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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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2
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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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3
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Jacques F, Baratchart E, Pienta KJ, Hammarlund EU. Origin and evolution of animal multicellularity in the light of phylogenomics and cancer genetics. Med Oncol 2022; 39:160. [PMID: 35972622 PMCID: PMC9381480 DOI: 10.1007/s12032-022-01740-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 04/23/2022] [Indexed: 11/07/2022]
Abstract
The rise of animals represents a major but enigmatic event in the evolutionary history of life. In recent years, numerous studies have aimed at understanding the genetic basis of this transition. However, genome comparisons of diverse animal and protist lineages suggest that the appearance of gene families that were previously considered animal specific indeed preceded animals. Animals' unicellular relatives, such as choanoflagellates, ichthyosporeans, and filastereans, demonstrate complex life cycles including transient multicellularity as well as genetic toolkits for temporal cell differentiation, cell-to-cell communication, apoptosis, and cell adhesion. This has warranted further exploration of the genetic basis underlying transitions in cellular organization. An alternative model for the study of transitions in cellular organization is tumors, which exploit physiological programs that characterize both unicellularity and multicellularity. Tumor cells, for example, switch adhesion on and off, up- or downregulate specific cell differentiation states, downregulate apoptosis, and allow cell migration within tissues. Here, we use insights from both the fields of phylogenomics and tumor biology to review the evolutionary history of the regulatory systems of multicellularity and discuss their overlap. We claim that while evolutionary biology has contributed to an increased understanding of cancer, broad investigations into tissue-normal and transformed-can also contribute the framework for exploring animal evolution.
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Affiliation(s)
- Florian Jacques
- Tissue Development and Evolution (TiDE), Department of Laboratory Medicine, Lund University, Lund, Sweden
- Department of Laboratory Medicine, Lund Stem Cell Center, Lund University, Lund, Sweden
| | - Etienne Baratchart
- Tissue Development and Evolution (TiDE), Department of Laboratory Medicine, Lund University, Lund, Sweden
- Department of Laboratory Medicine, Lund Stem Cell Center, Lund University, Lund, Sweden
| | - Kenneth J Pienta
- The Cancer Ecology Center, Brady Urological Institute, Johns Hopkins School of Medicine, Baltimore, USA
| | - Emma U Hammarlund
- Tissue Development and Evolution (TiDE), Department of Laboratory Medicine, Lund University, Lund, Sweden.
- Department of Laboratory Medicine, Lund Stem Cell Center, Lund University, Lund, Sweden.
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4
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Erofeeva TV, Grigorenko AP, Gusev FE, Kosevich IA, Rogaev EI. Studying of Molecular Regulation of Developmental Processes of Lower Metazoans Exemplified by Cnidaria Using High-Throughput Sequencing. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:269-293. [PMID: 35526848 DOI: 10.1134/s0006297922030075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 12/13/2021] [Accepted: 01/17/2022] [Indexed: 06/14/2023]
Abstract
A unique set of features and characteristics of species of the Cnidaria phylum is the one reason that makes them a model for a various studies. The plasticity of a life cycle and the processes of cell differentiation and development of an integral multicellular organism associated with it are of a specific scientific interest. A new stage of development of molecular genetic methods, including methods for high-throughput genome, transcriptome, and epigenome sequencing, both at the level of the whole organism and at the level of individual cells, makes it possible to obtain a detailed picture of the development of these animals. This review examines some modern approaches and advances in the reconstruction of the processes of ontogenesis of cnidarians by studying the regulatory signal transduction pathways and their interactions.
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Affiliation(s)
- Taisia V Erofeeva
- Department Research Center for Genetics and Life Sciences, Sirius University of Science and Technology, Sochi, Krasnodar Region, 354349, Russia
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia
| | - Anastasia P Grigorenko
- Department Research Center for Genetics and Life Sciences, Sirius University of Science and Technology, Sochi, Krasnodar Region, 354349, Russia.
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia
| | - Fedor E Gusev
- Department Research Center for Genetics and Life Sciences, Sirius University of Science and Technology, Sochi, Krasnodar Region, 354349, Russia
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia
| | - Igor A Kosevich
- Department Research Center for Genetics and Life Sciences, Sirius University of Science and Technology, Sochi, Krasnodar Region, 354349, Russia
- Lomonosov Moscow State University, Moscow, 119234, Russia
| | - Evgeny I Rogaev
- Department Research Center for Genetics and Life Sciences, Sirius University of Science and Technology, Sochi, Krasnodar Region, 354349, Russia
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia
- Lomonosov Moscow State University, Moscow, 119234, Russia
- Department of Psychiatry, UMass Chan Medical School, Shrewsbury, MA 01545, USA
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Habib EB, Mathavarajah S, Dellaire G. Tinker, Tailor, Tumour Suppressor: The Many Functions of PRP4K. Front Genet 2022; 13:839963. [PMID: 35281802 PMCID: PMC8912934 DOI: 10.3389/fgene.2022.839963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 01/28/2022] [Indexed: 11/13/2022] Open
Abstract
Pre-mRNA processing factor 4 kinase (PRP4K, also known as PRPF4B) is an essential kinase first identified in the fission yeast Schizosaccharomyces pombe that is evolutionarily conserved from amoebae to animals. During spliceosomal assembly, PRP4K interacts with and phosphorylates PRPF6 and PRPF31 to facilitate the formation of the spliceosome B complex. However, over the past decade additional evidence has emerged that PRP4K has many diverse cellular roles beyond splicing that contribute to tumour suppression and chemotherapeutic responses in mammals. For example, PRP4K appears to play roles in regulating transcription and the spindle assembly checkpoint (SAC), a key pathway in maintaining chromosomes stability and the response of cancer cells to taxane-based chemotherapy. In addition, PRP4K has been revealed to be a haploinsufficient tumour suppressor that promotes aggressive cancer phenotypes when partially depleted. PRP4K is regulated by both the HER2 and estrogen receptor, and its partial loss increases resistance to the taxanes in multiple malignancies including cervical, breast and ovarian cancer. Moreover, ovarian and triple negative breast cancer patients harboring tumours with low PRP4K expression exhibit worse overall survival. The depletion of PRP4K also enhances both Yap and epidermal growth factor receptor (EGFR) signaling, the latter promoting anoikis resistance in breast and ovarian cancer. Finally, PRP4K is negatively regulated during epithelial-to-mesenchymal transition (EMT), a process that promotes increased cell motility, drug resistance and cancer metastasis. Thus, as we discuss in this review, PRP4K likely plays evolutionarily conserved roles not only in splicing but in a number of cellular pathways that together contribute to tumour suppression.
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Affiliation(s)
- Elias B. Habib
- Dalhousie University, Department of Pathology, Halifax, NS, Canada
| | | | - Graham Dellaire
- Dalhousie University, Department of Pathology, Halifax, NS, Canada
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
- Beatrice Hunter Cancer Research Institute, Halifax, NS, Canada
- *Correspondence: Graham Dellaire,
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6
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Minelli A. On the Nature of Organs and Organ Systems – A Chapter in the History and Philosophy of Biology. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.745564] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Contrasting definitions of organs based either on function or on strictly morphological criteria are the legacy of a tradition starting with Aristotle. This floating characterization of organs in terms of both form and function extends also to organ systems. The first section of this review outlines the notions of organ and body part as defined, explicitly or implicitly, in representative works of nineteenth century’s comparative morphology. The lack of a clear distinction between the two notions led to problems in Owen’s approach to the comparative method (definition of homolog vs. nature of the vertebrate archetype) and to a paradoxical formulation, by Anton Dohrn, of the principle of functional change. Starting from the second half of the twentieth century, with the extensive use of morphological data in phylogenetic analyses, both terms – organ and body part – have been often set aside, to leave room for a comparison between variously characterized attributes (character states) of the taxa to be compared. Throughout the last two centuries, there have been also efforts to characterize organs or body parts in terms of the underlying developmental dynamics, both in the context of classical descriptive embryology and according to models suggested by developmental genetics. Functionally defined organ are occasionally co-extensive with morphologically defined body parts, nevertheless a clear distinction between the former and the latter is a necessary prerequisite to a study of their evolution: this issue is discussed here on the example of the evolution of hermaphroditism and gonad structure and function.
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7
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Kuznetsov AV, Vainer VI, Volkova YM, Kartashov LE. Motility disorders and disintegration into separate cells of Trichoplax sp. H2 in the presence of Zn 2+ ions and L-cysteine molecules: A systems approach. Biosystems 2021; 206:104444. [PMID: 34023485 DOI: 10.1016/j.biosystems.2021.104444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 05/08/2021] [Accepted: 05/09/2021] [Indexed: 01/01/2023]
Abstract
Placozoa remain an ancient multicellular system with a dynamic body structure where calcium ions carry out a primary role in maintaining the integrity of the entire animal. Zinc ions can compete with calcium ions adsorption. We studied the effect of zinc ions and l-cysteine molecules on the interaction of Trichoplax sp. H2 cells. The regularity of formless motion was diminished in the presence of 20-25 μM of Zn2+ ions leading to the formation of branching animal forms. Locomotor ciliated cells moved chaotically and independently of each other leaving the Trichoplax body and opening a network of fiber cells. Application of 100 μM cysteine resulted in dissociation of the plate into separate cells. The combined chemical treatment shifted the effect in a random sample of animals toward disintegration, i.e. initially leading to disorder of collective cell movement and then to total body fragmentation. Two dissociation patterns of Trichoplax plate as "expanding ring" and "bicycle wheel" were revealed. Analysis of the interaction of Ca2+ and Zn2+ ions with cadherin showed that more than half (54%) of the amino acid residues with which Ca2+ and Zn2+ ions bind are common. The contact interaction of cells covered by the cadherin molecules is important for the coordinated movements of Trichoplax organism, while zinc ions are capable to break junctions between the cells. The involvement of other players, for example, l-cysteine in the regulation of Ca2+-dependent adhesion may be critical leading to the typical dissociation of Trichoplax body like in a calcium-free environment. A hypothesis about the essential role of calcium ions in the emergence of Metazoa ancestor is proposed.
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Affiliation(s)
- A V Kuznetsov
- A.O. Kovalevsky Institute of Biology of the Southern Seas RAS, Leninsky Avenue 38, Moscow, 119991, Russia.
| | - V I Vainer
- A.O. Kovalevsky Institute of Biology of the Southern Seas RAS, Leninsky Avenue 38, Moscow, 119991, Russia
| | - Yu M Volkova
- A.O. Kovalevsky Institute of Biology of the Southern Seas RAS, Leninsky Avenue 38, Moscow, 119991, Russia
| | - L E Kartashov
- A.O. Kovalevsky Institute of Biology of the Southern Seas RAS, Leninsky Avenue 38, Moscow, 119991, Russia
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8
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Abstract
Phylogenomics, the study of phylogenetic relationships among taxa based on their genome sequences, has emerged as the preferred phylogenetic method because of the wealth of phylogenetic information contained in genome sequences. Genome sequencing, however, can be prohibitively expensive, especially for taxa with huge genomes and when many taxa need sequencing. Consequently, the less costly phylotranscriptomics has seen an increased use in recent years. Phylotranscriptomics reconstructs phylogenies using DNA sequences derived from transcriptomes, which are often orders of magnitude smaller than genomes. However, in the absence of corresponding genome sequences, comparative analyses of transcriptomes can be challenging and it is unclear whether phylotranscriptomics is as reliable as phylogenomics. Here, we respectively compare the phylogenomic and phylotranscriptomic trees of 22 mammals and 15 plants that have both sequenced nuclear genomes and publicly available RNA sequencing data from multiple tissues. We found that phylotranscriptomic analysis can be sensitive to orthologous gene identification. When a rigorous method for identifying orthologs is employed, phylogenomic and phylotranscriptomic trees are virtually identical to each other, regardless of the tissue of origin of the transcriptomes and whether the same tissue is used across species. These findings validate phylotranscriptomics, brighten its prospect, and illustrate the criticality of reliable ortholog detection in such practices.
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Affiliation(s)
- Seongmin Cheon
- School of Biological Sciences and Technology, Chonnam National University, Gwangju, Republic of Korea
| | - Jianzhi Zhang
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI
| | - Chungoo Park
- School of Biological Sciences and Technology, Chonnam National University, Gwangju, Republic of Korea
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Neumann JS, Desalle R, Narechania A, Schierwater B, Tessler M. Morphological Characters Can Strongly Influence Early Animal Relationships Inferred from Phylogenomic Data Sets. Syst Biol 2021; 70:360-375. [PMID: 32462193 PMCID: PMC7875439 DOI: 10.1093/sysbio/syaa038] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 01/27/2020] [Accepted: 01/29/2020] [Indexed: 12/19/2022] Open
Abstract
There are considerable phylogenetic incongruencies between morphological and phylogenomic data for the deep evolution of animals. This has contributed to a heated debate over the earliest-branching lineage of the animal kingdom: the sister to all other Metazoa (SOM). Here, we use published phylogenomic data sets ($\sim $45,000-400,000 characters in size with $\sim $15-100 taxa) that focus on early metazoan phylogeny to evaluate the impact of incorporating morphological data sets ($\sim $15-275 characters). We additionally use small exemplar data sets to quantify how increased taxon sampling can help stabilize phylogenetic inferences. We apply a plethora of common methods, that is, likelihood models and their "equivalent" under parsimony: character weighting schemes. Our results are at odds with the typical view of phylogenomics, that is, that genomic-scale data sets will swamp out inferences from morphological data. Instead, weighting morphological data 2-10$\times $ in both likelihood and parsimony can in some cases "flip" which phylum is inferred to be the SOM. This typically results in the molecular hypothesis of Ctenophora as the SOM flipping to Porifera (or occasionally Placozoa). However, greater taxon sampling improves phylogenetic stability, with some of the larger molecular data sets ($>$200,000 characters and up to $\sim $100 taxa) showing node stability even with $\geqq100\times $ upweighting of morphological data. Accordingly, our analyses have three strong messages. 1) The assumption that genomic data will automatically "swamp out" morphological data is not always true for the SOM question. Morphological data have a strong influence in our analyses of combined data sets, even when outnumbered thousands of times by molecular data. Morphology therefore should not be counted out a priori. 2) We here quantify for the first time how the stability of the SOM node improves for several genomic data sets when the taxon sampling is increased. 3) The patterns of "flipping points" (i.e., the weighting of morphological data it takes to change the inferred SOM) carry information about the phylogenetic stability of matrices. The weighting space is an innovative way to assess comparability of data sets that could be developed into a new sensitivity analysis tool. [Metazoa; Morphology; Phylogenomics; Weighting.].
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Affiliation(s)
- Johannes S Neumann
- Richard Gilder Graduate School, American Museum of Natural History, New York, NY 10024, USA
- Division of Invertebrate Zoology, American Museum of Natural History, New York, NY 10024, USA
- Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, NY 10024, USA
| | - Rob Desalle
- Division of Invertebrate Zoology, American Museum of Natural History, New York, NY 10024, USA
- Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, NY 10024, USA
| | - Apurva Narechania
- Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, NY 10024, USA
| | - Bernd Schierwater
- Division of Invertebrate Zoology, American Museum of Natural History, New York, NY 10024, USA
- Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, NY 10024, USA
- ITZ, Division of Ecology and Evolution, Tierärztliche Hochschule Hannover, Bünteweg 9, 30559 Hannover, Germany
| | - Michael Tessler
- Division of Invertebrate Zoology, American Museum of Natural History, New York, NY 10024, USA
- Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, NY 10024, USA
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Verkhratsky A. Early evolutionary history (from bacteria to hemichordata) of the omnipresent purinergic signalling: A tribute to Geoff Burnstock inquisitive mind. Biochem Pharmacol 2020; 187:114261. [PMID: 33011161 DOI: 10.1016/j.bcp.2020.114261] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 09/25/2020] [Accepted: 09/29/2020] [Indexed: 12/11/2022]
Abstract
Purines and pyrimidines are indispensable molecules of life; they are fundamental for genetic code and bioenergetics. From the very early evolution of life purines have acquired the meaning of damage-associated extracellular signaller and purinergic receptors emerged in unicellular organisms. Ancestral purinoceptors are P2X-like ionotropic ligand-gated cationic channels showing 20-40% of homology with vertebrate P2X receptors; genes encoding ancestral P2X receptors have been detected in Protozoa, Algae, Fungi and Sponges; they are also present in some invertebrates, but are absent from the genome of insects, nematodes, and higher plants. Plants nevertheless evolved a sophisticated and widespread purinergic signalling system relying on the idiosyncratic purinoceptor P2K1/DORN1 linked to intracellular Ca2+ signalling. The advance of metabotropic purinoceptors starts later in evolution with adenosine receptors preceding the emergence of P2Y nucleotide and P0 adenine receptors. In vertebrates and mammals the purinergic signalling system reaches the summit and operates throughout all tissues and systems without anatomical or functional segregation.
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Affiliation(s)
- Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, United Kingdom; Achucarro Center for Neuroscience, IKERBASQUE, 48011 Bilbao, Spain.
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11
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Binary fission in Trichoplax is orthogonal to the subsequent division plane. Mech Dev 2020; 162:103608. [PMID: 32387588 DOI: 10.1016/j.mod.2020.103608] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/17/2020] [Accepted: 04/09/2020] [Indexed: 11/20/2022]
Abstract
Asexual reproduction in Trichoplax occurs mainly by binary fission and occasionally by the budding of epithelial spheres called "swarmers". The process that leads to binary fission and the mechanisms involved in this segregation are practically unknown. Trichoplax lacks a defined shape, presenting a constantly changing outline due to its continuous movements and body contractions. For this reason, and due to the absence of anatomical references, it has been classified as an asymmetric organism. Here, we report that a transient wound is formed in the marginal epithelium of the two new individuals produced by binary fission. By tracking the location of this epithelial wound, we can determine that successive dichotomous divisions are orthogonal to the previous division. We also found that LiCl paralyzes the cilia beating movement and body contractions and causes the placozoans to become circular in shape. This effect, as well as a stereotypic body folding behavior observed in detached placozoans and cell labeling experiments of the upper epithelium, indicate a cylindrical body symmetry for Placozoa.
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12
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Tikhonenkov DV, Hehenberger E, Esaulov AS, Belyakova OI, Mazei YA, Mylnikov AP, Keeling PJ. Insights into the origin of metazoan multicellularity from predatory unicellular relatives of animals. BMC Biol 2020; 18:39. [PMID: 32272915 PMCID: PMC7147346 DOI: 10.1186/s12915-020-0762-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 03/02/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND The origin of animals from their unicellular ancestor was one of the most important events in evolutionary history, but the nature and the order of events leading up to the emergence of multicellular animals are still highly uncertain. The diversity and biology of unicellular relatives of animals have strongly informed our understanding of the transition from single-celled organisms to the multicellular Metazoa. Here, we analyze the cellular structures and complex life cycles of the novel unicellular holozoans Pigoraptor and Syssomonas (Opisthokonta), and their implications for the origin of animals. RESULTS Syssomonas and Pigoraptor are characterized by complex life cycles with a variety of cell types including flagellates, amoeboflagellates, amoeboid non-flagellar cells, and spherical cysts. The life cycles also include the formation of multicellular aggregations and syncytium-like structures, and an unusual diet for single-celled opisthokonts (partial cell fusion and joint sucking of a large eukaryotic prey), all of which provide new insights into the origin of multicellularity in Metazoa. Several existing models explaining the origin of multicellular animals have been put forward, but these data are interestingly consistent with one, the "synzoospore hypothesis." CONCLUSIONS The feeding modes of the ancestral metazoan may have been more complex than previously thought, including not only bacterial prey, but also larger eukaryotic cells and organic structures. The ability to feed on large eukaryotic prey could have been a powerful trigger in the formation and development of both aggregative (e.g., joint feeding, which also implies signaling) and clonal (e.g., hypertrophic growth followed by palintomy) multicellular stages that played important roles in the emergence of multicellular animals.
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Affiliation(s)
- Denis V Tikhonenkov
- Papanin Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, Russia, 152742.
- Department of Botany, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada.
| | - Elisabeth Hehenberger
- Ocean EcoSystems Biology Unit, RD3, GEOMAR Helmholtz Centre for Ocean Research Kiel, Duesternbrookerweg 20, 24105, Kiel, Germany
| | | | | | | | - Alexander P Mylnikov
- Papanin Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, Russia, 152742
| | - Patrick J Keeling
- Department of Botany, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada.
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13
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Li YX, Li ZH, Schuiteman A, Chase MW, Li JW, Huang WC, Hidayat A, Wu SS, Jin XH. Phylogenomics of Orchidaceae based on plastid and mitochondrial genomes. Mol Phylogenet Evol 2019; 139:106540. [DOI: 10.1016/j.ympev.2019.106540] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 06/05/2019] [Accepted: 06/18/2019] [Indexed: 10/26/2022]
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14
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Mayorova TD, Hammar K, Winters CA, Reese TS, Smith CL. The ventral epithelium of Trichoplax adhaerens deploys in distinct patterns cells that secrete digestive enzymes, mucus or diverse neuropeptides. Biol Open 2019; 8:bio045674. [PMID: 31366453 PMCID: PMC6737977 DOI: 10.1242/bio.045674] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 07/23/2019] [Indexed: 01/11/2023] Open
Abstract
The disk-shaped millimeter-sized marine animal, Trichoplax adhaerens, is notable because of its small number of cell types and primitive mode of feeding. It glides on substrates propelled by beating cilia on its lower surface and periodically pauses to feed on underlying microorganisms, which it digests externally. Here, a combination of advanced electron and light microscopic techniques are used to take a closer look at its secretory cell types and their roles in locomotion and feeding. We identify digestive enzymes in lipophils, a cell type implicated in external digestion and distributed uniformly throughout the ventral epithelium except for a narrow zone near its edge. We find three morphologically distinct types of gland cell. The most prevalent contains and secretes mucus, which is shown to be involved in adhesion and gliding. Half of the mucocytes are arrayed in a tight row around the edge of the ventral epithelium while the rest are scattered further inside, in the region containing lipophils. The secretory granules in mucocytes at the edge label with an antibody against a neuropeptide that was reported to arrest ciliary beating during feeding. A second type of gland cell is arrayed in a narrow row just inside the row of mucocytes while a third is located more centrally. Our maps of the positions of the structurally distinct secretory cell types provide a foundation for further characterization of the multiple peptidergic cell types in Trichoplax and the microscopic techniques we introduce provide tools for carrying out these studies.
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Affiliation(s)
- Tatiana D Mayorova
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 49 Convent Drive, Bethesda, MD 20892, USA
| | - Katherine Hammar
- Central Microscopy Facility, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA 02543, USA
| | - Christine A Winters
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 49 Convent Drive, Bethesda, MD 20892, USA
| | - Thomas S Reese
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 49 Convent Drive, Bethesda, MD 20892, USA
| | - Carolyn L Smith
- Light Imaging Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892, USA
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15
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Boutte J, Fishbein M, Liston A, Straub SCK. NGS-Indel Coder: A pipeline to code indel characters in phylogenomic data with an example of its application in milkweeds (Asclepias). Mol Phylogenet Evol 2019; 139:106534. [PMID: 31212081 DOI: 10.1016/j.ympev.2019.106534] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 05/12/2019] [Accepted: 06/13/2019] [Indexed: 12/30/2022]
Abstract
Targeted genome sequencing approaches allow characterization of evolutionary relationships using a considerable number of nuclear genes and informative characters. However, most phylogenomic analyses only utilize single nucleotide polymorphisms (SNPs). Studies at the species level, especially in groups that have recently radiated, often recover low amounts of phylogenetically informative variation in coding regions, and require non-coding sequences, which are richer in indels, to resolve gene trees. Here, NGS-Indel Coder, a pipeline to detect and omit false positive indels inferred from assemblies of short read sequence data, was developed to resolve the relationships among and within major clades of the American milkweeds (Asclepias), which are the result of a rapid and recent evolutionary radiation, and whose phylogeny has been difficult to resolve. This pipeline was applied to a Hyb-Seq data set of 768 loci including targeted exons and flanking intron regions from 33 milkweed species. Robust species tree inference was improved by excluding small alignment partitions (<100 bp) that increased gene tree ambiguity and incongruence. To further investigate the robustness of indel coding, data sets that included small and large indels were explored, and species trees derived from concatenated loci versus coalescent methods based on gene trees were compared. The phylogeny of Asclepias obtained using nuclear data was well resolved, and phylogenetic information from indels improved resolution of specific nodes. The Temperate North American, Mexican Highland, and Incarnatae clades were well supported as monophyletic. Asclepias coulteri, which has been considered part of the Sonoran Desert clade based on plastome analyses, was placed as sister to all the other milkweed species studied here, rather than as a member of that clade. Two groups within the Temperate North American and Mexican clades were not resolved, and the inferred relationships strongly conflicted when comparing results based on data sets that did or did not include indel characters. This new pipeline represents a step forward in making maximal use of the information content in phylogenomic data sets.
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Affiliation(s)
- Julien Boutte
- Department of Biology, Hobart and William Smith Colleges, Geneva, NY, USA
| | - Mark Fishbein
- Department of Plant Biology, Ecology and Evolution, Oklahoma State University, Stillwater, OK, USA
| | - Aaron Liston
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, USA
| | - Shannon C K Straub
- Department of Biology, Hobart and William Smith Colleges, Geneva, NY, USA.
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16
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Poelmann RE, Gittenberger-de Groot AC. Development and evolution of the metazoan heart. Dev Dyn 2019; 248:634-656. [PMID: 31063648 PMCID: PMC6767493 DOI: 10.1002/dvdy.45] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 04/25/2019] [Accepted: 04/29/2019] [Indexed: 12/19/2022] Open
Abstract
The mechanisms of the evolution and development of the heart in metazoans are highlighted, starting with the evolutionary origin of the contractile cell, supposedly the precursor of cardiomyocytes. The last eukaryotic common ancestor is likely a combination of several cellular organisms containing their specific metabolic pathways and genetic signaling networks. During evolution, these tool kits diversified. Shared parts of these conserved tool kits act in the development and functioning of pumping hearts and open or closed circulations in such diverse species as arthropods, mollusks, and chordates. The genetic tool kits became more complex by gene duplications, addition of epigenetic modifications, influence of environmental factors, incorporation of viral genomes, cardiac changes necessitated by air‐breathing, and many others. We evaluate mechanisms involved in mollusks in the formation of three separate hearts and in arthropods in the formation of a tubular heart. A tubular heart is also present in embryonic stages of chordates, providing the septated four‐chambered heart, in birds and mammals passing through stages with first and second heart fields. The four‐chambered heart permits the formation of high‐pressure systemic and low‐pressure pulmonary circulation in birds and mammals, allowing for high metabolic rates and maintenance of body temperature. Crocodiles also have a (nearly) separated circulation, but their resting temperature conforms with the environment. We argue that endothermic ancestors lost the capacity to elevate their body temperature during evolution, resulting in ectothermic modern crocodilians. Finally, a clinically relevant paragraph reviews the occurrence of congenital cardiac malformations in humans as derailments of signaling pathways during embryonic development. The cardiac regulatory toolkit contains many factors including epigenetic, genetic, viral, hemodynamic, and environmental factors, but also transcriptional activators, repressors, duplicated genes, redundancies and dose‐dependancies. Numerous toolkits regulate mechanisms including cell‐cell interactions, EMT, mitosis patterns, cell migration and differentiation and left/right sidedness involved in the development of endocardial cushions, looping, septum complexes, pharyngeal arch arteries, chamber and valve formation and conduction system. Evolutionary development of the yolk sac circulation likely preceded the advent of endothermy in amniotes. Parallel evolutionary traits regulate the development of contractile pumps in various taxa often in conjunction with the gut, lungs and excretory organs.
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Affiliation(s)
- Robert E Poelmann
- Institute of Biology, Department of Animal Sciences and Health, Leiden University, Leiden, The Netherlands.,Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands
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17
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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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18
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Albertini MC, Fraternale D, Semprucci F, Cecchini S, Colomba M, Rocchi MBL, 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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19
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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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20
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Richards EJ, Brown JM, Barley AJ, Chong RA, Thomson RC. Variation Across Mitochondrial Gene Trees Provides Evidence for Systematic Error: How Much Gene Tree Variation Is Biological? Syst Biol 2018; 67:847-860. [PMID: 29471536 DOI: 10.1093/sysbio/syy013] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 02/15/2018] [Indexed: 12/28/2022] Open
Abstract
The use of large genomic data sets in phylogenetics has highlighted extensive topological variation across genes. Much of this discordance is assumed to result from biological processes. However, variation among gene trees can also be a consequence of systematic error driven by poor model fit, and the relative importance of biological vs. methodological factors in explaining gene tree variation is a major unresolved question. Using mitochondrial genomes to control for biological causes of gene tree variation, we estimate the extent of gene tree discordance driven by systematic error and employ posterior prediction to highlight the role of model fit in producing this discordance. We find that the amount of discordance among mitochondrial gene trees is similar to the amount of discordance found in other studies that assume only biological causes of variation. This similarity suggests that the role of systematic error in generating gene tree variation is underappreciated and critical evaluation of fit between assumed models and the data used for inference is important for the resolution of unresolved phylogenetic questions.
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Affiliation(s)
- Emilie J Richards
- Department of Biology, University of Hawai'i, 2538 McCarthy Mall, Edmondson Hall 2016, Honolulu, HI 96822, USA.,Department of Biology, University of North Carolina, 120 South Road, Coker Hall CB 3280 Chapel Hill, NC 27599, USA
| | - Jeremy M Brown
- Department of Biological Sciences and Museum of Natural Science, Louisiana State University, 202 Life Sciences Building, Baton Rouge, LA 70803, USA
| | - Anthony J Barley
- Department of Biology, University of Hawai'i, 2538 McCarthy Mall, Edmondson Hall 2016, Honolulu, HI 96822, USA
| | - Rebecca A Chong
- Department of Biology, University of Hawai'i, 2538 McCarthy Mall, Edmondson Hall 2016, Honolulu, HI 96822, USA
| | - Robert C Thomson
- Department of Biology, University of Hawai'i, 2538 McCarthy Mall, Edmondson Hall 2016, Honolulu, HI 96822, USA
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21
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Abstract
The origin of animals, one of the major transitions in evolution, remains mysterious. Many key aspects of animal evolution can be reconstructed by comparing living species within a robust phylogenetic framework. However, uncertainty remains regarding the evolutionary relationships between two ancient animal lineages - sponges and ctenophores - and the remaining animal phyla. Comparative morphology and some phylogenomic analyses support the view that sponges represent the sister lineage to the rest of the animals, while other phylogenomic analyses support ctenophores, a phylum of carnivorous, gelatinous marine organisms, as the sister lineage. Here, we explore why different studies yield different answers and discuss the implications of the two alternative hypotheses for understanding the origin of animals. Reconstruction of ancient evolutionary radiations is devilishly difficult and will likely require broader sampling of sponge and ctenophore genomes, improved analytical strategies and critical analyses of the phylogenetic distribution and molecular mechanisms underlying apparently conserved traits. Rather than staking out positions in favor of the ctenophores-sister or the sponges-sister hypothesis, we submit that research programs aimed at understanding the biology of the first animals should instead embrace the uncertainty surrounding early animal evolution in their experimental designs.
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22
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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: 25] [Impact Index Per Article: 4.2] [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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23
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Kuang T, Tornabene L, Li J, Jiang J, Chakrabarty P, Sparks JS, Naylor GJP, Li C. Phylogenomic analysis on the exceptionally diverse fish clade Gobioidei (Actinopterygii: Gobiiformes) and data-filtering based on molecular clocklikeness. Mol Phylogenet Evol 2018; 128:192-202. [PMID: 30036699 DOI: 10.1016/j.ympev.2018.07.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 07/11/2018] [Accepted: 07/17/2018] [Indexed: 11/30/2022]
Abstract
The use of genome-scale data to infer phylogenetic relationships has gained in popularity in recent years due to the progress made in target-gene capture and sequencing techniques. Data filtering, the approach of excluding data inconsistent with the model from analyses, presumably could alleviate problems caused by systematic errors in phylogenetic inference. Different data filtering criteria, such as those based on evolutionary rate and molecular clocklikeness as well as others have been proposed for selecting useful phylogenetic markers, yet few studies have tested these criteria using phylogenomic data. We developed a novel set of single-copy nuclear coding markers to capture thousands of target genes in gobioid fishes, a species-rich lineages of vertebrates, and tested the effects of data-filtering methods based on substitution rate and molecular clocklikeness while attempting to control for the compounding effects of missing data and variation in locus length. We found that molecular clocklikeness was a better predictor than overall substitution rate for phylogenetic usefulness of molecular markers in our study. In addition, when the 100 best ranked loci for our predictors were concatenated and analyzed using maximum likelihood, or combined in a coalescent-based species-tree analysis, the resulting trees showed a well-resolved topology of Gobioidei that mostly agrees with previous studies. However, trees generated from the 100 least clocklike frequently recovered conflicting, and in some cases clearly erroneous topologies with strong support, thus indicating strong systematic biases in those datasets. Collectively these results suggest that data filtering has the potential improve the performance of phylogenetic inference when using both a concatenation approach as well as methods that rely on input from individual gene trees (i.e. coalescent species-tree approaches), which may be preferred in scenarios where incomplete lineage sorting is likely to be an issue.
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Affiliation(s)
- Ting Kuang
- Shanghai Universities Key Laboratory of Marine Animal Taxonomy and Evolution, Shanghai, China; Shanghai Collaborative Innovation for Aquatic Animal Genetics and Breeding, Shanghai, China; National Demonstration Center for Experimental Fisheries Science Education (Shanghai Ocean University), China
| | - Luke Tornabene
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA 98105, USA
| | - Jingyan Li
- Shanghai Universities Key Laboratory of Marine Animal Taxonomy and Evolution, Shanghai, China; Shanghai Collaborative Innovation for Aquatic Animal Genetics and Breeding, Shanghai, China; National Demonstration Center for Experimental Fisheries Science Education (Shanghai Ocean University), China
| | - Jiamei Jiang
- Shanghai Universities Key Laboratory of Marine Animal Taxonomy and Evolution, Shanghai, China; Shanghai Collaborative Innovation for Aquatic Animal Genetics and Breeding, Shanghai, China; National Demonstration Center for Experimental Fisheries Science Education (Shanghai Ocean University), China
| | - Prosanta Chakrabarty
- Louisiana State University, Museum of Natural Science, Department of Biological Sciences, Baton Rouge, LA 70803, USA
| | - John S Sparks
- American Museum of Natural History, Central Park West at 79th Street, NY, NY 10024, USA
| | | | - Chenhong Li
- Shanghai Universities Key Laboratory of Marine Animal Taxonomy and Evolution, Shanghai, China; Shanghai Collaborative Innovation for Aquatic Animal Genetics and Breeding, Shanghai, China; National Demonstration Center for Experimental Fisheries Science Education (Shanghai Ocean University), China.
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24
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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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25
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Senatore A, Reese TS, Smith CL. Neuropeptidergic integration of behavior in Trichoplax adhaerens, an animal without synapses. J Exp Biol 2017; 220:3381-3390. [PMID: 28931721 PMCID: PMC5612019 DOI: 10.1242/jeb.162396] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 07/04/2017] [Indexed: 12/17/2022]
Abstract
Trichoplax adhaerens is a flat, millimeter-sized marine animal that adheres to surfaces and grazes on algae. Trichoplax displays a repertoire of different feeding behaviors despite the apparent absence of a true nervous system with electrical or chemical synapses. It glides along surfaces to find food, propelled by beating cilia on cells at its ventral surface, and pauses during feeding by arresting ciliary beating. We found that when endomorphin-like peptides are applied to an animal, ciliary beating is arrested, mimicking natural feeding pauses. Antibodies against these neuropeptides label cells that express the neurosecretory proteins and voltage-gated calcium channels implicated in regulated secretion. These cells are embedded in the ventral epithelium, where they comprise only 4% of the total, and are concentrated around the edge of the animal. Each bears a cilium likely to be chemosensory and used to detect algae. Trichoplax pausing during feeding or spontaneously in the absence of food often induce their neighbors to pause as well, even neighbors not in direct contact. Pausing behavior propagates from animal to animal across distances much greater than the signal that diffuses from just one animal, so we presume that the peptides secreted from one animal elicit secretion from nearby animals. Signal amplification by peptide-induced peptide secretion explains how a small number of sensory secretory cells lacking processes and synapses can evoke a wave of peptide secretion across the entire animal to globally arrest ciliary beating and allow pausing during feeding.
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Affiliation(s)
- Adriano Senatore
- University of Toronto Mississauga, Mississauga, ON, Canada L5L 1C6
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26
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Russell JJ, Theriot JA, Sood P, Marshall WF, Landweber LF, Fritz-Laylin L, Polka JK, Oliferenko S, Gerbich T, Gladfelter A, Umen J, Bezanilla M, Lancaster MA, He S, Gibson MC, Goldstein B, Tanaka EM, Hu CK, Brunet A. Non-model model organisms. BMC Biol 2017; 15:55. [PMID: 28662661 PMCID: PMC5492503 DOI: 10.1186/s12915-017-0391-5] [Citation(s) in RCA: 124] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Model organisms are widely used in research as accessible and convenient systems to study a particular area or question in biology. Traditionally only a handful of organisms have been widely studied, but modern research tools are enabling researchers to extend the set of model organisms to include less-studied and more unusual systems. This Forum highlights a range of 'non-model model organisms' as emerging systems for tackling questions across the whole spectrum of biology (and beyond), the opportunities and challenges, and the outlook for the future.
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Affiliation(s)
- James J Russell
- Department of Biology, Howard Hughes Medical Institute Stanford University, Stanford, CA, 94305, USA
| | - Julie A Theriot
- Departments of Biochemistry and of Microbiology & Immunology, Howard Hughes Medical Institute Stanford University, Stanford, CA, 94305, USA.
| | - Pranidhi Sood
- Department of Biochemistry & Biophysics, University of California San Francisco, 600 16th St, San Francisco, CA, 94158, USA
| | - Wallace F Marshall
- Department of Biochemistry & Biophysics, University of California San Francisco, 600 16th St, San Francisco, CA, 94158, USA.
| | - Laura F Landweber
- Departments of Biochemistry & Molecular Biophysics and Biological Sciences, Columbia University, New York, NY, 10032, USA
| | | | - Jessica K Polka
- Visiting Scholar, Whitehead Institute, 9 Cambridge Center, Cambridge, MA, 02142, USA
| | - Snezhana Oliferenko
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
- Randall Division of Cell and Molecular Biophysics, New Hunt's House, Guy's Campus, King's College London, London, SE1 1UL, UK
| | - Therese Gerbich
- 516 Fordham Hall, University of North Carolina Chapel Hill, Chapel Hill, NC, 27514, USA
| | - Amy Gladfelter
- 516 Fordham Hall, University of North Carolina Chapel Hill, Chapel Hill, NC, 27514, USA
| | - James Umen
- Donald Danforth Plant Science Center, 975 N. Warson Rd, St. Louis, MO, 63132, USA
| | | | - Madeline A Lancaster
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, CB2 0QH, Cambridge, UK
| | - Shuonan He
- Stowers Institute for Medical Research, Kansas City, MO, 64110, USA
| | - Matthew C Gibson
- Stowers Institute for Medical Research, Kansas City, MO, 64110, USA
- Department of Anatomy and Cell Biology, The University of Kansas School of Medicine, Kansas City, KS, 66160, USA
| | - Bob Goldstein
- Biology Department, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Elly M Tanaka
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus Vienna Biocenter 1, 1030, Vienna, Austria
| | - Chi-Kuo Hu
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA
| | - Anne Brunet
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA
- Glenn Laboratories for the Biology of Aging at Stanford, Stanford, CA, 94305, USA
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27
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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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28
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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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29
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Abstract
Runx genes have been identified in all metazoans and considerable conservation of function observed across a wide range of phyla. Thus, insight gained from studying simple model organisms is invaluable in understanding RUNX biology in higher animals. Consequently, this chapter will focus on the Runx genes in the diploblasts, which includes sea anemones and sponges, as well as the lower triploblasts, including the sea urchin, nematode, planaria and insect. Due to the high degree of functional redundancy amongst vertebrate Runx genes, simpler model organisms with a solo Runx gene, like C. elegans, are invaluable systems in which to probe the molecular basis of RUNX function within a whole organism. Additionally, comparative analyses of Runx sequence and function allows for the development of novel evolutionary insights. Strikingly, recent data has emerged that reveals the presence of a Runx gene in a protist, demonstrating even more widespread occurrence of Runx genes than was previously thought. This review will summarize recent progress in using invertebrate organisms to investigate RUNX function during development and regeneration, highlighting emerging unifying themes.
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Affiliation(s)
- S Hughes
- Faculteit Techniek, Hogeschool van Arnhem en Nijmegen, Laan van Scheut 2, 6503 GL, Nijmegen, The Netherlands
| | - A Woollard
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.
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30
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Senatore A, Raiss H, Le P. Physiology and Evolution of Voltage-Gated Calcium Channels in Early Diverging Animal Phyla: Cnidaria, Placozoa, Porifera and Ctenophora. Front Physiol 2016; 7:481. [PMID: 27867359 PMCID: PMC5095125 DOI: 10.3389/fphys.2016.00481] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 10/07/2016] [Indexed: 12/18/2022] Open
Abstract
Voltage-gated calcium (Cav) channels serve dual roles in the cell, where they can both depolarize the membrane potential for electrical excitability, and activate transient cytoplasmic Ca2+ signals. In animals, Cav channels play crucial roles including driving muscle contraction (excitation-contraction coupling), gene expression (excitation-transcription coupling), pre-synaptic and neuroendocrine exocytosis (excitation-secretion coupling), regulation of flagellar/ciliary beating, and regulation of cellular excitability, either directly or through modulation of other Ca2+-sensitive ion channels. In recent years, genome sequencing has provided significant insights into the molecular evolution of Cav channels. Furthermore, expanded gene datasets have permitted improved inference of the species phylogeny at the base of Metazoa, providing clearer insights into the evolution of complex animal traits which involve Cav channels, including the nervous system. For the various types of metazoan Cav channels, key properties that determine their cellular contribution include: Ion selectivity, pore gating, and, importantly, cytoplasmic protein-protein interactions that direct sub-cellular localization and functional complexing. It is unclear when these defining features, many of which are essential for nervous system function, evolved. In this review, we highlight some experimental observations that implicate Cav channels in the physiology and behavior of the most early-diverging animals from the phyla Cnidaria, Placozoa, Porifera, and Ctenophora. Given our limited understanding of the molecular biology of Cav channels in these basal animal lineages, we infer insights from better-studied vertebrate and invertebrate animals. We also highlight some apparently conserved cellular functions of Cav channels, which might have emerged very early on during metazoan evolution, or perhaps predated it.
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Affiliation(s)
- Adriano Senatore
- Department of Biology, University of Toronto Mississauga Mississauga, ON, Canada
| | - Hamad Raiss
- Department of Biology, University of Toronto Mississauga Mississauga, ON, Canada
| | - Phuong Le
- Department of Biology, University of Toronto Mississauga Mississauga, ON, Canada
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31
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Kim S, Lee JH, Seok JH, Park YH, Jung SW, Cho AE, Lee C, Chung MS, Kim KH. Structural Basis of Novel Iron-Uptake Route and Reaction Intermediates in Ferritins from Gram-Negative Bacteria. J Mol Biol 2016; 428:5007-5018. [PMID: 27777002 DOI: 10.1016/j.jmb.2016.10.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 10/17/2016] [Accepted: 10/18/2016] [Indexed: 10/20/2022]
Abstract
Iron and oxygen chemistry is mediated by iron proteins for many biological functions. Carboxylate-bridged diiron enzymes including ferritin have the common mechanism of oxygen activation via peroxodiferric intermediates. However, the route for iron uptake and the structural identification of intermediates still remain incomplete. The 4-fold symmetry channel of Helicobacter pylori ferritin was previously proposed as the iron-uptake route in eubacteria, but the amino acid residues at the 4-fold channel are not highly conserved. Here, we show evidence for a short path for iron uptake from His93 on the surface to the ferroxidase center in H. pylori ferritin and Escherichia coli ferritin. The amino acid residues along this path are highly conserved in Gram-negative bacteria and some archaea, and the mutants containing S20A and H93L showed significantly decreased iron oxidation. Surprisingly, the E. coli ferritin S20A crystal structure showed oxygen binding and side-on, symmetric μ-η2:η2 peroxodiferric and oxodiferric intermediates. The results provide the structural basis for understanding the chemical nature of intermediates in iron oxidation in bacteria and some of archaea.
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Affiliation(s)
- Sella Kim
- Department of Biotechnology & Bioinformatics, Korea University, Sejong 339-700, Korea
| | - Ji-Hye Lee
- Department of Biotechnology & Bioinformatics, Korea University, Sejong 339-700, Korea
| | - Jong Hyeon Seok
- Department of Biotechnology & Bioinformatics, Korea University, Sejong 339-700, Korea
| | - Yi-Ho Park
- Department of Biotechnology & Bioinformatics, Korea University, Sejong 339-700, Korea
| | - Sang Won Jung
- Department of Biotechnology & Bioinformatics, Korea University, Sejong 339-700, Korea
| | - Art E Cho
- Department of Biotechnology & Bioinformatics, Korea University, Sejong 339-700, Korea
| | - Cheolju Lee
- Functional Proteomics Center, Korea Institute of Science and Technology, Seoul 136-791, Korea
| | - Mi Sook Chung
- Department of Food and Nutrition, Duksung Women's University, Seoul 132-714, Korea
| | - Kyung Hyun Kim
- Department of Biotechnology & Bioinformatics, Korea University, Sejong 339-700, Korea.
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32
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Glycogen Synthase Kinase-3 is involved in glycogen metabolism control and embryogenesis of Rhodnius prolixus. Parasitology 2016; 143:1569-79. [DOI: 10.1017/s0031182016001487] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
SUMMARYRhodnius prolixus is a blood-feeding insect that transmits Trypanosoma cruzi and Trypanosoma rangeli to vertebrate hosts. Rhodnius prolixus is also a classical model in insect physiology, and the recent availability of R. prolixus genome has opened new avenues on triatomine research. Glycogen synthase kinase 3 (GSK-3) is classically described as a key enzyme involved in glycogen metabolism, also acting as a downstream component of the Wnt pathway during embryogenesis. GSK-3 has been shown to be highly conserved among several organisms, mainly in the catalytic domain region. Meanwhile, the role of GSK-3 during R. prolixus embryogenesis or glycogen metabolism has not been investigated. Here we show that chemical inhibition of GSK-3 by alsterpaullone, an ATP-competitive inhibitor of GSK3, does not affect adult survival rate, though it alters oviposition and egg hatching. Specific GSK-3 gene silencing by dsRNA injection in adult females showed a similar phenotype. Furthermore, bright field and 4’−6-diamidino-2-phenylindole (DAPI) staining analysis revealed that ovaries and eggs from dsGSK-3 injected females exhibited specific morphological defects. We also demonstrate that glycogen content was inversely related to activity and transcription levels of GSK-3 during embryogenesis. Lastly, after GSK-3 knockdown, we observed changes in the expression of the Wingless (Wnt) downstream target β-catenin as well as in members of other pathways such as the receptor Notch. Taken together, our results show that GSK-3 regulation is essential for R. prolixus oogenesis and embryogenesis.
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33
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Adamska M. Sponges as models to study emergence of complex animals. Curr Opin Genet Dev 2016; 39:21-28. [PMID: 27318691 DOI: 10.1016/j.gde.2016.05.026] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 04/20/2016] [Accepted: 05/30/2016] [Indexed: 02/05/2023]
Abstract
The emergence of complex animal life forms remains poorly understood despite substantial interest and research in this area. To be informative, the ideal models to study transitions from single-cell organisms to the first animals and then to mammalian-level complexity should be phylogenetically strategically placed and retain ancestral characters. Sponges (Porifera) are likely to be the earliest branching animal phylum. When analysed from morphological, genomic and developmental perspectives, sponges appear to combine features of single-cell eukaryotic organisms and the complex multicellular animals (Eumetazoa). Intriguingly, homologues of components of the eumetazoan regulatory networks specifying the endoderm, the germ-cells and stem cells and (neuro) sensory cells are expressed in sponge choanocytes, archaeocytes and larval sensory cells. Studies using sponges as model systems are already bringing insights into animal evolution, and have opened avenues to further research benefitting from the recent spectacular expansion of genomic technologies.
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Affiliation(s)
- Maja Adamska
- Research School of Biology, Australian National University, Canberra, ACT 2601, Australia.
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34
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Scale and scope matter when explaining varying patterns of community diversity in riverine metacommunities. Basic Appl Ecol 2016. [DOI: 10.1016/j.baae.2015.10.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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35
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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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36
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Trapani MR, Parisi MG, Parrinello D, Sanfratello MA, Benenati G, Palla F, Cammarata M. Specific inflammatory response of Anemonia sulcata (Cnidaria) after bacterial injection causes tissue reaction and enzymatic activity alteration. J Invertebr Pathol 2016; 135:15-21. [PMID: 26836977 DOI: 10.1016/j.jip.2016.01.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Revised: 01/24/2016] [Accepted: 01/29/2016] [Indexed: 12/13/2022]
Abstract
The evolution of multicellular organisms was marked by adaptations to protect against pathogens. The mechanisms for discriminating the ''self'' from ''non-self" have evolved into a long history of cellular and molecular strategies, from damage repair to the co-evolution of host-pathogen interactions. We investigated the inflammatory response in Anemonia sulcata (Cnidaria: Anthozoa) following injection of substances that varied in type and dimension, and observed clear, strong and specific reactions, especially after injection of Escherichia coli and Vibrio alginolyticus. Moreover, we analyzed enzymatic activity of protease, phosphatase and esterase, showing how the injection of different bacterial strains alters the expression of these enzymes and suggesting a correlation between the appearance of the inflammatory reaction and the modification of enzymatic activities. Our study shows for the first time, a specific reaction and enzymatic responses following injection of bacteria in a cnidarian.
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Affiliation(s)
- M R Trapani
- Department of Biological, Chemical and Pharmaceutical Science and Technology, University of Palermo, Italy
| | - M G Parisi
- Department of Biological, Chemical and Pharmaceutical Science and Technology, University of Palermo, Italy
| | - D Parrinello
- Department of Biological, Chemical and Pharmaceutical Science and Technology, University of Palermo, Italy
| | - M A Sanfratello
- Department of Biological, Chemical and Pharmaceutical Science and Technology, University of Palermo, Italy
| | - G Benenati
- Department of Biological, Chemical and Pharmaceutical Science and Technology, University of Palermo, Italy
| | - F Palla
- Department of Biological, Chemical and Pharmaceutical Science and Technology, University of Palermo, Italy
| | - M Cammarata
- Department of Biological, Chemical and Pharmaceutical Science and Technology, University of Palermo, Italy.
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37
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O'Malley MA. Histories of molecules: Reconciling the past. STUDIES IN HISTORY AND PHILOSOPHY OF SCIENCE 2016; 55:69-83. [PMID: 26774071 DOI: 10.1016/j.shpsa.2015.09.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 09/07/2015] [Accepted: 09/08/2015] [Indexed: 06/05/2023]
Abstract
Molecular data and methods have become centrally important to evolutionary analysis, largely because they have enabled global phylogenetic reconstructions of the relationships between organisms in the tree of life. Often, however, molecular stories conflict dramatically with morphology-based histories of lineages. The evolutionary origin of animal groups provides one such case. In other instances, different molecular analyses have so far proved irreconcilable. The ancient and major divergence of eukaryotes from prokaryotic ancestors is an example of this sort of problem. Efforts to overcome these conflicts highlight the role models play in phylogenetic reconstruction. One crucial model is the molecular clock; another is that of 'simple-to-complex' modification. I will examine animal and eukaryote evolution against a backdrop of increasing methodological sophistication in molecular phylogeny, and conclude with some reflections on the nature of historical science in the molecular era of phylogeny.
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38
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Borowiec ML, Lee EK, Chiu JC, Plachetzki DC. Extracting phylogenetic signal and accounting for bias in whole-genome data sets supports the Ctenophora as sister to remaining Metazoa. BMC Genomics 2015; 16:987. [PMID: 26596625 PMCID: PMC4657218 DOI: 10.1186/s12864-015-2146-4] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 10/26/2015] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Understanding the phylogenetic relationships among major lineages of multicellular animals (the Metazoa) is a prerequisite for studying the evolution of complex traits such as nervous systems, muscle tissue, or sensory organs. Transcriptome-based phylogenies have dramatically improved our understanding of metazoan relationships in recent years, although several important questions remain. The branching order near the base of the tree, in particular the placement of the poriferan (sponges, phylum Porifera) and ctenophore (comb jellies, phylum Ctenophora) lineages is one outstanding issue. Recent analyses have suggested that the comb jellies are sister to all remaining metazoan phyla including sponges. This finding is surprising because it suggests that neurons and other complex traits, present in ctenophores and eumetazoans but absent in sponges or placozoans, either evolved twice in Metazoa or were independently, secondarily lost in the lineages leading to sponges and placozoans. RESULTS To address the question of basal metazoan relationships we assembled a novel dataset comprised of 1080 orthologous loci derived from 36 publicly available genomes representing major lineages of animals. From this large dataset we procured an optimized set of partitions with high phylogenetic signal for resolving metazoan relationships. This optimized data set is amenable to the most appropriate and computationally intensive analyses using site-heterogeneous models of sequence evolution. We also employed several strategies to examine the potential for long-branch attraction to bias our inferences. Our analyses strongly support the Ctenophora as the sister lineage to other Metazoa. We find no support for the traditional view uniting the ctenophores and Cnidaria. Our findings are supported by Bayesian comparisons of topological hypotheses and we find no evidence that they are biased by long-branch attraction. CONCLUSIONS Our study further clarifies relationships among early branching metazoan lineages. Our phylogeny supports the still-controversial position of ctenophores as sister group to all other metazoans. This study also provides a workflow and computational tools for minimizing systematic bias in genome-based phylogenetic analyses. Future studies of metazoan phylogeny will benefit from ongoing efforts to sequence the genomes of additional invertebrate taxa that will continue to inform our view of the relationships among the major lineages of animals.
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Affiliation(s)
- Marek L Borowiec
- Department of Entomology and Nematology, University of California, Davis, USA.
| | - Ernest K Lee
- Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, USA.
| | - Joanna C Chiu
- Department of Entomology and Nematology, University of California, Davis, USA.
| | - David C Plachetzki
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, USA.
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39
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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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40
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Halanych KM. The ctenophore lineage is older than sponges? That cannot be right! Or can it? ACTA ACUST UNITED AC 2015; 218:592-7. [PMID: 25696822 DOI: 10.1242/jeb.111872] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Recent phylogenetic analyses resulting from collection of whole genome data suggest that ctenophores, or comb jellies, are sister to all other animals. Even before publication, this result prompted discussion among researchers. Here, I counter common criticisms raised about this result and show that assumptions placing sponges as the basal-most extant animal lineage are based on limited evidence and questionable premises. For example, the idea that sponges are simple and the reported similarity of sponge choanocytes to Choanflagellata do not provide useful characters for determining the positions of sponges within the animal tree. Intertwined with discussion of basal metazoan phylogeny is consideration of the evolution of neuronal systems. Recent data show that neural systems of ctenophores are vastly different from those of other animals and use different sets of cellular and genetic mechanisms. Thus, neural systems appear to have at least two independent origins regardless of whether ctenophores or sponges are the earliest branching extant animal lineage.
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Affiliation(s)
- Kenneth M Halanych
- Department of Biological Sciences, 101 Life Sciences Building, Auburn University, Auburn, AL 36849, USA Friday Harbor Laboratories, 620 University Road, University of Washington, Friday Harbor, WA 98250, USA
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41
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Vervoort M, Meulemeester D, Béhague J, Kerner P. Evolution of Prdm Genes in Animals: Insights from Comparative Genomics. Mol Biol Evol 2015; 33:679-96. [PMID: 26560352 PMCID: PMC4760075 DOI: 10.1093/molbev/msv260] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Prdm genes encode transcription factors with a subtype of SET domain known as the PRDF1-RIZ (PR) homology domain and a variable number of zinc finger motifs. These genes are involved in a wide variety of functions during animal development. As most Prdm genes have been studied in vertebrates, especially in mice, little is known about the evolution of this gene family. We searched for Prdm genes in the fully sequenced genomes of 93 different species representative of all the main metazoan lineages. A total of 976 Prdm genes were identified in these species. The number of Prdm genes per species ranges from 2 to 19. To better understand how the Prdm gene family has evolved in metazoans, we performed phylogenetic analyses using this large set of identified Prdm genes. These analyses allowed us to define 14 different subfamilies of Prdm genes and to establish, through ancestral state reconstruction, that 11 of them are ancestral to bilaterian animals. Three additional subfamilies were acquired during early vertebrate evolution (Prdm5, Prdm11, and Prdm17). Several gene duplication and gene loss events were identified and mapped onto the metazoan phylogenetic tree. By studying a large number of nonmetazoan genomes, we confirmed that Prdm genes likely constitute a metazoan-specific gene family. Our data also suggest that Prdm genes originated before the diversification of animals through the association of a single ancestral SET domain encoding gene with one or several zinc finger encoding genes.
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Affiliation(s)
- Michel Vervoort
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, Paris, France Institut Universitaire de France, Paris, France
| | - David Meulemeester
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Julien Béhague
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Pierre Kerner
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
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42
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Kück P, Wägele JW. Plesiomorphic character states cause systematic errors in molecular phylogenetic analyses: a simulation study. Cladistics 2015; 32:461-478. [DOI: 10.1111/cla.12132] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/15/2015] [Indexed: 01/17/2023] Open
Affiliation(s)
- Patrick Kück
- The Natural History Museum Cromwell Road SW7 5BD London UK
| | - J. Wolfgang Wägele
- Zoologisches Forschungsmuseum Alexander Koenig Adenauerallee 160 53113 Bonn Germany
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Ou Q, Xiao S, Han J, Sun G, Zhang F, Zhang Z, Shu D. A vanished history of skeletonization in Cambrian comb jellies. SCIENCE ADVANCES 2015; 1:e1500092. [PMID: 26601209 PMCID: PMC4646772 DOI: 10.1126/sciadv.1500092] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 05/05/2015] [Indexed: 06/05/2023]
Abstract
Ctenophores are traditionally regarded as "lower" metazoans, sharing with cnidarians a diploblastic grade of organization. Unlike cnidarians, where skeletonization (biomineralization and sclerotization) evolved repeatedly among ecologically important taxa (for example, scleractinians and octocorals), living ctenophores are characteristically soft-bodied animals. We report six sclerotized and armored ctenophores from the early Cambrian period. They have diagnostic ctenophore features (for example, an octamerous symmetry, oral-aboral axis, aboral sense organ, and octaradially arranged ctene rows). Unlike most modern counterparts, however, they lack tentacles, have a sclerotized framework, and have eight pairs of ctene rows. They are resolved as a monophyletic group (Scleroctenophora new class) within the ctenophores. This clade reveals a cryptic history and sheds new light on the early evolution of this basal animal phylum. Skeletonization also occurs in some other Cambrian animal groups whose extant members are exclusively soft-bodied, suggesting the ecological importance of skeletonization in the Cambrian explosion.
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Affiliation(s)
- Qiang Ou
- Early Life Evolution Laboratory, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China
- Early Life Institute, Collaborative Innovation Center of Continental Tectonics, State Key Laboratory of Continental Dynamics, Northwest University, Xi’an 710069, China
| | - Shuhai Xiao
- Department of Geosciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Jian Han
- Early Life Institute, Collaborative Innovation Center of Continental Tectonics, State Key Laboratory of Continental Dynamics, Northwest University, Xi’an 710069, China
| | - Ge Sun
- Early Life Evolution Laboratory, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China
| | - Fang Zhang
- Tsinghua University, Beijing 100084, China
| | - Zhifei Zhang
- Early Life Institute, Collaborative Innovation Center of Continental Tectonics, State Key Laboratory of Continental Dynamics, Northwest University, Xi’an 710069, China
| | - Degan Shu
- Early Life Evolution Laboratory, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China
- Early Life Institute, Collaborative Innovation Center of Continental Tectonics, State Key Laboratory of Continental Dynamics, Northwest University, Xi’an 710069, China
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Schüler A, Schmitz G, Reft A, Özbek S, Thurm U, Bornberg-Bauer E. The Rise and Fall of TRP-N, an Ancient Family of Mechanogated Ion Channels, in Metazoa. Genome Biol Evol 2015; 7:1713-27. [PMID: 26100409 PMCID: PMC4494053 DOI: 10.1093/gbe/evv091] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Mechanoreception, the sensing of mechanical forces, is an ancient means of orientation and communication and tightly linked to the evolution of motile animals. In flies, the transient-receptor-potential N protein (TRP-N) was found to be a cilia-associated mechanoreceptor. TRP-N belongs to a large and diverse family of ion channels. Its unusually long N-terminal repeat of 28 ankyrin domains presumably acts as the gating spring by which mechanical energy induces channel gating. We analyzed the evolutionary origins and possible diversification of TRP-N. Using a custom-made set of highly discriminative sequence profiles we scanned a representative set of metazoan genomes and subsequently corrected several gene models. We find that, contrary to other ion channel families, TRP-N is remarkably conserved in its domain arrangements and copy number (1) in all Bilateria except for amniotes, even in the wake of several whole-genome duplications. TRP-N is absent in Porifera but present in Ctenophora and Placozoa. Exceptional multiplications of TRP-N occurred in Cnidaria, independently along the Hydra and the Nematostella lineage. Molecular signals of subfunctionalization can be attributed to different mechanisms of activation of the gating spring. In Hydra this is further supported by in situ hybridization and immune staining, suggesting that at least three paralogs adapted to nematocyte discharge, which is key for predation and defense. We propose that these new candidate proteins help explain the sensory complexity of Cnidaria which has been previously observed but so far has lacked a molecular underpinning. Also, the ancient appearance of TRP-N supports a common origin of important components of the nervous systems in Ctenophores, Cnidaria, and Bilateria.
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Affiliation(s)
- Andreas Schüler
- Institute for Evolution and Biodiversity, University of Muenster, Germany
| | - Gregor Schmitz
- Institute for Evolution and Biodiversity, University of Muenster, Germany
| | - Abigail Reft
- Centre for Organismal Studies, University of Heidelberg, Germany
| | - Suat Özbek
- Centre for Organismal Studies, University of Heidelberg, Germany HEIKA-Heidelberg Karlsruhe Research Partnership, Heidelberg University, Karlsruhe Institute of Technology (KIT), Heidelberg and Karlsruhe, Germany
| | - Ulrich Thurm
- Institute for Neurobiology and Behavioural Biology, University of Muenster, Germany
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Doyle VP, Young RE, Naylor GJP, Brown JM. Can We Identify Genes with Increased Phylogenetic Reliability? Syst Biol 2015; 64:824-37. [DOI: 10.1093/sysbio/syv041] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 06/09/2015] [Indexed: 12/19/2022] Open
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Fernandez-Valverde SL, Calcino AD, Degnan BM. Deep developmental transcriptome sequencing uncovers numerous new genes and enhances gene annotation in the sponge Amphimedon queenslandica. BMC Genomics 2015; 16:387. [PMID: 25975661 PMCID: PMC4432959 DOI: 10.1186/s12864-015-1588-z] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Accepted: 04/27/2015] [Indexed: 11/14/2022] Open
Abstract
Background The demosponge Amphimedon queenslandica is amongst the few early-branching metazoans with an assembled and annotated draft genome, making it an important species in the study of the origin and early evolution of animals. Current gene models in this species are largely based on in silico predictions and low coverage expressed sequence tag (EST) evidence. Results Amphimedon queenslandica protein-coding gene models are improved using deep RNA-Seq data from four developmental stages and CEL-Seq data from 82 developmental samples. Over 86% of previously predicted genes are retained in the new gene models, although 24% have additional exons; there is also a marked increase in the total number of annotated 3’ and 5’ untranslated regions (UTRs). Importantly, these new developmental transcriptome data reveal numerous previously unannotated protein-coding genes in the Amphimedon genome, increasing the total gene number by 25%, from 30,060 to 40,122. In general, Amphimedon genes have introns that are markedly smaller than those in other animals and most of the alternatively spliced genes in Amphimedon undergo intron-retention; exon-skipping is the least common mode of alternative splicing. Finally, in addition to canonical polyadenylation signal sequences, Amphimedon genes are enriched in a number of unique AT-rich motifs in their 3’ UTRs. Conclusions The inclusion of developmental transcriptome data has substantially improved the structure and composition of protein-coding gene models in Amphimedon queenslandica, providing a more accurate and comprehensive set of genes for functional and comparative studies. These improvements reveal the Amphimedon genome is comprised of a remarkably high number of tightly packed genes. These genes have small introns and there is pervasive intron retention amongst alternatively spliced transcripts. These aspects of the sponge genome are more similar unicellular opisthokont genomes than to other animal genomes. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1588-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Selene L Fernandez-Valverde
- Centre for Marine Sciences, School of Biological Sciences, The University of Queensland, Brisbane, 4072, Australia.
| | - Andrew D Calcino
- Centre for Marine Sciences, School of Biological Sciences, The University of Queensland, Brisbane, 4072, Australia.
| | - Bernard M Degnan
- Centre for Marine Sciences, School of Biological Sciences, The University of Queensland, Brisbane, 4072, Australia.
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Exploring the potential of small RNA subunit and ITS sequences for resolving phylogenetic relationships within the phylum Ctenophora. ZOOLOGY 2015; 118:102-14. [DOI: 10.1016/j.zool.2014.06.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 06/13/2014] [Accepted: 06/17/2014] [Indexed: 11/17/2022]
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Abstract
Neurons are defined as polarized secretory cells specializing in directional propagation of electrical signals leading to the release of extracellular messengers - features that enable them to transmit information, primarily chemical in nature, beyond their immediate neighbors without affecting all intervening cells en route. Multiple origins of neurons and synapses from different classes of ancestral secretory cells might have occurred more than once during ~600 million years of animal evolution with independent events of nervous system centralization from a common bilaterian/cnidarian ancestor without the bona fide central nervous system. Ctenophores, or comb jellies, represent an example of extensive parallel evolution in neural systems. First, recent genome analyses place ctenophores as a sister group to other animals. Second, ctenophores have a smaller complement of pan-animal genes controlling canonical neurogenic, synaptic, muscle and immune systems, and developmental pathways than most other metazoans. However, comb jellies are carnivorous marine animals with a complex neuromuscular organization and sophisticated patterns of behavior. To sustain these functions, they have evolved a number of unique molecular innovations supporting the hypothesis of massive homoplasies in the organization of integrative and locomotory systems. Third, many bilaterian/cnidarian neuron-specific genes and 'classical' neurotransmitter pathways are either absent or, if present, not expressed in ctenophore neurons (e.g. the bilaterian/cnidarian neurotransmitter, γ-amino butyric acid or GABA, is localized in muscles and presumed bilaterian neuron-specific RNA-binding protein Elav is found in non-neuronal cells). Finally, metabolomic and pharmacological data failed to detect either the presence or any physiological action of serotonin, dopamine, noradrenaline, adrenaline, octopamine, acetylcholine or histamine - consistent with the hypothesis that ctenophore neural systems evolved independently from those in other animals. Glutamate and a diverse range of secretory peptides are first candidates for ctenophore neurotransmitters. Nevertheless, it is expected that other classes of signal and neurogenic molecules would be discovered in ctenophores as the next step to decipher one of the most distinct types of neural organization in the animal kingdom.
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Affiliation(s)
- Leonid L Moroz
- The Whitney Laboratory of Marine Biosciences and Department of Neuroscience and McKnight Brain Institute, University of Florida, FL 32080, USA. The Whitney Laboratory, University of Florida, 9505 Ocean Shore Boulevard, St. Augustine, FL 32080, USA
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Moran Y, Barzilai MG, Liebeskind BJ, Zakon HH. Evolution of voltage-gated ion channels at the emergence of Metazoa. J Exp Biol 2015; 218:515-25. [DOI: 10.1242/jeb.110270] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Voltage-gated ion channels are large transmembrane proteins that enable the passage of ions through their pore across the cell membrane. These channels belong to one superfamily and carry pivotal roles such as the propagation of neuronal and muscular action potentials and the promotion of neurotransmitter secretion in synapses. In this review, we describe in detail the current state of knowledge regarding the evolution of these channels with a special emphasis on the metazoan lineage. We highlight the contribution of the genomic revolution to the understanding of ion channel evolution and for revealing that these channels appeared long before the appearance of the first animal. We also explain how the elucidation of channel selectivity properties and function in non-bilaterian animals such as cnidarians (sea anemones, corals, jellyfish and hydroids) can contribute to the study of channel evolution. Finally, we point to open questions and future directions in this field of research.
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Affiliation(s)
- Yehu Moran
- Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, Faculty of Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Maya Gur Barzilai
- Department of Molecular Biology and Ecology of Plants, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv 69978, Israel
| | - Benjamin J. Liebeskind
- Department of Integrative Biology and Center for Computational Biology and Bioinformatics, University of Texas, Austin, TX 78712, USA
| | - Harold H. Zakon
- Department of Integrative Biology and Center for Computational Biology and Bioinformatics, University of Texas, Austin, TX 78712, USA
- Department of Neuroscience, University of Texas at Austin, TX 78712, USA
- Josephine Bay Paul Center for Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, MA 02543, 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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