Long Fung Lau
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California
| | - Holly Fuong
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California.,Department of Ecology, Evolution, and Environmental Biology, Columbia University, New York, New York.,New York Consortium in Evolutionary Primatology, New York, New York
| | - Gregory Kao
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California
| | - Volker Hartenstein
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, California
| | - David K Jacobs
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California
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Gusmão LC, Grajales A, Rodríguez E. Sea Anemones through X-Rays: Visualization of Two Species ofDiadumene(Cnidaria, Actiniaria) Using Micro-CT. AMERICAN MUSEUM NOVITATES 2018. [DOI: 10.1206/3907.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Luciana C. Gusmão
- Department of Invertebrate Zoology, American Museum of Natural History, New York
| | - Alejandro Grajales
- Department of Invertebrate Zoology, American Museum of Natural History, New York
- Departamento de Ciencias Biológicas, Universidad de los Andes, Bogotá, Colombia
| | - Estefania Rodríguez
- Department of Invertebrate Zoology, American Museum of Natural History, New York
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Gold DA, Nakanishi N, Hensley NM, Cozzolino K, Tabatabaee M, Martin M, Hartenstein V, Jacobs DK. Structural and Developmental Disparity in the Tentacles of the Moon Jellyfish Aurelia sp.1. PLoS One 2015; 10:e0134741. [PMID: 26241309 PMCID: PMC4524682 DOI: 10.1371/journal.pone.0134741] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Accepted: 07/13/2015] [Indexed: 01/13/2023] Open
Abstract
Tentacles armed with stinging cells (cnidocytes) are a defining trait of the cnidarians, a phylum that includes sea anemones, corals, jellyfish, and hydras. While cnidarian tentacles are generally characterized as structures evolved for feeding and defense, significant variation exists between the tentacles of different species, and within the same species across different life stages and/or body regions. Such diversity suggests cryptic distinctions exist in tentacle function. In this paper, we use confocal and transmission electron microscopy to contrast the structure and development of tentacles in the moon jellyfish, Aurelia species 1. We show that polyp oral tentacles and medusa marginal tentacles display markedly different cellular and muscular architecture, as well as distinct patterns of cellular proliferation during growth. Many structural differences between these tentacle types may reflect biomechanical solutions to different feeding strategies, although further work would be required for a precise mechanistic understanding. However, differences in cell proliferation dynamics suggests that the two tentacle forms lack a conserved mechanism of development, challenging the textbook-notion that cnidarian tentacles can be homologized into a conserved bauplan.
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Affiliation(s)
- David A. Gold
- Department of Ecology and Evolutionary Biolology. University of California Los Angeles, Los Angeles, California, United States of America
| | - Nagayasu Nakanishi
- Department of Ecology and Evolutionary Biolology. University of California Los Angeles, Los Angeles, California, United States of America
| | - Nicholai M. Hensley
- Department of Ecology and Evolutionary Biolology. University of California Los Angeles, Los Angeles, California, United States of America
| | - Kira Cozzolino
- Department of Ecology and Evolutionary Biolology. University of California Los Angeles, Los Angeles, California, United States of America
| | - Mariam Tabatabaee
- Department of Ecology and Evolutionary Biolology. University of California Los Angeles, Los Angeles, California, United States of America
| | - Michelle Martin
- Department of Ecology and Evolutionary Biolology. University of California Los Angeles, Los Angeles, California, United States of America
| | - Volker Hartenstein
- Department of Molecular, Cell, and Developmental Biology. University of California Los Angeles, Los Angeles, California, United States of America
| | - David K. Jacobs
- Department of Ecology and Evolutionary Biolology. University of California Los Angeles, Los Angeles, California, United States of America
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Buss LW, Anderson C, Westerman E, Kritzberger C, Poudyal M, Moreno MA, Lakkis FG. Allorecognition triggers autophagy and subsequent necrosis in the cnidarian Hydractinia symbiolongicarpus. PLoS One 2012; 7:e48914. [PMID: 23145018 PMCID: PMC3493586 DOI: 10.1371/journal.pone.0048914] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Accepted: 10/03/2012] [Indexed: 11/18/2022] Open
Abstract
Transitory fusion is an allorecognition phenotype displayed by the colonial hydroid Hydractinia symbiolongicarpus when interacting colonies share some, but not all, loci within the allorecognition gene complex (ARC). The phenotype is characterized by an initial fusion followed by subsequent cell death resulting in separation of the two incompatible colonies. We here characterize this cell death process using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and continuous in vivo digital microscopy. These techniques reveal widespread autophagy and subsequent necrosis in both colony and grafted polyp assays. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays and ultrastructural observations revealed no evidence of apoptosis. Pharmacological inhibition of autophagy using 3-methyladenine (3-MA) completely suppressed transitory fusion in vivo in colony assays. Rapamycin did not have a significant effect in the same assays. These results establish the hydroid allorecognition system as a novel model for the study of cell death.
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Affiliation(s)
- Leo W Buss
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, USA.
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Wolenski FS, Bradham CA, Finnerty JR, Gilmore TD. NF-κB is required for cnidocyte development in the sea anemone Nematostella vectensis. Dev Biol 2012; 373:205-15. [PMID: 23063796 DOI: 10.1016/j.ydbio.2012.10.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 09/12/2012] [Accepted: 10/04/2012] [Indexed: 01/29/2023]
Abstract
The sea anemone Nematostella vectensis (Nv) is a leading model organism for the phylum Cnidaria, which includes anemones, corals, jellyfishes and hydras. A defining trait across this phylum is the cnidocyte, an ectodermal cell type with a variety of functions including defense, prey capture and environmental sensing. Herein, we show that the Nv-NF-κB transcription factor and its inhibitor Nv-IκB are expressed in a subset of cnidocytes in the body column of juvenile and adult anemones. The size and distribution of the Nv-NF-κB-positive cnidocytes suggest that they are in a subtype known as basitrichous haplonema cnidocytes. Nv-NF-κB is primarily cytoplasmic in cnidocytes in juvenile and adult animals, but is nuclear when first detected in the 30-h post-fertilization embryo. Morpholino-mediated knockdown of Nv-NF-κB expression results in greatly reduced cnidocyte formation in the 5 day-old animal. Taken together, these results indicate that NF-κB plays a key role in the development of the phylum-specific cnidocyte cell type in Nematostella, likely by nuclear Nv-NF-κB-dependent activation of genes required for cnidocyte development.
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Affiliation(s)
- Francis S Wolenski
- Boston University, Department of Biology, 5 Cummington Mall, Boston, MA 02215, USA
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Moran Y, Genikhovich G, Gordon D, Wienkoop S, Zenkert C, Ozbek S, Technau U, Gurevitz M. Neurotoxin localization to ectodermal gland cells uncovers an alternative mechanism of venom delivery in sea anemones. Proc Biol Sci 2011; 279:1351-8. [PMID: 22048953 DOI: 10.1098/rspb.2011.1731] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Jellyfish, hydras, corals and sea anemones (phylum Cnidaria) are known for their venomous stinging cells, nematocytes, used for prey and defence. Here we show, however, that the potent Type I neurotoxin of the sea anemone Nematostella vectensis, Nv1, is confined to ectodermal gland cells rather than nematocytes. We demonstrate massive Nv1 secretion upon encounter with a crustacean prey. Concomitant discharge of nematocysts probably pierces the prey, expediting toxin penetration. Toxin efficiency in sea water is further demonstrated by the rapid paralysis of fish or crustacean larvae upon application of recombinant Nv1 into their medium. Analysis of other anemone species reveals that in Anthopleura elegantissima, Type I neurotoxins also appear in gland cells, whereas in the common species Anemonia viridis, Type I toxins are localized to both nematocytes and ectodermal gland cells. The nematocyte-based and gland cell-based envenomation mechanisms may reflect substantial differences in the ecology and feeding habits of sea anemone species. Overall, the immunolocalization of neurotoxins to gland cells changes the common view in the literature that sea anemone neurotoxins are produced and delivered only by stinging nematocytes, and raises the possibility that this toxin-secretion mechanism is an ancestral evolutionary state of the venom delivery machinery in sea anemones.
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Affiliation(s)
- Yehu Moran
- Department of Molecular Biology and Ecology of Plants, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, 69978 Tel Aviv, Israel.
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Cilium Evolution: Identification of a Novel Protein, Nematocilin, in the Mechanosensory Cilium of Hydra Nematocytes. Mol Biol Evol 2008; 25:2009-17. [DOI: 10.1093/molbev/msn154] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
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10
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Kass-Simon G, Scappaticci, Jr. AA. The behavioral and developmental physiology of nematocysts. CAN J ZOOL 2002. [DOI: 10.1139/z02-135] [Citation(s) in RCA: 147] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Nematocysts are the nonliving secretions of specialized cells, the nematocytes, which develop from multipotent stem cells. Nematocysts are the means by which coelenterates capture prey and defend against predation. The 25 or more known types of nematocysts can be divided into to four functional categories: those that pierce, ensnare, or adhere to prey, and those that adhere to the substrate. During development a collagenous cyst, which may contain toxins, forms; a hollow thread, which becomes coiled as it invaginates, develops. Maturing nematocytenematocyst complexes migrate to their discharge sites and are deployed in specific patterns. The mechanisms of pattern determination are not clear. Discharge of nematocysts appears to involve increases in intracapsular osmotic pressure consequent upon release of bound calcium within the capsule; the eversion of the filament may depend upon release of structural tension consequent upon a loss of zinc from the thread. Evidence exists that discharge is initiated as a calcium-dependent exocytosis, triggered by an electrical signal resulting from the transduction of mechanical stimuli received at the nematocyte's cnidocil. Chemical signals transduced in adjacent sensory cells alter the frequency response of the nematocyte. In opposition to the nematocytenematocyst independent effector hypothesis, excitatory and inhibitory neuronal input appears to regulate discharge.
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11
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Abstract
Sea anemones are sessile invertebrates that detect movements of prey using numerous hair bundles located on tentacles surrounding their mouth. Previously we found that hair bundles of anemones are structurally and functionally similar to those of vertebrates. After 10-15 min exposure to calcium depleted buffers, hair bundles in chickens suffer moderate damage from which they recover in 12 h without requiring new protein synthesis [Zhao, Yamoah and Gillespie, Proc. Natl. Acad. Sci. USA 94 (1996) 15469-15474]. We find that after 1 h exposure to calcium free seawater, hair bundles of anemones suffer extensive damage from which they recover in 4 h, apparently because of newly synthesized, secretory proteins called 'repair proteins'. Recovery is delayed in a dose dependent fashion by cycloheximide. In the presence of exogenously added repair proteins, recovery occurs within 8 min and is cycloheximide insensitive. Recovery is ascertained by a bioassay performed on intact specimens, by electrophysiology, and by timelapse video microscopy. Fraction beta, a chromatographic fraction with bioactivity comparable to the complete mixture of repair proteins, consists of complexes having an estimated mass of 2000 kDa. Avidin based cytochemistry suggests that biotinylated fraction beta binds to damaged hair bundles. SDS-PAGE gel electrophoresis demonstrates that fraction beta contains 8-10 polypeptides of 90 kDa or smaller. At least four of these polypeptides apparently are consumed during the repair process. Negatively stained samples of fraction beta are shown by transmission electron microscopy to include filamentous structures similar in length (150 nm) and width (6 nm) to linkages between stereocilia. The filamentous structures can be associated with globular structures (20 nm in diameter). A model is presented wherein repair proteins comprise replacement linkages and enzymes that attach linkages to appropriate membrane proteins.
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Affiliation(s)
- G M Watson
- Department of Biology, University of Southwestern Louisiana, Lafayette 70504-2451, USA.
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12
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Confocal laser scanning light microscopy of the extra-thecal epithelia of undecalcified scleractinian corals. Cell Tissue Res 1993. [DOI: 10.1007/bf00318560] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Watson GM, Mariscal RN. Ultrastructure of nematocyst discharge in catch tentacles of the sea anemone Haliplanella luciae (Cnidaria: Anthozoa). Tissue Cell 1985; 17:199-213. [PMID: 2409634 DOI: 10.1016/0040-8166(85)90089-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The mature nematocyst lies just beneath the cnidodyte plasma membrane. A microtubule array surrounds the nematocyst capsule just beneath the capsule tip. We propose that the array helps to hold the capsule at the cnidocyte cell surface until discharge. The undischarged capsule tip is sealed by three apical flaps, joined together along complex radial seams. The seams are filled with subunits that appear to bind the flaps together. Upon discharge, the flaps separate along the radial seams to permit thread eversion. The everted thread is lined on both sides by subunits that are stained by antimonate, indicating that they bind calcium. We suggest that, together, the subunits hold the uneverted thread in its folded and coiled configuration. Thread eversion would follow subunit uncoupling. The capsule and thread interiors of partially discharged nematocysts are stained by antimonate. In contrast, the capsule and thread interiors of fully discharged nematocysts are not stained by antimonate. Thus, nematocyst calcium might be injected into the target tissue where it is presumed to act in conjunction with nematocyst venom to promote cell death.
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Watson GM, Mariscal RN. Ultrastructure and sulfur cytochemistry of nematocyst development in catch tentacles of the sea anemone Haliplanella luciae (cnidaria: Anthozoa). ACTA ACUST UNITED AC 1984. [DOI: 10.1016/s0022-5320(84)80075-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Watson GM, Mariscal RN. Calcium cytochemistry of nematocyst development in catch tentacles of the sea anemone Haliplanella luciae (Cnidaria: Anthozoa) and the molecular basis for tube inversion into the capsule. ACTA ACUST UNITED AC 1984. [DOI: 10.1016/s0022-5320(84)80059-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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