1
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Jense C, Adams M, Raadik TA, Waters JM, Morgan DL, Barmuta LA, Hardie SA, Deagle BE, Burridge CP. Cryptic diversity within two widespread diadromous freshwater fishes (Teleostei: Galaxiidae). Ecol Evol 2024; 14:e11201. [PMID: 38799386 PMCID: PMC11116845 DOI: 10.1002/ece3.11201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 03/03/2024] [Accepted: 03/19/2024] [Indexed: 05/29/2024] Open
Abstract
Identification of taxonomically cryptic species is essential for the effective conservation of biodiversity. Freshwater-limited organisms tend to be genetically isolated by drainage boundaries, and thus may be expected to show substantial cryptic phylogenetic and taxonomic diversity. By comparison, populations of diadromous taxa, that migrate between freshwater and marine environments, are expected to show less genetic differentiation. Here we test for cryptic diversity in Australasian populations (both diadromous and non-diadromous) of two widespread Southern Hemisphere fish species, Galaxias brevipinnis and Galaxias maculatus. Both mtDNA and nuclear markers reveal putative cryptic species within these taxa. The substantial diversity detected within G. brevipinnis may be explained by its strong climbing ability which allows it to form isolated inland populations. In island populations, G. brevipinnis similarly show deeper genetic divergence than those of G. maculatus, which may be explained by the greater abundance of G. maculatus larvae in the sea allowing more ongoing dispersal. Our study highlights that even widespread, 'high-dispersal' species can harbour substantial cryptic diversity and therefore warrant increased taxonomic and conservation attention.
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Affiliation(s)
- Charlotte Jense
- Discipline of Biological Sciences, School of Natural SciencesUniversity of TasmaniaHobartTasmaniaAustralia
| | - Mark Adams
- Evolutionary Biology UnitSouth Australian MuseumAdelaideSouth AustraliaAustralia
- School of Biological SciencesThe University of AdelaideAdelaideSouth AustraliaAustralia
| | - Tarmo A. Raadik
- Department of Energy, Environment and Climate ActionArthur Rylah Institute for Environmental ResearchHeidelbergVictoriaAustralia
| | | | - David L. Morgan
- Centre for Sustainable Aquatic Ecosystems, Harry Butler InstituteMurdoch UniversityMurdochWestern AustraliaAustralia
| | - Leon A. Barmuta
- Discipline of Biological Sciences, School of Natural SciencesUniversity of TasmaniaHobartTasmaniaAustralia
| | - Scott A. Hardie
- Discipline of Biological Sciences, School of Natural SciencesUniversity of TasmaniaHobartTasmaniaAustralia
| | - Bruce E. Deagle
- Australian National Fish CollectionCSIRO National Research Collections AustraliaHobartTasmaniaAustralia
| | - Christopher P. Burridge
- Discipline of Biological Sciences, School of Natural SciencesUniversity of TasmaniaHobartTasmaniaAustralia
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2
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Eitel M, Osigus H, Brenzinger B, Wörheide G. Beauty in the beast - Placozoan biodiversity explored through molluscan predator genomics. Ecol Evol 2024; 14:e11220. [PMID: 38606341 PMCID: PMC11007570 DOI: 10.1002/ece3.11220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 03/17/2024] [Accepted: 03/20/2024] [Indexed: 04/13/2024] Open
Abstract
The marine animal phylum Placozoa is characterized by a poorly explored cryptic biodiversity combined with very limited knowledge of their ecology. While placozoans are typically found as part of the epibenthos of coastal waters, known placozoan predators, namely small, shell-less sea slugs belonging to the family Rhodopidae (Mollusca: Gastropoda: Heterobranchia), inhabit the interstitium of seafloor sediment. In order to gain further insights into this predator-prey relationship and to expand our understanding of placozoan ecological niches, we screened publicly available whole-body metagenomic data from two rhodopid specimens collected from coastal sediments. Our analysis not only revealed the signatures of three previously unknown placozoan lineages in these sea slug samples but also enabled the assembly of three complete and two partial mitochondrial chromosomes belonging to four previously described placozoan genera, substantially extending the picture of placozoan biodiversity. Our findings further refine the molecular phylogeny of the Placozoa, corroborate the recently established taxonomic ranks in this phylum, and provide molecular support that known placozoan clades should be referred to as genera. We finally discuss the main finding of our study - the presence of placozoans in the sea floor sediment interstitium - in the context of their ecological, biological, and natural history implications.
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Affiliation(s)
- Michael Eitel
- GeoBio‐CenterLudwig‐Maximilians‐Universität MünchenMünchenDeutschland
- Department of Earth and Environmental Sciences, Paleontology and GeobiologyLudwig‐Maximilians‐Universität‐MünchenMünchenDeutschland
| | - Hans‐Jürgen Osigus
- Institut für TierökologieStiftung Tierärztliche Hochschule HannoverHannoverDeutschland
- Present address:
Hochschulbibliothek, Stiftung Tierärztliche Hochschule HannoverHannoverDeutschland
| | - Bastian Brenzinger
- Staatliche Naturwissenschaftliche Sammlungen Bayerns (SNSB) – Zoologische StaatssammlungMünchenDeutschland
| | - Gert Wörheide
- GeoBio‐CenterLudwig‐Maximilians‐Universität MünchenMünchenDeutschland
- Department of Earth and Environmental Sciences, Paleontology and GeobiologyLudwig‐Maximilians‐Universität‐MünchenMünchenDeutschland
- Staatliche Naturwissenschaftliche Sammlungen Bayerns (SNSB) – Bayerische Staatssammlung für Paläontologie und GeologieMünchenDeutschland
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3
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Leria M, Requin M, Le Bivic A, Pasini A. The placozoan Trichoplax. Nat Methods 2024; 21:543-545. [PMID: 38609555 DOI: 10.1038/s41592-024-02228-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2024]
Affiliation(s)
- Marvin Leria
- Aix Marseille Université, CNRS, IBDM-UMR7288, Turing Centre for Living Systems, Marseille, France
| | - Magali Requin
- Aix Marseille Université, CNRS, IBDM-UMR7288, Turing Centre for Living Systems, Marseille, France
| | - André Le Bivic
- Aix Marseille Université, CNRS, IBDM-UMR7288, Turing Centre for Living Systems, Marseille, France
| | - Andrea Pasini
- Aix Marseille Université, CNRS, IBDM-UMR7288, Turing Centre for Living Systems, Marseille, France.
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4
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Romanova DY, Varoqueaux F, Eitel M, Yoshida MA, Nikitin MA, Moroz LL. Long-Term Culturing of Placozoans (Trichoplax and Hoilungia). Methods Mol Biol 2024; 2757:509-529. [PMID: 38668981 DOI: 10.1007/978-1-0716-3642-8_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2024]
Abstract
The phylum Placozoa remains one of the least explored among early-branching metazoan lineages. For over 130 years, this phylum had been represented by the single species Trichoplax adhaerens-an animal with the simplest known body plan (three cell layers without any organs) but complex behaviors. Recently, extensive sampling of placozoans across the globe and their subsequent genetic analysis have revealed incredible biodiversity with numerous cryptic species worldwide. However, only a few culture protocols are available to date, and all are for one species only. Here, we describe the breeding of four different species representing two placozoan genera: Trichoplax adhaerens, Trichoplax sp. H2, Hoilungia sp. H4, and Hoilungia hongkongensis originating from diverse biotopes. Our protocols allow to culture all species under comparable conditions. Next, we outlined various food sources and optimized strain-specific parameters enabling long-term culturing. These protocols can facilitate comparative analyses of placozoan biology and behaviors, which together will contribute to deciphering general principles of animal organization.
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Affiliation(s)
- Daria Y Romanova
- Institute of Higher Nervous Activity and Neurophysiology of RAS, Moscow, Russia.
| | - Frédérique Varoqueaux
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland.
| | - Michael Eitel
- Department of Earth and Environmental Sciences Palaeontology & Geobiology, LMU München, Munich, Germany
| | - Masa-Aki Yoshida
- Marine Biological Science Section, Education and Research Center for Biological Resources, Faculty of Life and Environmental Science, Shimane University, Okinoshima, Oki, Shimane, Japan
| | - Mikhail A Nikitin
- Institute of Higher Nervous Activity and Neurophysiology of RAS, Moscow, Russia
- Belozersky Institute for Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- Kharkevich Institute for Information Transmission Problems, RAS, Moscow, Russia
| | - Leonid L Moroz
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA.
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL, USA.
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5
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Romanova DY, Moroz LL. Brief History of Placozoa. Methods Mol Biol 2024; 2757:103-122. [PMID: 38668963 DOI: 10.1007/978-1-0716-3642-8_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2024]
Abstract
Placozoans are morphologically the simplest free-living animals. They represent a unique window of opportunities to understand both the origin of the animal organization and the rules of life for the system and synthetic biology of the future. However, despite more than 100 years of their investigations, we know little about their organization, natural habitats, and life strategies. Here, we introduce this unique animal phylum and highlight some directions vital to broadening the frontiers of the biomedical sciences. In particular, understanding the genomic bases of placozoan biodiversity, cell identity, connectivity, reproduction, and cellular bases of behavior are critical hot spots for future studies.
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Affiliation(s)
- Daria Y Romanova
- Institute of Higher Nervous Activity and Neurophysiology of RAS, Moscow, Russian Federation.
| | - Leonid L Moroz
- Department of Neuroscience and McKnight Brain Institute, University of Florida, Gainesville, FL, USA.
- Whitney Laboratory for Marine Biosciences University of Florida, St. Augustine, FL, USA.
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6
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Gooshvar S, Madhu G, Ruszczyk M, Prakash VN. Non-Bilaterians as Model Systems for Tissue Mechanics. Integr Comp Biol 2023; 63:1442-1454. [PMID: 37355780 DOI: 10.1093/icb/icad074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 06/09/2023] [Accepted: 06/12/2023] [Indexed: 06/26/2023] Open
Abstract
In animals, epithelial tissues are barriers against the external environment, providing protection against biological, chemical, and physical damage. Depending on the organism's physiology and behavior, these tissues encounter different types of mechanical forces and need to provide a suitable adaptive response to ensure success. Therefore, understanding tissue mechanics in different contexts is an important research area. Here, we review recent tissue mechanics discoveries in three early divergent non-bilaterian systems-Trichoplax adhaerens, Hydra vulgaris, and Aurelia aurita. We highlight each animal's simple body plan and biology and unique, rapid tissue remodeling phenomena that play a crucial role in its physiology. We also discuss the emergent large-scale mechanics in these systems that arise from small-scale phenomena. Finally, we emphasize the potential of these non-bilaterian animals to be model systems in a bottom-up approach for further investigation in tissue mechanics.
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Affiliation(s)
- Setareh Gooshvar
- Department of Physics, College of Arts and Sciences, University of Miami, 33146 FL, USA
| | - Gopika Madhu
- Department of Physics, College of Arts and Sciences, University of Miami, 33146 FL, USA
| | - Melissa Ruszczyk
- Department of Physics, College of Arts and Sciences, University of Miami, 33146 FL, USA
| | - Vivek N Prakash
- Department of Physics, College of Arts and Sciences, University of Miami, 33146 FL, USA
- Department of Biology, College of Arts and Sciences, University of Miami, 33146 FL, USA
- Department of Marine Biology and Ecology, Rosenstiel School of Marine, Atmospheric and Earth Science, University of Miami, 33149 FL, USA
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7
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Tessler M, Galen SC, DeSalle R, Schierwater B. Let’s end taxonomic blank slates with molecular morphology. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.1016412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Many known evolutionary lineages have yet to be described formally due to a lack of traditional morphological characters. This is true for genetically distinctive groups within the amoeboid Placozoa animals, the protists in ponds, and the bacteria that cover nearly everything. These taxonomic tabula rasae, or blank slates, are problematic; without names, communication is hampered and other scientific progress is slowed. We suggest that the morphology of molecules be used to help alleviate this issue. Molecules, such as proteins, have structure. Proteins are even visualizable with X-ray crystallography, albeit more easily detected by and easier to work with using genomic sequencing. Given their structured nature, we believe they should not be considered as anything less than traditional morphology. Protein-coding gene content (presence/absence) can also be used easily with genomic sequences, and is a convenient binary character set. With molecular morphology, we believe that each taxonomic tabula rasa can be solved.
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8
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Tessler M, Neumann JS, Kamm K, Osigus HJ, Eshel G, Narechania A, Burns JA, DeSalle R, Schierwater B. Phylogenomics and the first higher taxonomy of Placozoa, an ancient and enigmatic animal phylum. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.1016357] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Placozoa is an ancient phylum of extraordinarily unusual animals: miniscule, ameboid creatures that lack most fundamental animal features. Despite high genetic diversity, only recently have the second and third species been named. While prior genomic studies suffer from incomplete placozoan taxon sampling, we more than double the count with protein sequences from seven key genomes and produce the first nuclear phylogenomic reconstruction of all major placozoan lineages. This leads us to the first complete Linnaean taxonomic classification of Placozoa, over a century after its discovery: This may be the only time in the 21st century when an entire higher taxonomy for a whole animal phylum is formalized. Our classification establishes 2 new classes, 4 new orders, 3 new families, 1 new genus, and 1 new species, namely classes Polyplacotomia and Uniplacotomia; orders Polyplacotomea, Trichoplacea, Cladhexea, and Hoilungea; families Polyplacotomidae, Cladtertiidae, and Hoilungidae; and genus Cladtertia with species Cladtertia collaboinventa, nov. Our likelihood and gene content tree topologies refine the relationships determined in previous studies. Adding morphological data into our phylogenomic matrices suggests sponges (Porifera) as the sister to other animals, indicating that modest data addition shifts this node away from comb jellies (Ctenophora). Furthermore, by adding the first genomic protein data of the exceptionally distinct and branching Polyplacotoma mediterranea, we solidify its position as sister to all other placozoans; a divergence we estimate to be over 400 million years old. Yet even this deep split sits on a long branch to other animals, suggesting a bottleneck event followed by diversification. Ancestral state reconstructions indicate large shifts in gene content within Placozoa, with Hoilungia hongkongensis and its closest relatives having the most unique genetics.
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9
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Fujita Y, Chokki T, Nishioka T, Morimoto K, Nakayama A, Nakae H, Ogasawara M, Terasaki AG. The emergence of nebulin repeats and evolution of lasp family proteins. Cytoskeleton (Hoboken) 2022; 78:419-435. [PMID: 35224880 DOI: 10.1002/cm.21693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 02/23/2022] [Accepted: 02/25/2022] [Indexed: 11/10/2022]
Abstract
The LIM and SH3 domain protein (lasp) family, the smallest proteins in the nebulin superfamily, consists of vertebrate lasp-1 expressed in various non-muscle tissues, vertebrate lasp-2 expressed in the brain and cardiac muscle, and invertebrate lasp whose functions have been analyzed in Ascidiacea and Insecta. Gene evolution of the lasp family proteins was investigated by multiple alignments, comparison of gene structure, and synteny analyses in eukaryotes in which mRNA expression was confirmed. All invertebrates analyzed in this study belonging to the clade Filasterea, with the exception of Placozoa, have at least one lasp gene. The minimal actin-binding region (LIM domain and first nebulin repeat) and SH3 domain detected in vertebrate lasp-2 were found to be conserved among the lasp family proteins, and we showed that nematode lasp has actin-binding activity. The linker sequences vary among invertebrate lasp proteins, implying that the lasp family proteins have universal and diverse functions. Gene structures and syntenic analyses suggest that a gene fragment encoding two nebulin repeats and a linker emerged in Filasterea or Holozoa, and the first lasp gene was generated following combination of three gene fragments encoding the LIM domain, two nebulin repeats with a linker, and the SH3 domain. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Yuki Fujita
- Department of Biology, Graduate School of Science, Chiba University, Yayoi-cho, Inage-ku, Chiba, Japan
| | - Tamami Chokki
- Department of Biology, Graduate School of Science, Chiba University, Yayoi-cho, Inage-ku, Chiba, Japan
| | - Tatsuji Nishioka
- Department of Biology, Graduate School of Science, Chiba University, Yayoi-cho, Inage-ku, Chiba, Japan
| | - Kouta Morimoto
- Department of Biology, Graduate School of Science, Chiba University, Yayoi-cho, Inage-ku, Chiba, Japan
| | - Ayako Nakayama
- Department of Biology, Graduate School of Science, Chiba University, Yayoi-cho, Inage-ku, Chiba, Japan
| | - Hiroki Nakae
- BIO-Business Solutions, Hisamoto, Takatsu-ku, Kawasaki, Japan
| | - Michio Ogasawara
- Department of Biology, Graduate School of Science, Chiba University, Yayoi-cho, Inage-ku, Chiba, Japan
| | - Asako G Terasaki
- Department of Biology, Graduate School of Science, Chiba University, Yayoi-cho, Inage-ku, Chiba, Japan
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10
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Romanova DY, Nikitin MA, Shchenkov SV, Moroz LL. Expanding of Life Strategies in Placozoa: Insights From Long-Term Culturing of Trichoplax and Hoilungia. Front Cell Dev Biol 2022; 10:823283. [PMID: 35223848 PMCID: PMC8864292 DOI: 10.3389/fcell.2022.823283] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Accepted: 01/20/2022] [Indexed: 12/05/2022] Open
Abstract
Placozoans are essential reference species for understanding the origins and evolution of animal organization. However, little is known about their life strategies in natural habitats. Here, by maintaining long-term culturing for four species of Trichoplax and Hoilungia, we extend our knowledge about feeding and reproductive adaptations relevant to the diversity of life forms and immune mechanisms. Three modes of population dynamics depended upon feeding sources, including induction of social behaviors, morphogenesis, and reproductive strategies. In addition to fission, representatives of all species produced “swarmers” (a separate vegetative reproduction stage), which could also be formed from the lower epithelium with greater cell-type diversity. We monitored the formation of specialized spheroid structures from the upper cell layer in aging culture. These “spheres” could be transformed into juvenile animals under favorable conditions. We hypothesize that spheroid structures represent a component of the innate immune defense response with the involvement of fiber cells. Finally, we showed that regeneration could be a part of the adaptive reproductive strategies in placozoans and a unique experimental model for regenerative biology.
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Affiliation(s)
- Daria Y. Romanova
- Institute of Higher Nervous Activity and Neurophysiology of RAS, Moscow, Russia
- *Correspondence: Daria Y. Romanova, ; Leonid L. Moroz,
| | - Mikhail A. Nikitin
- Belozersky Institute for Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia
| | - Sergey V. Shchenkov
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russia
| | - Leonid L. Moroz
- Departments of Neuroscience and McKnight Brain Institute, University of Florida, Gainesville, FL, United States
- Whitney Laboratory for Marine Biosciences, University of Florida, St. Augustine, FL, United States
- *Correspondence: Daria Y. Romanova, ; Leonid L. Moroz,
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11
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Schierwater B, Osigus HJ, Bergmann T, Blackstone NW, Hadrys H, Hauslage J, Humbert PO, Kamm K, Kvansakul M, Wysocki K, DeSalle R. The enigmatic Placozoa part 1: Exploring evolutionary controversies and poor ecological knowledge. Bioessays 2021; 43:e2100080. [PMID: 34472126 DOI: 10.1002/bies.202100080] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 07/21/2021] [Accepted: 08/16/2021] [Indexed: 12/13/2022]
Abstract
The placozoan Trichoplax adhaerens is a tiny hairy plate and more simply organized than any other living metazoan. After its original description by F.E. Schulze in 1883, it attracted attention as a potential model for the ancestral state of metazoan organization, the "Urmetazoon". Trichoplax lacks any kind of symmetry, organs, nerve cells, muscle cells, basal lamina, and extracellular matrix. Furthermore, the placozoan genome is the smallest (not secondarily reduced) genome of all metazoan genomes. It harbors a remarkably rich diversity of genes and has been considered the best living surrogate for a metazoan ancestor genome. The phylum Placozoa presently harbors three formally described species, while several dozen "cryptic" species are yet awaiting their description. The phylogenetic position of placozoans has recently become a contested arena for modern phylogenetic analyses and view-driven claims. Trichoplax offers unique prospects for understanding the minimal requirements of metazoan animal organization and their corresponding malfunctions.
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Affiliation(s)
- Bernd Schierwater
- Institute of Animal Ecology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Hans-Jürgen Osigus
- Institute of Animal Ecology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Tjard Bergmann
- Institute of Animal Ecology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Neil W Blackstone
- Department of Biological Sciences, Northern Illinois University, DeKalb, Illinois, USA
| | - Heike Hadrys
- Institute of Animal Ecology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Jens Hauslage
- Gravitational Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Patrick O Humbert
- Department of Biochemistry & Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia.,Research Centre for Molecular Cancer Prevention, La Trobe University, Melbourne, Victoria, 3086, Australia
| | - Kai Kamm
- Institute of Animal Ecology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Marc Kvansakul
- Department of Biochemistry & Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia.,Research Centre for Molecular Cancer Prevention, La Trobe University, Melbourne, Victoria, 3086, Australia
| | - Kathrin Wysocki
- Institute of Animal Ecology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Rob DeSalle
- American Museum of Natural History, New York, New York, USA
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12
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Romanova DY, Varoqueaux F, Daraspe J, Nikitin MA, Eitel M, Fasshauer D, Moroz LL. Hidden cell diversity in Placozoa: ultrastructural insights from Hoilungia hongkongensis. Cell Tissue Res 2021; 385:623-637. [PMID: 33876313 PMCID: PMC8523601 DOI: 10.1007/s00441-021-03459-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 03/31/2021] [Indexed: 12/17/2022]
Abstract
From a morphological point of view, placozoans are among the most simple free-living animals. This enigmatic phylum is critical for our understanding of the evolution of animals and their cell types. Their millimeter-sized, disc-like bodies consist of only three cell layers that are shaped by roughly seven major cell types. Placozoans lack muscle cells and neurons but are able to move using their ciliated lower surface and take up food in a highly coordinated manner. Intriguingly, the genome of Trichoplax adhaerens, the founding member of the enigmatic phylum, has disclosed a surprising level of genetic complexity. Moreover, recent molecular and functional investigations have uncovered a much larger, so-far hidden cell-type diversity. Here, we have extended the microanatomical characterization of a recently described placozoan species-Hoilungia hongkongensis. In H. hongkongensis, we recognized the established canonical three-layered placozoan body plan but also came across several morphologically distinct and potentially novel cell types, among them novel gland cells and "shiny spheres"-bearing cells at the upper epithelium. Thus, the diversity of cell types in placozoans is indeed higher than anticipated.
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Affiliation(s)
- Daria Y Romanova
- Department of Fundamental Neurosciences, University of Lausanne, 1005, Lausanne, Switzerland.
- Cellular Neurobiology of Learning Lab, Institute of Higher Nervous Activity and Neurophysiology, Moscow, 117485, Russia.
| | - Frédérique Varoqueaux
- Department of Fundamental Neurosciences, University of Lausanne, 1005, Lausanne, Switzerland
- Department of Computational Biology, University of Lausanne, 1015, Lausanne, Switzerland
| | - Jean Daraspe
- Electron Microscopy Facility, University of Lausanne, Lausanne, Switzerland
| | - Mikhail A Nikitin
- Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, 119991, Russia
- Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, 127994, Russia
| | - Michael Eitel
- Department of Earth and Environmental Sciences, Paleontology and Geobiology, Ludwig-Maximilians Universität München, Munich, Germany
| | - Dirk Fasshauer
- Department of Fundamental Neurosciences, University of Lausanne, 1005, Lausanne, Switzerland.
- Department of Computational Biology, University of Lausanne, 1015, Lausanne, Switzerland.
| | - Leonid L Moroz
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL, 32080, USA.
- Departments of Neuroscience and McKnight Brain Institute, University of Florida, Gainesville, FL, 32610, USA.
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13
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Moroz LL, Romanova DY, Kohn AB. Neural versus alternative integrative systems: molecular insights into origins of neurotransmitters. Philos Trans R Soc Lond B Biol Sci 2021; 376:20190762. [PMID: 33550949 PMCID: PMC7935107 DOI: 10.1098/rstb.2019.0762] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2020] [Indexed: 12/18/2022] Open
Abstract
Transmitter signalling is the universal chemical language of any nervous system, but little is known about its early evolution. Here, we summarize data about the distribution and functions of neurotransmitter systems in basal metazoans as well as outline hypotheses of their origins. We explore the scenario that neurons arose from genetically different populations of secretory cells capable of volume chemical transmission and integration of behaviours without canonical synapses. The closest representation of this primordial organization is currently found in Placozoa, disk-like animals with the simplest known cell composition but complex behaviours. We propose that injury-related signalling was the evolutionary predecessor for integrative functions of early transmitters such as nitric oxide, ATP, protons, glutamate and small peptides. By contrast, acetylcholine, dopamine, noradrenaline, octopamine, serotonin and histamine were recruited as canonical neurotransmitters relatively later in animal evolution, only in bilaterians. Ligand-gated ion channels often preceded the establishment of novel neurotransmitter systems. Moreover, lineage-specific diversification of neurotransmitter receptors occurred in parallel within Cnidaria and several bilaterian lineages, including acoels. In summary, ancestral diversification of secretory signal molecules provides unique chemical microenvironments for behaviour-driven innovations that pave the way to complex brain functions and elementary cognition. This article is part of the theme issue 'Basal cognition: multicellularity, neurons and the cognitive lens'.
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Affiliation(s)
- Leonid L. Moroz
- Department of Neuroscience, McKnight Brain Institute and Whitney laboratory, University of Florida, 9505 Ocean shore Blvd, St Augustine, FL 32080, USA
| | - Daria Y. Romanova
- Laboratory of Cellular Neurobiology of Learning, Institute of Higher Nervous Activity and Neurophysiology of RAS, 5A Butlerova Street, Moscow 117485, Russia
| | - Andrea B. Kohn
- Department of Neuroscience, McKnight Brain Institute and Whitney laboratory, University of Florida, 9505 Ocean shore Blvd, St Augustine, FL 32080, USA
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14
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Smith CL, Mayorova TD, Winters CA, Reese TS, Leys SP, Heyland A. Microscopy Studies of Placozoans. Methods Mol Biol 2021; 2219:99-118. [PMID: 33074536 DOI: 10.1007/978-1-0716-0974-3_6] [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] [Indexed: 12/04/2022]
Abstract
Trichoplax adhaerens is an enigmatic animal with an extraordinarily simple morphology and a cellular organization, which are the focus of current research. Protocols outlined here provide detailed descriptions of advanced techniques for light and electron microscopic studies of Trichoplax. Studies using these techniques have enhanced our understanding of cell type diversity and function in placozoans and have provided insight into the evolution, development, and physiology of this little understood group.
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Affiliation(s)
- Carolyn L Smith
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Tatiana D Mayorova
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Christine A Winters
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Thomas S Reese
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Sally P Leys
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Andreas Heyland
- Department of Integrative Biology, College of Biological Science, University of Guelph, Guelph, ON, Canada.
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15
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Miyazawa H, Osigus HJ, Rolfes S, Kamm K, Schierwater B, Nakano H. Mitochondrial Genome Evolution of Placozoans: Gene Rearrangements and Repeat Expansions. Genome Biol Evol 2020; 13:5919586. [PMID: 33031489 PMCID: PMC7813641 DOI: 10.1093/gbe/evaa213] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/30/2020] [Indexed: 12/16/2022] Open
Abstract
Placozoans, nonbilaterian animals with the simplest known metazoan bauplan, are currently classified into 20 haplotypes belonging to three genera, Polyplacotoma, Trichoplax, and Hoilungia. The latter two comprise two and five clades, respectively. In Trichoplax and Hoilungia, previous studies on six haplotypes belonging to four different clades have shown that their mtDNAs are circular chromosomes of 32–43 kb in size, which encode 12 protein-coding genes, 24 tRNAs, and two rRNAs. These mitochondrial genomes (mitogenomes) also show unique features rarely seen in other metazoans, including open reading frames (ORFs) of unknown function, and group I and II introns. Here, we report seven new mitogenomes, covering the five previously described haplotypes H2, H17, H19, H9, and H11, as well as two new haplotypes, H23 (clade III) and H24 (clade VII). The overall gene content is shared between all placozoan mitochondrial genomes, but genome sizes, gene orders, and several exon–intron boundaries vary among clades. Phylogenomic analyses strongly support a tree topology different from previous 16S rRNA analyses, with clade VI as the sister group to all other Hoilungia clades. We found small inverted repeats in all 13 mitochondrial genomes of the Trichoplax and Hoilungia genera and evaluated their distribution patterns among haplotypes. Because Polyplacotoma mediterranea (H0), the sister to the remaining haplotypes, has a small mitochondrial genome with few small inverted repeats and ORFs, we hypothesized that the proliferation of inverted repeats and ORFs substantially contributed to the observed increase in the size and GC content of the Trichoplax and Hoilungia mitochondrial genomes.
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Affiliation(s)
- Hideyuki Miyazawa
- Center for Genome Informatics, Joint Support-Center for Data Science Research, Research Organization of Information and Systems, Mishima, Shizuoka, Japan.,Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan
| | - Hans-Jürgen Osigus
- Division of Molecular Evolution, Institute of Animal Ecology, University of Veterinary Medicine Hannover, Foundation, Germany
| | - Sarah Rolfes
- Division of Molecular Evolution, Institute of Animal Ecology, University of Veterinary Medicine Hannover, Foundation, Germany
| | - Kai Kamm
- Division of Molecular Evolution, Institute of Animal Ecology, University of Veterinary Medicine Hannover, Foundation, Germany
| | - Bernd Schierwater
- Division of Molecular Evolution, Institute of Animal Ecology, University of Veterinary Medicine Hannover, Foundation, Germany
| | - Hiroaki Nakano
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan
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16
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Moroz LL, Romanova DY, Nikitin MA, Sohn D, Kohn AB, Neveu E, Varoqueaux F, Fasshauer D. The diversification and lineage-specific expansion of nitric oxide signaling in Placozoa: insights in the evolution of gaseous transmission. Sci Rep 2020; 10:13020. [PMID: 32747709 PMCID: PMC7400543 DOI: 10.1038/s41598-020-69851-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 07/16/2020] [Indexed: 12/11/2022] Open
Abstract
Nitric oxide (NO) is a ubiquitous gaseous messenger, but we know little about its early evolution. Here, we analyzed NO synthases (NOS) in four different species of placozoans-one of the early-branching animal lineages. In contrast to other invertebrates studied, Trichoplax and Hoilungia have three distinct NOS genes, including PDZ domain-containing NOS. Using ultra-sensitive capillary electrophoresis assays, we quantified nitrites (products of NO oxidation) and L-citrulline (co-product of NO synthesis from L-arginine), which were affected by NOS inhibitors confirming the presence of functional enzymes in Trichoplax. Using fluorescent single-molecule in situ hybridization, we showed that distinct NOSs are expressed in different subpopulations of cells, with a noticeable distribution close to the edge regions of Trichoplax. These data suggest both the compartmentalized release of NO and a greater diversity of cell types in placozoans than anticipated. NO receptor machinery includes both canonical and novel NIT-domain containing soluble guanylate cyclases as putative NO/nitrite/nitrate sensors. Thus, although Trichoplax and Hoilungia exemplify the morphologically simplest free-living animals, the complexity of NO-cGMP-mediated signaling in Placozoa is greater to those in vertebrates. This situation illuminates multiple lineage-specific diversifications of NOSs and NO/nitrite/nitrate sensors from the common ancestor of Metazoa and the preservation of conservative NOS architecture from prokaryotic ancestors.
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Affiliation(s)
- Leonid L Moroz
- Whitney Laboratory for Marine Bioscience and Departments of Neuroscience, University of Florida, St. Augustine and Gainesville, FL, 32080, USA.
| | - Daria Y Romanova
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, 117485, Russia
| | - Mikhail A Nikitin
- Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, 119991, Russia
| | - Dosung Sohn
- Whitney Laboratory for Marine Bioscience and Departments of Neuroscience, University of Florida, St. Augustine and Gainesville, FL, 32080, USA
| | - Andrea B Kohn
- Whitney Laboratory for Marine Bioscience and Departments of Neuroscience, University of Florida, St. Augustine and Gainesville, FL, 32080, USA
| | - Emilie Neveu
- Department of Fundamental Neurosciences, University of Lausanne, 1005, Lausanne, Switzerland
| | - Frederique Varoqueaux
- Department of Fundamental Neurosciences, University of Lausanne, 1005, Lausanne, Switzerland
| | - Dirk Fasshauer
- Department of Fundamental Neurosciences, University of Lausanne, 1005, Lausanne, Switzerland
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17
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Kamm K, Osigus HJ, Stadler PF, DeSalle R, Schierwater B. Genome analyses of a placozoan rickettsial endosymbiont show a combination of mutualistic and parasitic traits. Sci Rep 2019; 9:17561. [PMID: 31772223 PMCID: PMC6879607 DOI: 10.1038/s41598-019-54037-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 10/25/2019] [Indexed: 12/16/2022] Open
Abstract
Symbiotic relationships between eukaryotic hosts and bacteria range from parasitism to mutualism and may deeply influence both partners' fitness. The presence of intracellular bacteria in the metazoan phylum Placozoa has been reported several times, but without any knowledge about the nature of this relationship and possible implications for the placozoan holobiont. This information may be of crucial significance since little is known about placozoan ecology and how different species adapt to different environmental conditions, despite being almost invariable at the morphological level. We here report on the novel genome of the rickettsial endosymbiont of Trichoplax sp. H2 (strain "Panama"). The combination of eliminated and retained metabolic pathways of the bacterium indicates a potential for a mutualistic as well as for a parasitic relationship, whose outcome could depend on the environmental context. In particular we show that the endosymbiont is dependent on the host for growth and reproduction and that the latter could benefit from a supply with essential amino acids and important cofactors. These findings call for further studies to clarify the actual benefit for the placozoan host and to investigate a possible role of the endosymbiont for ecological separation between placozoan species.
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Affiliation(s)
- Kai Kamm
- University of Veterinary Medicine Hannover, Foundation, Institute of Animal Ecology, Bünteweg 17d, D-30559, Hannover, Germany.
| | - Hans-Jürgen Osigus
- University of Veterinary Medicine Hannover, Foundation, Institute of Animal Ecology, Bünteweg 17d, D-30559, Hannover, Germany
| | - Peter F Stadler
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, University of Leipzig, Härtelstraße 16-18, D-04107, Leipzig, Germany
| | - Rob DeSalle
- Sackler Institute for Comparative Genomics and Division of Invertebrate Zoology, American Museum of Natural History, New York, New York, USA
| | - Bernd Schierwater
- University of Veterinary Medicine Hannover, Foundation, Institute of Animal Ecology, Bünteweg 17d, D-30559, Hannover, Germany. .,Sackler Institute for Comparative Genomics and Division of Invertebrate Zoology, American Museum of Natural History, New York, New York, USA.
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18
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Paulin MG, Cahill‐Lane J. Events in Early Nervous System Evolution. Top Cogn Sci 2019; 13:25-44. [DOI: 10.1111/tops.12461] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 09/09/2019] [Accepted: 09/09/2019] [Indexed: 12/20/2022]
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19
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Modelling the early evolution of extracellular matrix from modern Ctenophores and Sponges. Essays Biochem 2019; 63:389-405. [DOI: 10.1042/ebc20180048] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 07/29/2019] [Accepted: 08/01/2019] [Indexed: 12/14/2022]
Abstract
AbstractAnimals (metazoans) include some of the most complex living organisms on Earth, with regard to their multicellularity, numbers of differentiated cell types, and lifecycles. The metazoan extracellular matrix (ECM) is well-known to have major roles in the development of tissues during embryogenesis and in maintaining homoeostasis throughout life, yet insight into the ECM proteins which may have contributed to the transition from unicellular eukaryotes to multicellular animals remains sparse. Recent phylogenetic studies place either ctenophores or poriferans as the closest modern relatives of the earliest emerging metazoans. Here, we review the literature and representative genomic and transcriptomic databases for evidence of ECM and ECM-affiliated components known to be conserved in bilaterians, that are also present in ctenophores and/or poriferans. Whereas an extensive set of related proteins are identifiable in poriferans, there is a strikingly lack of conservation in ctenophores. From this perspective, much remains to be learnt about the composition of ctenophore mesoglea. The principal ECM-related proteins conserved between ctenophores, poriferans, and bilaterians include collagen IV, laminin-like proteins, thrombospondin superfamily members, integrins, membrane-associated proteoglycans, and tissue transglutaminase. These are candidates for a putative ancestral ECM that may have contributed to the emergence of the metazoans.
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20
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Abstract
Schierwater & DeSalle introduce the enigmatic phylum Placozoa.
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Affiliation(s)
- Bernd Schierwater
- TiHo Hannover, ITZ Ecology & Evolution, Buenteweg 17d, 30559 Hannover.
| | - Rob DeSalle
- Comparative Genomics Institute at the American Museum of Natural History, 79th Street at Central Park West, New York, NY 10024, USA
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21
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Gruber-Vodicka HR, Leisch N, Kleiner M, Hinzke T, Liebeke M, McFall-Ngai M, Hadfield MG, Dubilier N. Two intracellular and cell type-specific bacterial symbionts in the placozoan Trichoplax H2. Nat Microbiol 2019; 4:1465-1474. [PMID: 31182796 PMCID: PMC6784892 DOI: 10.1038/s41564-019-0475-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Accepted: 04/26/2019] [Indexed: 02/02/2023]
Abstract
Placozoa is an enigmatic phylum of simple, microscopic, marine metazoans1,2. Although intracellular bacteria have been found in all members of this phylum, almost nothing is known about their identity, location and interactions with their host3–6. We used metagenomic and metatranscriptomic sequencing of single host individuals, plus metaproteomic and imaging analyses, to show that the placozoan Trichoplax sp. H2 lives in symbiosis with two intracellular bacteria. One symbiont forms an undescribed genus in the Midichloriaceae (Rickettsiales)7,8 and has a genomic repertoire similar to that of rickettsial parasites9,10, but does not seem to express key genes for energy parasitism. Correlative image analyses and three-dimensional electron tomography revealed that this symbiont resides in the rough endoplasmic reticulum of its host’s internal fibre cells. The second symbiont belongs to the Margulisbacteria, a phylum without cultured representatives and not known to form intracellular associations11–13. This symbiont lives in the ventral epithelial cells of Trichoplax, probably metabolizes algal lipids digested by its host and has the capacity to supplement the placozoan’s nutrition. Our study shows that one of the simplest animals has evolved highly specific and intimate associations with symbiotic, intracellular bacteria and highlights that symbioses can provide access to otherwise elusive microbial dark matter. Using a multi-omics approach, together with imaging analyses, the authors characterize the two intracellular bacterial symbionts of Trichoplax, one of the simplest animals.
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Affiliation(s)
| | - Nikolaus Leisch
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Manuel Kleiner
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, USA
| | - Tjorven Hinzke
- Department of Pharmaceutical Biotechnology, Institute of Pharmacy, University of Greifswald, Greifswald, Germany.,Institute of Marine Biotechnology, Greifswald, Germany.,Department of Geoscience, University of Calgary, Calgary, Alberta, Canada
| | - Manuel Liebeke
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Margaret McFall-Ngai
- Kewalo Marine Laboratory, Pacific Biosciences Research Center, University of Hawai'i at Mānoa, Honolulu, HI, USA
| | - Michael G Hadfield
- Kewalo Marine Laboratory, Pacific Biosciences Research Center, University of Hawai'i at Mānoa, Honolulu, HI, USA.
| | - Nicole Dubilier
- Max Planck Institute for Marine Microbiology, Bremen, Germany.
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22
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DuBuc TQ, Ryan JF, Martindale MQ. "Dorsal-Ventral" Genes Are Part of an Ancient Axial Patterning System: Evidence from Trichoplax adhaerens (Placozoa). Mol Biol Evol 2019; 36:966-973. [PMID: 30726986 PMCID: PMC6501881 DOI: 10.1093/molbev/msz025] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Placozoa are a morphologically simplistic group of marine animals found globally in tropical and subtropical environments. They consist of two named species, Trichoplax adhaerens and more recently Hoilungia hongkongensis, both with roughly six morphologically distinct cell types. With a sequenced genome, a limited number of cell types, and a simple flattened morphology, Trichoplax is an ideal model organism from which to explore the biology of an animal with a cellular complexity analagous to that of the earliest animals. Using a new approach for identification of gene expression patterns, this research looks at the relationship of Chordin/TgfΒ signaling and the axial patterning system of Placozoa. Our results suggest that placozoans have an oral-aboral axis similar to cnidarians and that the parahoxozoan ancestor (common ancestor of Placozoa and Cnidaria) was likely radially symmetric.
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Affiliation(s)
- Timothy Q DuBuc
- Whitney Lab for Marine Bioscience and the Department of Biology, University of Florida, St. Augustine, FL
- Kewalo Marine Laboratory and the Department of Biology, University of Hawaii, Manoa, Honolulu, HI
- Centre for Chromosome Biology, Bioscience Building, National University of Ireland Galway, Galway, Ireland
| | - Joseph F Ryan
- Whitney Lab for Marine Bioscience and the Department of Biology, University of Florida, St. Augustine, FL
| | - Mark Q Martindale
- Whitney Lab for Marine Bioscience and the Department of Biology, University of Florida, St. Augustine, FL
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23
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Albertini MC, Fraternale D, Semprucci F, Cecchini S, Colomba M, Rocchi MB, Sisti D, Di Giacomo B, Mari M, Sabatini L, Cesaroni L, Balsamo M, Guidi L. Bioeffects of Prunus spinosa L. fruit ethanol extract on reproduction and phenotypic plasticity of Trichoplax adhaerens Schulze, 1883 (Placozoa). PeerJ 2019; 7:e6789. [PMID: 31024778 PMCID: PMC6475577 DOI: 10.7717/peerj.6789] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 03/14/2019] [Indexed: 12/17/2022] Open
Abstract
The aim of this work was to test and analyse the bioeffects of Prunus spinosa L. (Rosacaee) fruit ethanol extract on Trichoplax adhaerens Schulze, 1883 (Placozoa) laboratory cultures which-for the first time-were employed as in vivo biological model to assess the bioactivity of a natural extract. The ethanol extract of P. spinosa was administrated during a 46 day experimental period; ultrastructural (by optical, confocal, TEM and SEM microscopy) and morphometric analyses indicated that treated Trichoplax adhaerens showed significant differences in viability, reproductive modalities, body shape and colour with respect to the control group. Finally, P. spinosa bioactive compounds seem to exert profound protective effects on T. adhaerens reproduction and phenotype. Our results may support additional investigations related to other bioactive compounds properties useful for nutraceutical preparations to be used as food supplements.
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Affiliation(s)
| | - Daniele Fraternale
- Department of Biomolecular Sciences, University of Urbino, Urbino, Pesaro-Urbino, Italia
| | - Federica Semprucci
- Department of Biomolecular Sciences, University of Urbino, Urbino, Pesaro-Urbino, Italia
| | - Silvio Cecchini
- Department of Biomolecular Sciences, University of Urbino, Urbino, Pesaro-Urbino, Italia
| | - Mariastella Colomba
- Department of Biomolecular Sciences, University of Urbino, Urbino, Pesaro-Urbino, Italia
| | - Marco B.L. Rocchi
- Department of Biomolecular Sciences, University of Urbino, Urbino, Pesaro-Urbino, Italia
| | - Davide Sisti
- Department of Biomolecular Sciences, University of Urbino, Urbino, Pesaro-Urbino, Italia
| | - Barbara Di Giacomo
- Department of Biomolecular Sciences, University of Urbino, Urbino, Pesaro-Urbino, Italia
| | - Michele Mari
- Department of Biomolecular Sciences, University of Urbino, Urbino, Pesaro-Urbino, Italia
| | - Luigia Sabatini
- Department of Biomolecular Sciences, University of Urbino, Urbino, Pesaro-Urbino, Italia
| | - Lucia Cesaroni
- Department of Biomolecular Sciences, University of Urbino, Urbino, Pesaro-Urbino, Italia
| | - Maria Balsamo
- Department of Biomolecular Sciences, University of Urbino, Urbino, Pesaro-Urbino, Italia
| | - Loretta Guidi
- Department of Biomolecular Sciences, University of Urbino, Urbino, Pesaro-Urbino, Italia
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24
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Abstract
Animals have evolved different foraging strategies in which some animals forage independently and others forage in groups. The evolution of social feeding does not necessarily require cooperation; social feeding can be a beneficial individual-level strategy if it provides mutualistic benefits, for example though increasing the efficiency of resource extraction or processing. We found that Trichoplax adhaerens, the simplest multicellular animal ever described, engages in social feeding behavior. T. adhaerens lacks muscle tissue, nervous and digestive systems - yet is capable of aggregating and forming groups of closely connected individuals who collectively feed. The tight physical interactions between the animals are transitory and appear to serve the goal of staying connected to neighbors during the external digestion of algae when enzymes are released on the biofilm and nutrients are absorbed through the ventral epithelium. We found that T. adhaerens are more likely to engage in social feeding when the concentrations of algae are high - both in a semi-natural conditions and in vitro. It is surprising that T. adhaerens - an organism without a nervous system - is able to engage in this social feeding behavior. Whether this behavior is cooperative is still an open question. Nevertheless, the social feeding behavior of T. adhaerens, an early multicellular animal, suggests that sociality may have played an important role in the early evolution of animals. It also suggests that T. adhaerens could be used as a simple model organism for exploring questions regarding ecology and sociobiology.
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Affiliation(s)
- Angelo Fortunato
- Biodesign Center for Biocomputing, Security and Society, Arizona State University
| | - Athena Aktipis
- Biodesign Center for Biocomputing, Security and Society, Arizona State University.,Department of Psychology, Arizona State University
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25
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High Cell Diversity and Complex Peptidergic Signaling Underlie Placozoan Behavior. Curr Biol 2018; 28:3495-3501.e2. [DOI: 10.1016/j.cub.2018.08.067] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Revised: 07/20/2018] [Accepted: 08/31/2018] [Indexed: 12/17/2022]
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26
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Laumer CE, Gruber-Vodicka H, Hadfield MG, Pearse VB, Riesgo A, Marioni JC, Giribet G. Support for a clade of Placozoa and Cnidaria in genes with minimal compositional bias. eLife 2018; 7:e36278. [PMID: 30373720 PMCID: PMC6277202 DOI: 10.7554/elife.36278] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 10/11/2018] [Indexed: 12/22/2022] Open
Abstract
The phylogenetic placement of the morphologically simple placozoans is crucial to understanding the evolution of complex animal traits. Here, we examine the influence of adding new genomes from placozoans to a large dataset designed to study the deepest splits in the animal phylogeny. Using site-heterogeneous substitution models, we show that it is possible to obtain strong support, in both amino acid and reduced-alphabet matrices, for either a sister-group relationship between Cnidaria and Placozoa, or for Cnidaria and Bilateria as seen in most published work to date, depending on the orthologues selected to construct the matrix. We demonstrate that a majority of genes show evidence of compositional heterogeneity, and that support for the Cnidaria + Bilateria clade can be assigned to this source of systematic error. In interpreting these results, we caution against a peremptory reading of placozoans as secondarily reduced forms of little relevance to broader discussions of early animal evolution.
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Affiliation(s)
- Christopher E Laumer
- Wellcome Trust Sanger InstituteHinxtonUnited Kingdom
- European Molecular Biology Laboratories-European Bioinformatics InstituteHinxtonUnited Kingdom
| | | | - Michael G Hadfield
- Kewalo Marine LaboratoryPacific Biosciences Research Center and the University of Hawaii-ManoaHonoluluUnited States
| | - Vicki B Pearse
- Institute of Marine SciencesUniversity of CaliforniaSanta CruzUnited States
| | - Ana Riesgo
- Invertebrate Division, Life Sciences DepartmentThe Natural History MuseumLondonUnited Kingdom
| | - John C Marioni
- Wellcome Trust Sanger InstituteHinxtonUnited Kingdom
- European Molecular Biology Laboratories-European Bioinformatics InstituteHinxtonUnited Kingdom
- Cancer Research UK Cambridge InstituteUniversity of CambridgeCambridgeUnited Kingdom
| | - Gonzalo Giribet
- Museum of Comparative Zoology, Department of Organismic and Evolutionary BiologyHarvard UniversityCambridgeUnited States
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27
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Kamm K, Osigus HJ, Stadler PF, DeSalle R, Schierwater B. Trichoplax genomes reveal profound admixture and suggest stable wild populations without bisexual reproduction. Sci Rep 2018; 8:11168. [PMID: 30042472 PMCID: PMC6057997 DOI: 10.1038/s41598-018-29400-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 07/09/2018] [Indexed: 12/24/2022] Open
Abstract
The phylum Placozoa officially consists of only a single described species, Trichoplax adhaerens, although several lineages can be separated by molecular markers, geographical distributions and environmental demands. The placozoan 16S haplotype H2 (Trichoplax sp. H2) is the most robust and cosmopolitan lineage of placozoans found to date. In this study, its genome was found to be distinct but highly related to the Trichoplax adhaerens reference genome, for remarkably unique reasons. The pattern of variation and allele distribution between the two lineages suggests that both originate from a single interbreeding event in the wild, dating back at least several decades ago, and both seem not to have engaged in sexual reproduction since. We conclude that populations of certain placozoan haplotypes remain stable for long periods without bisexual reproduction. Furthermore, allelic variation within and between the two Trichoplax lineages indicates that successful bisexual reproduction between related placozoan lineages might serve to either counter accumulated negative somatic mutations or to cope with changing environmental conditions. On the other hand, enrichment of neutral or beneficial somatic mutations by vegetative reproduction, combined with rare sexual reproduction, could instantaneously boost genetic variation, generating novel ecotypes and eventually species.
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Affiliation(s)
- Kai Kamm
- University of Veterinary Medicine Hannover, Foundation, ITZ Ecology and Evolution, Bünteweg 17d, D-30559, Hannover, Germany.
| | - Hans-Jürgen Osigus
- University of Veterinary Medicine Hannover, Foundation, ITZ Ecology and Evolution, Bünteweg 17d, D-30559, Hannover, Germany
| | - Peter F Stadler
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, University of Leipzig, Härtelstraße 16-18, D-04107, Leipzig, Germany
| | - Rob DeSalle
- Sackler Institute for Comparative Genomics and Division of Invertebrate Zoology, American Museum of Natural History, New York, New York, USA
| | - Bernd Schierwater
- University of Veterinary Medicine Hannover, Foundation, ITZ Ecology and Evolution, Bünteweg 17d, D-30559, Hannover, Germany. .,Sackler Institute for Comparative Genomics and Division of Invertebrate Zoology, American Museum of Natural History, New York, New York, USA. .,Yale University, Molecular, Cellular and Developmental Biology, New Haven, CT, 06520, USA.
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28
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Eitel M, Francis WR, Varoqueaux F, Daraspe J, Osigus HJ, Krebs S, Vargas S, Blum H, Williams GA, Schierwater B, Wörheide G. Comparative genomics and the nature of placozoan species. PLoS Biol 2018; 16:e2005359. [PMID: 30063702 PMCID: PMC6067683 DOI: 10.1371/journal.pbio.2005359] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 06/28/2018] [Indexed: 12/30/2022] Open
Abstract
Placozoans are a phylum of nonbilaterian marine animals currently represented by a single described species, Trichoplax adhaerens, Schulze 1883. Placozoans arguably show the simplest animal morphology, which is identical among isolates collected worldwide, despite an apparently sizeable genetic diversity within the phylum. Here, we use a comparative genomics approach for a deeper appreciation of the structure and causes of the deeply diverging lineages in the Placozoa. We generated a high-quality draft genome of the genetic lineage H13 isolated from Hong Kong and compared it to the distantly related T. adhaerens. We uncovered substantial structural differences between the two genomes that point to a deep genomic separation and provide support that adaptation by gene duplication is likely a crucial mechanism in placozoan speciation. We further provide genetic evidence for reproductively isolated species and suggest a genus-level difference of H13 to T. adhaerens, justifying the designation of H13 as a new species, Hoilungia hongkongensis nov. gen., nov. spec., now the second described placozoan species and the first in a new genus. Our multilevel comparative genomics approach is, therefore, likely to prove valuable for species distinctions in other cryptic microscopic animal groups that lack diagnostic morphological characters, such as some nematodes, copepods, rotifers, or mites.
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Affiliation(s)
- Michael Eitel
- Department of Earth and Environmental Sciences, Paleontology and Geobiology, Ludwig-Maximilians-Universität München, Munich, Germany
- Stiftung Tierärztliche Hochschule Hannover, Institut für Tierökologie und Zellbiologie, Ecology and Evolution, Hannover, Germany
| | - Warren R. Francis
- Department of Earth and Environmental Sciences, Paleontology and Geobiology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Frédérique Varoqueaux
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Jean Daraspe
- Electron Microscopy Facility, University of Lausanne, Lausanne, Switzerland
| | - Hans-Jürgen Osigus
- Stiftung Tierärztliche Hochschule Hannover, Institut für Tierökologie und Zellbiologie, Ecology and Evolution, Hannover, Germany
| | - Stefan Krebs
- Laboratory for Functional Genome Analysis (LAFUGA), Gene Center, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Sergio Vargas
- Department of Earth and Environmental Sciences, Paleontology and Geobiology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Helmut Blum
- Laboratory for Functional Genome Analysis (LAFUGA), Gene Center, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Gray A. Williams
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Hong Kong
| | - Bernd Schierwater
- Stiftung Tierärztliche Hochschule Hannover, Institut für Tierökologie und Zellbiologie, Ecology and Evolution, Hannover, Germany
- Sackler Institute for Comparative Genomics and Division of Invertebrate Zoology, American Museum of Natural History, New York, New York, United States of America
- Department of Ecology & Evolution, Yale University, New Haven, Connecticut, United States of America
| | - Gert Wörheide
- Department of Earth and Environmental Sciences, Paleontology and Geobiology, Ludwig-Maximilians-Universität München, Munich, Germany
- GeoBio-Center, Ludwig-Maximilians-Universität München, Munich, Germany
- Staatliche Naturwissenschaftliche Sammlungen Bayerns (SNSB)–Bayerische Staatssammlung für Paläontologie und Geologie, Munich, Germany
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29
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Kaelberer MM, Bohórquez DV. The now and then of gut-brain signaling. Brain Res 2018; 1693:192-196. [PMID: 29580839 DOI: 10.1016/j.brainres.2018.03.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 03/19/2018] [Accepted: 03/21/2018] [Indexed: 01/06/2023]
Abstract
Since their very beginnings, animals had gut sensory epithelial cells. In one of the first multicellular animals, Trichoplax - a literal wandering gut - food sensing and feeding was coordinated by specialized ventral sensor cells. In mammals, including humans, gut epithelial sensor cells (a.k.a enteroendocrine cells) have been recognized for an array of neuropeptides, like ghrelin and cholecystokinin, that modulate hunger or satiety. Indeed, since first described as "clear cells" by Rudfolf Heidenhain (1868), research efforts increasingly focused on their hormone neuropeptides leading to the alphabetical classification of one cell-one hormone (e.g. I-cell synthesizes only cholecystokinin). A recent explosion of molecular tools to study the biology of single cells is expanding the imagination of studies and unveiling intriguing aspects of gut sensory transduction. To mention a few: multimodal sensing, one cell expressing both ghrelin and cholecystokinin-the yin and yang of appetite-, and synapses with nerves. This brief account examines recent advances on gut sensory transduction to highlight how food and bacteria in the gut alter eating.
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Affiliation(s)
- Melanie M Kaelberer
- Division of Gastroenterology, Department of Medicine, Duke University, #221A, Medical Sciences Research Building 1, 203 Research Drive, Durham, NC, USA
| | - Diego V Bohórquez
- Division of Gastroenterology, Department of Medicine, Duke University, #221A, Medical Sciences Research Building 1, 203 Research Drive, Durham, NC, USA; Department of Neurobiology, Duke University, #221A, Medical Sciences Research Building 1, 203 Research Drive, Durham, NC, USA.
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Miyazawa H, Nakano H. Multiple surveys employing a new sample-processing protocol reveal the genetic diversity of placozoans in Japan. Ecol Evol 2018; 8:2407-2417. [PMID: 29531663 PMCID: PMC5838039 DOI: 10.1002/ece3.3861] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 12/19/2017] [Accepted: 01/02/2018] [Indexed: 11/08/2022] Open
Abstract
Placozoans, flat free-living marine invertebrates, possess an extremely simple bauplan lacking neurons and muscle cells and represent one of the earliest-branching metazoan phyla. They are widely distributed from temperate to tropical oceans. Based on mitochondrial 16S rRNA sequences, 19 haplotypes forming seven distinct clades have been reported in placozoans to date. In Japan, placozoans have been found at nine locations, but 16S genotyping has been performed at only two of these locations. Here, we propose a new processing protocol, "ethanol-treated substrate sampling," for collecting placozoans from natural environments. We also report the collection of placozoans from three new locations, the islands of Shikine-jima, Chichi-jima, and Haha-jima, and we present the distribution of the 16S haplotypes of placozoans in Japan. Multiple surveys conducted at multiple locations yielded five haplotypes that were not reported previously, revealing high genetic diversity in Japan, especially at Shimoda and Shikine-jima Island. The observed geographic distribution patterns were different among haplotypes; some were widely distributed, while others were sampled only from a single location. However, samplings conducted on different dates at the same sites yielded different haplotypes, suggesting that placozoans of a given haplotype do not inhabit the same site constantly throughout the year. Continued sampling efforts conducted during all seasons at multiple locations worldwide and the development of molecular markers within the haplotypes are needed to reveal the geographic distribution pattern and dispersal history of placozoans in greater detail.
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Affiliation(s)
- Hideyuki Miyazawa
- Shimoda Marine Research CenterUniversity of TsukubaShimodaShizuokaJapan
| | - Hiroaki Nakano
- Shimoda Marine Research CenterUniversity of TsukubaShimodaShizuokaJapan
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Mills DB, Francis WR, Vargas S, Larsen M, Elemans CP, Canfield DE, Wörheide G. The last common ancestor of animals lacked the HIF pathway and respired in low-oxygen environments. eLife 2018; 7:31176. [PMID: 29402379 PMCID: PMC5800844 DOI: 10.7554/elife.31176] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 12/21/2017] [Indexed: 12/30/2022] Open
Abstract
Animals have a carefully orchestrated relationship with oxygen. When exposed to low environmental oxygen concentrations, and during periods of increased energy expenditure, animals maintain cellular oxygen homeostasis by enhancing internal oxygen delivery, and by enabling the anaerobic production of ATP. These low-oxygen responses are thought to be controlled universally across animals by the hypoxia-inducible factor (HIF). We find, however, that sponge and ctenophore genomes lack key components of the HIF pathway. Since sponges and ctenophores are likely sister to all remaining animal phyla, the last common ancestor of extant animals likely lacked the HIF pathway as well. Laboratory experiments show that the marine sponge Tethya wilhelma maintains normal transcription under oxygen levels down to 0.25% of modern atmospheric saturation, the lowest levels we investigated, consistent with the predicted absence of HIF or any other HIF-like pathway. Thus, the last common ancestor of all living animals could have metabolized aerobically under very low environmental oxygen concentrations. Almost all animals need oxygen to live. This is because they use oxygen to release much of the energy locked up in their diets. Oxygen may have also played a crucial role in the early evolution of animal life. Animals evolved from single-celled ancestors in the ocean over 800 million years ago. Before then, it is debated whether the atmosphere and ocean had enough oxygen to permit animals to evolve. Oxygen levels are much higher now, but oxygen availability still varies in some environments. If oxygen becomes limited (a condition known as hypoxia), almost all animals react using a specific set of molecules known as the HIF pathway. This pathway – which is named after proteins called “hypoxia-inducible factors” – triggers changes that help the animal to maintain a stable level of oxygen in its cells. Yet it was not clear if the capacity to sense hypoxia and regulate oxygen demands within the body evolved in the ancestor of all animals, or if it evolved more recently. When trying to understand early evolution, scientists often turn to some living species that sit on the oldest branches of a group’s family tree. In the animal kingdom, sponges and comb jellies occupy those branches. Mills, Francis et al. have now searched the genomes of several of these animals to ask how oxygen sensing evolved. The genomes of the sponges and comb jellies surveyed lack key components of the HIF pathway, suggesting that the last common ancestor of living animals lacked the HIF pathway as well. This also implies that the ancestor of all animals probably did not respond to oxygen stress or used unknown mechanisms to deal with it instead. In laboratory experiments, Mills, Francis et al. saw that a marine sponge named Tethya wilhelma does not alter its gene activity even when the oxygen levels are reduced to 0.25% of modern levels. This is consistent with the predicted absence of a HIF pathway or anything similar. Together these finding may indicate that the last common ancestor of all living animals maintained normal gene activity even at very low concentrations of oxygen. These findings help scientists understand how life and the global environment have shaped each other since the origin of life over 3.5 billion years ago. This fundamental knowledge may provide the context needed to help society navigate through current and on-going environmental changes, including the dropping oxygen levels in the world’s oceans.
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Affiliation(s)
- Daniel B Mills
- Department of Biology, University of Southern Denmark, Odense, Denmark
| | - Warren R Francis
- Paleontology & Geobiology, Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Sergio Vargas
- Paleontology & Geobiology, Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Morten Larsen
- Department of Biology, University of Southern Denmark, Odense, Denmark
| | - Coen Ph Elemans
- Department of Biology, University of Southern Denmark, Odense, Denmark
| | - Donald E Canfield
- Department of Biology, University of Southern Denmark, Odense, Denmark
| | - Gert Wörheide
- Paleontology & Geobiology, Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität München, Munich, Germany.,GeoBio-Center, Ludwig-Maximilians-Universität München, Munich, Germany.,SNSB - Bayerische Staatssammlung für Paläontologie und Geologie, Munich, Germany
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Haen Whitmer KM. Model Systems for Exploring the Evolutionary Origins of the Nervous System. Results Probl Cell Differ 2018; 65:185-196. [PMID: 30083921 DOI: 10.1007/978-3-319-92486-1_10] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
The development of nervous systems can be seen as one of the key transitions in animal evolution, allowing the efficient integration of sensory input and motor output and the expedient transmission of impulses over relatively long distances inside an organism. With the increased availability of genome sequences for animals at the base of the metazoan phylogenetic tree, two alternative hypotheses have been proposed regarding nervous system evolutionary origins, ultimately prompting a debate whether an enormously complicated system like the nervous system could have evolved more than once. This review summarizes what is currently known about nervous system origins, concentrating on the evolution of synapse components, with respect to phylogenetic knowledge of early diverging animal groups, comprising members of the Porifera, Ctenophora, Placozoa, and Cnidaria.
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Affiliation(s)
- Karri M Haen Whitmer
- Department of Genetics, Development & Cell Biology, Iowa State University, Ames, IA, USA.
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33
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Abstract
The evolution of a nervous system as a control system of the body's functions is a key innovation of animals. Its fundamental units are neurons, highly specialized cells dedicated to fast cell-cell communication. Neurons pass signals to other neurons, muscle cells, or gland cells at specialized junctions, the synapses, where transmitters are released from vesicles in a Ca2+-dependent fashion to activate receptors in the membrane of the target cell. Reconstructing the origins of neuronal communication out of a more simple process remains a central challenge in biology. Recent genomic comparisons have revealed that all animals, including the nerveless poriferans and placozoans, share a basic set of genes for neuronal communication. This suggests that the first animal, the Urmetazoan, was already endowed with neurosecretory cells that probably started to connect into neuronal networks soon afterward. Here, we discuss scenarios for this pivotal transition in animal evolution.
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Affiliation(s)
- Frederique Varoqueaux
- Département des Neurosciences Fondamentales, Université de Lausanne, Lausanne, CH-1005 Switzerland; ,
| | - Dirk Fasshauer
- Département des Neurosciences Fondamentales, Université de Lausanne, Lausanne, CH-1005 Switzerland; ,
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34
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Cuervo-González R. Rhodope placozophagus (Heterobranchia) a new species of turbellarian-like Gastropoda that preys on placozoans. ZOOL ANZ 2017. [DOI: 10.1016/j.jcz.2017.09.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Osigus HJ, Eitel M, Schierwater B. Deep RNA sequencing reveals the smallest known mitochondrial micro exon in animals: The placozoan cox1 single base pair exon. PLoS One 2017; 12:e0177959. [PMID: 28542197 PMCID: PMC5436844 DOI: 10.1371/journal.pone.0177959] [Citation(s) in RCA: 11] [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: 08/22/2016] [Accepted: 05/05/2017] [Indexed: 11/18/2022] Open
Abstract
The phylum Placozoa holds a key position for our understanding of the evolution of mitochondrial genomes in Metazoa. Placozoans possess large mitochondrial genomes which harbor several remarkable characteristics such as a fragmented cox1 gene and trans-splicing cox1 introns. A previous study also suggested the existence of cox1 mRNA editing in Trichoplax adhaerens, yet the only formally described species in the phylum Placozoa. We have analyzed RNA-seq data of the undescribed sister species, Placozoa sp. H2 ("Panama" clone), with special focus on the mitochondrial mRNA. While we did not find support for a previously postulated cox1 mRNA editing mechanism, we surprisingly found two independent transcripts representing intermediate cox1 mRNA splicing stages. Both transcripts consist of partial cox1 exon as well as overlapping intron fragments. The data suggest that the cox1 gene harbors a single base pair (cytosine) micro exon. Furthermore, conserved group I intron structures flank this unique micro exon also in other placozoans. We discuss the evolutionary origin of this micro exon in the context of a self-splicing intron gain in the cox1 gene of the last common ancestor of extant placozoans.
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Affiliation(s)
- Hans-Jürgen Osigus
- ITZ, Ecology & Evolution, Stiftung Tierärztliche Hochschule Hannover, Hannover, Germany
| | - Michael Eitel
- ITZ, Ecology & Evolution, Stiftung Tierärztliche Hochschule Hannover, Hannover, Germany
| | - Bernd Schierwater
- ITZ, Ecology & Evolution, Stiftung Tierärztliche Hochschule Hannover, Hannover, Germany
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, United States of America
- Sackler Institute for Comparative Genomics and Division of Invertebrate Zoology, American Museum of Natural History, New York, New York, United States of America
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36
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Schleicherová D, Dulias K, Osigus HJ, Paknia O, Hadrys H, Schierwater B. The most primitive metazoan animals, the placozoans, show high sensitivity to increasing ocean temperatures and acidities. Ecol Evol 2017; 7:895-904. [PMID: 28168026 PMCID: PMC5288258 DOI: 10.1002/ece3.2678] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 11/09/2016] [Accepted: 11/13/2016] [Indexed: 01/14/2023] Open
Abstract
The increase in atmospheric carbon dioxide (CO2) leads to rising temperatures and acidification in the oceans, which directly or indirectly affects all marine organisms, from bacteria to animals. We here ask whether the simplest-and possibly also the oldest-metazoan animals, the placozoans, are particularly sensitive to ocean warming and acidification. Placozoans are found in all warm and temperate oceans and are soft-bodied, microscopic invertebrates lacking any calcified structures, organs, or symmetry. We here show that placozoans respond highly sensitive to temperature and acidity stress. The data reveal differential responses in different placozoan lineages and encourage efforts to develop placozoans as a potential biomarker system.
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Affiliation(s)
| | - Katharina Dulias
- ITZ, Ecology and EvolutionTiHo Hannover Hannover Germany; Present address: Department of Biological Sciences School of Applied Sciences University of Huddersfield Huddersfield UK
| | | | - Omid Paknia
- ITZ, Ecology and Evolution TiHo Hannover Hannover Germany
| | - Heike Hadrys
- ITZ, Ecology and Evolution TiHo Hannover Hannover Germany
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37
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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: 43] [Impact Index Per Article: 5.4] [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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38
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Affiliation(s)
- Gonzalo Giribet
- Museum of Comparative Zoology & Department of Organismic and Evolutionary Biology Harvard University 26 Oxford Street Cambridge MA 02138 USA
- Department of Life Sciences The Natural History Museum Cromwell Road London SW7 5BD UK
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39
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Lavrov DV, Pett W. Animal Mitochondrial DNA as We Do Not Know It: mt-Genome Organization and Evolution in Nonbilaterian Lineages. Genome Biol Evol 2016; 8:2896-2913. [PMID: 27557826 PMCID: PMC5633667 DOI: 10.1093/gbe/evw195] [Citation(s) in RCA: 126] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/06/2016] [Indexed: 12/11/2022] Open
Abstract
Animal mitochondrial DNA (mtDNA) is commonly described as a small, circular molecule that is conserved in size, gene content, and organization. Data collected in the last decade have challenged this view by revealing considerable diversity in animal mitochondrial genome organization. Much of this diversity has been found in nonbilaterian animals (phyla Cnidaria, Ctenophora, Placozoa, and Porifera), which, from a phylogenetic perspective, form the main branches of the animal tree along with Bilateria. Within these groups, mt-genomes are characterized by varying numbers of both linear and circular chromosomes, extra genes (e.g. atp9, polB, tatC), large variation in the number of encoded mitochondrial transfer RNAs (tRNAs) (0-25), at least seven different genetic codes, presence/absence of introns, tRNA and mRNA editing, fragmented ribosomal RNA genes, translational frameshifting, highly variable substitution rates, and a large range of genome sizes. This newly discovered diversity allows a better understanding of the evolutionary plasticity and conservation of animal mtDNA and provides insights into the molecular and evolutionary mechanisms shaping mitochondrial genomes.
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Affiliation(s)
- Dennis V Lavrov
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University
| | - Walker Pett
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University Laboratoire de Biométrie et Biologie Évolutive, Université Lyon 1, Villeurbanne, France
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40
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Schierwater B, Holland PWH, Miller DJ, Stadler PF, Wiegmann BM, Wörheide G, Wray GA, DeSalle R. Never Ending Analysis of a Century Old Evolutionary Debate: “Unringing” the Urmetazoon Bell. Front Ecol Evol 2016. [DOI: 10.3389/fevo.2016.00005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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41
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Paknia O, Schierwater B. Global Habitat Suitability and Ecological Niche Separation in the Phylum Placozoa. PLoS One 2015; 10:e0140162. [PMID: 26580806 PMCID: PMC4651326 DOI: 10.1371/journal.pone.0140162] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 09/10/2015] [Indexed: 02/02/2023] Open
Abstract
The enigmatic placozoans, which hold a key position in the metazoan Tree of Life, have attracted substantial attention in many areas of biological and biomedical research. While placozoans have become an emerging model system, their ecology and particularly biogeography remain widely unknown. In this study, we use modelling approaches to explore habitat preferences, and distribution pattern of the placozoans phylum. We provide hypotheses for discrete ecological niche separation between genetic placozoan lineages, which may also help to understand biogeography patterns in other small marine invertebrates. We, here, used maximum entropy modelling to predict placozoan distribution using 20 environmental grids of 9.2 km2 resolution. In addition, we used recently developed metrics of niche overlap to compare habitat suitability models of three genetic clades. The predicted distributions range from 55°N to 44°S and are restricted to regions of intermediate to warm sea surface temperatures. High concentrations of salinity and low nutrient concentrations appear as secondary factors. Tests of niche equivalency reveal the largest differences between placozoan clades I and III. Interestingly, the genetically well-separated clades I and V appear to be ecologically very similar. Our habitat suitability models predict a wider latitudinal distribution for placozoans, than currently described, especially in the northern hemisphere. With respect to biogeography modelling, placozoans show patterns somewhere between higher metazoan taxa and marine microorganisms, with the first group usually showing complex biogeographies and the second usually showing “no biogeography.”
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Affiliation(s)
- Omid Paknia
- ITZ, Ecology and Evolution, TiHo Hannover, Hannover, Germany
- * E-mail:
| | - Bernd Schierwater
- ITZ, Ecology and Evolution, TiHo Hannover, Hannover, Germany
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, United States of America
- Sackler Institute for Comparative Genomics and Division of Invertebrate Zoology, American Museum of Natural History, New York, New York, United States of America
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42
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Costello MJ, Vanhoorne B, Appeltans W. Conservation of biodiversity through taxonomy, data publication, and collaborative infrastructures. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2015; 29:1094-1099. [PMID: 25858475 DOI: 10.1111/cobi.12496] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 07/24/2014] [Indexed: 06/04/2023]
Abstract
Taxonomy is the foundation of biodiversity science because it furthers discovery of new species. Globally, there have never been so many people involved in naming species new to science. The number of new marine species described per decade has never been greater. Nevertheless, it is estimated that tens of thousands of marine species, and hundreds of thousands of terrestrial species, are yet to be discovered; many of which may already be in specimen collections. However, naming species is only a first step in documenting knowledge about their biology, biogeography, and ecology. Considering the threats to biodiversity, new knowledge of existing species and discovery of undescribed species and their subsequent study are urgently required. To accelerate this research, we recommend, and cite examples of, more and better communication: use of collaborative online databases; easier access to knowledge and specimens; production of taxonomic revisions and species identification guides; engagement of nonspecialists; and international collaboration. "Data-sharing" should be abandoned in favor of mandated data publication by the conservation science community. Such a step requires support from peer reviewers, editors, journals, and conservation organizations. Online data publication infrastructures (e.g., Global Biodiversity Information Facility, Ocean Biogeographic Information System) illustrate gaps in biodiversity sampling and may provide common ground for long-term international collaboration between scientists and conservation organizations.
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Affiliation(s)
- Mark J Costello
- Institute of Marine Science, University of Auckland, Post Bag 92019, Auckland, 1142, New Zealand
| | - Bart Vanhoorne
- Flanders Marine Institute, Wandelaarkaai 7, Ostend, 8400, Belgium
| | - Ward Appeltans
- Ocean Biogeographic Information System, IODE, Intergovernmental Oceanographic Commission, UNESCO, Wandelaarkaai 7/61, Ostend, 8400, Belgium
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43
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Aktipis CA, Boddy AM, Jansen G, Hibner U, Hochberg ME, Maley CC, Wilkinson GS. Cancer across the tree of life: cooperation and cheating in multicellularity. Philos Trans R Soc Lond B Biol Sci 2015; 370:20140219. [PMID: 26056363 PMCID: PMC4581024 DOI: 10.1098/rstb.2014.0219] [Citation(s) in RCA: 209] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/30/2015] [Indexed: 02/06/2023] Open
Abstract
Multicellularity is characterized by cooperation among cells for the development, maintenance and reproduction of the multicellular organism. Cancer can be viewed as cheating within this cooperative multicellular system. Complex multicellularity, and the cooperation underlying it, has evolved independently multiple times. We review the existing literature on cancer and cancer-like phenomena across life, not only focusing on complex multicellularity but also reviewing cancer-like phenomena across the tree of life more broadly. We find that cancer is characterized by a breakdown of the central features of cooperation that characterize multicellularity, including cheating in proliferation inhibition, cell death, division of labour, resource allocation and extracellular environment maintenance (which we term the five foundations of multicellularity). Cheating on division of labour, exhibited by a lack of differentiation and disorganized cell masses, has been observed in all forms of multicellularity. This suggests that deregulation of differentiation is a fundamental and universal aspect of carcinogenesis that may be underappreciated in cancer biology. Understanding cancer as a breakdown of multicellular cooperation provides novel insights into cancer hallmarks and suggests a set of assays and biomarkers that can be applied across species and characterize the fundamental requirements for generating a cancer.
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Affiliation(s)
- C Athena Aktipis
- Center for Evolution and Cancer, University of California San Francisco, San Francisco, CA 94143, USA Department of Psychology, Arizona State University, Tempe, AZ 85287-4501, USA Centre for Evolution and Cancer, Institute for Cancer Research, 123 Old Brompton Road, London SW7 3RP, UK Institute for Advanced Study, Wissenschaftskolleg zu Berlin, Berlin, Germany
| | - Amy M Boddy
- Center for Evolution and Cancer, University of California San Francisco, San Francisco, CA 94143, USA Department of Psychology, Arizona State University, Tempe, AZ 85287-4501, USA Institute for Advanced Study, Wissenschaftskolleg zu Berlin, Berlin, Germany
| | - Gunther Jansen
- Department of Evolutionary Ecology and Genetics, University of Kiel, Am Botanischen Garten 1-9, 24118 Kiel, Germany Institute for Advanced Study, Wissenschaftskolleg zu Berlin, Berlin, Germany
| | - Urszula Hibner
- CNRS, UMR 5535, Institut de Génétique Moléculaire de Montpellier, Université de Montpellier, Montpellier, France Institute for Advanced Study, Wissenschaftskolleg zu Berlin, Berlin, Germany
| | - Michael E Hochberg
- Institut des Sciences de l'Evolution, CNRS UMR5554, Université Montpellier, 34095 Montpellier, France Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87501, USA Institute for Advanced Study, Wissenschaftskolleg zu Berlin, Berlin, Germany
| | - Carlo C Maley
- Center for Evolution and Cancer, University of California San Francisco, San Francisco, CA 94143, USA Centre for Evolution and Cancer, Institute for Cancer Research, 123 Old Brompton Road, London SW7 3RP, UK Biodesign Institute, School of Life Sciences, Arizona State University, PO Box 8724501, Tempe, AZ 85287-4501, USA Institute for Advanced Study, Wissenschaftskolleg zu Berlin, Berlin, Germany
| | - Gerald S Wilkinson
- Department of Biology, University of Maryland, College Park, MD 20742, USA Institute for Advanced Study, Wissenschaftskolleg zu Berlin, Berlin, Germany
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Takeuchi F, Sekizuka T, Ogasawara Y, Yokoyama H, Kamikawa R, Inagaki Y, Nozaki T, Sugita-Konishi Y, Ohnishi T, Kuroda M. The Mitochondrial Genomes of a Myxozoan Genus Kudoa Are Extremely Divergent in Metazoa. PLoS One 2015; 10:e0132030. [PMID: 26148004 PMCID: PMC4492933 DOI: 10.1371/journal.pone.0132030] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 06/09/2015] [Indexed: 12/18/2022] Open
Abstract
The Myxozoa are oligo-cellular parasites with alternate hosts--fish and annelid worms--and some myxozoan species harm farmed fish. The phylum Myxozoa, comprising 2,100 species, was difficult to position in the tree of life, due to its fast evolutionary rate. Recent phylogenomic studies utilizing an extensive number of nuclear-encoded genes have confirmed that Myxozoans belong to Cnidaria. Nevertheless, the evolution of parasitism and extreme body simplification in Myxozoa is not well understood, and no myxozoan mitochondrial DNA sequence has been reported to date. To further elucidate the evolution of Myxozoa, we sequenced the mitochondrial genomes of the myxozoan species Kudoa septempunctata, K. hexapunctata and K. iwatai and compared them with those of other metazoans. The Kudoa mitochondrial genomes code for ribosomal RNAs, transfer RNAs, eight proteins for oxidative phosphorylation and three proteins of unknown function, and they are among the metazoan mitochondrial genomes coding the fewest proteins. The mitochondrial-encoded proteins were extremely divergent, exhibiting the fastest evolutionary rate in Metazoa. Nevertheless, the dN/dS ratios of the protein genes in genus Kudoa were approximately 0.1 and similar to other cnidarians, indicating that the genes are under negative selection. Despite the divergent genetic content, active oxidative phosphorylation was indicated by the transcriptome, metabolism and structure of mitochondria in K. septempunctata. As possible causes, we attributed the divergence to the population genetic characteristics shared between the two most divergent clades, Ctenophora and Myxozoa, and to the parasitic lifestyle of Myxozoa. The fast-evolving, functional mitochondria of the genus Kudoa expanded our understanding of metazoan mitochondrial evolution.
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Affiliation(s)
- Fumihiko Takeuchi
- Pathogen Genomics Center, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo, Japan
| | - Tsuyoshi Sekizuka
- Pathogen Genomics Center, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo, Japan
| | - Yumiko Ogasawara
- Pathogen Genomics Center, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo, Japan
| | - Hiroshi Yokoyama
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Ryoma Kamikawa
- Graduate School of Human and Environmental Studies, Graduate School of Global Environmental Studies, Kyoto University, Sakyou-ku, Kyoto, Japan
| | - Yuji Inagaki
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Tomoyoshi Nozaki
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
- Department of Parasitology, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo, Japan
| | | | - Takahiro Ohnishi
- Division of Microbiology, National Institute of Health Sciences, Setagaya-ku, Tokyo, Japan
| | - Makoto Kuroda
- Pathogen Genomics Center, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo, Japan
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45
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Brockmann B, Mastel H, Oswald F, Maier D. Analysis of the interaction between human RITA and Drosophila Suppressor of Hairless. Hereditas 2015; 151:209-19. [PMID: 25588307 DOI: 10.1111/hrd2.00074] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 12/01/2014] [Indexed: 10/24/2022] Open
Abstract
Notch signalling mediates intercellular communication, which is effected by the transcription factor CSL, an acronym for vertebrate CBF1/RBP-J, Drosophila Suppressor of Hairless [Su(H)] and C. elegans Lag1. Nuclear import of CBF1/RBP-J depends on co-activators and co-repressors, whereas the export relies on RITA. RITA is a tubulin and CBF1/RBP-J binding protein acting as a negative regulator of Notch signalling in vertebrates. RITA protein is highly conserved in eumatazoa, but no Drosophila homologue was yet identified. In this work, the activity of human RITA in the fly was addressed. To this end, we generated transgenic flies that allow a tissue specific induction of human RITA, which was demonstrated by Western blotting and in fly tissues. Unexpectedly, overexpression of RITA during fly development had little phenotypic consequences, even when overexpressed simultaneously with either Su(H) or the Notch antagonist Hairless. We demonstrate the in vivo binding of human RITA to Su(H) and to tubulin by co-immune precipitation. Moreover, RITA and tubulin co-localized to some degree in several Drosophila tissues. Overall our data show that human RITA, albeit binding to Drosophila Su(H) and tubulin, cannot influence the Notch signalling pathway in the fly, suggesting that a nuclear export mechanism of Su(H), if existent in Drosophila, does not depend on RITA.
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Affiliation(s)
- Birgit Brockmann
- Institute of Genetics, University of Hohenheim, Stuttgart, Germany
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Whelan NV, Kocot KM, Halanych KM. Employing Phylogenomics to Resolve the Relationships among Cnidarians, Ctenophores, Sponges, Placozoans, and Bilaterians. Integr Comp Biol 2015; 55:1084-95. [PMID: 25972566 DOI: 10.1093/icb/icv037] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Despite an explosion in the amount of sequence data, phylogenomics has failed to settle controversy regarding some critical nodes on the animal tree of life. Understanding relationships among Bilateria, Ctenophora, Cnidaria, Placozoa, and Porifera is essential for studying how complex traits such as neurons, muscles, and gastrulation have evolved. Recent studies have cast doubt on the historical viewpoint that sponges are sister to all other animal lineages with recent studies recovering ctenophores as sister. However, the ctenophore-sister hypothesis has been criticized as unrealistic and caused by systematic error. We review past phylogenomic studies and potential causes of systematic error in an effort to identify areas that can be improved in future studies. Increased sampling of taxa, less missing data, and a priori removal of sequences and taxa that may cause systematic error in phylogenomic inference will likely be the most fruitful areas of focus when assembling future datasets. Ultimately, we foresee metazoan relationships being resolved with higher support in the near future, and we caution against dismissing novel hypotheses merely because they conflict with historical viewpoints of animal evolution.
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Affiliation(s)
- Nathan V Whelan
- *Department of Biological Sciences, Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, 101 Life Sciences Building, Auburn, AL 36849, USA;
| | - Kevin M Kocot
- School of Biological Sciences, The University of Queensland, 325 Goddard Building, St Lucia, QLD 4101, Australia
| | - Kenneth M Halanych
- *Department of Biological Sciences, Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, 101 Life Sciences Building, Auburn, AL 36849, USA
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Nikitin M. Bioinformatic prediction of Trichoplax adhaerens regulatory peptides. Gen Comp Endocrinol 2015; 212:145-55. [PMID: 24747483 DOI: 10.1016/j.ygcen.2014.03.049] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 03/29/2014] [Accepted: 03/31/2014] [Indexed: 01/29/2023]
Abstract
Trichoplax adhaerens (phylum Placozoa) is a very simple organism that lacks a nervous system. However, its genome contains many genes essential for neuronal function and development. I report the results of regulatory peptide predictions for this enigmatic animal. Extensive transcriptome, genome, and predicted proteome mining allowed us to predict four insulins, at least five short peptide precursors, one granulin, one paracrine regulator of cell growth, and one complex temptin-attractin pheromone signaling system. The expression of three insulins, four short peptide precursors, granulin, and one out of the six temptin genes was detected. Five predicted regulatory peptide precursors could potentially release over 60 different mature peptides. Some of the predicted peptides are somewhat similar to anthozoan RW amides, Aplysia pedal peptide 3, and PRQFV amide. Other predicted short peptides could not readily be classified into established families. These data provide the foundation for the molecular, biochemical, physiological, and behavioral studies of one the most primitive animal coordination systems, and give unique insight into the origins and early evolution of the nervous system.
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Affiliation(s)
- Mikhail Nikitin
- Lomonosov Moscow State University, A.N. Belozersky Institute of Physico-chemical Biology, Leninskie Gory 1, Bldg. 40, Moscow 119991, Russia.
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48
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Biscotti MA, Canapa A, Forconi M, Barucca M. HoxandParaHoxgenes: A review on molluscs. Genesis 2014; 52:935-45. [DOI: 10.1002/dvg.22839] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 11/10/2014] [Accepted: 11/11/2014] [Indexed: 01/28/2023]
Affiliation(s)
- Maria Assunta Biscotti
- Dipartimento di Scienze della Vita e dell'Ambiente; Università Politecnica delle Marche; Ancona Italy
| | - Adriana Canapa
- Dipartimento di Scienze della Vita e dell'Ambiente; Università Politecnica delle Marche; Ancona Italy
| | - Mariko Forconi
- Dipartimento di Scienze della Vita e dell'Ambiente; Università Politecnica delle Marche; Ancona Italy
| | - Marco Barucca
- Dipartimento di Scienze della Vita e dell'Ambiente; Università Politecnica delle Marche; Ancona Italy
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49
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Suurväli J, Jouneau L, Thépot D, Grusea S, Pontarotti P, Du Pasquier L, Rüütel Boudinot S, Boudinot P. The Proto-MHC of Placozoans, a Region Specialized in Cellular Stress and Ubiquitination/Proteasome Pathways. THE JOURNAL OF IMMUNOLOGY 2014; 193:2891-901. [DOI: 10.4049/jimmunol.1401177] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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50
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Survey of the Japanese coast reveals abundant placozoan populations in the Northern Pacific Ocean. Sci Rep 2014; 4:5356. [PMID: 24942227 PMCID: PMC4062898 DOI: 10.1038/srep05356] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 05/22/2014] [Indexed: 11/27/2022] Open
Abstract
Placozoans are the simplest extant free-living animals consisting of only five cell types and lacking neurons and muscle cells. Their phylogenetic position implies they are important for uncovering the origins of metazoans. Although recent studies show multiple groups within the phylum, most placozoan research has been performed on laboratory-cultured clones deriving from a single specimen. Reports of placozoan discovery are concentrated in the tropic and subtropic seas, especially in the Mediterranean and the Caribbean. Here, I report the unexpected abundance of placozoans from the Japanese coast. They were found from all six studied sites, even during winter for two sites, suggesting that they are more tolerant to low temperatures than previously regarded. These results suggest an unknown abundance of placozoans in the Northern Pacific Ocean and further studies on these populations may be essential in solving important biological problems of the phylum.
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