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Sheloukhova L, Watanabe H. Evolution of glial cells: a non-bilaterian perspective. Neural Dev 2024; 19:10. [PMID: 38907299 PMCID: PMC11193209 DOI: 10.1186/s13064-024-00184-4] [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] [Received: 09/19/2023] [Accepted: 06/06/2024] [Indexed: 06/23/2024] Open
Abstract
Nervous systems of bilaterian animals generally consist of two cell types: neurons and glial cells. Despite accumulating data about the many important functions glial cells serve in bilaterian nervous systems, the evolutionary origin of this abundant cell type remains unclear. Current hypotheses regarding glial evolution are mostly based on data from model bilaterians. Non-bilaterian animals have been largely overlooked in glial studies and have been subjected only to morphological analysis. Here, we provide a comprehensive overview of conservation of the bilateral gliogenic genetic repertoire of non-bilaterian phyla (Cnidaria, Placozoa, Ctenophora, and Porifera). We overview molecular and functional features of bilaterian glial cell types and discuss their possible evolutionary history. We then examine which glial features are present in non-bilaterians. Of these, cnidarians show the highest degree of gliogenic program conservation and may therefore be crucial to answer questions about glial evolution.
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Affiliation(s)
- Larisa Sheloukhova
- Evolutionary Neurobiology Unit, Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0412, Japan
| | - Hiroshi Watanabe
- Evolutionary Neurobiology Unit, Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0412, Japan.
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2
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Paré L, Bideau L, Baduel L, Dalle C, Benchouaia M, Schneider SQ, Laplane L, Clément Y, Vervoort M, Gazave E. Transcriptomic landscape of posterior regeneration in the annelid Platynereis dumerilii. BMC Genomics 2023; 24:583. [PMID: 37784028 PMCID: PMC10546743 DOI: 10.1186/s12864-023-09602-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: 05/25/2023] [Accepted: 08/18/2023] [Indexed: 10/04/2023] Open
Abstract
BACKGROUND Restorative regeneration, the capacity to reform a lost body part following amputation or injury, is an important and still poorly understood process in animals. Annelids, or segmented worms, show amazing regenerative capabilities, and as such are a crucial group to investigate. Elucidating the molecular mechanisms that underpin regeneration in this major group remains a key goal. Among annelids, the nereididae Platynereis dumerilii (re)emerged recently as a front-line regeneration model. Following amputation of its posterior part, Platynereis worms can regenerate both differentiated tissues of their terminal part as well as a growth zone that contains putative stem cells. While this regeneration process follows specific and reproducible stages that have been well characterized, the transcriptomic landscape of these stages remains to be uncovered. RESULTS We generated a high-quality de novo Reference transcriptome for the annelid Platynereis dumerilii. We produced and analyzed three RNA-sequencing datasets, encompassing five stages of posterior regeneration, along with blastema stages and non-amputated tissues as controls. We included two of these regeneration RNA-seq datasets, as well as embryonic and tissue-specific datasets from the literature to produce a Reference transcriptome. We used this Reference transcriptome to perform in depth analyzes of RNA-seq data during the course of regeneration to reveal the important dynamics of the gene expression, process with thousands of genes differentially expressed between stages, as well as unique and specific gene expression at each regeneration stage. The study of these genes highlighted the importance of the nervous system at both early and late stages of regeneration, as well as the enrichment of RNA-binding proteins (RBPs) during almost the entire regeneration process. CONCLUSIONS In this study, we provided a high-quality de novo Reference transcriptome for the annelid Platynereis that is useful for investigating various developmental processes, including regeneration. Our extensive stage-specific transcriptional analysis during the course of posterior regeneration sheds light upon major molecular mechanisms and pathways, and will foster many specific studies in the future.
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Affiliation(s)
- Louis Paré
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, F-75013, France
| | - Loïc Bideau
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, F-75013, France
| | - Loeiza Baduel
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, F-75013, France
| | - Caroline Dalle
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, F-75013, France
| | - Médine Benchouaia
- Département de biologie, GenomiqueENS, Institut de Biologie de l'ENS (IBENS), École normale supérieure, CNRS, INSERM, Université PSL, Paris, 75005, France
| | - Stephan Q Schneider
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - Lucie Laplane
- Université Paris I Panthéon-Sorbonne, CNRS UMR 8590 Institut d'Histoire et de Philosophie des Sciences et des Techniques (IHPST), Paris, France
- Gustave Roussy, UMR 1287, Villejuif, France
| | - Yves Clément
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, F-75013, France
| | - Michel Vervoort
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, F-75013, France
| | - Eve Gazave
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, F-75013, France.
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3
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Rinkevich B, Ballarin L, Martinez P, Somorjai I, Ben-Hamo O, Borisenko I, Berezikov E, Ereskovsky A, Gazave E, Khnykin D, Manni L, Petukhova O, Rosner A, Röttinger E, Spagnuolo A, Sugni M, Tiozzo S, Hobmayer B. A pan-metazoan concept for adult stem cells: the wobbling Penrose landscape. Biol Rev Camb Philos Soc 2021; 97:299-325. [PMID: 34617397 PMCID: PMC9292022 DOI: 10.1111/brv.12801] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 09/20/2021] [Accepted: 09/22/2021] [Indexed: 12/17/2022]
Abstract
Adult stem cells (ASCs) in vertebrates and model invertebrates (e.g. Drosophila melanogaster) are typically long‐lived, lineage‐restricted, clonogenic and quiescent cells with somatic descendants and tissue/organ‐restricted activities. Such ASCs are mostly rare, morphologically undifferentiated, and undergo asymmetric cell division. Characterized by ‘stemness’ gene expression, they can regulate tissue/organ homeostasis, repair and regeneration. By contrast, analysis of other animal phyla shows that ASCs emerge at different life stages, present both differentiated and undifferentiated phenotypes, and may possess amoeboid movement. Usually pluri/totipotent, they may express germ‐cell markers, but often lack germ‐line sequestering, and typically do not reside in discrete niches. ASCs may constitute up to 40% of animal cells, and participate in a range of biological phenomena, from whole‐body regeneration, dormancy, and agametic asexual reproduction, to indeterminate growth. They are considered legitimate units of selection. Conceptualizing this divergence, we present an alternative stemness metaphor to the Waddington landscape: the ‘wobbling Penrose’ landscape. Here, totipotent ASCs adopt ascending/descending courses of an ‘Escherian stairwell’, in a lifelong totipotency pathway. ASCs may also travel along lower stemness echelons to reach fully differentiated states. However, from any starting state, cells can change their stemness status, underscoring their dynamic cellular potencies. Thus, vertebrate ASCs may reflect just one metazoan ASC archetype.
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Affiliation(s)
- Baruch Rinkevich
- Israel Oceanographic & Limnological Research, National Institute of Oceanography, POB 9753, Tel Shikmona, Haifa, 3109701, Israel
| | - Loriano Ballarin
- Department of Biology, University of Padova, Via Ugo Bassi 58/B, Padova, 35121, Italy
| | - Pedro Martinez
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Av. Diagonal 643, Barcelona, 08028, Spain.,Institut Català de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, Barcelona, 08010, Spain
| | - Ildiko Somorjai
- School of Biology, University of St Andrews, St Andrews, Fife, KY16 9ST, Scotland, UK
| | - Oshrat Ben-Hamo
- Israel Oceanographic & Limnological Research, National Institute of Oceanography, POB 9753, Tel Shikmona, Haifa, 3109701, Israel
| | - Ilya Borisenko
- Department of Embryology, Faculty of Biology, Saint-Petersburg State University, University Embankment, 7/9, Saint-Petersburg, 199034, Russia
| | - Eugene Berezikov
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, Antonius Deusinglaan 1, Groningen, 9713 AV, The Netherlands
| | - Alexander Ereskovsky
- Department of Embryology, Faculty of Biology, Saint-Petersburg State University, University Embankment, 7/9, Saint-Petersburg, 199034, Russia.,Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale (IMBE), Aix Marseille University, CNRS, IRD, Avignon University, Jardin du Pharo, 58 Boulevard Charles Livon, Marseille, 13007, France.,Koltzov Institute of Developmental Biology of Russian Academy of Sciences, Ulitsa Vavilova, 26, Moscow, 119334, Russia
| | - Eve Gazave
- Université de Paris, CNRS, Institut Jacques Monod, Paris, F-75006, France
| | - Denis Khnykin
- Department of Pathology, Oslo University Hospital, Bygg 19, Gaustad Sykehus, Sognsvannsveien 21, Oslo, 0188, Norway
| | - Lucia Manni
- Department of Biology, University of Padova, Via Ugo Bassi 58/B, Padova, 35121, Italy
| | - Olga Petukhova
- Collection of Vertebrate Cell Cultures, Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Ave. 4, St. Petersburg, 194064, Russia
| | - Amalia Rosner
- Israel Oceanographic & Limnological Research, National Institute of Oceanography, POB 9753, Tel Shikmona, Haifa, 3109701, Israel
| | - Eric Röttinger
- Université Côte d'Azur, CNRS, INSERM, Institute for Research on Cancer and Aging, Nice (IRCAN), Nice, 06107, France.,Université Côte d'Azur, Federative Research Institute - Marine Resources (IFR MARRES), 28 Avenue de Valrose, Nice, 06103, France
| | - Antonietta Spagnuolo
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, Naples, 80121, Italy
| | - Michela Sugni
- Department of Environmental Science and Policy (ESP), Università degli Studi di Milano, Via Celoria 26, Milan, 20133, Italy
| | - Stefano Tiozzo
- Sorbonne Université, CNRS, Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV), 06234 Villefranche-sur-Mer, Villefranche sur Mer, Cedex, France
| | - Bert Hobmayer
- Institute of Zoology and Center for Molecular Biosciences, University of Innsbruck, Technikerstr, Innsbruck, 256020, Austria
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4
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Özpolat BD, Randel N, Williams EA, Bezares-Calderón LA, Andreatta G, Balavoine G, Bertucci PY, Ferrier DEK, Gambi MC, Gazave E, Handberg-Thorsager M, Hardege J, Hird C, Hsieh YW, Hui J, Mutemi KN, Schneider SQ, Simakov O, Vergara HM, Vervoort M, Jékely G, Tessmar-Raible K, Raible F, Arendt D. The Nereid on the rise: Platynereis as a model system. EvoDevo 2021; 12:10. [PMID: 34579780 PMCID: PMC8477482 DOI: 10.1186/s13227-021-00180-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 08/20/2021] [Indexed: 01/02/2023] Open
Abstract
The Nereid Platynereis dumerilii (Audouin and Milne Edwards (Annales des Sciences Naturelles 1:195-269, 1833) is a marine annelid that belongs to the Nereididae, a family of errant polychaete worms. The Nereid shows a pelago-benthic life cycle: as a general characteristic for the superphylum of Lophotrochozoa/Spiralia, it has spirally cleaving embryos developing into swimming trochophore larvae. The larvae then metamorphose into benthic worms living in self-spun tubes on macroalgae. Platynereis is used as a model for genetics, regeneration, reproduction biology, development, evolution, chronobiology, neurobiology, ecology, ecotoxicology, and most recently also for connectomics and single-cell genomics. Research on the Nereid started with studies on eye development and spiralian embryogenesis in the nineteenth and early twentieth centuries. Transitioning into the molecular era, Platynereis research focused on posterior growth and regeneration, neuroendocrinology, circadian and lunar cycles, fertilization, and oocyte maturation. Other work covered segmentation, photoreceptors and other sensory cells, nephridia, and population dynamics. Most recently, the unique advantages of the Nereid young worm for whole-body volume electron microscopy and single-cell sequencing became apparent, enabling the tracing of all neurons in its rope-ladder-like central nervous system, and the construction of multimodal cellular atlases. Here, we provide an overview of current topics and methodologies for P. dumerilii, with the aim of stimulating further interest into our unique model and expanding the active and vibrant Platynereis community.
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Affiliation(s)
- B. Duygu Özpolat
- Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, Woods Hole, MA 02543 USA
| | - Nadine Randel
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ UK
| | - Elizabeth A. Williams
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | | | - Gabriele Andreatta
- Max Perutz Labs, University of Vienna, Dr. Bohr-Gasse 9/4, 1030 Vienna, Austria
| | - Guillaume Balavoine
- Institut Jacques Monod, University of Paris/CNRS, 15 rue Hélène Brion, 75013 Paris, France
| | - Paola Y. Bertucci
- European Molecular Biology Laboratory, Developmental Biology Unit, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - David E. K. Ferrier
- Gatty Marine Laboratory, The Scottish Oceans Institute, University of St Andrews, East Sands, St Andrews, Fife, KY16 8LB UK
| | | | - Eve Gazave
- Institut Jacques Monod, University of Paris/CNRS, 15 rue Hélène Brion, 75013 Paris, France
| | - Mette Handberg-Thorsager
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Jörg Hardege
- Department of Biological & Marine Sciences, Hull University, Cottingham Road, Hull, HU67RX UK
| | - Cameron Hird
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, UK
| | - Yu-Wen Hsieh
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Jerome Hui
- School of Life Sciences, Simon F.S. Li Marine Science Laboratory, State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China
| | - Kevin Nzumbi Mutemi
- European Molecular Biology Laboratory, Developmental Biology Unit, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Stephan Q. Schneider
- Institute of Cellular and Organismic Biology, Academia Sinica, No. 128, Sec. 2, Academia Road, Nankang, Taipei, 11529 Taiwan
| | - Oleg Simakov
- Department for Neurosciences and Developmental Biology, University of Vienna, Vienna, Austria
| | - Hernando M. Vergara
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, Howland Street 25, London, W1T 4JG UK
| | - Michel Vervoort
- Institut Jacques Monod, University of Paris/CNRS, 15 rue Hélène Brion, 75013 Paris, France
| | - Gáspár Jékely
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, UK
| | | | - Florian Raible
- Max Perutz Labs, University of Vienna, Dr. Bohr-Gasse 9/4, 1030 Vienna, Austria
| | - Detlev Arendt
- European Molecular Biology Laboratory, Developmental Biology Unit, Meyerhofstrasse 1, 69117 Heidelberg, Germany
- Centre for Organismal Studies (COS), University of Heidelberg, 69120 Heidelberg, Germany
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5
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Sachslehner A, Zieger E, Calcino A, Wanninger A. HES and Mox genes are expressed during early mesoderm formation in a mollusk with putative ancestral features. Sci Rep 2021; 11:18030. [PMID: 34504115 PMCID: PMC8429573 DOI: 10.1038/s41598-021-96711-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 08/13/2021] [Indexed: 11/08/2022] Open
Abstract
The mesoderm is considered the youngest of the three germ layers. Although its morphogenesis has been studied in some metazoans, the molecular components underlying this process remain obscure for numerous phyla including the highly diverse Mollusca. Here, expression of Hairy and enhancer of split (HES), Mox, and myosin heavy chain (MHC) was investigated in Acanthochitona fascicularis, a representative of Polyplacophora with putative ancestral molluscan features. While AfaMHC is expressed throughout myogenesis, AfaMox1 is only expressed during early stages of mesodermal band formation and in the ventrolateral muscle, an autapomorphy of the polyplacophoran trochophore. Comparing our findings to previously published data across Metazoa reveals Mox expression in the mesoderm in numerous bilaterians including gastropods, polychaetes, and brachiopods. It is also involved in myogenesis in molluscs, annelids, tunicates, and craniates, suggesting a dual role of Mox in mesoderm and muscle formation in the last common bilaterian ancestor. AfaHESC2 is expressed in the ectoderm of the polyplacophoran gastrula and later in the mesodermal bands and in putative neural tissue, whereas AfaHESC7 is expressed in the trochoblasts of the gastrula and during foregut formation. This confirms the high developmental variability of HES gene expression and demonstrates that Mox and HES genes are pleiotropic.
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Affiliation(s)
- Attila Sachslehner
- Department of Evolutionary Biology, Unit for Integrative Zoology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Elisabeth Zieger
- Department of Evolutionary Biology, Unit for Integrative Zoology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Andrew Calcino
- Department of Evolutionary Biology, Unit for Integrative Zoology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Andreas Wanninger
- Department of Evolutionary Biology, Unit for Integrative Zoology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria.
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6
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Genome-wide identification and characterization of basic helix-loop-helix genes in nine molluscs. Gene 2021; 785:145604. [PMID: 33766707 DOI: 10.1016/j.gene.2021.145604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 03/03/2021] [Accepted: 03/17/2021] [Indexed: 11/23/2022]
Abstract
The basic helix-loop-helix (bHLH) transcription factors form a large superfamily that plays an important role in numerous physiological processes, including development and response to environmental stresses. In this study, the distribution of bHLH genes in nine molluscs was systematically investigated (including five bivalves, three gastropods and one cephalopod). Finally, 53-85 bHLH genes were identified from each genome and classified into corresponding families by using phylogenetic analysis. The results of gene structure and conserved motif analysis illustrated the hereditary conservation of bHLH transcription factors during evolution but showed low similarity in group C. Through transcription profile analysis of C. gigas and T. granosa, we found a important role of bHLH genes in responding to multiple external challenges and development; meanwhile, they also exhibited tissue-specific expression. Interestingly, we were also surprised to find different bHLH genes from the same group generally possess similar patterns expression that tends to simultaneously present high or lower expression of multiple challenges and different tissues in this study. In summary, this study lays the foundation for further investigation of the biological functions and evolution of molluscan bHLH genes.
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7
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Shimizu K, Kimura K, Isowa Y, Oshima K, Ishikawa M, Kagi H, Kito K, Hattori M, Chiba S, Endo K. Insights into the Evolution of Shells and Love Darts of Land Snails Revealed from Their Matrix Proteins. Genome Biol Evol 2019; 11:380-397. [PMID: 30388206 PMCID: PMC6368272 DOI: 10.1093/gbe/evy242] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/31/2018] [Indexed: 12/14/2022] Open
Abstract
Over the past decade, many skeletal matrix proteins that are possibly related to calcification have been reported in various calcifying animals. Molluscs are among the most diverse calcifying animals and some gastropods have adapted to terrestrial ecological niches. Although many shell matrix proteins (SMPs) have already been reported in molluscs, most reports have focused on marine molluscs, and the SMPs of terrestrial snails remain unclear. In addition, some terrestrial stylommatophoran snails have evolved an additional unique calcified character, called a "love dart," used for mating behavior. We identified 54 SMPs in the terrestrial snail Euhadra quaesita, and found that they contain specific domains that are widely conserved in molluscan SMPs. However, our results also suggest that some of them possibly have evolved independently by domain shuffling, domain recruitment, or gene co-option. We then identified four dart matrix proteins, and found that two of them are the same proteins as those identified as SMPs. Our results suggest that some dart matrix proteins possibly have evolved by independent gene co-option from SMPs during dart evolution events. These results provide a new perspective on the evolution of SMPs and "love darts" in land snails.
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Affiliation(s)
- Keisuke Shimizu
- Department of Earth and Planetary Science, The University of Tokyo, Hongo, Japan
- College of Life and Environmental Sciences, University of Exeter, United Kingdom
| | - Kazuki Kimura
- Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi, Japan
- Research Institute for Ulleungdo and Dokdo Islands, Kyungpook National University, Bukgu, Daegu, Korea
| | - Yukinobu Isowa
- Organization for the Strategic Coordination of Research and Intellectual Properties, Meiji University, Kawasaki, Kanagawa, Japan
| | - Kenshiro Oshima
- Center for Omics and Bioinformatics, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Makiko Ishikawa
- Department of Earth and Planetary Science, The University of Tokyo, Hongo, Japan
- Faculty of Animal Health Technology, Yamazaki University of Animal Health Technology, Hachioji, Tokyo, Japan
| | - Hiroyuki Kagi
- Geochemical Research Center, Graduate School of Science, The University of Tokyo, Hongo, Japan
| | - Keiji Kito
- Department of Life Sciences, School of Agriculture, Meiji University, Kawasaki, Kanagawa, Japan
| | - Masahira Hattori
- Center for Omics and Bioinformatics, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan
- Cooperative Major of Advanced Health Science, Graduate School of Advanced Science and Engineering, Waseda University, Japan
| | - Satoshi Chiba
- Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Kazuyoshi Endo
- Department of Earth and Planetary Science, The University of Tokyo, Hongo, Japan
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8
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Renard E, Leys SP, Wörheide G, Borchiellini C. Understanding Animal Evolution: The Added Value of Sponge Transcriptomics and Genomics: The disconnect between gene content and body plan evolution. Bioessays 2018; 40:e1700237. [PMID: 30070368 DOI: 10.1002/bies.201700237] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 06/22/2018] [Indexed: 02/06/2023]
Abstract
Sponges are important but often-neglected organisms. The absence of classical animal traits (nerves, digestive tract, and muscles) makes sponges challenging for non-specialists to work with and has delayed getting high quality genomic data compared to other invertebrates. Yet analyses of sponge genomes and transcriptomes currently available have radically changed our understanding of animal evolution. Sponges are of prime evolutionary importance as one of the best candidates to form the sister group of all other animals, and genomic data are essential to understand the mechanisms that control animal evolution and diversity. Here we review the most significant outcomes of current genomic and transcriptomic analyses of sponges, and discuss limitations and future directions of sponge transcriptomic and genomic studies.
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Affiliation(s)
- Emmanuelle Renard
- Aix Marseille Univ., Univ Avignon, CNRS, IRD, UMR 7263, Mediterranean Institute of Marine and Continental Biodiversity and Ecology (IMBE), Station Marine d'Endoume, Marseille, France.,Aix Marseille Univ., CNRS, UMR 7288, IBDM, Marseille, France
| | - Sally P Leys
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Gert Wörheide
- Department of Earth and Environmental Sciences, Paleontology and Geobiology, Ludwig-Maximilians-Universität München, Richard-Wagner Straße 10, 80333 Munich, Germany.,GeoBio-Center, Ludwig-Maximilians-Universität München, Munich, Germany.,Bavarian State Collection for Paleontology and Geology, Munich, Germany
| | - Carole Borchiellini
- Aix Marseille Univ., Univ Avignon, CNRS, IRD, UMR 7263, Mediterranean Institute of Marine and Continental Biodiversity and Ecology (IMBE), Station Marine d'Endoume, Marseille, France
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9
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Janghorban M, Xin L, Rosen JM, Zhang XHF. Notch Signaling as a Regulator of the Tumor Immune Response: To Target or Not To Target? Front Immunol 2018; 9:1649. [PMID: 30061899 PMCID: PMC6055003 DOI: 10.3389/fimmu.2018.01649] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Accepted: 07/04/2018] [Indexed: 01/05/2023] Open
Abstract
The Notch signaling pathway regulates important cellular processes involved in stem cell maintenance, proliferation, development, survival, and inflammation. These responses to Notch signaling involving both canonical and non-canonical pathways can be spatially and temporally variable and are highly cell-type dependent. Notch signaling can elicit opposite effects in regulating tumorigenicity (tumor-promoting versus tumor-suppressing function) as well as controlling immune cell responses. In various cancer types, Notch signaling elicits a "cancer stem cell (CSC)" phenotype that results in decreased proliferation, but resistance to various therapies, hence potentially contributing to cell dormancy and relapse. CSCs can reshape their niche by releasing paracrine factors and inflammatory cytokines, and the niche in return can support their quiescence and resistance to therapies as well as the immune response. Moreover, Notch signaling is one of the key regulators of hematopoiesis, immune cell differentiation, and inflammation and is implicated in various autoimmune diseases, carcinogenesis (leukemia), and tumor-induced immunosuppression. Notch can control the fate of various T cell types, including Th1, Th2, and the regulatory T cells (Tregs), and myeloid cells including macrophages, dendritic cells, and myeloid-derived suppressor cells (MDSCs). Both MDSCs and Tregs play an important role in supporting tumor cells (and CSCs) and in evading the immune response. In this review, we will discuss how Notch signaling regulates multiple aspects of the tumor-promoting environment by elucidating its role in CSCs, hematopoiesis, normal immune cell differentiation, and subsequently in tumor-supporting immunogenicity.
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Affiliation(s)
- Mahnaz Janghorban
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, United States
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX, United States
| | - Li Xin
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, United States
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, United States
| | - Jeffrey M. Rosen
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, United States
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, United States
| | - Xiang H.-F. Zhang
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, United States
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX, United States
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, United States
- McNair Medical Institute, Baylor College of Medicine, Houston, TX, United States
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10
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Gazave E, Lemaître QIB, Balavoine G. The Notch pathway in the annelid Platynereis: insights into chaetogenesis and neurogenesis processes. Open Biol 2017; 7:rsob.160242. [PMID: 28148821 PMCID: PMC5356439 DOI: 10.1098/rsob.160242] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 01/03/2017] [Indexed: 01/13/2023] Open
Abstract
Notch is a key signalling pathway playing multiple and varied functions during development. Notch regulates the selection of cells with a neurogenic fate and maintains a pool of yet uncommitted precursors through lateral inhibition, both in insects and in vertebrates. Here, we explore the functions of Notch in the annelid Platynereis dumerilii (Lophotrochozoa). Conserved components of the pathway are identified and a scenario for their evolution in metazoans is proposed. Unexpectedly, neither Notch nor its ligands are expressed in the neurogenic epithelia of the larva at the time when massive neurogenesis begins. Using chemical inhibitors and neural markers, we demonstrate that Notch plays no major role in the general neurogenesis of larvae. Instead, we find Notch components expressed in nascent chaetal sacs, the organs that produce the annelid bristles. Impairing Notch signalling induces defects in chaetal sac formation, abnormalities in chaetae producing cells and a change of identity of chaeta growth accessory cells. This is the first bilaterian species in which the early neurogenesis processes appear to occur without a major involvement of the Notch pathway. Instead, Notch is co-opted to pattern annelid-specific organs, likely through a lateral inhibition process. These features reinforce the view that Notch signalling has been recruited multiple times in evolution due to its remarkable ‘toolkit’ nature.
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Affiliation(s)
- Eve Gazave
- Institut Jacques Monod, CNRS, UMR 7592, Univ Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France
| | - Quentin I B Lemaître
- Institut Jacques Monod, CNRS, UMR 7592, Univ Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France
| | - Guillaume Balavoine
- Institut Jacques Monod, CNRS, UMR 7592, Univ Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France
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11
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Gyoja F. Basic helix-loop-helix transcription factors in evolution: Roles in development of mesoderm and neural tissues. Genesis 2017; 55. [PMID: 28804953 DOI: 10.1002/dvg.23051] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 08/10/2017] [Accepted: 08/10/2017] [Indexed: 12/12/2022]
Abstract
Basic helix-loop-helix (bHLH) transcription factors have attracted the attention of developmental and evolutionary biologists for decades because of their conserved functions in mesodermal and neural tissue formation in both vertebrates and fruit flies. Their evolutionary history is of special interest because it will likely provide insights into developmental processes and refinement of metazoan-specific traits. This review briefly considers advances in developmental biological studies on bHLHs/HLHs. I also discuss recent genome-wide surveys and molecular phylogenetic analyses of these factors in a wide range of metazoans. I hypothesize that interactions between metazoan-specific Group A, D, and E bHLH/HLH factors enabled a sophisticated transition system from cell proliferation to differentiation in multicellular development. This control mechanism probably emerged initially to organize a multicellular animal body and was subsequently recruited to form evolutionarily novel tissues, which differentiated during a later ontogenetic phase.
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Affiliation(s)
- Fuki Gyoja
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 904-0495, Japan.,Department of Biology, Faculty of Science and Engineering, Konan University, 8-9-1 Okamoto, Higashinada, Kobe, 658-8501, Japan
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12
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Bao Y, Xu F, Shimeld SM. Phylogenetics of Lophotrochozoan bHLH Genes and the Evolution of Lineage-Specific Gene Duplicates. Genome Biol Evol 2017; 9:869-886. [PMID: 28338988 PMCID: PMC5381572 DOI: 10.1093/gbe/evx047] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/10/2017] [Indexed: 12/23/2022] Open
Abstract
The gain and loss of genes encoding transcription factors is of importance to understanding the evolution of gene regulatory complexity. The basic helix–loop–helix (bHLH) genes encode a large superfamily of transcription factors. We systematically classify the bHLH genes from five mollusc, two annelid and one brachiopod genomes, tracing the pattern of bHLH gene evolution across these poorly studied Phyla. In total, 56–88 bHLH genes were identified in each genome, with most identifiable as members of previously described bilaterian families, or of new families we define. Of such families only one, Mesp, appears lost by all these species. Additional duplications have also played a role in the evolution of the bHLH gene repertoire, with many new lophotrochozoan-, mollusc-, bivalve-, or gastropod-specific genes defined. Using a combination of transcriptome mining, RT-PCR, and in situ hybridization we compared the expression of several of these novel genes in tissues and embryos of the molluscs Crassostrea gigas and Patella vulgata, finding both conserved expression and evidence for neofunctionalization. We also map the positions of the genes across these genomes, identifying numerous gene linkages. Some reflect recent paralog divergence by tandem duplication, others are remnants of ancient tandem duplications dating to the lophotrochozoan or bilaterian common ancestors. These data are built into a model of the evolution of bHLH genes in molluscs, showing formidable evolutionary stasis at the family level but considerable within-family diversification by tandem gene duplication.
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Affiliation(s)
- Yongbo Bao
- Department of Zoology, University of Oxford, United Kingdom.,Zhejiang Key Laboratory of Aquatic Germplasm Resources, College of Biological & Environmental Sciences, Zhejiang Wanli University, Zhejiang, China
| | - Fei Xu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,National & Local Joint Engineering Laboratory of Ecological Mariculture, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
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13
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Clustered brachiopod Hox genes are not expressed collinearly and are associated with lophotrochozoan novelties. Proc Natl Acad Sci U S A 2017; 114:E1913-E1922. [PMID: 28228521 DOI: 10.1073/pnas.1614501114] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Temporal collinearity is often considered the main force preserving Hox gene clusters in animal genomes. Studies that combine genomic and gene expression data are scarce, however, particularly in invertebrates like the Lophotrochozoa. As a result, the temporal collinearity hypothesis is currently built on poorly supported foundations. Here we characterize the complement, cluster, and expression of Hox genes in two brachiopod species, Terebratalia transversa and Novocrania anomalaT. transversa has a split cluster with 10 genes (lab, pb, Hox3, Dfd, Scr, Lox5, Antp, Lox4, Post2, and Post1), whereas N. anomala has 9 genes (apparently missing Post1). Our in situ hybridization, real-time quantitative PCR, and stage-specific transcriptomic analyses show that brachiopod Hox genes are neither strictly temporally nor spatially collinear; only pb (in T. transversa), Hox3 (in both brachiopods), and Dfd (in both brachiopods) show staggered mesodermal expression. Thus, our findings support the idea that temporal collinearity might contribute to keeping Hox genes clustered. Remarkably, expression of the Hox genes in both brachiopod species demonstrates cooption of Hox genes in the chaetae and shell fields, two major lophotrochozoan morphological novelties. The shared and specific expression of Hox genes, together with Arx, Zic, and Notch pathway components in chaetae and shell fields in brachiopods, mollusks, and annelids provide molecular evidence supporting the conservation of the molecular basis for these lophotrochozoan hallmarks.
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14
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Towards a systems-level understanding of development in the marine annelid Platynereis dumerilii. Curr Opin Genet Dev 2016; 39:175-181. [PMID: 27501412 DOI: 10.1016/j.gde.2016.07.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 05/30/2016] [Accepted: 07/07/2016] [Indexed: 01/12/2023]
Abstract
Platynereis dumerilii is a segmented marine worm from the phylum Annelida, a member of the Lophotrochozoans. Platynereis is easily maintained in the lab and exhibits a highly stereotypic development through spiral cleavage with a small, transparent, free-swimming larva highly suitable for microscopy studies. A protocol for embryo microinjection in Platynereis has enabled several genetic tools to be developed, paving the way for functional studies. Recent Platynereis studies have provided insights into the function of several signaling pathways in development. Platynereis has also proven a useful model system for comparative evolutionary developmental studies, allowing the formation of new hypotheses on the evolution of neuroendocrine signaling, body patterning, and organ development. Combining existing large datasets of spatial gene expression mapping, cell lineage mapping, and neuronal circuits with functional analyses of developmental genes represents a promising approach for future studies aiming at a systems-level understanding of development in Platynereis.
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15
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Özpolat BD, Bely AE. Developmental and molecular biology of annelid regeneration: a comparative review of recent studies. Curr Opin Genet Dev 2016; 40:144-153. [PMID: 27505269 DOI: 10.1016/j.gde.2016.07.010] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 07/12/2016] [Accepted: 07/13/2016] [Indexed: 11/29/2022]
Abstract
Studies of annelid regeneration have greatly increased in frequency in recent years, providing new insights into the developmental basis and evolution of regeneration. In this review, we summarize recent findings related to regeneration in annelids, focusing on molecular and developmental studies of epimorphic (blastema-based) regeneration, morphallactic (tissue-remodeling based) regeneration, and development and regeneration of putative stem cells of the posterior growth zone and germline. Regeneration is being investigated in a broad range of annelids spanning the phylum, and comparing findings among species reveals both widely conserved features that may be ancestral for the phylum as well as features that are variable across the group.
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Affiliation(s)
- B Duygu Özpolat
- Department of Biology, University of Maryland, College Park, MD, USA.
| | - Alexandra E Bely
- Department of Biology, University of Maryland, College Park, MD, USA.
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16
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Perry KJ, Lyons DC, Truchado-Garcia M, Fischer AHL, Helfrich LW, Johansson KB, Diamond JC, Grande C, Henry JQ. Deployment of regulatory genes during gastrulation and germ layer specification in a model spiralian mollusc Crepidula. Dev Dyn 2016. [PMID: 26197970 DOI: 10.1002/dvdy.24308] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND During gastrulation, endoderm and mesoderm are specified from a bipotential precursor (endomesoderm) that is argued to be homologous across bilaterians. Spiralians also generate mesoderm from ectodermal precursors (ectomesoderm), which arises near the blastopore. While a conserved gene regulatory network controls specification of endomesoderm in deuterostomes and ecdysozoans, little is known about genes controlling specification or behavior of either source of spiralian mesoderm or the digestive tract. RESULTS Using the mollusc Crepidula, we examined conserved regulatory factors and compared their expression to fate maps to score expression in the germ layers, blastopore lip, and digestive tract. Many genes were expressed in both ecto- and endomesoderm, but only five were expressed in ectomesoderm exclusively. The latter may contribute to epithelial-to-mesenchymal transition seen in ectomesoderm. CONCLUSIONS We present the first comparison of genes expressed during spiralian gastrulation in the context of high-resolution fate maps. We found variation of genes expressed in the blastopore lip, mouth, and cells that will form the anus. Shared expression of many genes in both mesodermal sources suggests that components of the conserved endomesoderm program were either co-opted for ectomesoderm formation or that ecto- and endomesoderm are derived from a common mesodermal precursor that became subdivided into distinct domains during evolution.
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Affiliation(s)
- Kimberly J Perry
- University of Illinois, Department of Cell and Developmental Biology, Urbana, Illinois
| | | | - Marta Truchado-Garcia
- Departamento de Biología Molecular and Centro de Biología Molecular, "Severo Ochoa" (CSIC, Universidad Autónoma de Madrid), Madrid, Spain
| | - Antje H L Fischer
- Department of Metabolic Biochemistry, Ludwig-Maximilians-University, Munich, Germany.,Marine Biological Laboratory, Woods Hole, Massachusetts
| | | | - Kimberly B Johansson
- Marine Biological Laboratory, Woods Hole, Massachusetts.,Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts
| | | | - Cristina Grande
- Departamento de Biología Molecular and Centro de Biología Molecular, "Severo Ochoa" (CSIC, Universidad Autónoma de Madrid), Madrid, Spain
| | - Jonathan Q Henry
- University of Illinois, Department of Cell and Developmental Biology, Urbana, Illinois
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17
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Wollesen T, Rodríguez Monje SV, Todt C, Degnan BM, Wanninger A. Ancestral role of Pax2/5/8 in molluscan brain and multimodal sensory system development. BMC Evol Biol 2015; 15:231. [PMID: 26511716 PMCID: PMC4625944 DOI: 10.1186/s12862-015-0505-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 10/01/2015] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Mollusks represent the largest lophotrochozoan phylum and exhibit highly diverse body plans. Previous studies have demonstrated that transcription factors such as Pax genes play important roles during their development. Accordingly, in ecdysozoan and vertebrate model organisms, orthologs of Pax2/5/8 are among others involved in the formation of the midbrain/hindbrain boundary, the auditory/geosensory organ systems, and the excretory system. METHODS Pax2/5/8 expression was investigated by in situ hybridization during the development of representatives of the two major molluscan subclades, Aculifera and Conchifera. RESULTS Compared to the investigated polyplacophoran and bivalve species that lack larval statocysts as geosensory organs and elaborate central nervous systems (CNS), cephalopods possess highly centralized brains and statocysts. Pax2/5/8 is expressed in regions where sensory cells develop subsequently during ontogenesis. Expression domains include esthetes and the ampullary system in polyplacophorans as well as the eyes of cephalopods. No Pax2/5/8 expression was observed in the less centralized CNS of bivalve, polyplacophoran, and gastropod embryos, thus arguing for a loss of Pax2/5/8 involvement in CNS development in these lineages. In contrast, Pax2/5/8 is expressed among others in brain lobes along the trajectory of the esophagus that divides the cephalopod brain. CONCLUSIONS Our results, along with those on Otx- and Hox-gene expression, demonstrate that the cephalopod condition is similar to that in mouse and fruit fly, with Otx being expressed in the anterior-most brain region (except for the vertical lobe) and a Pax2/5/8 expression domain separating the Otx-domain from a Hox-gene expressing posterior brain region. Thus, Pax2/5/8 appears to have been recruited independently into regionalization of non-homologous complex brains of organisms as different as squid, fruit fly, and mouse. In addition, Pax2/5/8 is expressed in multimodal sensory systems in mollusks such as the esthetes and the ampullary system of polyplacophorans as well as the eyes of cephalopods. Pax2/5/8-expressing cells are present in regions where the future sensory cells such as the polyplacophoran esthetes are situated and hence Pax2/5/8 expression probably predates sensory cell development during ontogeny. In mollusks, Pax2/5/8 is only expressed in derivatives of the ectoderm and hence an ancestral role in molluscan ectoderm differentiation is inferred.
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Affiliation(s)
- Tim Wollesen
- Department of Integrative Zoology, Faculty of Sciences, University of Vienna, 1090, Vienna, Austria.
| | | | - Christiane Todt
- University Museum of Bergen, University of Bergen, Allégaten 41, 5007, Bergen, Norway.
| | - Bernard M Degnan
- School of Biological Sciences, The University of Queensland, Brisbane, QLD, 4072, Australia.
| | - Andreas Wanninger
- Department of Integrative Zoology, Faculty of Sciences, University of Vienna, 1090, Vienna, Austria.
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18
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Dearden PK. Origin and evolution of the enhancer of split complex. BMC Genomics 2015; 16:712. [PMID: 26384649 PMCID: PMC4575448 DOI: 10.1186/s12864-015-1926-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 09/12/2015] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND The Enhancer of split complex is an unusual gene complex found in Arthropod genomes. Where known this complex of genes is often regulated by Notch cell signalling and is critically important for neurogenesis. The Enhancer of split complex is made up of two different classes of genes, basic helix-loop-helix-orange domain transcription factors and bearded class genes. The association of these genes has been detected in the genomes of insects and crustaceans. RESULTS Tracing the evolution of the Enhancer of split complex in recently sequenced Arthropod genomes indicates that enhancer of split basic helix-loop-helix orange domain genes arose before the common ancestor of insects and Crustacea, and before the formation of the complex. Throughout insect and crustacean evolution, a four-gene cluster has been present with lineage specific gene losses and duplications. The complex can be found in the vast majority of genomes, but appears to be missing from the genomes of chalcid wasps, raising questions as to how they carry out neurogenesis in the absence of these crucial genes. CONCLUSIONS The enhancer of split complex arose in the common ancestor of Crustacea and insects, probably through the linkage of a basic helix-loop-helix orange domain gene and a bearded class gene. The complex has been maintained, with variations, throughout insect and crustacean evolution indicating some function of the complex, such as coordinate regulation, may maintain its structure through evolutionary time.
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Affiliation(s)
- Peter K Dearden
- Genetics Otago and Gravida (National Centre for Growth and Development), Biochemistry Department, University of Otago, Dunedin, Aotearoa, New Zealand.
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