1
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Kollmar M, Welz T, Ravi A, Kaufmann T, Alzahofi N, Hatje K, Alghamdi A, Kim J, Briggs DA, Samol-Wolf A, Pylypenko O, Hume AN, Burkhardt P, Faix J, Kerkhoff E. Actomyosin organelle functions of SPIRE actin nucleators precede animal evolution. Commun Biol 2024; 7:832. [PMID: 38977899 DOI: 10.1038/s42003-024-06458-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 06/14/2024] [Indexed: 07/10/2024] Open
Abstract
An important question in cell biology is how cytoskeletal proteins evolved and drove the development of novel structures and functions. Here we address the origin of SPIRE actin nucleators. Mammalian SPIREs work with RAB GTPases, formin (FMN)-subgroup actin assembly proteins and class-5 myosin (MYO5) motors to transport organelles along actin filaments towards the cell membrane. However, the origin and extent of functional conservation of SPIRE among species is unknown. Our sequence searches show that SPIRE exist throughout holozoans (animals and their closest single-celled relatives), but not other eukaryotes. SPIRE from unicellular holozoans (choanoflagellate), interacts with RAB, FMN and MYO5 proteins, nucleates actin filaments and complements mammalian SPIRE function in organelle transport. Meanwhile SPIRE and MYO5 proteins colocalise to organelles in Salpingoeca rosetta choanoflagellates. Based on these observations we propose that SPIRE originated in unicellular ancestors of animals providing an actin-myosin driven exocytic transport mechanism that may have contributed to the evolution of complex multicellular animals.
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Affiliation(s)
- Martin Kollmar
- Group Systems Biology of Motor Proteins, Department of NMR-based Structural Biology, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany.
| | - Tobias Welz
- Molecular Cell Biology Laboratory, Department of Neurology, University Hospital Regensburg, Regensburg, Germany
| | - Aishwarya Ravi
- Michael Sars Centre, University of Bergen, Bergen, Norway
| | - Thomas Kaufmann
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Noura Alzahofi
- School of Life Sciences, University of Nottingham, Nottingham, UK
- Biology Department, College of Science, Taibah University, Medina, Kingdom of Saudi Arabia
| | - Klas Hatje
- Group Systems Biology of Motor Proteins, Department of NMR-based Structural Biology, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
- Roche Pharmaceutical Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Asmahan Alghamdi
- School of Life Sciences, University of Nottingham, Nottingham, UK
- Department of Biology, College of Sciences, Princess Nourah bint Abdulrahman University, Riyadh, Kingdom of Saudi Arabia
| | - Jiyu Kim
- Molecular Cell Biology Laboratory, Department of Neurology, University Hospital Regensburg, Regensburg, Germany
- Department of Anatomy, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Deborah A Briggs
- School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Annette Samol-Wolf
- Molecular Cell Biology Laboratory, Department of Neurology, University Hospital Regensburg, Regensburg, Germany
| | - Olena Pylypenko
- Dynamics of Intra-Cellular Organization, Institute Curie, PSL Research University, CNRS UMR144, Paris, France
| | - Alistair N Hume
- School of Life Sciences, University of Nottingham, Nottingham, UK
| | | | - Jan Faix
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Eugen Kerkhoff
- Molecular Cell Biology Laboratory, Department of Neurology, University Hospital Regensburg, Regensburg, Germany.
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2
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McCoy MJ, Fire AZ. Parallel gene size and isoform expansion of ancient neuronal genes. Curr Biol 2024; 34:1635-1645.e3. [PMID: 38460513 PMCID: PMC11043017 DOI: 10.1016/j.cub.2024.02.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 12/16/2023] [Accepted: 02/11/2024] [Indexed: 03/11/2024]
Abstract
How nervous systems evolved is a central question in biology. A diversity of synaptic proteins is thought to play a central role in the formation of specific synapses leading to nervous system complexity. The largest animal genes, often spanning hundreds of thousands of base pairs, are known to be enriched for expression in neurons at synapses and are frequently mutated or misregulated in neurological disorders and diseases. Although many of these genes have been studied independently in the context of nervous system evolution and disease, general principles underlying their parallel evolution remain unknown. To investigate this, we directly compared orthologous gene sizes across eukaryotes. By comparing relative gene sizes within organisms, we identified a distinct class of large genes with origins predating the diversification of animals and, in many cases, the emergence of neurons as dedicated cell types. We traced this class of ancient large genes through evolution and found orthologs of the large synaptic genes potentially driving the immense complexity of metazoan nervous systems, including in humans and cephalopods. Moreover, we found that while these genes are evolving under strong purifying selection, as demonstrated by low dN/dS ratios, they have simultaneously grown larger and gained the most isoforms in animals. This work provides a new lens through which to view this distinctive class of large and multi-isoform genes and demonstrates how intrinsic genomic properties, such as gene length, can provide flexibility in molecular evolution and allow groups of genes and their host organisms to evolve toward complexity.
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Affiliation(s)
- Matthew J McCoy
- Department of Pathology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.
| | - Andrew Z Fire
- Department of Pathology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA; Department of Genetics, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.
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3
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Ros-Rocher N, Brunet T. What is it like to be a choanoflagellate? Sensation, processing and behavior in the closest unicellular relatives of animals. Anim Cogn 2023; 26:1767-1782. [PMID: 37067637 PMCID: PMC10770216 DOI: 10.1007/s10071-023-01776-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 04/05/2023] [Accepted: 04/07/2023] [Indexed: 04/18/2023]
Abstract
All animals evolved from a single lineage of unicellular precursors more than 600 million years ago. Thus, the biological and genetic foundations for animal sensation, cognition and behavior must necessarily have arisen by modifications of pre-existing features in their unicellular ancestors. Given that the single-celled ancestors of the animal kingdom are extinct, the only way to reconstruct how these features evolved is by comparing the biology and genomic content of extant animals to their closest living relatives. Here, we reconstruct the Umwelt (the subjective, perceptive world) inhabited by choanoflagellates, a group of unicellular (or facultatively multicellular) aquatic microeukaryotes that are the closest living relatives of animals. Although behavioral research on choanoflagellates remains patchy, existing evidence shows that they are capable of chemosensation, photosensation and mechanosensation. These processes often involve specialized sensorimotor cellular appendages (cilia, microvilli, and/or filopodia) that resemble those that underlie perception in most animal sensory cells. Furthermore, comparative genomics predicts an extensive "sensory molecular toolkit" in choanoflagellates, which both provides a potential basis for known behaviors and suggests the existence of a largely undescribed behavioral complexity that presents exciting avenues for future research. Finally, we discuss how facultative multicellularity in choanoflagellates might help us understand how evolution displaced the locus of decision-making from a single cell to a collective, and how a new space of behavioral complexity might have become accessible in the process.
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Affiliation(s)
- Núria Ros-Rocher
- Evolutionary Cell Biology and Evolution of Morphogenesis Unit, Institut Pasteur, Université Paris-Cité, CNRS UMR3691, 25-28 Rue du Docteur Roux, 75015, Paris, France
| | - Thibaut Brunet
- Evolutionary Cell Biology and Evolution of Morphogenesis Unit, Institut Pasteur, Université Paris-Cité, CNRS UMR3691, 25-28 Rue du Docteur Roux, 75015, Paris, France.
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4
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Xiang X, Vilar Gomez AA, Blomberg SP, Yuan H, Degnan BM, Degnan SM. Potential for host-symbiont communication via neurotransmitters and neuromodulators in an aneural animal, the marine sponge Amphimedon queenslandica. Front Neural Circuits 2023; 17:1250694. [PMID: 37841893 PMCID: PMC10570526 DOI: 10.3389/fncir.2023.1250694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 09/12/2023] [Indexed: 10/17/2023] Open
Abstract
Interkingdom signalling within a holobiont allows host and symbionts to communicate and to regulate each other's physiological and developmental states. Here we show that a suite of signalling molecules that function as neurotransmitters and neuromodulators in most animals with nervous systems, specifically dopamine and trace amines, are produced exclusively by the bacterial symbionts of the demosponge Amphimedon queenslandica. Although sponges do not possess a nervous system, A. queenslandica expresses rhodopsin class G-protein-coupled receptors that are structurally similar to dopamine and trace amine receptors. When sponge larvae, which express these receptors, are exposed to agonists and antagonists of bilaterian dopamine and trace amine receptors, we observe marked changes in larval phototactic swimming behaviour, consistent with the sponge being competent to recognise and respond to symbiont-derived trace amine signals. These results indicate that monoamines synthesised by bacterial symbionts may be able to influence the physiology of the host sponge.
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Affiliation(s)
| | | | | | | | | | - Sandie M. Degnan
- Centre for Marine Science, School of the Environment, The University of Queensland, Brisbane, QLD, Australia
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5
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The premetazoan ancestry of the synaptic toolkit and appearance of first neurons. Essays Biochem 2022; 66:781-795. [PMID: 36205407 DOI: 10.1042/ebc20220042] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/31/2022] [Accepted: 09/13/2022] [Indexed: 12/13/2022]
Abstract
Neurons, especially when coupled with muscles, allow animals to interact with and navigate through their environment in ways unique to life on earth. Found in all major animal lineages except sponges and placozoans, nervous systems range widely in organization and complexity, with neurons possibly representing the most diverse cell-type. This diversity has led to much debate over the evolutionary origin of neurons as well as synapses, which allow for the directed transmission of information. The broad phylogenetic distribution of neurons and presence of many of the defining components outside of animals suggests an early origin of this cell type, potentially in the time between the first animal and the last common ancestor of extant animals. Here, we highlight the occurrence and function of key aspects of neurons outside of animals as well as recent findings from non-bilaterian animals in order to make predictions about when and how the first neuron(s) arose during animal evolution and their relationship to those found in extant lineages. With advancing technologies in single cell transcriptomics and proteomics as well as expanding functional techniques in non-bilaterian animals and the close relatives of animals, it is an exciting time to begin unraveling the complex evolutionary history of this fascinating animal cell type.
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6
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Losada-Pérez M, Hernández García-Moreno M, García-Ricote I, Casas-Tintó S. Synaptic components are required for glioblastoma progression in Drosophila. PLoS Genet 2022; 18:e1010329. [PMID: 35877760 PMCID: PMC9352205 DOI: 10.1371/journal.pgen.1010329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 08/04/2022] [Accepted: 07/06/2022] [Indexed: 11/18/2022] Open
Abstract
Glioblastoma (GB) is the most aggressive, lethal and frequent primary brain tumor. It originates from glial cells and is characterized by rapid expansion through infiltration. GB cells interact with the microenvironment and healthy surrounding tissues, mostly neurons and vessels. GB cells project tumor microtubes (TMs) contact with neurons, and exchange signaling molecules related to Wingless/WNT, JNK, Insulin or Neuroligin-3 pathways. This cell to cell communication promotes GB expansion and neurodegeneration. Moreover, healthy neurons form glutamatergic functional synapses with GB cells which facilitate GB expansion and premature death in mouse GB xerograph models. Targeting signaling and synaptic components of GB progression may become a suitable strategy against glioblastoma. In a Drosophila GB model, we have determined the post-synaptic nature of GB cells with respect to neurons, and the contribution of post-synaptic genes expressed in GB cells to tumor progression. In addition, we document the presence of intratumoral synapses between GB cells, and the functional contribution of pre-synaptic genes to GB calcium dependent activity and expansion. Finally, we explore the relevance of synaptic genes in GB cells to the lifespan reduction caused by GB advance. Our results indicate that both presynaptic and postsynaptic proteins play a role in GB progression and lethality. Glioblastoma (GB) is the most frequent and aggressive type of brain tumor. It is originated from glial cells that expand and proliferate very fast in the brain. GB cells infiltrate and establish cell to cell communication with healthy neurons. Currently there is no effective treatment for GB and these tumors result incurable with an average survival of 16 months after diagnosis. Here we used a Drosophila melanogaster model to search for genetic suppressors of GB progression. The results show that genes involved in the formation of synapses are required for glial cell number increase, expansion of tumoral volume and premature death. Among these synaptic genes we found that post-synaptic genes that contribute to Neuron-GB interaction which validate previous findings in human GB. Moreover, we found electro dense structures between GB cells that are compatible with synapses and that expression of pre-synaptic genes, including brp, Lip-α and syt 1, is required for GB progression and aggressiveness. These results suggest a contribution of synapses between GB cells to disease progression, named as intratumoral synapses.
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Affiliation(s)
| | | | | | - Sergio Casas-Tintó
- Instituto Cajal-CSIC, Madrid, Spain
- IIER-Instituto de Salud CarlosIII, Majadahonda, Spain
- * E-mail:
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7
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The evolution of synaptic and cognitive capacity: Insights from the nervous system transcriptome of Aplysia. Proc Natl Acad Sci U S A 2022; 119:e2122301119. [PMID: 35867761 PMCID: PMC9282427 DOI: 10.1073/pnas.2122301119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The gastropod mollusk Aplysia is an important model for cellular and molecular neurobiological studies, particularly for investigations of molecular mechanisms of learning and memory. We developed an optimized assembly pipeline to generate an improved Aplysia nervous system transcriptome. This improved transcriptome enabled us to explore the evolution of cognitive capacity at the molecular level. Were there evolutionary expansions of neuronal genes between this relatively simple gastropod Aplysia (20,000 neurons) and Octopus (500 million neurons), the invertebrate with the most elaborate neuronal circuitry and greatest behavioral complexity? Are the tremendous advances in cognitive power in vertebrates explained by expansion of the synaptic proteome that resulted from multiple rounds of whole genome duplication in this clade? Overall, the complement of genes linked to neuronal function is similar between Octopus and Aplysia. As expected, a number of synaptic scaffold proteins have more isoforms in humans than in Aplysia or Octopus. However, several scaffold families present in mollusks and other protostomes are absent in vertebrates, including the Fifes, Lev10s, SOLs, and a NETO family. Thus, whereas vertebrates have more scaffold isoforms from select families, invertebrates have additional scaffold protein families not found in vertebrates. This analysis provides insights into the evolution of the synaptic proteome. Both synaptic proteins and synaptic plasticity evolved gradually, yet the last deuterostome-protostome common ancestor already possessed an elaborate suite of genes associated with synaptic function, and critical for synaptic plasticity.
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8
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Piekut T, Wong YY, Walker SE, Smith CL, Gauberg J, Harracksingh AN, Lowden C, Novogradac BB, Cheng HYM, Spencer GE, Senatore A. Early Metazoan Origin and Multiple Losses of a Novel Clade of RIM Presynaptic Calcium Channel Scaffolding Protein Homologs. Genome Biol Evol 2021; 12:1217-1239. [PMID: 32413100 PMCID: PMC7456537 DOI: 10.1093/gbe/evaa097] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/11/2020] [Indexed: 12/18/2022] Open
Abstract
The precise localization of CaV2 voltage-gated calcium channels at the synapse active zone requires various interacting proteins, of which, Rab3-interacting molecule or RIM is considered particularly important. In vertebrates, RIM interacts with CaV2 channels in vitro via a PDZ domain that binds to the extreme C-termini of the channels at acidic ligand motifs of D/E-D/E/H-WC-COOH, and knockout of RIM in vertebrates and invertebrates disrupts CaV2 channel synaptic localization and synapse function. Here, we describe a previously uncharacterized clade of RIM proteins bearing domain architectures homologous to those of known RIM homologs, but with some notable differences including key amino acids associated with PDZ domain ligand specificity. This novel RIM emerged near the stem lineage of metazoans and underwent extensive losses, but is retained in select animals including the early-diverging placozoan Trichoplax adhaerens, and molluscs. RNA expression and localization studies in Trichoplax and the mollusc snail Lymnaea stagnalis indicate differential regional/tissue type expression, but overlapping expression in single isolated neurons from Lymnaea. Ctenophores, the most early-diverging animals with synapses, are unique among animals with nervous systems in that they lack the canonical RIM, bearing only the newly identified homolog. Through phylogenetic analysis, we find that CaV2 channel D/E-D/E/H-WC-COOH like PDZ ligand motifs were present in the common ancestor of cnidarians and bilaterians, and delineate some deeply conserved C-terminal structures that distinguish CaV1 from CaV2 channels, and CaV1/CaV2 from CaV3 channels.
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Affiliation(s)
| | | | - Sarah E Walker
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada
| | - Carolyn L Smith
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | | | | | | | | | | | - Gaynor E Spencer
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada
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9
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Viscardi LH, Imparato DO, Bortolini MC, Dalmolin RJS. Ionotropic Receptors as a Driving Force behind Human Synapse Establishment. Mol Biol Evol 2021; 38:735-744. [PMID: 32986821 PMCID: PMC7947827 DOI: 10.1093/molbev/msaa252] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The origin of nervous systems is a main theme in biology and its mechanisms are largely underlied by synaptic neurotransmission. One problem to explain synapse establishment is that synaptic orthologs are present in multiple aneural organisms. We questioned how the interactions among these elements evolved and to what extent it relates to our understanding of the nervous systems complexity. We identified the human neurotransmission gene network based on genes present in GABAergic, glutamatergic, serotonergic, dopaminergic, and cholinergic systems. The network comprises 321 human genes, 83 of which act exclusively in the nervous system. We reconstructed the evolutionary scenario of synapse emergence by looking for synaptic orthologs in 476 eukaryotes. The Human–Cnidaria common ancestor displayed a massive emergence of neuroexclusive genes, mainly ionotropic receptors, which might have been crucial to the evolution of synapses. Very few synaptic genes had their origin after the Human–Cnidaria common ancestor. We also identified a higher abundance of synaptic proteins in vertebrates, which suggests an increase in the synaptic network complexity of those organisms.
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Affiliation(s)
- Lucas Henriques Viscardi
- Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Danilo Oliveira Imparato
- Bioinformatics Multidisciplinary Environment-BioME, IMD, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Maria Cátira Bortolini
- Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Rodrigo Juliani Siqueira Dalmolin
- Bioinformatics Multidisciplinary Environment-BioME, IMD, Federal University of Rio Grande do Norte, Natal, RN, Brazil.,Department of Biochemistry, CB, Federal University of Rio Grande do Norte, Natal, RN, Brazil
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10
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11
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Stroebel D, Paoletti P. Architecture and function of NMDA receptors: an evolutionary perspective. J Physiol 2020; 599:2615-2638. [PMID: 32786006 DOI: 10.1113/jp279028] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 07/21/2020] [Indexed: 12/20/2022] Open
Abstract
Ionotropic glutamate receptors (iGluRs) are a major class of ligand-gated ion channels that are widespread in the living kingdom. Their critical role in excitatory neurotransmission and brain function of arthropods and vertebrates has made them a compelling subject of interest for neurophysiologists and pharmacologists. This is particularly true for NMDA receptor (NMDARs), a subclass of iGluRs that act as central drivers of synaptic plasticity in the CNS. How and when the unique properties of NMDARs arose during evolution, and how they relate to the evolution of the nervous system, remain open questions. Recent years have witnessed a boom in both genomic and structural data, such that it is now possible to analyse the evolution of iGluR genes on an unprecedented scale and within a solid molecular framework. In this review, combining insights from phylogeny, atomic structure and physiological and mechanistic data, we discuss how evolution of NMDAR motifs and sequences shaped their architecture and functionalities. We trace differences and commonalities between NMDARs and other iGluRs, emphasizing a few distinctive properties of the former regarding ligand binding and gating, permeation, allosteric modulation and intracellular signalling. Finally, we speculate on how specific molecular properties of iGuRs arose to supply new functions to the evolving structure of the nervous system, from early metazoan to present mammals.
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Affiliation(s)
- David Stroebel
- Ecole Normale Supérieure, CNRS, INSERM, Institute de Biologie de l'Ecole Normale Supérieure (IBENS), Université PSL, Paris, France
| | - Pierre Paoletti
- Ecole Normale Supérieure, CNRS, INSERM, Institute de Biologie de l'Ecole Normale Supérieure (IBENS), Université PSL, Paris, France
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12
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Kenny NJ, Francis WR, Rivera-Vicéns RE, Juravel K, de Mendoza A, Díez-Vives C, Lister R, Bezares-Calderón LA, Grombacher L, Roller M, Barlow LD, Camilli S, Ryan JF, Wörheide G, Hill AL, Riesgo A, Leys SP. Tracing animal genomic evolution with the chromosomal-level assembly of the freshwater sponge Ephydatia muelleri. Nat Commun 2020; 11:3676. [PMID: 32719321 PMCID: PMC7385117 DOI: 10.1038/s41467-020-17397-w] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 06/23/2020] [Indexed: 11/09/2022] Open
Abstract
The genomes of non-bilaterian metazoans are key to understanding the molecular basis of early animal evolution. However, a full comprehension of how animal-specific traits, such as nervous systems, arose is hindered by the scarcity and fragmented nature of genomes from key taxa, such as Porifera. Ephydatia muelleri is a freshwater sponge found across the northern hemisphere. Here, we present its 326 Mb genome, assembled to high contiguity (N50: 9.88 Mb) with 23 chromosomes on 24 scaffolds. Our analyses reveal a metazoan-typical genome architecture, with highly shared synteny across Metazoa, and suggest that adaptation to the extreme temperatures and conditions found in freshwater often involves gene duplication. The pancontinental distribution and ready laboratory culture of E. muelleri make this a highly practical model system which, with RNAseq, DNA methylation and bacterial amplicon data spanning its development and range, allows exploration of genomic changes both within sponges and in early animal evolution.
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Affiliation(s)
- Nathan J Kenny
- Department of Life Sciences, The Natural History Museum, Cromwell Rd, London, SW7 5BD, UK. .,Faculty of Health and Life Sciences, Oxford Brookes, Oxford, OX3 0BP, UK.
| | - Warren R Francis
- Department of Biology, University of Southern Denmark, Odense, Denmark
| | - Ramón E Rivera-Vicéns
- Department of Earth and Environmental Sciences, Paleontology & Geobiology, Ludwig-Maximilians-Universität München, Richard-Wagner-Str. 10, 80333, München, Germany
| | - Ksenia Juravel
- Department of Earth and Environmental Sciences, Paleontology & Geobiology, Ludwig-Maximilians-Universität München, Richard-Wagner-Str. 10, 80333, München, Germany
| | - Alex de Mendoza
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Perth, WA, 6009, Australia.,Harry Perkins Institute of Medical Research, Perth, WA, 6009, Australia.,School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Cristina Díez-Vives
- Department of Life Sciences, The Natural History Museum, Cromwell Rd, London, SW7 5BD, UK
| | - Ryan Lister
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Perth, WA, 6009, Australia.,Harry Perkins Institute of Medical Research, Perth, WA, 6009, Australia
| | - Luis A Bezares-Calderón
- College of Life and Environmental Sciences, University of Exeter, Stocker Rd, Exeter, EX4 4QD, UK
| | - Lauren Grombacher
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - Maša Roller
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Cambridge, CB10 1SD, UK
| | - Lael D Barlow
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - Sara Camilli
- Department of Biology, Bates College, Lewiston, ME, 04240, USA
| | - Joseph F Ryan
- Whitney Lab for Marine Bioscience and the Department of Biology, University of Florida, St. Augustine, FL, 32080, USA
| | - Gert Wörheide
- Department of Earth and Environmental Sciences, Paleontology & Geobiology, Ludwig-Maximilians-Universität München, Richard-Wagner-Str. 10, 80333, München, Germany.,SNSB-Bayerische Staatssammlung für Paläontologie und Geologie, Richard-Wagner-Str. 10, 80333, München, Germany.,GeoBio-Center, Ludwig-Maximilians-Universität München, Richard-Wagner-Str. 10, 80333, München, Germany
| | - April L Hill
- Department of Biology, Bates College, Lewiston, ME, 04240, USA
| | - Ana Riesgo
- Department of Life Sciences, The Natural History Museum, Cromwell Rd, London, SW7 5BD, UK
| | - Sally P Leys
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada.
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13
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Hulett RE, Potter D, Srivastava M. Neural architecture and regeneration in the acoel Hofstenia miamia. Proc Biol Sci 2020; 287:20201198. [PMID: 32693729 PMCID: PMC7423668 DOI: 10.1098/rspb.2020.1198] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The origin of bilateral symmetry, a major transition in animal evolution, coincided with the evolution of organized nervous systems that show regionalization along major body axes. Studies of Xenacoelomorpha, the likely outgroup lineage to all other animals with bilateral symmetry, can inform the evolutionary history of animal nervous systems. Here, we characterized the neural anatomy of the acoel Hofstenia miamia. Our analysis of transcriptomic data uncovered orthologues of enzymes for all major neurotransmitter synthesis pathways. Expression patterns of these enzymes revealed the presence of a nerve net and an anterior condensation of neural cells. The anterior condensation was layered, containing several cell types with distinct molecular identities organized in spatially distinct territories. Using these anterior cell types and structures as landmarks, we obtained a detailed timeline for regeneration of the H. miamia nervous system, showing that the anterior condensation is restored by eight days after amputation. Our work detailing neural anatomy in H. miamia will enable mechanistic studies of neural cell type diversity and regeneration and provide insight into the evolution of these processes.
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Affiliation(s)
- Ryan E Hulett
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, Cambridge, MA, USA
| | - Deirdre Potter
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA
| | - Mansi Srivastava
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, Cambridge, MA, USA
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14
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Leys SP, Mah JL, McGill PR, Hamonic L, De Leo FC, Kahn AS. Sponge Behavior and the Chemical Basis of Responses: A Post-Genomic View. Integr Comp Biol 2020; 59:751-764. [PMID: 31268144 DOI: 10.1093/icb/icz122] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Sponges perceive and respond to a range of stimuli. How they do this is still difficult to pin down despite now having transcriptomes and genomes of an array of species. Here we evaluate the current understanding of sponge behavior and present new observations on sponge activity in situ. We also explore biosynthesis pathways available to sponges from data in genomes/transcriptomes of sponges and other non-bilaterians with a focus on exploring the role of chemical signaling pathways mediating sponge behavior and how such chemical signal pathways may have evolved. Sponge larvae respond to light but opsins are not used, nor is there a common photoreceptor molecule or mechanism used across sponge groups. Other cues are gravity and chemicals. In situ recordings of behavior show that both shallow and deep-water sponges move a lot over minutes and hours, and correlation of behavior with temperature, pressure, oxygen, and water movement suggests that at least one sponge responds to changes in atmospheric pressure. The sensors for these cues as far as we know are individual cells and, except in the case of electrical signaling in Hexactinellida, these most likely act as independent effectors, generating a whole-body reaction by the global reach of the stimulus to all parts of the animal. We found no evidence for use of conventional neurotransmitters such as serotonin and dopamine. Intriguingly, some chemicals synthesized by symbiont microbes could mean other more complex signaling occurs, but how that interplay might happen is not understood. Our review suggests chemical signaling pathways found in sponges do not reflect loss of a more complex set.
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Affiliation(s)
- Sally P Leys
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E9
| | - Jasmine L Mah
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E9.,Department of Ecology and Evolutionary Biology, Yale University, 165 Prospect Street, New Haven, CT 06511, USA
| | - Paul R McGill
- Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, CA 95039, USA
| | - Laura Hamonic
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E9
| | - Fabio C De Leo
- Ocean Networks Canada, University of Victoria, Queenswood Campus 100-2474 Arbutus Road, Victoria, British Columbia, Canada V8N 1V8.,Department of Biology, University of Victoria, PO Box 3080, Victoria, British Columbia, Canada V8W 2Y2
| | - Amanda S Kahn
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E9.,Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, CA 95039, USA.,Moss Landing Marine Laboratories, 8272 Moss Landing Road, Moss Landing, CA 95039, USA
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15
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Pazos Obregón F, Palazzo M, Soto P, Guerberoff G, Yankilevich P, Cantera R. An improved catalogue of putative synaptic genes defined exclusively by temporal transcription profiles through an ensemble machine learning approach. BMC Genomics 2019; 20:1011. [PMID: 31870293 PMCID: PMC6929295 DOI: 10.1186/s12864-019-6380-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 12/09/2019] [Indexed: 11/25/2022] Open
Abstract
Background Assembly and function of neuronal synapses require the coordinated expression of a yet undetermined set of genes. Previously, we had trained an ensemble machine learning model to assign a probability of having synaptic function to every protein-coding gene in Drosophila melanogaster. This approach resulted in the publication of a catalogue of 893 genes which we postulated to be very enriched in genes with a still undocumented synaptic function. Since then, the scientific community has experimentally identified 79 new synaptic genes. Here we use these new empirical data to evaluate our original prediction. We also implement a series of changes to the training scheme of our model and using the new data we demonstrate that this improves its predictive power. Finally, we added the new synaptic genes to the training set and trained a new model, obtaining a new, enhanced catalogue of putative synaptic genes. Results The retrospective analysis demonstrate that our original catalogue was significantly enriched in new synaptic genes. When the changes to the training scheme were implemented using the original training set we obtained even higher enrichment. Finally, applying the new training scheme with a training set including the 79 new synaptic genes, resulted in an enhanced catalogue of putative synaptic genes. Here we present this new catalogue and announce that a regularly updated version will be available online at: http://synapticgenes.bnd.edu.uy Conclusions We show that training an ensemble of machine learning classifiers solely with the whole-body temporal transcription profiles of known synaptic genes resulted in a catalogue with a significant enrichment in undiscovered synaptic genes. Using new empirical data provided by the scientific community, we validated our original approach, improved our model an obtained an arguably more precise prediction. This approach reduces the number of genes to be tested through hypothesis-driven experimentation and will facilitate our understanding of neuronal function. Availability http://synapticgenes.bnd.edu.uy
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Affiliation(s)
- Flavio Pazos Obregón
- Neurodevelopmental Biology Department, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay.
| | - Martín Palazzo
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA), CONICET - Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | - Pablo Soto
- Neurodevelopmental Biology Department, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Gustavo Guerberoff
- Instituto de Matemática y Estadística "Prof. Ing. Rafael Laguardia", Facultad de Ingeniería, UDELAR, Montevideo, Uruguay
| | - Patricio Yankilevich
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA), CONICET - Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | - Rafael Cantera
- Neurodevelopmental Biology Department, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
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16
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Levin M. The Computational Boundary of a "Self": Developmental Bioelectricity Drives Multicellularity and Scale-Free Cognition. Front Psychol 2019; 10:2688. [PMID: 31920779 PMCID: PMC6923654 DOI: 10.3389/fpsyg.2019.02688] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 11/14/2019] [Indexed: 12/12/2022] Open
Abstract
All epistemic agents physically consist of parts that must somehow comprise an integrated cognitive self. Biological individuals consist of subunits (organs, cells, and molecular networks) that are themselves complex and competent in their own native contexts. How do coherent biological Individuals result from the activity of smaller sub-agents? To understand the evolution and function of metazoan creatures' bodies and minds, it is essential to conceptually explore the origin of multicellularity and the scaling of the basal cognition of individual cells into a coherent larger organism. In this article, I synthesize ideas in cognitive science, evolutionary biology, and developmental physiology toward a hypothesis about the origin of Individuality: "Scale-Free Cognition." I propose a fundamental definition of an Individual based on the ability to pursue goals at an appropriate level of scale and organization and suggest a formalism for defining and comparing the cognitive capacities of highly diverse types of agents. Any Self is demarcated by a computational surface - the spatio-temporal boundary of events that it can measure, model, and try to affect. This surface sets a functional boundary - a cognitive "light cone" which defines the scale and limits of its cognition. I hypothesize that higher level goal-directed activity and agency, resulting in larger cognitive boundaries, evolve from the primal homeostatic drive of living things to reduce stress - the difference between current conditions and life-optimal conditions. The mechanisms of developmental bioelectricity - the ability of all cells to form electrical networks that process information - suggest a plausible set of gradual evolutionary steps that naturally lead from physiological homeostasis in single cells to memory, prediction, and ultimately complex cognitive agents, via scale-up of the basic drive of infotaxis. Recent data on the molecular mechanisms of pre-neural bioelectricity suggest a model of how increasingly sophisticated cognitive functions emerge smoothly from cell-cell communication used to guide embryogenesis and regeneration. This set of hypotheses provides a novel perspective on numerous phenomena, such as cancer, and makes several unique, testable predictions for interdisciplinary research that have implications not only for evolutionary developmental biology but also for biomedicine and perhaps artificial intelligence and exobiology.
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Affiliation(s)
- Michael Levin
- Allen Discovery Center at Tufts University, Medford, MA, United States
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, United States
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17
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Wong E, Mölter J, Anggono V, Degnan SM, Degnan BM. Co-expression of synaptic genes in the sponge Amphimedon queenslandica uncovers ancient neural submodules. Sci Rep 2019; 9:15781. [PMID: 31673079 PMCID: PMC6823388 DOI: 10.1038/s41598-019-51282-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 09/28/2019] [Indexed: 12/13/2022] Open
Abstract
The synapse is a complex cellular module crucial to the functioning of neurons. It evolved largely through the exaptation of pre-existing smaller submodules, each of which are comprised of ancient sets of proteins that are conserved in modern animals and other eukaryotes. Although these ancient submodules themselves have non-neural roles, it has been hypothesized that they may mediate environmental sensing behaviors in aneural animals, such as sponges. Here we identify orthologues in the sponge Amphimedon queenslandica of genes encoding synaptic submodules in neural animals, and analyse their cell-type specific and developmental expression to determine their potential to be co-regulated. We find that genes comprising certain synaptic submodules, including those involved in vesicle trafficking, calcium-regulation and scaffolding of postsynaptic receptor clusters, are co-expressed in adult choanocytes and during metamorphosis. Although these submodules may contribute to sensory roles in this cell type and this life cycle stage, total synaptic gene co-expression profiles do not support the existence of a functional synapse in A. queenslandica. The lack of evidence for the co-regulation of genes necessary for pre- and post-synaptic functioning in A. queenslandica suggests that sponges, and perhaps the last common ancestor of sponges and other extant animals, had the ability to promulgate sensory inputs without complete synapse-like functionalities. The differential co-expression of multiple synaptic submodule genes in sponge choanocytes, which have sensory and feeding roles, however, is consistent with the metazoan ancestor minimally being able to undergo exo- and endocytosis in a controlled and localized manner.
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Affiliation(s)
- Eunice Wong
- School of Biological Sciences, University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Jan Mölter
- Queensland Brain Institute, University of Queensland, Brisbane, Queensland, 4072, Australia
- School of Mathematics and Physics, University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Victor Anggono
- Queensland Brain Institute, University of Queensland, Brisbane, Queensland, 4072, Australia
- Clem Jones Centre for Ageing Dementia Research, University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Sandie M Degnan
- School of Biological Sciences, University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Bernard M Degnan
- School of Biological Sciences, University of Queensland, Brisbane, Queensland, 4072, Australia.
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18
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Arendt D, Bertucci PY, Achim K, Musser JM. Evolution of neuronal types and families. Curr Opin Neurobiol 2019; 56:144-152. [PMID: 30826503 PMCID: PMC6556553 DOI: 10.1016/j.conb.2019.01.022] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 01/25/2019] [Accepted: 01/27/2019] [Indexed: 12/12/2022]
Abstract
Solving nervous system evolution requires cross-species comparison of neuronal types. Neuronal types are commonly defined by their specific structure and function. We provide an operational definition of cell types that allows evolutionary comparison. The identity of neuronal types is best reflected by specifying transcription factors. Families of related neuronal types are conserved across large evolutionary distances.
Major questions in the evolution of neurons and nervous systems remain unsolved, such as the origin of the first neuron, the possible convergent evolution of neuronal phenotypes, and the transition from a relatively simple decentralized nerve net to the complex, centralized nervous systems found in modern bilaterian animals. In recent years, comparative single-cell transcriptomics has opened up new research avenues addressing these issues. Here, we review recent conceptual progress toward an evolutionary definition of cell types, and how it facilitates the identification and large-scale comparison of neuronal types and neuron type families from single-cell data — with the family of GABAergic neurons in distinct parts of the vertebrate forebrain as prime example. We also highlight strategies to infer cell type-specific innovation, so-called apomeres, from single-cell data.
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Affiliation(s)
- Detlev Arendt
- Developmental Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69012, Heidelberg, Germany.
| | - Paola Yanina Bertucci
- Developmental Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69012, Heidelberg, Germany
| | - Kaia Achim
- Developmental Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69012, Heidelberg, Germany
| | - Jacob M Musser
- Developmental Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69012, Heidelberg, Germany
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19
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Whitten AE, Jarrott RJ, Hu SH, Duff AP, King GJ, Martin JL, Christie MP. Studying Munc18:Syntaxin Interactions Using Small-Angle Scattering. Methods Mol Biol 2019; 1860:115-144. [PMID: 30317501 DOI: 10.1007/978-1-4939-8760-3_7] [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: 06/08/2023]
Abstract
The interaction between the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein syntaxin (Sx) and regulatory partner Sec/Munc18 (SM) protein is a critical step in vesicle fusion. The exact role played by SM proteins, whether positive or negative, has been the topic of much debate. High-resolution structures of the SM:Sx complex have shown that SM proteins can bind syntaxin in a closed fusion incompetent state. However, in vitro and in vivo experiments also point to a positive regulatory role for SM proteins that is inconsistent with binding syntaxin in a closed conformation. Here we present protocols we used for the expression and purification of the SM proteins Munc18a and Munc18c and syntaxins 1 and 4 along with procedures used for small-angle X-ray and neutron scattering that showed that syntaxins can bind in an open conformation to SM proteins. We also describe methods for chemical cross-linking experiments and detail how this information can be combined with scattering data to obtain low-resolution structural models for SM:Sx protein complexes.
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Affiliation(s)
- Andrew E Whitten
- Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, Australia
| | - Russell J Jarrott
- Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD, Australia
| | - Shu-Hong Hu
- Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD, Australia
| | - Anthony P Duff
- Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, Australia
| | - Gordon J King
- Centre for Microscopy and Microanalysis, The University of Queensland, St Lucia, QLD, Australia
| | - Jennifer L Martin
- Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD, Australia
| | - Michelle P Christie
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia.
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20
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The remembrance of the things past: Conserved signalling pathways link protozoa to mammalian nervous system. Cell Calcium 2018; 73:25-39. [DOI: 10.1016/j.ceca.2018.04.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/01/2018] [Accepted: 04/01/2018] [Indexed: 12/13/2022]
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21
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de Wiljes OO, van Elburg RAJ, Keijzer FA. Modelling the effects of short and random proto-neural elongations. J R Soc Interface 2018; 14:rsif.2017.0399. [PMID: 29070590 DOI: 10.1098/rsif.2017.0399] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 10/05/2017] [Indexed: 11/12/2022] Open
Abstract
To understand how neurons and nervous systems first evolved, we need an account of the origins of neural elongations: why did neural elongations (axons and dendrites) first originate, such that they could become the central component of both neurons and nervous systems? Two contrasting conceptual accounts provide different answers to this question. Braitenberg's vehicles provide the iconic illustration of the dominant input-output (IO) view. Here, the basic role of neural elongations is to connect sensors to effectors, both situated at different positions within the body. For this function, neural elongations are thought of as comparatively long and specific connections, which require an articulated body involving substantial developmental processes to build. Internal coordination (IC) models stress a different function for early nervous systems. Here, the coordination of activity across extended parts of a multicellular body is held central, in particular, for the contractions of (muscle) tissue. An IC perspective allows the hypothesis that the earliest proto-neural elongations could have been functional even when they were initially simple, short and random connections, as long as they enhanced the patterning of contractile activity across a multicellular surface. The present computational study provides a proof of concept that such short and random neural elongations can play this role. While an excitable epithelium can generate basic forms of patterning for small body configurations, adding elongations allows such patterning to scale up to larger bodies. This result supports a new, more gradual evolutionary route towards the origins of the very first neurons and nervous systems.
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Affiliation(s)
- Oltman O de Wiljes
- Department of Theoretical Philosophy, University of Groningen, Groningen, The Netherlands .,Research School of Behavioural and Cognitive Neurosciences, University of Groningen, Groningen, The Netherlands
| | - R A J van Elburg
- Institute of Artificial Intelligence, University of Groningen, Groningen, The Netherlands
| | - Fred A Keijzer
- Department of Theoretical Philosophy, University of Groningen, Groningen, The Netherlands.,Research School of Behavioural and Cognitive Neurosciences, University of Groningen, Groningen, The Netherlands
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22
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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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23
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Cavalier-Smith T. Origin of animal multicellularity: precursors, causes, consequences-the choanoflagellate/sponge transition, neurogenesis and the Cambrian explosion. Philos Trans R Soc Lond B Biol Sci 2017; 372:rstb.2015.0476. [PMID: 27994119 PMCID: PMC5182410 DOI: 10.1098/rstb.2015.0476] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/05/2016] [Indexed: 02/07/2023] Open
Abstract
Evolving multicellularity is easy, especially in phototrophs and osmotrophs whose multicells feed like unicells. Evolving animals was much harder and unique; probably only one pathway via benthic ‘zoophytes’ with pelagic ciliated larvae allowed trophic continuity from phagocytic protozoa to gut-endowed animals. Choanoflagellate protozoa produced sponges. Converting sponge flask cells mediating larval settling to synaptically controlled nematocysts arguably made Cnidaria. I replace Haeckel's gastraea theory by a sponge/coelenterate/bilaterian pathway: Placozoa, hydrozoan diploblasty and ctenophores were secondary; stem anthozoan developmental mutations arguably independently generated coelomate bilateria and ctenophores. I emphasize animal origin's conceptual aspects (selective, developmental) related to feeding modes, cell structure, phylogeny of related protozoa, sequence evidence, ecology and palaeontology. Epithelia and connective tissue could evolve only by compensating for dramatically lower feeding efficiency that differentiation into non-choanocytes entails. Consequentially, larger bodies enabled filtering more water for bacterial food and harbouring photosynthetic bacteria, together adding more food than cell differentiation sacrificed. A hypothetical presponge of sessile triploblastic sheets (connective tissue sandwiched between two choanocyte epithelia) evolved oogamy through selection for larger dispersive ciliated larvae to accelerate benthic trophic competence and overgrowing protozoan competitors. Extinct Vendozoa might be elaborations of this organismal grade with choanocyte-bearing epithelia, before poriferan water channels and cnidarian gut/nematocysts/synapses evolved. This article is part of the themed issue ‘Evo-devo in the genomics era, and the origins of morphological diversity’.
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24
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Highly diversified expansions shaped the evolution of membrane bound proteins in metazoans. Sci Rep 2017; 7:12387. [PMID: 28959054 PMCID: PMC5620054 DOI: 10.1038/s41598-017-11543-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 08/15/2017] [Indexed: 11/20/2022] Open
Abstract
The dramatic increase in membrane proteome complexity is arguably one of the most pivotal evolutionary events that underpins the origin of multicellular animals. However, the origin of a significant number of membrane families involved in metazoan development has not been clarified. In this study, we have manually curated the membrane proteomes of 22 metazoan and 2 unicellular holozoan species. We identify 123,014 membrane proteins in these 24 eukaryotic species and classify 86% of the dataset. We determine 604 functional clusters that are present from the last holozoan common ancestor (LHCA) through many metazoan species. Intriguingly, we show that more than 70% of the metazoan membrane protein families have a premetazoan origin. The data show that enzymes are more highly represented in the LHCA and expand less than threefold throughout metazoan species; in contrast to receptors that are relatively few in the LHCA but expand nearly eight fold within metazoans. Expansions related to cell adhesion, communication, immune defence, and developmental processes are shown in conjunction with emerging biological systems, such as neuronal development, cytoskeleton organization, and the adaptive immune response. This study defines the possible LHCA membrane proteome and describes the fundamental functional clusters that underlie metazoan diversity and innovation.
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25
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Abstract
The evolution of a nervous system as a control system of the body's functions is a key innovation of animals. Its fundamental units are neurons, highly specialized cells dedicated to fast cell-cell communication. Neurons pass signals to other neurons, muscle cells, or gland cells at specialized junctions, the synapses, where transmitters are released from vesicles in a Ca2+-dependent fashion to activate receptors in the membrane of the target cell. Reconstructing the origins of neuronal communication out of a more simple process remains a central challenge in biology. Recent genomic comparisons have revealed that all animals, including the nerveless poriferans and placozoans, share a basic set of genes for neuronal communication. This suggests that the first animal, the Urmetazoan, was already endowed with neurosecretory cells that probably started to connect into neuronal networks soon afterward. Here, we discuss scenarios for this pivotal transition in animal evolution.
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Affiliation(s)
- Frederique Varoqueaux
- Département des Neurosciences Fondamentales, Université de Lausanne, Lausanne, CH-1005 Switzerland; ,
| | - Dirk Fasshauer
- Département des Neurosciences Fondamentales, Université de Lausanne, Lausanne, CH-1005 Switzerland; ,
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26
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Plattner H. Evolutionary Cell Biology of Proteins from Protists to Humans and Plants. J Eukaryot Microbiol 2017; 65:255-289. [PMID: 28719054 DOI: 10.1111/jeu.12449] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 07/04/2017] [Accepted: 07/07/2017] [Indexed: 01/10/2023]
Abstract
During evolution, the cell as a fine-tuned machine had to undergo permanent adjustments to match changes in its environment, while "closed for repair work" was not possible. Evolution from protists (protozoa and unicellular algae) to multicellular organisms may have occurred in basically two lineages, Unikonta and Bikonta, culminating in mammals and angiosperms (flowering plants), respectively. Unicellular models for unikont evolution are myxamoebae (Dictyostelium) and increasingly also choanoflagellates, whereas for bikonts, ciliates are preferred models. Information accumulating from combined molecular database search and experimental verification allows new insights into evolutionary diversification and maintenance of genes/proteins from protozoa on, eventually with orthologs in bacteria. However, proteins have rarely been followed up systematically for maintenance or change of function or intracellular localization, acquirement of new domains, partial deletion (e.g. of subunits), and refunctionalization, etc. These aspects are discussed in this review, envisaging "evolutionary cell biology." Protozoan heritage is found for most important cellular structures and functions up to humans and flowering plants. Examples discussed include refunctionalization of voltage-dependent Ca2+ channels in cilia and replacement by other types during evolution. Altogether components serving Ca2+ signaling are very flexible throughout evolution, calmodulin being a most conservative example, in contrast to calcineurin whose catalytic subunit is lost in plants, whereas both subunits are maintained up to mammals for complex functions (immune defense and learning). Domain structure of R-type SNAREs differs in mono- and bikonta, as do Ca2+ -dependent protein kinases. Unprecedented selective expansion of the subunit a which connects multimeric base piece and head parts (V0, V1) of H+ -ATPase/pump may well reflect the intriguing vesicle trafficking system in ciliates, specifically in Paramecium. One of the most flexible proteins is centrin when its intracellular localization and function throughout evolution is traced. There are many more examples documenting evolutionary flexibility of translation products depending on requirements and potential for implantation within the actual cellular context at different levels of evolution. From estimates of gene and protein numbers per organism, it appears that much of the basic inventory of protozoan precursors could be transmitted to highest eukaryotic levels, with some losses and also with important additional "inventions."
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Affiliation(s)
- Helmut Plattner
- Department of Biology, University of Konstanz, P. O. Box M625, Konstanz, 78457, Germany
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27
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Bosch TCG, Klimovich A, Domazet-Lošo T, Gründer S, Holstein TW, Jékely G, Miller DJ, Murillo-Rincon AP, Rentzsch F, Richards GS, Schröder K, Technau U, Yuste R. Back to the Basics: Cnidarians Start to Fire. Trends Neurosci 2016; 40:92-105. [PMID: 28041633 DOI: 10.1016/j.tins.2016.11.005] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 11/22/2016] [Accepted: 11/23/2016] [Indexed: 12/15/2022]
Abstract
The nervous systems of cnidarians, pre-bilaterian animals that diverged close to the base of the metazoan radiation, are structurally simple and thus have great potential to reveal fundamental principles of neural circuits. Unfortunately, cnidarians have thus far been relatively intractable to electrophysiological and genetic techniques and consequently have been largely passed over by neurobiologists. However, recent advances in molecular and imaging methods are fueling a renaissance of interest in and research into cnidarians nervous systems. Here, we review current knowledge on the nervous systems of cnidarian species and propose that researchers should seize this opportunity and undertake the study of members of this phylum as strategic experimental systems with great basic and translational relevance for neuroscience.
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Affiliation(s)
| | | | - Tomislav Domazet-Lošo
- Ruđer Bošković Institute, Zagreb, Croatia; Catholic University of Croatia, Zagreb, Croatia
| | - Stefan Gründer
- Institute of Physiology, RWTH Aachen University, Germany
| | | | - Gáspár Jékely
- Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - David J Miller
- ARC Centre of Excellence for Coral Reef Studies, Townsville, Australia
| | | | - Fabian Rentzsch
- Sars International Centre for Marine Molecular Biology, University of Bergen, Norway
| | - Gemma S Richards
- Sars International Centre for Marine Molecular Biology, University of Bergen, Norway; University of Queensland, Brisbane, Australia
| | | | | | - Rafael Yuste
- Neurotechnology Center, Columbia University, New York, NY, USA.
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28
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Wray GA. Molecular clocks and the early evolution of metazoan nervous systems. Philos Trans R Soc Lond B Biol Sci 2016; 370:rstb.2015.0046. [PMID: 26554040 DOI: 10.1098/rstb.2015.0046] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The timing of early animal evolution remains poorly resolved, yet remains critical for understanding nervous system evolution. Methods for estimating divergence times from sequence data have improved considerably, providing a more refined understanding of key divergences. The best molecular estimates point to the origin of metazoans and bilaterians tens to hundreds of millions of years earlier than their first appearances in the fossil record. Both the molecular and fossil records are compatible, however, with the possibility of tiny, unskeletonized, low energy budget animals during the Proterozoic that had planktonic, benthic, or meiofaunal lifestyles. Such animals would likely have had relatively simple nervous systems equipped primarily to detect food, avoid inhospitable environments and locate mates. The appearance of the first macropredators during the Cambrian would have changed the selective landscape dramatically, likely driving the evolution of complex sense organs, sophisticated sensory processing systems, and diverse effector systems involved in capturing prey and avoiding predation.
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Affiliation(s)
- Gregory A Wray
- Department of Biology and Center for Genomic and Computational Biology, Duke University, Durham, NC 27708, USA
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Arendt D, Benito-Gutierrez E, Brunet T, Marlow H. Gastric pouches and the mucociliary sole: setting the stage for nervous system evolution. Philos Trans R Soc Lond B Biol Sci 2016; 370:rstb.2015.0286. [PMID: 26554050 PMCID: PMC4650134 DOI: 10.1098/rstb.2015.0286] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Prerequisite for tracing nervous system evolution is understanding of the body plan, feeding behaviour and locomotion of the first animals in which neurons evolved. Here, a comprehensive scenario is presented for the diversification of cell types in early metazoans, which enhanced feeding efficiency and led to the emergence of larger animals that were able to move. Starting from cup-shaped, gastraea-like animals with outer and inner choanoflagellate-like cells, two major innovations are discussed that set the stage for nervous system evolution. First, the invention of a mucociliary sole entailed a switch from intra- to extracellular digestion and increased the concentration of nutrients flowing into the gastric cavity. In these animals, an initial nerve net may have evolved via division of labour from mechanosensory-contractile cells in the lateral body wall, enabling coordinated movement of the growing body that involved both mucociliary creeping and changes of body shape. Second, the inner surface of the animals folded into metameric series of gastric pouches, which optimized nutrient resorption and allowed larger body sizes. The concomitant acquisition of bilateral symmetry may have allowed more directed locomotion and, with more demanding coordinative tasks, triggered the evolution of specialized nervous subsystems. Animals of this organizational state would have resembled Ediacarian fossils such as Dickinsonia and may have been close to the cnidarian–bilaterian ancestor. In the bilaterian lineage, the mucociliary sole was used mostly for creeping, or frequently lost. One possible remnant is the enigmatic Reissner's fibre in the ventral neural tube of cephalochordates and vertebrates.
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Affiliation(s)
- Detlev Arendt
- European Molecular Biology Laboratory, Meyerhofstrasse 1, 69012 Heidelberg, Germany Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | | | - Thibaut Brunet
- European Molecular Biology Laboratory, Meyerhofstrasse 1, 69012 Heidelberg, Germany
| | - Heather Marlow
- European Molecular Biology Laboratory, Meyerhofstrasse 1, 69012 Heidelberg, Germany
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Choanoflagellate models - Monosiga brevicollis and Salpingoeca rosetta. Curr Opin Genet Dev 2016; 39:42-47. [PMID: 27318693 DOI: 10.1016/j.gde.2016.05.016] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 05/23/2016] [Accepted: 05/26/2016] [Indexed: 11/21/2022]
Abstract
Choanoflagellates are the closest single-celled relatives of animals and provide fascinating insights into developmental processes in animals. Two species, the choanoflagellates Monosiga brevicollis and Salpingoeca rosetta are emerging as promising model organisms to reveal the evolutionary origin of key animal innovations. In this review, we highlight how choanoflagellates are used to study the origin of multicellularity in animals. The newly available genomic resources and functional techniques provide important insights into the function of choanoflagellate pre- and postsynaptic proteins, cell-cell adhesion and signaling molecules and the evolution of animal filopodia and thus underscore the relevance of choanoflagellate models for evolutionary biology, neurobiology and cell biology research.
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Abstract
An actin filament coat promotes cargo expulsion from large exocytosing vesicles, but the mechanisms of coat formation and force generation have been poorly characterized. Elegant imaging studies of the Drosophila melanogaster salivary gland now reveal how actin and myosin are recruited, and show that myosin II forms a contractile 'cage' that facilitates exocytosis.
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Affiliation(s)
- Christien J Merrifield
- Institute for Integrative Biology of the Cell, Bât. 34, Avenue de la Terrasse, 9198 Gif sur Yvette cedex, France
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Ryan JF, Chiodin M. Where is my mind? How sponges and placozoans may have lost neural cell types. Philos Trans R Soc Lond B Biol Sci 2015; 370:20150059. [PMID: 26554046 PMCID: PMC4650130 DOI: 10.1098/rstb.2015.0059] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/12/2015] [Indexed: 01/01/2023] Open
Abstract
Recent phylogenomic evidence suggests that ctenophores may be the sister group to the rest of animals. This phylogenetic arrangement opens the possibility that sponges and placozoans could have lost neural cell types or that the ctenophore nervous system evolved independently. We critically review evidence to date that has been put forth in support of independent evolution of neural cell types in ctenophores. We observe a reluctance in the literature to consider a lost nervous system in sponges and placozoans and suggest that this may be due to historical bias and the commonly misconstrued concept of animal complexity. In support of the idea of loss (or modification beyond recognition), we provide hypothetical scenarios to show how sponges and placozoans may have benefitted from the loss and/or modification of their neural cell types.
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Affiliation(s)
- Joseph F Ryan
- Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Blvd, St Augustine, FL 32080, USA Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Marta Chiodin
- Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Blvd, St Augustine, FL 32080, USA Department of Biology, University of Florida, Gainesville, FL 32611, USA
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Pazos Obregón F, Papalardo C, Castro S, Guerberoff G, Cantera R. Putative synaptic genes defined from a Drosophila whole body developmental transcriptome by a machine learning approach. BMC Genomics 2015; 16:694. [PMID: 26370122 PMCID: PMC4570697 DOI: 10.1186/s12864-015-1888-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 09/01/2015] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Assembly and function of neuronal synapses require the coordinated expression of a yet undetermined set of genes. Although roughly a thousand genes are expected to be important for this function in Drosophila melanogaster, just a few hundreds of them are known so far. RESULTS In this work we trained three learning algorithms to predict a "synaptic function" for genes of Drosophila using data from a whole-body developmental transcriptome published by others. Using statistical and biological criteria to analyze and combine the predictions, we obtained a gene catalogue that is highly enriched in genes of relevance for Drosophila synapse assembly and function but still not recognized as such. CONCLUSIONS The utility of our approach is that it reduces the number of genes to be tested through hypothesis-driven experimentation.
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Affiliation(s)
- Flavio Pazos Obregón
- Departamento de Biología del Neurodesarrollo, Instituto de Investigaciones Biológicas Clemente Estable, Avenida Italia 3318, PC 11600, Montevideo, Uruguay.
| | - Cecilia Papalardo
- Instituto de Matemática y Estadística "Prof. Ing. Rafael Laguardia", Facultad de Ingeniería, Universidad de la República, Montevideo, Uruguay.
| | - Sebastián Castro
- Instituto de Matemática y Estadística "Prof. Ing. Rafael Laguardia", Facultad de Ingeniería, Universidad de la República, Montevideo, Uruguay.
| | - Gustavo Guerberoff
- Instituto de Matemática y Estadística "Prof. Ing. Rafael Laguardia", Facultad de Ingeniería, Universidad de la República, Montevideo, Uruguay.
| | - Rafael Cantera
- Departamento de Biología del Neurodesarrollo, Instituto de Investigaciones Biológicas Clemente Estable, Avenida Italia 3318, PC 11600, Montevideo, Uruguay.
- Zoology Department, Stockholm University, Stockholm, Sweden.
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Affiliation(s)
- Dirk Bucher
- New Jersey Institute of Technology and Rutgers University, USA.
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