1
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Musser JM, Schippers KJ, Nickel M, Mizzon G, Kohn AB, Pape C, Ronchi P, Papadopoulos N, Tarashansky AJ, Hammel JU, Wolf F, Liang C, Hernández-Plaza A, Cantalapiedra CP, Achim K, Schieber NL, Pan L, Ruperti F, Francis WR, Vargas S, Kling S, Renkert M, Polikarpov M, Bourenkov G, Feuda R, Gaspar I, Burkhardt P, Wang B, Bork P, Beck M, Schneider TR, Kreshuk A, Wörheide G, Huerta-Cepas J, Schwab Y, Moroz LL, Arendt D. Profiling cellular diversity in sponges informs animal cell type and nervous system evolution. Science 2021; 374:717-723. [PMID: 34735222 DOI: 10.1126/science.abj2949] [Citation(s) in RCA: 91] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Jacob M Musser
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Klaske J Schippers
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Michael Nickel
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.,Friedrich-Schiller-Universität Jena, Institut für Zoologie und Evolutionsforschung mit Phyletischem Museum, Ernst-Haeckel-Haus und Biologiedidaktik, 07743 Jena, Germany.,GeoBio-Center, Ludwig-Maximilians-Universität München, 80333 München, Germany
| | - Giulia Mizzon
- Electron Microscopy Core Facility, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Andrea B Kohn
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL 32080, USA
| | - Constantin Pape
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Paolo Ronchi
- Electron Microscopy Core Facility, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Nikolaos Papadopoulos
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | | | - Jörg U Hammel
- Friedrich-Schiller-Universität Jena, Institut für Zoologie und Evolutionsforschung mit Phyletischem Museum, Ernst-Haeckel-Haus und Biologiedidaktik, 07743 Jena, Germany.,Institute for Materials Physics, Helmholtz-Zentrum Hereon, 21502 Geesthacht, Germany
| | - Florian Wolf
- Friedrich-Schiller-Universität Jena, Institut für Zoologie und Evolutionsforschung mit Phyletischem Museum, Ernst-Haeckel-Haus und Biologiedidaktik, 07743 Jena, Germany
| | - Cong Liang
- Center for Applied Mathematics, Tianjin University, Tianjin 300072, China
| | - Ana Hernández-Plaza
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) and Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), 28223 Madrid, Spain
| | - Carlos P Cantalapiedra
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) and Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), 28223 Madrid, Spain
| | - Kaia Achim
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Nicole L Schieber
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Leslie Pan
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Fabian Ruperti
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.,Collaboration for joint Ph.D. degree between EMBL and Heidelberg University, Faculty of Biosciences 69117 Heidelberg, Germany
| | - Warren R Francis
- Department of Earth and Environmental Sciences, Paleontology & Geobiology, Ludwig-Maximilians-Universität München, 80333 München, Germany
| | - Sergio Vargas
- Department of Earth and Environmental Sciences, Paleontology & Geobiology, Ludwig-Maximilians-Universität München, 80333 München, Germany
| | - Svenja Kling
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.,Centre for Organismal Studies (COS), University of Heidelberg, 69120 Heidelberg, Germany
| | - Maike Renkert
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Maxim Polikarpov
- Hamburg Unit c/o DESY, European Molecular Biology Laboratory, Hamburg, 22607 Germany.,Department of Information Technology and Electrical Engineering, ETH Zurich, CH-8092 Zurich, Switzerland
| | - Gleb Bourenkov
- Hamburg Unit c/o DESY, European Molecular Biology Laboratory, Hamburg, 22607 Germany
| | - Roberto Feuda
- Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK
| | - Imre Gaspar
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.,Department of Totipotency, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Pawel Burkhardt
- Sars International Centre for Marine Molecular Biology, University of Bergen, 5008 Bergen, Norway
| | - Bo Wang
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.,Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Peer Bork
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Martin Beck
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Thomas R Schneider
- Hamburg Unit c/o DESY, European Molecular Biology Laboratory, Hamburg, 22607 Germany
| | - Anna Kreshuk
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Gert Wörheide
- GeoBio-Center, Ludwig-Maximilians-Universität München, 80333 München, Germany.,Department of Earth and Environmental Sciences, Paleontology & Geobiology, Ludwig-Maximilians-Universität München, 80333 München, Germany.,Bayerische Staatssammlung für Paläontologie und Geologie (SNSB), 80333 München, Germany
| | - Jaime Huerta-Cepas
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) and Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), 28223 Madrid, Spain.,Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Yannick Schwab
- Electron Microscopy Core Facility, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.,Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Leonid L Moroz
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL 32080, USA.,Department of Neuroscience and Brain Institute, University of Florida, Gainesville, FL 32610, USA.,McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA
| | - Detlev Arendt
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.,Centre for Organismal Studies (COS), University of Heidelberg, 69120 Heidelberg, Germany
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2
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Borchiellini C, Degnan SM, Le Goff E, Rocher C, Vernale A, Baghdiguian S, Séjourné N, Marschal F, Le Bivic A, Godefroy N, Degnan BM, Renard E. Staining and Tracking Methods for Studying Sponge Cell Dynamics. Methods Mol Biol 2021; 2219:81-97. [PMID: 33074535 DOI: 10.1007/978-1-0716-0974-3_5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
To better understand the origin of animal cell types, body plans, and other morphological features, further biological knowledge and understanding are needed from non-bilaterian phyla, namely, Placozoa, Ctenophora, and Porifera. This chapter describes recent cell staining approaches that have been developed in three phylogenetically distinct sponge species-the homoscleromorph Oscarella lobularis, and the demosponges Amphimedon queenslandica and Lycopodina hypogea-to enable analyses of cell death, proliferation, and migration. These methods allow for a more detailed understanding of cellular behaviors and fates, and morphogenetic processes in poriferans, building on current knowledge of sponge cell biology that relies chiefly on classical (static) histological observations.
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Affiliation(s)
| | - Sandie M Degnan
- Centre for Marine Science, School of Biological Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Emilie Le Goff
- ISEM, University of Montpellier, CNRS, EPHE, IRD, Montpellier, France
| | - Caroline Rocher
- Aix Marseille Univ, Avignon Université, CNRS, IRD, IMBE, Marseille, France
| | - Amélie Vernale
- Aix Marseille Univ, Avignon Université, CNRS, IRD, IMBE, Marseille, France
- Aix Marseille University, CNRS, UMR 7288, IBDM, Marseille, France
| | | | - Nina Séjourné
- Aix Marseille Univ, Avignon Université, CNRS, IRD, IMBE, Marseille, France
| | - Florent Marschal
- Aix Marseille Univ, Avignon Université, CNRS, IRD, IMBE, Marseille, France
| | - André Le Bivic
- Aix Marseille University, CNRS, UMR 7288, IBDM, Marseille, France
| | - Nelly Godefroy
- ISEM, University of Montpellier, CNRS, EPHE, IRD, Montpellier, France.
| | - Bernard M Degnan
- Centre for Marine Science, School of Biological Sciences, The University of Queensland, Brisbane, QLD, Australia.
| | - Emmanuelle Renard
- Aix Marseille Univ, Avignon Université, CNRS, IRD, IMBE, Marseille, France.
- Aix Marseille University, CNRS, UMR 7288, IBDM, Marseille, France.
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3
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Fierro-Constaín L, Rocher C, Marschal F, Schenkelaars Q, Séjourné N, Borchiellini C, Renard E. In Situ Hybridization Techniques in the Homoscleromorph Sponge Oscarella lobularis. Methods Mol Biol 2021; 2219:181-194. [PMID: 33074541 DOI: 10.1007/978-1-0716-0974-3_11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The Porifera are one of the best candidates as the sister group to all other metazoans. Studies on this phylum are therefore expected to shed light on the origin and early evolution of key animal features. Transcriptomic or genomic data acquired during the last 10 years have highlighted the conservation of most of the main genes and pathways involved in the development of the other metazoans. The next step is to determine how similar genetic tool boxes can result in widely dissimilar body plan organization, dynamics, and life histories. To answer these questions, three main axes of research are necessary: (1) conducting more gene expression studies; (2) developing knockdown protocols; and (3) reinterpreting sponge cell biology using modern tools. In this chapter we focus on the in situ hybridization (ISH) technique, needed to establish the spatiotemporal expression of genes, both on whole mount individuals and paraffin sections, and at different stages of development (adults, embryos, larvae, buds) of the homoscleromorph sponge Oscarella lobularis.
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Affiliation(s)
| | - Caroline Rocher
- Aix Marseille Univ, Avignon Université, CNRS, IRD, IMBE, Marseille, France
| | - Florent Marschal
- Aix Marseille Univ, Avignon Université, CNRS, IRD, IMBE, Marseille, France
| | - Quentin Schenkelaars
- Department of Genetics and Evolution, Faculty of Sciences, Institute of Genetics and Genomics in Geneva (IGe3), University of Geneva, Geneva, Switzerland
- Aix Marseille Univ, Avignon Université, CNRS, IRD, IMBE, Marseille, France
| | - Nina Séjourné
- Aix Marseille Univ, Avignon Université, CNRS, IRD, IMBE, Marseille, France
| | | | - Emmanuelle Renard
- Aix Marseille Univ, Avignon Université, CNRS, IRD, IMBE, Marseille, France.
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4
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Gainett G, Ballesteros JA, Kanzler CR, Zehms JT, Zern JM, Aharon S, Gavish-Regev E, Sharma PP. Systemic paralogy and function of retinal determination network homologs in arachnids. BMC Genomics 2020; 21:811. [PMID: 33225889 PMCID: PMC7681978 DOI: 10.1186/s12864-020-07149-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 10/13/2020] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Arachnids are important components of cave ecosystems and display many examples of troglomorphisms, such as blindness, depigmentation, and elongate appendages. Little is known about how the eyes of arachnids are specified genetically, let alone the mechanisms for eye reduction and loss in troglomorphic arachnids. Additionally, duplication of Retinal Determination Gene Network (RDGN) homologs in spiders has convoluted functional inferences extrapolated from single-copy homologs in pancrustacean models. RESULTS We investigated a sister species pair of Israeli cave whip spiders, Charinus ioanniticus and C. israelensis (Arachnopulmonata, Amblypygi), of which one species has reduced eyes. We generated embryonic transcriptomes for both Amblypygi species, and discovered that several RDGN homologs exhibit duplications. We show that duplication of RDGN homologs is systemic across arachnopulmonates (arachnid orders that bear book lungs), rather than being a spider-specific phenomenon. A differential gene expression (DGE) analysis comparing the expression of RDGN genes in field-collected embryos of both species identified candidate RDGN genes involved in the formation and reduction of eyes in whip spiders. To ground bioinformatic inference of expression patterns with functional experiments, we interrogated the function of three candidate RDGN genes identified from DGE using RNAi in the spider Parasteatoda tepidariorum. We provide functional evidence that one of these paralogs, sine oculis/Six1 A (soA), is necessary for the development of all arachnid eye types. CONCLUSIONS Our work establishes a foundation to investigate the genetics of troglomorphic adaptations in cave arachnids, and links differential gene expression to an arthropod eye phenotype for the first time outside of Pancrustacea. Our results support the conservation of at least one RDGN component across Arthropoda and provide a framework for identifying the role of gene duplications in generating arachnid eye diversity.
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Affiliation(s)
- Guilherme Gainett
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, 53706, USA.
| | - Jesús A Ballesteros
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, 53706, USA.
| | - Charlotte R Kanzler
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Jakob T Zehms
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - John M Zern
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Shlomi Aharon
- National Natural History Collections, The Hebrew University of Jerusalem , Jerusalem, 9190401, Israel
| | - Efrat Gavish-Regev
- National Natural History Collections, The Hebrew University of Jerusalem , Jerusalem, 9190401, Israel
| | - Prashant P Sharma
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, 53706, USA
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5
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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: 53] [Impact Index Per Article: 13.3] [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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6
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Calheira L, Lanna E, Pinheiro U. Tropical freshwater sponges develop from gemmules faster than their temperate-region counterparts. ZOOMORPHOLOGY 2019. [DOI: 10.1007/s00435-019-00458-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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7
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Hall C, Rodriguez M, Garcia J, Posfai D, DuMez R, Wictor E, Quintero OA, Hill MS, Rivera AS, Hill AL. Secreted frizzled related protein is a target of PaxB and plays a role in aquiferous system development in the freshwater sponge, Ephydatia muelleri. PLoS One 2019; 14:e0212005. [PMID: 30794564 PMCID: PMC6386478 DOI: 10.1371/journal.pone.0212005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 01/25/2019] [Indexed: 12/19/2022] Open
Abstract
Canonical and non-canonical Wnt signaling, as well as the Pax/Six gene network, are involved in patterning the freshwater sponge aquiferous system. Using computational approaches to identify transcription factor binding motifs in a freshwater sponge genome, we located putative PaxB binding sites near a Secreted Frizzled Related Protein (SFRP) gene in Ephydatia muelleri. EmSFRP is expressed throughout development, but with highest levels in juvenile sponges. In situ hybridization and antibody staining show EmSFRP expression throughout the pinacoderm and choanoderm in a subpopulation of amoeboid cells that may be differentiating archeocytes. Knockdown of EmSFRP leads to ectopic oscula formation during development, suggesting that EmSFRP acts as an antagonist of Wnt signaling in E. muelleri. Our findings support a hypothesis that regulation of the Wnt pathway by the Pax/Six network as well as the role of Wnt signaling in body plan morphogenesis was established before sponges diverged from the rest of the metazoans.
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Affiliation(s)
- Chelsea Hall
- Department of Biology, University of Richmond, Richmond, Virginia, United States of America
| | - Melanie Rodriguez
- Department of Biology, University of Richmond, Richmond, Virginia, United States of America
| | - Josephine Garcia
- Department of Biology, University of Richmond, Richmond, Virginia, United States of America
| | - Dora Posfai
- Department of Biology, University of Richmond, Richmond, Virginia, United States of America
| | - Rachel DuMez
- Department of Biology, University of Richmond, Richmond, Virginia, United States of America
| | - Erik Wictor
- Department of Biological Sciences, University of the Pacific, Stockton, California, United States of America
| | - Omar A. Quintero
- Department of Biology, University of Richmond, Richmond, Virginia, United States of America
| | - Malcolm S. Hill
- Department of Biology, University of Richmond, Richmond, Virginia, United States of America
- Department of Biology, Bates College, Lewiston, Maine, United States of America
| | - Ajna S. Rivera
- Department of Biological Sciences, University of the Pacific, Stockton, California, United States of America
| | - April L. Hill
- Department of Biology, University of Richmond, Richmond, Virginia, United States of America
- Department of Biology, Bates College, Lewiston, Maine, United States of America
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8
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9
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Establishment of Transgenesis in the Demosponge Suberites domuncula. Genetics 2018; 210:435-443. [PMID: 30143594 PMCID: PMC6216596 DOI: 10.1534/genetics.118.301121] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 07/27/2018] [Indexed: 12/20/2022] Open
Abstract
Sponges (Porifera) represent one of the most basally branching animal clades with key relevance for evolutionary studies, stem cell biology, and development. Despite a long history of sponges as experimental model systems, however, functional molecular studies are still very difficult to perform in these animals. Here, we report the establishment of transgenic technology as a basic and versatile experimental tool for sponge research. We demonstrate that slice explants of the demosponge Suberites domuncula regenerate functional sponge tissue and can be cultured for extended periods of time, providing easy experimental access under controlled conditions. We further show that an engineered expression construct driving the enhanced green fluorescence protein (egfp) gene under control of the Suberites domuncula β-actin locus can be transfected into such tissue cultures, and that faithfully spliced transcripts are produced from such transfected DNA. Finally, by combining fluorescence-activated cell sorting (FACS) with quantitative PCR, we validate that transfected cells can be specifically reisolated from tissue based on their fluorescence. Although the number of detected enhanced green fluorescent protein (EGFP)-expressing cells is still limited, our approach represents the first successful introduction and expression of exogenous DNA in a sponge. These results represent a significant advance for the use of transgenic technology in a cornerstone phylum, for instance for the use in lineage tracing experiments.
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10
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Abstract
AbstractAlthough the color violet is now used in a wide variety of everyday products, ranging from toys to clothing to cars, and although it now appears commonly in artistic works, violet was rarely used in fine art before the early 1860s. The color violet only became an integral part of modern culture and life with the rise of the French Impressionists. I investigated the use of violet in over 130,000 artworks prior to 1863 and found that it appeared in about .06 percent of the paintings. Violet was used substantially more frequently in Impressionist works, and remains popular in fine art and in popular culture today. I examine several explanations for the explosion of the use of violet in the art world during the Impressionist era, and conclude that a cognitive-perceptual explanation, based on the heightened sensitivity of the Impressionists to short wavelengths, may account for it. The findings fit with a new understanding about evolutionary changes in planetary light and human adaptation to light.
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11
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Abstract
Background The Wnt signaling pathway is uniquely metazoan and used in many processes during development, including the formation of polarity and body axes. In sponges, one of the earliest diverging animal groups, Wnt pathway genes have diverse expression patterns in different groups including along the anterior-posterior axis of two sponge larvae, and in the osculum and ostia of others. We studied the function of Wnt signaling and body polarity formation through expression, knockdown, and larval manipulation in several freshwater sponge species. Results Sponge Wnts fall into sponge-specific and sponge-class specific subfamilies of Wnt proteins. Notably Wnt genes were not found in transcriptomes of the glass sponge Aphrocallistes vastus. Wnt and its signaling genes were expressed in archaeocytes of the mesohyl throughout developing freshwater sponges. Osculum formation was enhanced by GSK3 knockdown, and Wnt antagonists inhibited both osculum development and regeneration. Using dye tracking we found that the posterior poles of freshwater sponge larvae give rise to tissue that will form the osculum following metamorphosis. Conclusions Together the data indicate that while components of canonical Wnt signaling may be used in development and maintenance of osculum tissue, it is likely that Wnt signaling itself occurs between individual cells rather than whole tissues or structures in freshwater sponges. Electronic supplementary material The online version of this article (10.1186/s12862-018-1118-0) contains supplementary material, which is available to authorized users.
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12
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Abstract
A complex genetic repertoire underlies the apparently simple body plan of sponges. Among the genes present in poriferans are those fundamental to the sensory and nervous systems of other animals. Sponges are dynamic and sensitive animals and it is intuitive to link these genes to behaviour. The proposal that ctenophores are the earliest diverging metazoan has led to the question of whether sponges possess a 'pre-nervous' system or have undergone nervous system loss. Both lines of thought generally assume that the last common ancestor of sponges and eumetazoans possessed the genetic modules that underlie sensory abilities. By corollary extant sponges may possess a sensory cell homologous to one present in the last common ancestor, a hypothesis that has been studied by gene expression. We have performed a meta-analysis of all gene expression studies published to date to explore whether gene expression is indicative of a feature's sensory function. In sponges we find that eumetazoan sensory-neural markers are not particularly expressed in structures with known sensory functions. Instead it is common for these genes to be expressed in cells with no known or uncharacterized sensory function. Indeed, many sensory-neural markers so far studied are expressed during development, perhaps because many are transcription factors. This suggests that the genetic signal of a sponge sensory cell is dissimilar enough to be unrecognizable when compared to a bilaterian sensory or neural cell. It is possible that sensory-neural markers have as yet unknown functions in sponge cells, such as assembling an immunological synapse in the larval globular cell. Furthermore, the expression of sensory-neural markers in non-sensory cells, such as adult and larval epithelial cells, suggest that these cells may have uncharacterized sensory functions. While this does not rule out the co-option of ancestral sensory modules in later evolving groups, a distinct genetic foundation may underlie the sponge sensory system.
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Affiliation(s)
- Jasmine L Mah
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Sally P Leys
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada.
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Cramer JM, Pohlmann D, Gomez F, Mark L, Kornegay B, Hall C, Siraliev-Perez E, Walavalkar NM, Sperlazza MJ, Bilinovich S, Prokop JW, Hill AL, Williams Jr. DC. Methylation specific targeting of a chromatin remodeling complex from sponges to humans. Sci Rep 2017; 7:40674. [PMID: 28094816 PMCID: PMC5240623 DOI: 10.1038/srep40674] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 12/09/2016] [Indexed: 12/31/2022] Open
Abstract
DNA cytosine methylation and methyl-cytosine binding domain (MBD) containing proteins are found throughout all vertebrate species studied to date. However, both the presence of DNA methylation and pattern of methylation varies among invertebrate species. Invertebrates generally have only a single MBD protein, MBD2/3, that does not always contain appropriate residues for selectively binding methylated DNA. Therefore, we sought to determine whether sponges, one of the most ancient extant metazoan lineages, possess an MBD2/3 capable of recognizing methylated DNA and recruiting the associated nucleosome remodeling and deacetylase (NuRD) complex. We find that Ephydatia muelleri has genes for each of the NuRD core components including an EmMBD2/3 that selectively binds methylated DNA. NMR analyses reveal a remarkably conserved binding mode, showing almost identical chemical shift changes between binding to methylated and unmethylated CpG dinucleotides. In addition, we find that EmMBD2/3 and EmGATAD2A/B proteins form a coiled-coil interaction known to be critical for the formation of NuRD. Finally, we show that knockdown of EmMBD2/3 expression disrupts normal cellular architecture and development of E. muelleri. These data support a model in which the MBD2/3 methylation-dependent functional role emerged with the earliest multicellular organisms and has been maintained to varying degrees across animal evolution.
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Affiliation(s)
- Jason M. Cramer
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA, USA
| | - Deborah Pohlmann
- Department of Biology, University of Richmond, Richmond, VA, USA
| | - Fernando Gomez
- Department of Biology, University of Richmond, Richmond, VA, USA
| | - Leslie Mark
- Department of Biology, University of Richmond, Richmond, VA, USA
| | | | - Chelsea Hall
- Department of Biology, University of Richmond, Richmond, VA, USA
| | - Edhriz Siraliev-Perez
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Ninad M. Walavalkar
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - M. Jeannette Sperlazza
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Stephanie Bilinovich
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | | - April L. Hill
- Department of Biology, University of Richmond, Richmond, VA, USA
| | - David C. Williams Jr.
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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A new transcriptome and transcriptome profiling of adult and larval tissue in the box jellyfish Alatina alata: an emerging model for studying venom, vision and sex. BMC Genomics 2016; 17:650. [PMID: 27535656 PMCID: PMC4989536 DOI: 10.1186/s12864-016-2944-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 07/18/2016] [Indexed: 12/28/2022] Open
Abstract
Background Cubozoans (box jellyfish) are cnidarians that have evolved a number of distinguishing features. Many cubozoans have a particularly potent sting, effected by stinging structures called nematocysts; cubozoans have well-developed light sensation, possessing both image-forming lens eyes and light-sensitive eye spots; and some cubozoans have complex mating behaviors, including aggregations, copulation and internal fertilization. The cubozoan Alatina alata is emerging as a cnidarian model because it forms predictable monthly nearshore breeding aggregations in tropical to subtropical waters worldwide, making both adult and larval material reliably accessible. To develop resources for A. alata, this study generated a functionally annotated transcriptome of adult and larval tissue, applying preliminary differential expression analyses to identify candidate genes involved in nematogenesis and venom production, vision and extraocular sensory perception, and sexual reproduction, which for brevity we refer to as “venom”, “vision” and “sex”. Results We assembled a transcriptome de novo from RNA-Seq data pooled from multiple body parts (gastric cirri, ovaries, tentacle (with pedalium base) and rhopalium) of an adult female A. alata medusa and larval planulae. Our transcriptome comprises ~32 K transcripts, after filtering, and provides a basis for analyzing patterns of gene expression in adult and larval box jellyfish tissues. Furthermore, we annotated a large set of candidate genes putatively involved in venom, vision and sex, providing an initial molecular characterization of these complex features in cubozoans. Expression profiles and gene tree reconstruction provided a number of preliminary insights into the putative sites of nematogenesis and venom production, regions of phototransduction activity and fertilization dynamics in A. alata. Conclusions Our Alatina alata transcriptome significantly adds to the genomic resources for this emerging cubozoan model. This study provides the first annotated transcriptome from multiple tissues of a cubozoan focusing on both the adult and larvae. Our approach of using multiple body parts and life stages to generate this transcriptome effectively identified a broad range of candidate genes for the further study of coordinated processes associated with venom, vision and sex. This new genomic resource and the candidate gene dataset are valuable for further investigating the evolution of distinctive features of cubozoans, and of cnidarians more broadly. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2944-3) contains supplementary material, which is available to authorized users.
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15
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Schenkelaars Q, Quintero O, Hall C, Fierro-Constain L, Renard E, Borchiellini C, Hill AL. ROCK inhibition abolishes the establishment of the aquiferous system in Ephydatia muelleri (Porifera, Demospongiae). Dev Biol 2016; 412:298-310. [PMID: 26944094 DOI: 10.1016/j.ydbio.2016.02.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Revised: 02/16/2016] [Accepted: 02/26/2016] [Indexed: 01/16/2023]
Abstract
The Rho associated coiled-coil protein kinase (ROCK) plays crucial roles in development across bilaterian animals. The fact that the Rho/Rock pathway is required to initiate epithelial morphogenesis and thus to establish body plans in bilaterians makes this conserved signaling pathway key for studying the molecular mechanisms that may control early development of basally branching metazoans. The purpose of this study was to evaluate whether or not the main components of this signaling pathway exist in sponges, and if present, to investigate the possible role of the regulatory network in an early branching non-bilaterian species by evaluating ROCK function during Ephydatia muelleri development. Molecular phylogenetic analyses and protein domain predictions revealed the existence of Rho/Rock components in all studied poriferan lineages. Binding assays revealed that both Y-27632 and GSK429286A are capable of inhibiting Em-ROCK activity in vitro. Treatment with both drugs leads to impairment of growth and formation of the basal pinacoderm layer in the developing sponge. Furthermore, inhibition of Em-Rock prevents the establishment of a functional aquiferous system, including the absence of an osculum. In contrast, no effect of ROCK inhibition was observed in juvenile sponges that already possess a fully developed and functional aquiferous system. Thus, the Rho/Rock pathway appears to be essential for the proper development of the freshwater sponge, and may play a role in various cell behaviors (e.g. cell proliferation, cell adhesion and cell motility). Taken together, these data are consistent with an ancestral function of Rho/Rock signaling in playing roles in early developmental processes and may provide a new framework to study the interaction between Wnt signaling and the Rho/Rock pathway.
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Affiliation(s)
- Quentin Schenkelaars
- Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale (IMBE) - UMR CNRS 7263- IRD 237 - UAPV, Aix-Marseille Université, Marseille, France; Department of Genetics and Evolution, Institute of Genetics and Genomics in Geneva (IGe3), Faculty of Sciences, University of Geneva, Switzerland.
| | - Omar Quintero
- Department of Biology, University of Richmond, Richmond, VA 23173, USA
| | - Chelsea Hall
- Department of Biology, University of Richmond, Richmond, VA 23173, USA
| | - Laura Fierro-Constain
- Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale (IMBE) - UMR CNRS 7263- IRD 237 - UAPV, Aix-Marseille Université, Marseille, France
| | - Emmanuelle Renard
- Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale (IMBE) - UMR CNRS 7263- IRD 237 - UAPV, Aix-Marseille Université, Marseille, France
| | - Carole Borchiellini
- Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale (IMBE) - UMR CNRS 7263- IRD 237 - UAPV, Aix-Marseille Université, Marseille, France
| | - April L Hill
- Department of Biology, University of Richmond, Richmond, VA 23173, USA.
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Abstract
Stem cells are pivotal for development and tissue homeostasis of multicellular animals, and the quest for a gene toolkit associated with the emergence of stem cells in a common ancestor of all metazoans remains a major challenge for evolutionary biology. We reconstructed the conserved gene repertoire of animal stem cells by transcriptomic profiling of totipotent archeocytes in the demosponge Ephydatia fluviatilis and by tracing shared molecular signatures with flatworm and Hydra stem cells. Phylostratigraphy analyses indicated that most of these stem-cell genes predate animal origin, with only few metazoan innovations, notably including several partners of the Piwi machinery known to promote genome stability. The ancestral stem-cell transcriptome is strikingly poor in transcription factors. Instead, it is rich in RNA regulatory actors, including components of the "germ-line multipotency program" and many RNA-binding proteins known as critical regulators of mammalian embryonic stem cells.
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Martik ML, McClay DR. Deployment of a retinal determination gene network drives directed cell migration in the sea urchin embryo. eLife 2015; 4. [PMID: 26402456 PMCID: PMC4621380 DOI: 10.7554/elife.08827] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 09/23/2015] [Indexed: 12/29/2022] Open
Abstract
Gene regulatory networks (GRNs) provide a systems-level orchestration of an organism's genome encoded anatomy. As biological networks are revealed, they continue to answer many questions including knowledge of how GRNs control morphogenetic movements and how GRNs evolve. The migration of the small micromeres to the coelomic pouches in the sea urchin embryo provides an exceptional model for understanding the genomic regulatory control of morphogenesis. An assay using the robust homing potential of these cells reveals a ‘coherent feed-forward’ transcriptional subcircuit composed of Pax6, Six3, Six1/2, Eya, and Dach1 that is responsible for the directed homing mechanism of these multipotent progenitors. The linkages of that circuit are strikingly similar to a circuit involved in retinal specification in Drosophila suggesting that systems-level tasks can be highly conserved even though the tasks drive unrelated processes in different animals. DOI:http://dx.doi.org/10.7554/eLife.08827.001 Within an animal embryo, groups of cells tend to move, or migrate, between different areas before they form into tissues and organs. These cell migrations are regulated by hundreds of genes, which must be expressed at the right time and in the right place. Cells use proteins called transcription factors to regulate the expression of genes. These proteins work together in circuit board-like networks called gene regulatory networks in order to drive different aspects of development, including cell migration. The sea urchin is a useful model organism to study how animals develop. This is because these marine animals express many of the same genes as humans, but they can be easily manipulated and studied in the laboratory. In a developing sea urchin embryo, cells called the small micromeres move towards one end of animal and get incorporated into a pocket-like structure known as the coelomic pouch. From this pouch, these cells mature and eventually contribute to the adult germ cells (the precursors to the sperm and eggs). Martik and McClay have now analyzed how small micromeres make their way to their final location in the coelomic pouch. Micromeres were labeled with a dye that fluoresces green so that they could be tracked under a microscope. This revealed that, like other moving cells, micromeres actively change their shape as they migrate. Furthermore, when micromeres were experimentally moved to abnormal locations in the sea urchin embryo, they were still able to actively home in on the coelomic pouch no matter their starting location. Martik and McClay then identified five transcription factors expressed in the coelomic pouch in the sea urchin that are involved in this homing activity. Reducing the expression of any of these transcription factors was enough to hinder the ability of the micromeres to find their way to the coelomic pouch. Further experiments and analysis then revealed that these five transcription factors work together in a sub-circuit, which is in turn embedded in a larger gene regulatory network. This sub-circuit that drives cell migration is unexpectedly similar to another circuit in the fruit fly Drosophila. Intriguingly, the sub-circuit in the fly controls eye development, which is unrelated to cell homing and migration. These observations raise the possibility that this circuit has been conserved as a unit over millions of years of evolution and redeployed in new networks under completely different circumstances. The data also suggest the possibility that additional conserved sub-circuits will be identified as more systems are analyzed in detail. DOI:http://dx.doi.org/10.7554/eLife.08827.002
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Affiliation(s)
- Megan L Martik
- University Program in Genetics and Genomics, Duke University, Durham, United States
| | - David R McClay
- Department of Biology, Duke University, Durham, United States
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Fortunato SAV, Adamski M, Adamska M. Comparative analyses of developmental transcription factor repertoires in sponges reveal unexpected complexity of the earliest animals. Mar Genomics 2015; 24 Pt 2:121-9. [PMID: 26253310 DOI: 10.1016/j.margen.2015.07.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Revised: 07/27/2015] [Accepted: 07/27/2015] [Indexed: 12/18/2022]
Abstract
Developmental transcription factors (DTFs) control development of animals by affecting expression of target genes, some of which are transcription factors themselves. In bilaterians and cnidarians, conserved DTFs are involved in homologous processes such as gastrulation or specification of neurons. The genome of Amphimedon queenslandica, the first sponge to be sequenced, revealed that only a fraction of these conserved DTF families are present in demosponges. This finding was in line with the view that morphological complexity in the animal lineage correlates with developmental toolkit complexity. However, as the phylum Porifera is very diverse, Amphimedon's genome may not be representative of all sponges. The recently sequenced genomes of calcareous sponges Sycon ciliatum and Leucosolenia complicata allowed investigations of DTFs in a sponge lineage evolutionarily distant from demosponges. Surprisingly, the phylogenetic analyses of identified DTFs revealed striking differences between the calcareous sponges and Amphimedon. As these differences appear to be a result of independent gene loss events in the two sponge lineages, the last common ancestor of sponges had to possess a much more diverse repertoire of DTFs than extant sponges. Developmental expression of sponge homologs of genes involved in specification of the Bilaterian endomesoderm and the neurosensory cells suggests that roles of many DTFs date back to the last common ancestor of all animals. Strikingly, even DTFs displaying apparent pan-metazoan conservation of sequence and function are not immune to being lost from individual species genomes. The quest for a comprehensive picture of the developmental toolkit in the last common metazoan ancestor is thus greatly benefitting from the increasing accessibility of sequencing, allowing comparisons of multiple genomes within each phylum.
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Affiliation(s)
- Sofia A V Fortunato
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate 55, 5008 Bergen, Norway; Department of Biology, University of Bergen, Thormøhlensgate 55, 5008 Bergen, Norway
| | - Marcin Adamski
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate 55, 5008 Bergen, Norway
| | - Maja Adamska
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate 55, 5008 Bergen, Norway.
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Schlosser G. Vertebrate cranial placodes as evolutionary innovations--the ancestor's tale. Curr Top Dev Biol 2015; 111:235-300. [PMID: 25662263 DOI: 10.1016/bs.ctdb.2014.11.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Evolutionary innovations often arise by tinkering with preexisting components building new regulatory networks by the rewiring of old parts. The cranial placodes of vertebrates, ectodermal thickenings that give rise to many of the cranial sense organs (ear, nose, lateral line) and ganglia, originated as such novel structures, when vertebrate ancestors elaborated their head in support of a more active and exploratory life style. This review addresses the question of how cranial placodes evolved by tinkering with ectodermal patterning mechanisms and sensory and neurosecretory cell types that have their own evolutionary history. With phylogenetic relationships among the major branches of metazoans now relatively well established, a comparative approach is used to infer, which structures evolved in which lineages and allows us to trace the origin of placodes and their components back from ancestor to ancestor. Some of the core networks of ectodermal patterning and sensory and neurosecretory differentiation were already established in the common ancestor of cnidarians and bilaterians and were greatly elaborated in the bilaterian ancestor (with BMP- and Wnt-dependent patterning of dorsoventral and anteroposterior ectoderm and multiple neurosecretory and sensory cell types). Rostral and caudal protoplacodal domains, giving rise to some neurosecretory and sensory cells, were then established in the ectoderm of the chordate and tunicate-vertebrate ancestor, respectively. However, proper cranial placodes as clusters of proliferating progenitors producing high-density arrays of neurosecretory and sensory cells only evolved and diversified in the ancestors of vertebrates.
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Affiliation(s)
- Gerhard Schlosser
- School of Natural Sciences & Regenerative Medicine Institute (REMEDI), National University of Ireland, Galway, Ireland.
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20
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Fortunato SA, Leininger S, Adamska M. Evolution of the Pax-Six-Eya-Dach network: the calcisponge case study. EvoDevo 2014; 5:23. [PMID: 25002963 PMCID: PMC4083861 DOI: 10.1186/2041-9139-5-23] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 05/15/2014] [Indexed: 12/21/2022] Open
Abstract
Background The Pax-Six-Eya-Dach network (PSEDN) is involved in a variety of developmental processes, including well documented roles in determination of sensory organs and morphogenesis in bilaterian animals. Expression of PSEDN components in cnidarians is consistent with function in sensory organ development. Recent work in demosponges demonstrated the presence of single homologs of Pax and Six genes, and their possible involvement in morphogenesis, but the absence of the remaining network components. Calcisponges are evolutionarily distant from demosponges, and the developmental toolkits of these two lineages differ significantly. We used an emerging model system, Sycon ciliatum, to identify components of the PSEDN and study their expression during embryonic and postembryonic development. Results We identified two Pax, three Six and one Eya genes in calcisponges, a situation strikingly different than in the previously studied demosponges. One of the calcisponge Pax genes can be identified as PaxB, while the second Pax gene has no clear affiliation. The three calcisponge Six genes could not be confidently classified within any known family of Six genes. Expression analysis in adult S. ciliatum demonstrated that representatives of Pax, Six and Eya are expressed in patterns consistent with roles in morphogenesis of the choanocyte chambers. Distinct paralogues of Pax and Six genes were expressed early in the development of the putative larval sensory cells, the cruciform cells. While lack of known photo pigments in calcisponge genomes precludes formal assignment of function to the cruciform cells, we also show that they express additional eumetazoan genes involved in specification of sensory and neuronal cells: Elav and Msi. Conclusions Our results indicate that the role of a Pax-Six-Eya network in morphogenesis likely predates the animal divergence. In addition, Pax and Six, as well as Elav and Msi are expressed during differentiation of cruciform cells, which are good candidates for being sensory cells of the calcaronean sponge larvae.
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Affiliation(s)
- Sofia Av Fortunato
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgt. 55, Bergen 5008, Norway ; Department of Biology, University of Bergen, Thormøhlensgt. 55, Bergen 5008, Norway
| | - Sven Leininger
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgt. 55, Bergen 5008, Norway ; Current address: Institute of Marine Research, Nordnesgaten 50, Bergen 5005, Norway
| | - Maja Adamska
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgt. 55, Bergen 5008, Norway
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Onset of atonal expression in Drosophila retinal progenitors involves redundant and synergistic contributions of Ey/Pax6 and So binding sites within two distant enhancers. Dev Biol 2013; 386:152-64. [PMID: 24247006 DOI: 10.1016/j.ydbio.2013.11.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 11/06/2013] [Accepted: 11/09/2013] [Indexed: 11/23/2022]
Abstract
Proneural transcription factors drive the generation of specialized neurons during nervous system development, and their dynamic expression pattern is critical to their function. The activation of the proneural gene atonal (ato) in the Drosophila eye disc epithelium represents a critical step in the transition from retinal progenitor cell to developing photoreceptor neuron. We show here that the onset of ato transcription depends on two distant enhancers that function differently in subsets of retinal progenitor cells. A detailed analysis of the crosstalk between these enhancers identifies a critical role for three binding sites for the Retinal Determination factors Eyeless (Ey) and Sine oculis (So). We show how these sites interact to induce ato expression in distinct regions of the eye field and confirm them to be occupied by endogenous Ey and So proteins in vivo. Our study suggests that Ey and So operate differently through the same 3' cis-regulatory sites in distinct populations of retinal progenitors.
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