1
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Romanova DY, Moroz LL. Parallel evolution of gravity sensing. Front Cell Dev Biol 2024; 12:1346032. [PMID: 38516131 PMCID: PMC10954788 DOI: 10.3389/fcell.2024.1346032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 02/27/2024] [Indexed: 03/23/2024] Open
Abstract
Omnipresent gravity affects all living organisms; it was a vital factor in the past and the current bottleneck for future space exploration. However, little is known about the evolution of gravity sensing and the comparative biology of gravity reception. Here, by tracing the parallel evolution of gravity sensing, we encounter situations when assemblies of homologous modules result in the emergence of non-homologous structures with similar systemic properties. This is a perfect example to study homoplasy at all levels of biological organization. Apart from numerous practical implementations for bioengineering and astrobiology, the diversity of gravity signaling presents unique reference paradigms to understand hierarchical homology transitions to the convergent evolution of integrative systems. Second, by comparing gravisensory systems in major superclades of basal metazoans (ctenophores, sponges, placozoans, cnidarians, and bilaterians), we illuminate parallel evolution and alternative solutions implemented by basal metazoans toward spatial orientation, focusing on gravitational sensitivity and locomotory integrative systems.
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Affiliation(s)
- Daria Y. Romanova
- Institute of Higher Nervous Activity and Neurophysiology of RAS, Moscow, Russia
| | - Leonid L. Moroz
- Departments of Neuroscience and McKnight Brain Institute, University of Florida, Gainesville, FL, United States
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL, United States
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2
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Schultz DT, Haddock SHD, Bredeson JV, Green RE, Simakov O, Rokhsar DS. Ancient gene linkages support ctenophores as sister to other animals. Nature 2023; 618:110-117. [PMID: 37198475 PMCID: PMC10232365 DOI: 10.1038/s41586-023-05936-6] [Citation(s) in RCA: 65] [Impact Index Per Article: 65.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 03/09/2023] [Indexed: 05/19/2023]
Abstract
A central question in evolutionary biology is whether sponges or ctenophores (comb jellies) are the sister group to all other animals. These alternative phylogenetic hypotheses imply different scenarios for the evolution of complex neural systems and other animal-specific traits1-6. Conventional phylogenetic approaches based on morphological characters and increasingly extensive gene sequence collections have not been able to definitively answer this question7-11. Here we develop chromosome-scale gene linkage, also known as synteny, as a phylogenetic character for resolving this question12. We report new chromosome-scale genomes for a ctenophore and two marine sponges, and for three unicellular relatives of animals (a choanoflagellate, a filasterean amoeba and an ichthyosporean) that serve as outgroups for phylogenetic analysis. We find ancient syntenies that are conserved between animals and their close unicellular relatives. Ctenophores and unicellular eukaryotes share ancestral metazoan patterns, whereas sponges, bilaterians, and cnidarians share derived chromosomal rearrangements. Conserved syntenic characters unite sponges with bilaterians, cnidarians, and placozoans in a monophyletic clade to the exclusion of ctenophores, placing ctenophores as the sister group to all other animals. The patterns of synteny shared by sponges, bilaterians, and cnidarians are the result of rare and irreversible chromosome fusion-and-mixing events that provide robust and unambiguous phylogenetic support for the ctenophore-sister hypothesis. These findings provide a new framework for resolving deep, recalcitrant phylogenetic problems and have implications for our understanding of animal evolution.
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Affiliation(s)
- Darrin T Schultz
- Department of Neuroscience and Developmental Biology, University of Vienna, Vienna, Austria.
- Monterey Bay Aquarium Research Institute, Moss Landing, CA, USA.
- Department of Biomolecular Engineering and Bioinformatics, University of California, Santa Cruz, CA, USA.
| | - Steven H D Haddock
- Monterey Bay Aquarium Research Institute, Moss Landing, CA, USA
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, USA
| | - Jessen V Bredeson
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Richard E Green
- Department of Biomolecular Engineering and Bioinformatics, University of California, Santa Cruz, CA, USA
| | - Oleg Simakov
- Department of Neuroscience and Developmental Biology, University of Vienna, Vienna, Austria.
| | - Daniel S Rokhsar
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA.
- Molecular Genetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan.
- Chan Zuckerberg Biohub, San Francisco, CA, USA.
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3
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Moroz LL, Romanova DY. Alternative neural systems: What is a neuron? (Ctenophores, sponges and placozoans). Front Cell Dev Biol 2022; 10:1071961. [PMID: 36619868 PMCID: PMC9816575 DOI: 10.3389/fcell.2022.1071961] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022] Open
Abstract
How to make a neuron, a synapse, and a neural circuit? Is there only one 'design' for a neural architecture with a universally shared genomic blueprint across species? The brief answer is "No." Four early divergent lineages from the nerveless common ancestor of all animals independently evolved distinct neuroid-type integrative systems. One of these is a subset of neural nets in comb jellies with unique synapses; the second lineage is the well-known Cnidaria + Bilateria; the two others are non-synaptic neuroid systems in sponges and placozoans. By integrating scRNA-seq and microscopy data, we revise the definition of neurons as synaptically-coupled polarized and highly heterogenous secretory cells at the top of behavioral hierarchies with learning capabilities. This physiological (not phylogenetic) definition separates 'true' neurons from non-synaptically and gap junction-coupled integrative systems executing more stereotyped behaviors. Growing evidence supports the hypothesis of multiple origins of neurons and synapses. Thus, many non-bilaterian and bilaterian neuronal classes, circuits or systems are considered functional rather than genetic categories, composed of non-homologous cell types. In summary, little-explored examples of convergent neuronal evolution in representatives of early branching metazoans provide conceptually novel microanatomical and physiological architectures of behavioral controls in animals with prospects of neuro-engineering and synthetic biology.
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Affiliation(s)
- Leonid L. Moroz
- Departments of Neuroscience and McKnight Brain Institute, University of Florida, Gainesville, FL, United States,Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL, United States,*Correspondence: Leonid L. Moroz, ; Daria Y. Romanova,
| | - Daria Y. Romanova
- Institute of Higher Nervous Activity and Neurophysiology of RAS, 5A Butlerova, Moscow, Russia,*Correspondence: Leonid L. Moroz, ; Daria Y. Romanova,
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Larouche-Bilodeau C, Cameron CB. Acorn worm ossicle ultrastructure and composition and the origin of the echinoderm skeleton. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220773. [PMID: 36147942 PMCID: PMC9490348 DOI: 10.1098/rsos.220773] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 08/31/2022] [Indexed: 05/02/2023]
Abstract
Here, we describe the shape and mineral composition of ossicles from eight acorn worm species, bringing the total known biomineralizing enteropneusts to 10 and confirming that ossicles are widespread in Enteropneusta. Three general forms were identified including a globular form that occurs in all three major enteropneust families. The biomineral compositions included all three polymorphs of calcium carbonate; calcite, aragonite and vaterite, and low to high magnesium concentrations. Calcite was the most common and characteristic of echinoderm ossicles. Based on these findings we hypothesize that an enteropneust-like ancestor to the Ambulacraria had ectodermal ossicles, formed in an extracellular occluded space bordered by a sheath of sclerocyte cells. The ossicles were microscopic, monotypic globular shaped, calcite ossicles with low to high Mg content and MSP130 proteins. The ossicles lacked intercalation with other ossicles. The function of acorn worm ossicles is unknown, but the position of ossicles in the trunk epithelia and near to the surface suggests predator deterrence, to provide grip on the walls of a burrow or tube, as storage of metabolic waste, or to regulate blood pH, rather than as an endoskeleton function seen in fossil and crown group Echinodermata.
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Affiliation(s)
| | - Christopher B. Cameron
- Département de sciences biologiques, University of Montreal, Montreal, Quebec, Canada H3C 3J7
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5
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Larouche-Bilodeau C, Cameron CB. Acorn worm ossicle ultrastructure and composition and the origin of the echinoderm skeleton. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220773. [PMID: 36147942 DOI: 10.5281/zenodo.5103051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 08/31/2022] [Indexed: 05/18/2023]
Abstract
Here, we describe the shape and mineral composition of ossicles from eight acorn worm species, bringing the total known biomineralizing enteropneusts to 10 and confirming that ossicles are widespread in Enteropneusta. Three general forms were identified including a globular form that occurs in all three major enteropneust families. The biomineral compositions included all three polymorphs of calcium carbonate; calcite, aragonite and vaterite, and low to high magnesium concentrations. Calcite was the most common and characteristic of echinoderm ossicles. Based on these findings we hypothesize that an enteropneust-like ancestor to the Ambulacraria had ectodermal ossicles, formed in an extracellular occluded space bordered by a sheath of sclerocyte cells. The ossicles were microscopic, monotypic globular shaped, calcite ossicles with low to high Mg content and MSP130 proteins. The ossicles lacked intercalation with other ossicles. The function of acorn worm ossicles is unknown, but the position of ossicles in the trunk epithelia and near to the surface suggests predator deterrence, to provide grip on the walls of a burrow or tube, as storage of metabolic waste, or to regulate blood pH, rather than as an endoskeleton function seen in fossil and crown group Echinodermata.
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Affiliation(s)
| | - Christopher B Cameron
- Département de sciences biologiques, University of Montreal, Montreal, Quebec, Canada H3C 3J7
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6
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Multigenerational laboratory culture of pelagic ctenophores and CRISPR-Cas9 genome editing in the lobate Mnemiopsis leidyi. Nat Protoc 2022; 17:1868-1900. [PMID: 35697825 DOI: 10.1038/s41596-022-00702-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 03/23/2022] [Indexed: 11/08/2022]
Abstract
Despite long-standing experimental interest in ctenophores due to their unique biology, ecological influence and evolutionary status, previous work has largely been constrained by the periodic seasonal availability of wild-caught animals and difficulty in reliably closing the life cycle. To address this problem, we have developed straightforward protocols that can be easily implemented to establish long-term multigenerational cultures for biological experimentation in the laboratory. In this protocol, we describe the continuous culture of the Atlantic lobate ctenophore Mnemiopsis leidyi. A rapid 3-week egg-to-egg generation time makes Mnemiopsis suitable for a wide range of experimental genetic, cellular, embryological, physiological, developmental, ecological and evolutionary studies. We provide recommendations for general husbandry to close the life cycle of Mnemiopsis in the laboratory, including feeding requirements, light-induced spawning, collection of embryos and rearing of juveniles to adults. These protocols have been successfully applied to maintain long-term multigenerational cultures of several species of pelagic ctenophores, and can be utilized by laboratories lacking easy access to the ocean. We also provide protocols for targeted genome editing via microinjection with CRISPR-Cas9 that can be completed within ~2 weeks, including single-guide RNA synthesis, early embryo microinjection, phenotype assessment and sequence validation of genome edits. These protocols provide a foundation for using Mnemiopsis as a model organism for functional genomic analyses in ctenophores.
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7
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Parry LA, Lerosey-Aubril R, Weaver JC, Ortega-Hernández J. Cambrian comb jellies from Utah illuminate the early evolution of nervous and sensory systems in ctenophores. iScience 2021; 24:102943. [PMID: 34522849 PMCID: PMC8426560 DOI: 10.1016/j.isci.2021.102943] [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: 04/02/2021] [Revised: 06/01/2021] [Accepted: 07/30/2021] [Indexed: 12/11/2022] Open
Abstract
Ctenophores are a group of predatory macroinvertebrates whose controversial phylogenetic position has prompted several competing hypotheses regarding the evolution of animal organ systems. Although ctenophores date back at least to the Cambrian, they have a poor fossil record due to their gelatinous bodies. Here, we describe two ctenophore species from the Cambrian of Utah, which illuminate the early evolution of nervous and sensory features in the phylum. Thalassostaphylos elegans has 16 comb rows, an oral skirt, and an apical organ with polar fields. Ctenorhabdotus campanelliformis has 24 comb rows, an oral skirt, an apical organ enclosed by a capsule and neurological tissues preserved as carbonaceous films. These are concentrated around the apical organ and ciliated furrows, which connect to a circumoral nerve ring via longitudinal axons. C. campanelliformis deviates from the neuroanatomy of living ctenophores and demonstrates a substantial complexity in the nervous system of Cambrian ctenophores. Two species of rare fossil ctenophores are described from the Cambrian of Utah Fossil ctenophores preserve remains of nervous tissue and sensory structures Neurological structures include an oral nerve ring and giant longitudinal axons Cambrian ctenophores had a more complex neuroanatomy than living species
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Affiliation(s)
- Luke A Parry
- Department of Earth Sciences, University of Oxford, 3 South Parks Road, Oxford, OX1 3AN, UK.,Department of Geology and Geophysics, Yale University, 210 Whitney Avenue, New Haven, CT 06511, USA
| | - Rudy Lerosey-Aubril
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
| | - James C Weaver
- Wyss Institute for Biologically Inspired Engineering, Harvard University, 60 Oxford Street, Cambridge, MA 02138, USA
| | - Javier Ortega-Hernández
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
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8
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Presnell JS, Browne WE. Krüppel-like factor gene function in the ctenophore Mnemiopsis leidyi assessed by CRISPR/Cas9-mediated genome editing. Development 2021; 148:272041. [PMID: 34373891 DOI: 10.1242/dev.199771] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 07/26/2021] [Indexed: 12/21/2022]
Abstract
The Krüppel-like factor (Klf) gene family encodes transcription factors that play an important role in the regulation of stem cell proliferation, cell differentiation and development in bilaterians. Although Klf genes have been shown to specify functionally various cell types in non-bilaterian animals, their role in early-diverging animal lineages has not been assessed. Thus, the ancestral activity of these transcription factors in animal development is not well understood. The ctenophore Mnemiopsis leidyi has emerged as an important non-bilaterian model system for understanding early animal evolution. Here, we characterize the expression and functional role of Klf genes during M. leidyi embryogenesis. Zygotic Klf gene function was assessed with both CRISPR/Cas9-mediated genome editing and splice-blocking morpholino oligonucleotide knockdown approaches. Abrogation of zygotic Klf expression during M. leidyi embryogenesis resulted in abnormal development of several organs, including the pharynx, tentacle bulbs and apical organ. Our data suggest an ancient role for Klf genes in regulating endodermal patterning, possibly through regulation of cell proliferation.
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Affiliation(s)
- Jason S Presnell
- Department of Biology, University of Miami, Cox Science Center, 1301 Memorial Drive, Miami, FL 33146, USA
| | - William E Browne
- Department of Biology, University of Miami, Cox Science Center, 1301 Memorial Drive, Miami, FL 33146, USA
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9
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Structural analysis of the statocyst and nervous system of Praesagittifera naikaiensis, an acoel flatworm, during development after hatching. ZOOMORPHOLOGY 2021. [DOI: 10.1007/s00435-021-00521-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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10
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Mayorova TD, Smith CL, Hammar K, Winters CA, Pivovarova NB, Aronova MA, Leapman RD, Reese TS. Cells containing aragonite crystals mediate responses to gravity in Trichoplax adhaerens (Placozoa), an animal lacking neurons and synapses. PLoS One 2018; 13:e0190905. [PMID: 29342202 PMCID: PMC5771587 DOI: 10.1371/journal.pone.0190905] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 12/21/2017] [Indexed: 11/23/2022] Open
Abstract
Trichoplax adhaerens has only six cell types. The function as well as the structure of crystal cells, the least numerous cell type, presented an enigma. Crystal cells are arrayed around the perimeter of the animal and each contains a birefringent crystal. Crystal cells resemble lithocytes in other animals so we looked for evidence they are gravity sensors. Confocal microscopy showed that their cup-shaped nuclei are oriented toward the edge of the animal, and that the crystal shifts downward under the influence of gravity. Some animals spontaneously lack crystal cells and these animals behaved differently upon being tilted vertically than animals with a typical number of crystal cells. EM revealed crystal cell contacts with fiber cells and epithelial cells but these contacts lacked features of synapses. EM spectroscopic analyses showed that crystals consist of the aragonite form of calcium carbonate. We thus provide behavioral evidence that Trichoplax are able to sense gravity, and that crystal cells are likely to be their gravity receptors. Moreover, because placozoans are thought to have evolved during Ediacaran or Cryogenian eras associated with aragonite seas, and their crystals are made of aragonite, they may have acquired gravity sensors during this early era.
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Affiliation(s)
- Tatiana D. Mayorova
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
- Laboratory of Developmental Neurobiology, Koltzov Institute of Developmental Biology, Russian Academy of Science, Moscow, Russia
| | - Carolyn L. Smith
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Katherine Hammar
- Central Microscopy Facility, Marine Biological Laboratory, Woods Hole, MA, United States of America
| | - Christine A. Winters
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Natalia B. Pivovarova
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Maria A. Aronova
- Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Rockville Pike, Bethesda, Maryland, United States of America
| | - Richard D. Leapman
- Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Rockville Pike, Bethesda, Maryland, United States of America
| | - Thomas S. Reese
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
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11
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Solé M, Lenoir M, Fortuño JM, Durfort M, van der Schaar M, André M. Evidence of Cnidarians sensitivity to sound after exposure to low frequency underwater sources. Sci Rep 2016; 6:37979. [PMID: 28000727 PMCID: PMC5175278 DOI: 10.1038/srep37979] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 10/24/2016] [Indexed: 11/30/2022] Open
Abstract
Jellyfishes represent a group of species that play an important role in oceans, particularly as a food source for different taxa and as a predator of fish larvae and planktonic prey. The massive introduction of artificial sound sources in the oceans has become a concern to science and society. While we are only beginning to understand that non-hearing specialists like cephalopods can be affected by anthropogenic noises and regulation is underway to measure European water noise levels, we still don’t know yet if the impact of sound may be extended to other lower level taxa of the food web. Here we exposed two species of Mediterranean Scyphozoan medusa, Cotylorhiza tuberculata and Rhizostoma pulmo to a sweep of low frequency sounds. Scanning electron microscopy (SEM) revealed injuries in the statocyst sensory epithelium of both species after exposure to sound, that are consistent with the manifestation of a massive acoustic trauma observed in other species. The presence of acoustic trauma in marine species that are not hearing specialists, like medusa, shows the magnitude of the problem of noise pollution and the complexity of the task to determine threshold values that would help building up regulation to prevent permanent damage of the ecosystems.
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Affiliation(s)
- Marta Solé
- Laboratory of Applied Bioacoustics, Technical University of Catalonia, Barcelona, Spain
| | - Marc Lenoir
- INSERM U.1051, Institute of Neurosciences of Montpellier, Montpellier, France
| | - José Manuel Fortuño
- Institute of Marine Sciences, Spanish National Research Council, Barcelona, Spain
| | - Mercè Durfort
- Department of Cellular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Mike van der Schaar
- Laboratory of Applied Bioacoustics, Technical University of Catalonia, Barcelona, Spain
| | - Michel André
- Laboratory of Applied Bioacoustics, Technical University of Catalonia, Barcelona, Spain
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12
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Senatore A, Raiss H, Le P. Physiology and Evolution of Voltage-Gated Calcium Channels in Early Diverging Animal Phyla: Cnidaria, Placozoa, Porifera and Ctenophora. Front Physiol 2016; 7:481. [PMID: 27867359 PMCID: PMC5095125 DOI: 10.3389/fphys.2016.00481] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 10/07/2016] [Indexed: 12/18/2022] Open
Abstract
Voltage-gated calcium (Cav) channels serve dual roles in the cell, where they can both depolarize the membrane potential for electrical excitability, and activate transient cytoplasmic Ca2+ signals. In animals, Cav channels play crucial roles including driving muscle contraction (excitation-contraction coupling), gene expression (excitation-transcription coupling), pre-synaptic and neuroendocrine exocytosis (excitation-secretion coupling), regulation of flagellar/ciliary beating, and regulation of cellular excitability, either directly or through modulation of other Ca2+-sensitive ion channels. In recent years, genome sequencing has provided significant insights into the molecular evolution of Cav channels. Furthermore, expanded gene datasets have permitted improved inference of the species phylogeny at the base of Metazoa, providing clearer insights into the evolution of complex animal traits which involve Cav channels, including the nervous system. For the various types of metazoan Cav channels, key properties that determine their cellular contribution include: Ion selectivity, pore gating, and, importantly, cytoplasmic protein-protein interactions that direct sub-cellular localization and functional complexing. It is unclear when these defining features, many of which are essential for nervous system function, evolved. In this review, we highlight some experimental observations that implicate Cav channels in the physiology and behavior of the most early-diverging animals from the phyla Cnidaria, Placozoa, Porifera, and Ctenophora. Given our limited understanding of the molecular biology of Cav channels in these basal animal lineages, we infer insights from better-studied vertebrate and invertebrate animals. We also highlight some apparently conserved cellular functions of Cav channels, which might have emerged very early on during metazoan evolution, or perhaps predated it.
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Affiliation(s)
- Adriano Senatore
- Department of Biology, University of Toronto Mississauga Mississauga, ON, Canada
| | - Hamad Raiss
- Department of Biology, University of Toronto Mississauga Mississauga, ON, Canada
| | - Phuong Le
- Department of Biology, University of Toronto Mississauga Mississauga, ON, Canada
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13
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Tamm SL. Novel Structures Associated with Presumed Photoreceptors in the Aboral Sense Organ of Ctenophores. THE BIOLOGICAL BULLETIN 2016; 231:97-102. [PMID: 27820909 DOI: 10.1086/690089] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
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Tamm SL. Functional consequences of the asymmetric architecture of the ctenophore statocyst. THE BIOLOGICAL BULLETIN 2015; 229:173-184. [PMID: 26504158 DOI: 10.1086/bblv229n2p173] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Ctenophores, or comb jellies, are geotactic with a statocyst that controls the activity of the eight ciliary comb rows. If a ctenophore is tilted or displaced from a position of vertical balance, it rights itself by asymmetric frequencies of beating on the uppermost and lowermost comb rows, turning to swim up or down depending on its mood. I recently discovered that the statocyst of ctenophores has an asymmetric architecture related to the sagittal and tentacular planes along the oral-aboral axis. The four groups of pacemaker balancer cilia are arranged in a rectangle along the tentacular plane, and support a superellipsoidal statolith elongated in the tentacular plane. By controlled tilting of immobilized ctenophores in either body plane with video recording of activated comb rows, I found that higher beat frequencies occurred in the sagittal than in the tentacular plane at orthogonal orientations. Similar tilting experiments on isolated statocyst slices showed that statolith displacement due to gravity and the resulting deflection of the mechanoresponsive balancers are greater in the sagittal plane. Finally, tilting experiments on a mechanical model gave results similar to those of real statocysts, indicating that the geometric asymmetries of statolith design are sufficient to account for my findings. The asymmetric architecture of the ctenophore statocyst thus has functional consequences, but a possible adaptive value is not known.
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Affiliation(s)
- Sidney L Tamm
- Bell Center, Marine Biological Laboratory, Woods Hole, Massachusetts 02543
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15
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Ou Q, Xiao S, Han J, Sun G, Zhang F, Zhang Z, Shu D. A vanished history of skeletonization in Cambrian comb jellies. SCIENCE ADVANCES 2015; 1:e1500092. [PMID: 26601209 PMCID: PMC4646772 DOI: 10.1126/sciadv.1500092] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 05/05/2015] [Indexed: 06/05/2023]
Abstract
Ctenophores are traditionally regarded as "lower" metazoans, sharing with cnidarians a diploblastic grade of organization. Unlike cnidarians, where skeletonization (biomineralization and sclerotization) evolved repeatedly among ecologically important taxa (for example, scleractinians and octocorals), living ctenophores are characteristically soft-bodied animals. We report six sclerotized and armored ctenophores from the early Cambrian period. They have diagnostic ctenophore features (for example, an octamerous symmetry, oral-aboral axis, aboral sense organ, and octaradially arranged ctene rows). Unlike most modern counterparts, however, they lack tentacles, have a sclerotized framework, and have eight pairs of ctene rows. They are resolved as a monophyletic group (Scleroctenophora new class) within the ctenophores. This clade reveals a cryptic history and sheds new light on the early evolution of this basal animal phylum. Skeletonization also occurs in some other Cambrian animal groups whose extant members are exclusively soft-bodied, suggesting the ecological importance of skeletonization in the Cambrian explosion.
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Affiliation(s)
- Qiang Ou
- Early Life Evolution Laboratory, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China
- Early Life Institute, Collaborative Innovation Center of Continental Tectonics, State Key Laboratory of Continental Dynamics, Northwest University, Xi’an 710069, China
| | - Shuhai Xiao
- Department of Geosciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Jian Han
- Early Life Institute, Collaborative Innovation Center of Continental Tectonics, State Key Laboratory of Continental Dynamics, Northwest University, Xi’an 710069, China
| | - Ge Sun
- Early Life Evolution Laboratory, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China
| | - Fang Zhang
- Tsinghua University, Beijing 100084, China
| | - Zhifei Zhang
- Early Life Institute, Collaborative Innovation Center of Continental Tectonics, State Key Laboratory of Continental Dynamics, Northwest University, Xi’an 710069, China
| | - Degan Shu
- Early Life Evolution Laboratory, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China
- Early Life Institute, Collaborative Innovation Center of Continental Tectonics, State Key Laboratory of Continental Dynamics, Northwest University, Xi’an 710069, China
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Noda N, Tamm SL. Lithocytes are transported along the ciliary surface to build the statolith of ctenophores. Curr Biol 2015; 24:R951-2. [PMID: 25291633 DOI: 10.1016/j.cub.2014.08.045] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Naoki Noda
- Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA 02543, USA; Department of Life Science, Gakushuin University, Mejiro 1-5-1, Toshima-ku, Tokyo, 171-8588, Japan.
| | - Sidney L Tamm
- Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA 02543, USA; Biology Department, Boston University, Boston, MA 02215, USA.
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