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Deppisch P, Helfrich-Förster C, Senthilan PR. The Gain and Loss of Cryptochrome/Photolyase Family Members during Evolution. Genes (Basel) 2022; 13:genes13091613. [PMID: 36140781 PMCID: PMC9498864 DOI: 10.3390/genes13091613] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 09/02/2022] [Accepted: 09/05/2022] [Indexed: 11/20/2022] Open
Abstract
The cryptochrome/photolyase (CRY/PL) family represents an ancient group of proteins fulfilling two fundamental functions. While photolyases repair UV-induced DNA damages, cryptochromes mainly influence the circadian clock. In this study, we took advantage of the large number of already sequenced and annotated genes available in databases and systematically searched for the protein sequences of CRY/PL family members in all taxonomic groups primarily focusing on metazoans and limiting the number of species per taxonomic order to five. Using BLASTP searches and subsequent phylogenetic tree and motif analyses, we identified five distinct photolyases (CPDI, CPDII, CPDIII, 6-4 photolyase, and the plant photolyase PPL) and six cryptochrome subfamilies (DASH-CRY, mammalian-type MCRY, Drosophila-type DCRY, cnidarian-specific ACRY, plant-specific PCRY, and the putative magnetoreceptor CRY4. Manually assigning the CRY/PL subfamilies to the species studied, we have noted that over evolutionary history, an initial increase of various CRY/PL subfamilies was followed by a decrease and specialization. Thus, in more primitive organisms (e.g., bacteria, archaea, simple eukaryotes, and in basal metazoans), we find relatively few CRY/PL members. As species become more evolved (e.g., cnidarians, mollusks, echinoderms, etc.), the CRY/PL repertoire also increases, whereas it appears to decrease again in more recent organisms (humans, fruit flies, etc.). Moreover, our study indicates that all cryptochromes, although largely active in the circadian clock, arose independently from different photolyases, explaining their different modes of action.
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Barve A, Galande AA, Ghaskadbi SS, Ghaskadbi S. DNA Repair Repertoire of the Enigmatic Hydra. Front Genet 2021; 12:670695. [PMID: 33995496 PMCID: PMC8117345 DOI: 10.3389/fgene.2021.670695] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 04/12/2021] [Indexed: 12/20/2022] Open
Abstract
Since its discovery by Abraham Trembley in 1744, hydra has been a popular research organism. Features like spectacular regeneration capacity, peculiar tissue dynamics, continuous pattern formation, unique evolutionary position, and an apparent lack of organismal senescence make hydra an intriguing animal to study. While a large body of work has taken place, particularly in the domain of evolutionary developmental biology of hydra, in recent years, the focus has shifted to molecular mechanisms underlying various phenomena. DNA repair is a fundamental cellular process that helps to maintain integrity of the genome through multiple repair pathways found across taxa, from archaea to higher animals. DNA repair capacity and senescence are known to be closely associated, with mutations in several repair pathways leading to premature ageing phenotypes. Analysis of DNA repair in an animal like hydra could offer clues into several aspects including hydra’s purported lack of organismal ageing, evolution of DNA repair systems in metazoa, and alternative functions of repair proteins. We review here the different DNA repair mechanisms known so far in hydra. Hydra genes from various DNA repair pathways show very high similarity with their vertebrate orthologues, indicating conservation at the level of sequence, structure, and function. Notably, most hydra repair genes are more similar to deuterostome counterparts than to common model invertebrates, hinting at ancient evolutionary origins of repair pathways and further highlighting the relevance of organisms like hydra as model systems. It appears that hydra has the full repertoire of DNA repair pathways, which are employed in stress as well as normal physiological conditions and may have a link with its observed lack of senescence. The close correspondence of hydra repair genes with higher vertebrates further demonstrates the need for deeper studies of various repair components, their interconnections, and functions in this early metazoan.
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Affiliation(s)
- Apurva Barve
- Developmental Biology Group, MACS-Agharkar Research Institute, Pune, India.,Centre of Excellence in Science and Mathematics Education, Indian Institute of Science Education and Research (IISER), Pune, India
| | - Alisha A Galande
- Developmental Biology Group, MACS-Agharkar Research Institute, Pune, India
| | - Saroj S Ghaskadbi
- Department of Zoology, Savitribai Phule Pune University, Pune, India
| | - Surendra Ghaskadbi
- Developmental Biology Group, MACS-Agharkar Research Institute, Pune, India
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3
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Ledda B, Ottaggio L, Izzotti A, Sukkar SG, Miele M. Small RNAs in eucaryotes: new clues for amplifying microRNA benefits. Cell Biosci 2020; 10:1. [PMID: 31911829 PMCID: PMC6942390 DOI: 10.1186/s13578-019-0370-3] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 12/23/2019] [Indexed: 12/31/2022] Open
Abstract
miRNAs, the smallest nucleotide molecules able to regulate gene expression at post transcriptional level, are found in both animals and plants being involved in fundamental processes for growth and development of living organisms. The number of miRNAs has been hypothesized to increase when some organisms specialized the process of mastication and grinding of food. Further to the vertical transmission, miRNAs can undergo horizontal transmission among different species, in particular between plants and animals. In the last years, an increasing number of studies reported that miRNA passage occurs through feeding, and that in animals, plant miRNAs can survive the gastro intestinal digestion and transferred by blood into host cells, where they can exert their functions modulating gene expression. The present review reports studies on miRNAs during evolution, with particular focus on biogenesis and mechanisms regulating their stability in plants and animals. The different biogenesis and post biogenesis modifications allow to discriminate miRNAs of plant origin from those of animal origin, and make it possible to better clarify the controversial question on whether a possible cross-kingdom miRNA transfer through food does exist. The majority of human medicines and supplements derive from plants and a regular consumption of plant food is suggested for their beneficial effects in the prevention of metabolic diseases, cancers, and dietary related disorders. So far, these beneficial effects have been generally attributed to the content of secondary metabolites, whereas mechanisms regarding other components remain unclear. Therefore, in light of the above reported studies miRNAs could result another component for the medical properties of plants. miRNAs have been mainly studied in mammals characterizing their sequences and molecular targets as available in public databases. The herein presented studies provide evidences that miRNA situation is much more complex than the static situation reported in databases. Indeed, miRNAs may have redundant activities, variable sequences, different methods of biogenesis, and may be differently influenced by external and environmental factors. In-depth knowledge of mechanisms of synthesis, regulation and transfer of plant miRNAs to other species can open new frontiers in the therapy of many human diseases, including cancer.
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Affiliation(s)
- Bernardetta Ledda
- 1Department of Health Sciences, University of Genoa, Via A. Pastore 1, 16132 Genoa, Italy
| | - Laura Ottaggio
- Mutagenesis and Cancer Prevention Unit, IRCCS Ospedale Policlinico San Martino, L.Go R. Benzi, 10, Genoa, Italy
| | - Alberto Izzotti
- 1Department of Health Sciences, University of Genoa, Via A. Pastore 1, 16132 Genoa, Italy.,Mutagenesis and Cancer Prevention Unit, IRCCS Ospedale Policlinico San Martino, L.Go R. Benzi, 10, Genoa, Italy
| | - Samir G Sukkar
- UOD Dietetic and Clinical Nutrition, IRCCS Ospedale Policlinico San Martino, L.Go R. Benzi, 10, Genoa, Italy
| | - Mariangela Miele
- Mutagenesis and Cancer Prevention Unit, IRCCS Ospedale Policlinico San Martino, L.Go R. Benzi, 10, Genoa, Italy
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4
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Galtier d'Auriac I, Quinn RA, Maughan H, Nothias LF, Little M, Kapono CA, Cobian A, Reyes BT, Green K, Quistad SD, Leray M, Smith JE, Dorrestein PC, Rohwer F, Deheyn DD, Hartmann AC. Before platelets: the production of platelet-activating factor during growth and stress in a basal marine organism. Proc Biol Sci 2018; 285:rspb.2018.1307. [PMID: 30111600 PMCID: PMC6111180 DOI: 10.1098/rspb.2018.1307] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 07/20/2018] [Indexed: 11/17/2022] Open
Abstract
Corals and humans represent two extremely disparate metazoan lineages and are therefore useful for comparative evolutionary studies. Two lipid-based molecules that are central to human immunity, platelet-activating factor (PAF) and Lyso-PAF were recently identified in scleractinian corals. To identify processes in corals that involve these molecules, PAF and Lyso-PAF biosynthesis was quantified in conditions known to stimulate PAF production in mammals (tissue growth and exposure to elevated levels of ultraviolet light) and in conditions unique to corals (competing with neighbouring colonies over benthic space). Similar to observations in mammals, PAF production was higher in regions of active tissue growth and increased when corals were exposed to elevated levels of ultraviolet light. PAF production also increased when corals were attacked by the stinging cells of a neighbouring colony, though only the attacked coral exhibited an increase in PAF. This reaction was observed in adjacent areas of the colony, indicating that this response is coordinated across multiple polyps including those not directly subject to the stress. PAF and Lyso-PAF are involved in coral stress responses that are both shared with mammals and unique to the ecology of cnidarians.
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Affiliation(s)
| | - Robert A Quinn
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, CA 92093, USA
| | | | - Louis-Felix Nothias
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, CA 92093, USA
| | - Mark Little
- Department of Biology, San Diego State University, San Diego, CA 92182-4614, USA
| | - Clifford A Kapono
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, CA 92093, USA
| | - Ana Cobian
- Department of Biology, San Diego State University, San Diego, CA 92182-4614, USA
| | - Brandon T Reyes
- Department of Biology, San Diego State University, San Diego, CA 92182-4614, USA
| | - Kevin Green
- Department of Biology, San Diego State University, San Diego, CA 92182-4614, USA
| | - Steven D Quistad
- Department of Biology, San Diego State University, San Diego, CA 92182-4614, USA.,Laboratoire de Génétique de l'Evolution (LGE), Institute of Chemistry, Biology, and Innovation, ESPCI ParisTech/CNRS UMR 8231/PSL Research University, Paris, France
| | - Matthieu Leray
- Smithsonian Tropical Research Institute, Smithsonian Institution, Panama City, Republic of Panama
| | - Jennifer E Smith
- Scripps Institution of Oceanography, University of California, San Diego, CA 92093, USA
| | - Pieter C Dorrestein
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, CA 92093, USA
| | - Forest Rohwer
- Department of Biology, San Diego State University, San Diego, CA 92182-4614, USA
| | - Dimitri D Deheyn
- Scripps Institution of Oceanography, University of California, San Diego, CA 92093, USA
| | - Aaron C Hartmann
- Department of Biology, San Diego State University, San Diego, CA 92182-4614, USA .,National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
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5
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Interacting-heads motif has been conserved as a mechanism of myosin II inhibition since before the origin of animals. Proc Natl Acad Sci U S A 2018; 115:E1991-E2000. [PMID: 29444861 DOI: 10.1073/pnas.1715247115] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Electron microscope studies have shown that the switched-off state of myosin II in muscle involves intramolecular interaction between the two heads of myosin and between one head and the tail. The interaction, seen in both myosin filaments and isolated molecules, inhibits activity by blocking actin-binding and ATPase sites on myosin. This interacting-heads motif is highly conserved, occurring in invertebrates and vertebrates, in striated, smooth, and nonmuscle myosin IIs, and in myosins regulated by both Ca2+ binding and regulatory light-chain phosphorylation. Our goal was to determine how early this motif arose by studying the structure of inhibited myosin II molecules from primitive animals and from earlier, unicellular species that predate animals. Myosin II from Cnidaria (sea anemones, jellyfish), the most primitive animals with muscles, and Porifera (sponges), the most primitive of all animals (lacking muscle tissue) showed the same interacting-heads structure as myosins from higher animals, confirming the early origin of the motif. The social amoeba Dictyostelium discoideum showed a similar, but modified, version of the motif, while the amoeba Acanthamoeba castellanii and fission yeast (Schizosaccharomyces pombe) showed no head-head interaction, consistent with the different sequences and regulatory mechanisms of these myosins compared with animal myosin IIs. Our results suggest that head-head/head-tail interactions have been conserved, with slight modifications, as a mechanism for regulating myosin II activity from the emergence of the first animals and before. The early origins of these interactions highlight their importance in generating the inhibited (relaxed) state of myosin in muscle and nonmuscle cells.
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Dohrmann M, Wörheide G. Novel scenarios of early animal evolution--is it time to rewrite textbooks? Integr Comp Biol 2013; 53:503-11. [PMID: 23539635 DOI: 10.1093/icb/ict008] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Understanding how important phenotypic, developmental, and genomic features of animals originated and evolved is essential for many fields of biological research, but such understanding depends on robust hypotheses about the phylogenetic interrelationships of the higher taxa to which the studied species belong. Molecular approaches to phylogenetics have proven able to revolutionize our knowledge of organismal evolution. However, with respect to the deepest splits in the metazoan Tree of Life-the relationships between Bilateria and the four non-bilaterian phyla (Porifera, Placozoa, Ctenophora, and Cnidaria)-no consensus has been reached yet, since a number of different, often contradictory, hypotheses with sometimes spectacular implications have been proposed in recent years. Here, we review the recent literature on the topic and contrast it with more classical perceptions based on analyses of morphological characters. We conclude that the time is not yet ripe to rewrite zoological textbooks and advocate a conservative approach when it comes to developing scenarios of the early evolution of animals.
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Affiliation(s)
- Martin Dohrmann
- *Meiborssen 12, 37647 Vahlbruch, Germany; Department of Earth and Environmental Sciences, Palaeontology & Geobiology, Ludwig-Maximilians-Universität München, 80333 München, Germany; GeoBio-Center, Ludwig-Maximilians-Universität München, 80333 München, Germany; Bayerische Staatssammlung für Paläontologie und Geologie, 80333 München, Germany
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7
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Mayorova T, Kosevich I. FMRF-amide immunoreactivity pattern in the planula and colony of the hydroid Gonothyraea loveni. ZOOLOGY 2013; 116:9-19. [DOI: 10.1016/j.zool.2012.07.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 06/15/2012] [Accepted: 07/30/2012] [Indexed: 12/16/2022]
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8
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Kayal E, Roure B, Philippe H, Collins AG, Lavrov DV. Cnidarian phylogenetic relationships as revealed by mitogenomics. BMC Evol Biol 2013; 13:5. [PMID: 23302374 PMCID: PMC3598815 DOI: 10.1186/1471-2148-13-5] [Citation(s) in RCA: 129] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 12/21/2012] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Cnidaria (corals, sea anemones, hydroids, jellyfish) is a phylum of relatively simple aquatic animals characterized by the presence of the cnidocyst: a cell containing a giant capsular organelle with an eversible tubule (cnida). Species within Cnidaria have life cycles that involve one or both of the two distinct body forms, a typically benthic polyp, which may or may not be colonial, and a typically pelagic mostly solitary medusa. The currently accepted taxonomic scheme subdivides Cnidaria into two main assemblages: Anthozoa (Hexacorallia + Octocorallia) - cnidarians with a reproductive polyp and the absence of a medusa stage - and Medusozoa (Cubozoa, Hydrozoa, Scyphozoa, Staurozoa) - cnidarians that usually possess a reproductive medusa stage. Hypothesized relationships among these taxa greatly impact interpretations of cnidarian character evolution. RESULTS We expanded the sampling of cnidarian mitochondrial genomes, particularly from Medusozoa, to reevaluate phylogenetic relationships within Cnidaria. Our phylogenetic analyses based on a mitochogenomic dataset support many prior hypotheses, including monophyly of Hexacorallia, Octocorallia, Medusozoa, Cubozoa, Staurozoa, Hydrozoa, Carybdeida, Chirodropida, and Hydroidolina, but reject the monophyly of Anthozoa, indicating that the Octocorallia + Medusozoa relationship is not the result of sampling bias, as proposed earlier. Further, our analyses contradict Scyphozoa [Discomedusae + Coronatae], Acraspeda [Cubozoa + Scyphozoa], as well as the hypothesis that Staurozoa is the sister group to all the other medusozoans. CONCLUSIONS Cnidarian mitochondrial genomic data contain phylogenetic signal informative for understanding the evolutionary history of this phylum. Mitogenome-based phylogenies, which reject the monophyly of Anthozoa, provide further evidence for the polyp-first hypothesis. By rejecting the traditional Acraspeda and Scyphozoa hypotheses, these analyses suggest that the shared morphological characters in these groups are plesiomorphies, originated in the branch leading to Medusozoa. The expansion of mitogenomic data along with improvements in phylogenetic inference methods and use of additional nuclear markers will further enhance our understanding of the phylogenetic relationships and character evolution within Cnidaria.
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Affiliation(s)
- Ehsan Kayal
- Dept. Ecology, Evolution, and Organismal Biology, Iowa State University, 50011, Ames, Iowa, USA
- Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, 20013-7012, Washington, DC, USA
| | - Béatrice Roure
- Dept. Biochimie, Fac. Médecine, Université de Montral, Pavillon Roger-Gaudry, C.P. 6128, Succ. Centre-Ville, H3C 3J7, Montral, QC, Canada
| | - Hervé Philippe
- Dept. Biochimie, Fac. Médecine, Université de Montral, Pavillon Roger-Gaudry, C.P. 6128, Succ. Centre-Ville, H3C 3J7, Montral, QC, Canada
| | - Allen G Collins
- National Systematics Laboratory of NOAA’s Fisheries Service, National Museum of Natural History, MRC-153, Smithsonian Institution, PO Box 37012, 20013-7012, Washington, DC, USA
| | - Dennis V Lavrov
- Dept. Ecology, Evolution, and Organismal Biology, Iowa State University, 50011, Ames, Iowa, USA
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9
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Guerriero G. Putative chitin synthases from Branchiostoma floridae show extracellular matrix-related domains and mosaic structures. GENOMICS PROTEOMICS & BIOINFORMATICS 2012; 10:197-207. [PMID: 23084775 PMCID: PMC4937987 DOI: 10.1016/j.gpb.2012.07.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2012] [Revised: 03/27/2012] [Accepted: 04/23/2012] [Indexed: 01/04/2023]
Abstract
The transition from unicellular to multicellular life forms requires the development of a specialized structural component, the extracellular matrix (ECM). In Metazoans, there are two main supportive systems, which are based on chitin and collagen/hyaluronan, respectively. Chitin is the major constituent of fungal cell walls and arthropod exoskeleton. However, presence of chitin/chitooligosaccharides has been reported in lower chordates and during specific stages of vertebrate development. In this study, the occurrence of chitin synthases (CHSs) was investigated with a bioinformatics approach in the cephalochordate Branchiostoma floridae, in which the presence of chitin was initially reported in the skeletal rods of the pharyngeal gill basket. Twelve genes coding for proteins containing conserved amino acid residues of processive glycosyltransferases from GT2 family were found and 10 of them display mosaic structures with novel domains never reported previously in a chitin synthase. In particular, the presence of a discoidin (DS) and a sterile alpha motif (SAM) domain was found in nine identified proteins. Sequence analyses and homology modelling suggest that these domains might interact with the extracellular matrix and mediate protein–protein interaction. The multi-domain putative chitin synthases from B. floridae constitute an emblematic example of the explosion of domain innovation and shuffling which predate Metazoans.
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Affiliation(s)
- Gea Guerriero
- Fungal Genetics and Genomics Unit, Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Science Vienna, University and Research Center Campus Tulln-Technopol, Tulln, Austria.
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10
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Osigus HJ, Eitel M, Schierwater B. Chasing the urmetazoon: striking a blow for quality data? Mol Phylogenet Evol 2012; 66:551-7. [PMID: 22683435 DOI: 10.1016/j.ympev.2012.05.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 05/24/2012] [Indexed: 10/28/2022]
Abstract
The ever-lingering question: "What did the urmetazoan look like?" has not lost its charm, appeal or elusiveness for one and a half centuries. A solid amount of organismal data give what some feel is a clear answer (e.g. Placozoa are at the base of the metazoan tree of life (ToL)), but a diversity of modern molecular data gives almost as many answers as there are exemplars, and even the largest molecular data sets could not solve the question and sometimes even suggest obvious zoological nonsense. Since the problems involved in this phylogenetic conundrum encompass a wide array of analytical freedom and uncertainty it seems questionable whether a further increase in molecular data (quantity) can solve this classical deep phylogeny problem. This review thus strikes a blow for evaluating quality data (including morphological, molecule morphologies, gene arrangement, and gene loss versus gene gain data) in an appropriate manner.
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Affiliation(s)
- Hans-Jürgen Osigus
- ITZ, Division of Ecology and Evolution, Stiftung Tieraerztliche Hochschule Hannover, Germany
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11
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Hroudova M, Vojta P, Strnad H, Krejcik Z, Ridl J, Paces J, Vlcek C, Paces V. Diversity, phylogeny and expression patterns of Pou and Six homeodomain transcription factors in hydrozoan jellyfish Craspedacusta sowerbyi. PLoS One 2012; 7:e36420. [PMID: 22558464 PMCID: PMC3340352 DOI: 10.1371/journal.pone.0036420] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 03/31/2012] [Indexed: 01/10/2023] Open
Abstract
Formation of all metazoan bodies is controlled by a group of selector genes including homeobox genes, highly conserved across the entire animal kingdom. The homeobox genes from Pou and Six classes are key members of the regulation cascades determining development of sensory organs, nervous system, gonads and muscles. Besides using common bilaterian models, more attention has recently been targeted at the identification and characterization of these genes within the basal metazoan phyla. Cnidaria as a diploblastic sister group to bilateria with simple and yet specialized organs are suitable models for studies on the sensory organ origin and the associated role of homeobox genes. In this work, Pou and Six homeobox genes, together with a broad range of other sensory-specific transcription factors, were identified in the transcriptome of hydrozoan jellyfish Craspedacusta sowerbyi. Phylogenetic analyses of Pou and Six proteins revealed cnidarian-specific sequence motifs and contributed to the classification of individual factors. The majority of the Craspedacusta sowerbyi Pou and Six homeobox genes are predominantly expressed in statocysts, manubrium and nerve ring, the tissues with sensory and nervous activities. The described diversity and expression patterns of Pou and Six factors in hydrozoan jellyfish highlight their evolutionarily conserved functions. This study extends the knowledge of the cnidarian genome complexity and shows that the transcriptome of hydrozoan jellyfish is generally rich in homeodomain transcription factors employed in the regulation of sensory and nervous functions.
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Affiliation(s)
- Miluse Hroudova
- Department of Genomics and Bioinformatics, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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12
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O'Brien LJ, Caron JB. A new stalked filter-feeder from the middle Cambrian Burgess Shale, British Columbia, Canada. PLoS One 2012; 7:e29233. [PMID: 22279532 PMCID: PMC3261148 DOI: 10.1371/journal.pone.0029233] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Accepted: 11/22/2011] [Indexed: 11/18/2022] Open
Abstract
Burgess Shale-type deposits provide invaluable insights into the early evolution of body plans and the ecological structure of Cambrian communities, but a number of species, continue to defy phylogenetic interpretations. Here we extend this list to include a new soft-bodied animal, Siphusauctum gregarium n. gen. and n. sp., from the Tulip Beds (Campsite Cliff Shale Member, Burgess Shale Formation) of Mount Stephen (Yoho National Park, British Columbia). With 1,133 specimens collected, S. gregarium is clearly the most abundant animal from this locality.This stalked animal (reaching at least 20 cm in length), has a large ovoid calyx connected to a narrow bilayered stem and a small flattened or bulb-like holdfast. The calyx is enclosed by a flexible sheath with six small openings at the base, and a central terminal anus near the top encircled by indistinct openings. A prominent organ, represented by six radially symmetrical segments with comb-like elements, surrounds an internal body cavity with a large stomach, conical median gut and straight intestine. Siphusauctum gregarium was probably an active filter-feeder, with water passing through the calyx openings, capturing food particles with its comb-like elements. It often occurs in large assemblages on single bedding planes suggesting a gregarious lifestyle, with the animal living in high tier clusters. These were probably buried en masse more or less in-situ by rapid mud flow events.Siphusauctum gregarium resembles Dinomischus, another Cambrian enigmatic stalked animal. Principal points of comparison include a long stem with a calyx containing a visceral mass and bract-like elements, and a similar lifestyle albeit occupying different tiering levels. The presence in both animals of a digestive tract with a potential stomach and anus suggest a grade of organization within bilaterians, but relationships with extant phyla are not straightforward. Thus, the broader affinities of S. gregarium remain largely unconstrained.
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Affiliation(s)
- Lorna J O'Brien
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada.
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13
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Piraino S, Zega G, Di Benedetto C, Leone A, Dell'Anna A, Pennati R, Candia Carnevali D, Schmid V, Reichert H. Complex neural architecture in the diploblastic larva of Clava multicornis (Hydrozoa, Cnidaria). J Comp Neurol 2011; 519:1931-51. [DOI: 10.1002/cne.22614] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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14
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Erwin DH. Early origin of the bilaterian developmental toolkit. Philos Trans R Soc Lond B Biol Sci 2009; 364:2253-61. [PMID: 19571245 DOI: 10.1098/rstb.2009.0038] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Whole-genome sequences from the choanoflagellate Monosiga brevicollis, the placozoan Trichoplax adhaerens and the cnidarian Nematostella vectensis have confirmed results from comparative evolutionary developmental studies that much of the developmental toolkit once thought to be characteristic of bilaterians appeared much earlier in the evolution of animals. The diversity of transcription factors and signalling pathway genes in animals with a limited number of cell types and a restricted developmental repertoire is puzzling, particularly in light of claims that such highly conserved elements among bilaterians provide evidence of a morphologically complex protostome-deuterostome ancestor. Here, I explore the early origination of elements of what became the bilaterian toolkit, and suggest that placozoans and cnidarians represent a depauperate residue of a once more diverse assemblage of early animals, some of which may be represented in the Ediacaran fauna (c. 585-542 Myr ago).
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Affiliation(s)
- Douglas H Erwin
- Department of Paleobiology, MRC-121, National Museum of Natural History, Washington, DC 20013-7012, USA.
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Schierwater B, Eitel M, Jakob W, Osigus HJ, Hadrys H, Dellaporta SL, Kolokotronis SO, Desalle R. Concatenated analysis sheds light on early metazoan evolution and fuels a modern "urmetazoon" hypothesis. PLoS Biol 2009; 7:e20. [PMID: 19175291 PMCID: PMC2631068 DOI: 10.1371/journal.pbio.1000020] [Citation(s) in RCA: 212] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2008] [Accepted: 12/08/2008] [Indexed: 01/06/2023] Open
Abstract
For more than a century, the origin of metazoan animals has been debated. One aspect of this debate has been centered on what the hypothetical “urmetazoon” bauplan might have been. The morphologically most simply organized metazoan animal, the placozoan Trichoplax adhaerens, resembles an intriguing model for one of several “urmetazoon” hypotheses: the placula hypothesis. Clear support for a basal position of Placozoa would aid in resolving several key issues of metazoan-specific inventions (including, for example, head–foot axis, symmetry, and coelom) and would determine a root for unraveling their evolution. Unfortunately, the phylogenetic relationships at the base of Metazoa have been controversial because of conflicting phylogenetic scenarios generated while addressing the question. Here, we analyze the sum of morphological evidence, the secondary structure of mitochondrial ribosomal genes, and molecular sequence data from mitochondrial and nuclear genes that amass over 9,400 phylogenetically informative characters from 24 to 73 taxa. Together with mitochondrial DNA genome structure and sequence analyses and Hox-like gene expression patterns, these data (1) provide evidence that Placozoa are basal relative to all other diploblast phyla and (2) spark a modernized “urmetazoon” hypothesis. Following one of the basic principles in evolutionary biology that complex life forms derive from more primitive ancestors, it has long been believed that the higher animals, the Bilateria, arose from simpler (diploblastic) organisms such as the cnidarians (corals, polyps, and jellyfishes). A large number of studies, using different datasets and different methods, have tried to determine the most ancestral animal group as well as the ancestor of the higher animals. Here, we use “total evidence” analysis, which incorporates all available data (including morphology, genome, and gene expression data) and come to a surprising conclusion. The Bilateria and Cnidaria (together with the other diploblastic animals) are in fact sister groups: that is, they evolved in parallel from a very simple common ancestor. We conclude that the higher animals (Bilateria) and lower animals (diploblasts), probably separated very early, at the very beginning of metazoan animal evolution and independently evolved their complex body plans, including body axes, nervous system, sensory organs, and other characteristics. The striking similarities in several complex characters (such as the eyes) resulted from both lineages using the same basic genetic tool kit, which was already present in the common ancestor. The study identifies Placozoa as the most basal diploblast group and thus a living fossil genome that nicely demonstrates, not only that complex genetic tool kits arise before morphological complexity, but also that these kits may form similar morphological structures in parallel. Total evidence analyses reveal a surprise: Higher animals did not evolve from any known lower animal group.
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Affiliation(s)
- Bernd Schierwater
- ITZ, Ecology and Evolution, Tierärztliche Hochschule Hannover, Hannover, Germany.
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Schierwater B, de Jong D, Desalle R. Placozoa and the evolution of Metazoa and intrasomatic cell differentiation. Int J Biochem Cell Biol 2008; 41:370-9. [PMID: 18935972 DOI: 10.1016/j.biocel.2008.09.023] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2008] [Revised: 09/19/2008] [Accepted: 09/19/2008] [Indexed: 11/28/2022]
Abstract
The multicellular Metazoa evolved from single-celled organisms (Protozoa) and usually - but not necessarily - consist of more cells than Protozoa. In all cases, and thus by definition, Metazoa possess more than one somatic cell type, i.e. they show-in sharp contrast to protists-intrasomatic differentiation. Placozoa have the lowest degree of intrasomatic variation; the number of somatic cell types according to text books is four (but see also Jakob W, Sagasser S, Dellaporta S, Holland P, Kuhn K, and Schierwater B. The Trox-2 Hox/ParaHox gene of Trichoplax (Placozoa) marks an epithelial boundary. Dev Genes Evol 2004;214:170-5). For this and several other reasons Placozoa have been regarded by many as the most basal metazoan phylum. Thus, the morphologically most simply organized metazoan animal, the placozoan Trichoplax adhaerens, resembles a unique model system for cell differentiation studies and also an intriguing model for a prominent "urmetazoon" hypotheses-the placula hypothesis. A basal position of Placozoa would provide answers to several key issues of metazoan-specific inventions (including for example different lines of somatic cell differentiation leading to organ development and axis formation) and would determine a root for unraveling their evolution. However, the phylogenetic relationships at the base of Metazoa are controversial and a basal position of Placozoa is not generally accepted (e.g. Schierwater B, DeSalle R. Can we ever identify the Urmetazoan? Integr Comp Biol 2007;47:670-76; DeSalle R, Schierwater B. An even "newer" animal phylogeny. Bioessays 2008;30:1043-47). Here we review and discuss (i) long-standing morphological evidence for the simple placozoan bauplan resembling an ancestral metazoan stage, (ii) some rapidly changing alternative hypotheses derived from molecular analyses, (iii) the surprising idea that triploblasts (Bilateria) and diploblasts may be sister groups, and (iv) the presence of genes involved in cell differentiation and signaling pathways in the placozoan genome.
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Affiliation(s)
- Bernd Schierwater
- Ecology and Evolution, Tierärztliche Hochschule Hannover, D-30559 Hannover, Germany.
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Baguñà J, Martinez P, Paps J, Riutort M. Back in time: a new systematic proposal for the Bilateria. Philos Trans R Soc Lond B Biol Sci 2008; 363:1481-91. [PMID: 18192186 PMCID: PMC2615819 DOI: 10.1098/rstb.2007.2238] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Conventional wisdom suggests that bilateral organisms arose from ancestors that were radially, rather than bilaterally, symmetrical and, therefore, had a single body axis and no mesoderm. The two main hypotheses on how this transformation took place consider either a simple organism akin to the planula larva of extant cnidarians or the acoel Platyhelminthes (planuloid-acoeloid theory), or a rather complex organism bearing several or most features of advanced coelomate bilaterians (archicoelomate theory). We report phylogenetic analyses of bilaterian metazoans using quantitative (ribosomal, nuclear and expressed sequence tag sequences) and qualitative (HOX cluster genes and microRNA sets) markers. The phylogenetic trees obtained corroborate the position of acoel and nemertodermatid flatworms as the earliest branching extant members of the Bilateria. Moreover, some acoelomate and pseudocoelomate clades appear as early branching lophotrochozoans and deuterostomes. These results strengthen the view that stem bilaterians were small, acoelomate/pseudocoelomate, benthic organisms derived from planuloid-like organisms. Because morphological and recent gene expression data suggest that cnidarians are actually bilateral, the origin of the last common bilaterian ancestor has to be put back in time earlier than the cnidarian-bilaterian split in the form of a planuloid animal. A new systematic scheme for the Bilateria that includes the Cnidaria is suggested and its main implications discussed.
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Affiliation(s)
- Jaume Baguñà
- Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain.
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