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Kuo DH, Szczupak L, Weisblat DA, Portiansky EL, Winchell CJ, Lee JR, Tsai FY. Transgenesis enables mapping of segmental ganglia in the leech Helobdella austinensis. J Exp Biol 2024; 227:jeb247419. [PMID: 38940760 DOI: 10.1242/jeb.247419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 06/10/2024] [Indexed: 06/29/2024]
Abstract
The analysis of how neural circuits function in individuals and change during evolution is simplified by the existence of neurons identified as homologous within and across species. Invertebrates, including leeches, have been used for these purposes in part because their nervous systems comprise a high proportion of identified neurons, but technical limitations make it challenging to assess the full extent to which assumptions of stereotypy hold true. Here, we introduce Minos plasmid-mediated transgenesis as a tool for introducing transgenes into the embryos of the leech Helobdella austinensis (Spiralia; Lophotrochozoa; Annelida; Clitellata; Hirudinida; Glossiphoniidae). We identified an enhancer driving pan-neuronal expression of markers, including histone2B:mCherry, which allowed us to enumerate neurons in segmental ganglia. Unexpectedly, we found that the segmental ganglia of adult transgenic H. austinensis contain fewer and more variable numbers of neurons than in previously examined leech species.
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Affiliation(s)
- Dian-Han Kuo
- Department of Life Science, National Taiwan University, Taipei, Taiwan116
- Museum of Zoology, National Taiwan University, Taipei, Taiwan106
| | - Lidia Szczupak
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBYNE UBA-CONICET, Ciudad Universitaria, 1428 Buenos Aires, Argentina
| | - David A Weisblat
- Department of Molecular & Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3200, USA
| | - Enrique L Portiansky
- Laboratory of Image Analysis, School of Veterinary Sciences, National University of La Plata, CONICET, B1900 La Plata, Argentina
| | - Christopher J Winchell
- Department of Molecular & Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3200, USA
| | - Jun-Ru Lee
- Department of Life Science, National Taiwan University, Taipei, Taiwan116
| | - Fu-Yu Tsai
- Department of Life Science, National Taiwan University, Taipei, Taiwan116
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2
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Ikeda KN, Belevich I, Zelaya-Lainez L, Orel L, Füssl J, Gumulec J, Hellmich C, Jokitalo E, Raible F. Dynamic microvilli sculpt bristles at nanometric scale. Nat Commun 2024; 15:3733. [PMID: 38740737 DOI: 10.1038/s41467-024-48044-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 04/19/2024] [Indexed: 05/16/2024] Open
Abstract
Organisms generate shapes across size scales. Whereas patterning and morphogenesis of macroscopic tissues has been extensively studied, the principles underlying the formation of micrometric and submicrometric structures remain largely enigmatic. Individual cells of polychaete annelids, so-called chaetoblasts, are associated with the generation of chitinous bristles of highly stereotypic geometry. Here we show that bristle formation requires a chitin-producing enzyme specifically expressed in the chaetoblasts. Chaetoblasts exhibit dynamic cell surfaces with stereotypical patterns of actin-rich microvilli. These microvilli can be matched with internal and external structures of bristles reconstructed from serial block-face electron micrographs. Individual chitin teeth are deposited by microvilli in an extension-disassembly cycle resembling a biological 3D printer. Consistently, pharmacological interference with actin dynamics leads to defects in tooth formation. Our study reveals that both material and shape of bristles are encoded by the same cell, and that microvilli play a role in micro- to submicrometric sculpting of biomaterials.
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Affiliation(s)
- Kyojiro N Ikeda
- Max Perutz Labs; University of Vienna, 1030, Vienna, Austria.
| | - Ilya Belevich
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Luis Zelaya-Lainez
- Institute for Mechanics of Materials and Structures, TU Wien-Vienna University of Technology, Vienna, Austria
| | - Lukas Orel
- Max Perutz Labs; University of Vienna, 1030, Vienna, Austria
| | - Josef Füssl
- Institute for Mechanics of Materials and Structures, TU Wien-Vienna University of Technology, Vienna, Austria
| | - Jaromír Gumulec
- Department of Pathophysiology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Christian Hellmich
- Institute for Mechanics of Materials and Structures, TU Wien-Vienna University of Technology, Vienna, Austria
| | - Eija Jokitalo
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Florian Raible
- Max Perutz Labs; University of Vienna, 1030, Vienna, Austria.
- Research Platform "Single-Cell Regulation of Stem Cells", University of Vienna, Vienna, Austria.
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3
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Legras M, Ghisleni G, Regnard L, Dias M, Soilihi R, Celmar E, Balavoine G. Fast cycling culture of the annelid model Platynereis dumerilii. PLoS One 2023; 18:e0295290. [PMID: 38127889 PMCID: PMC10735030 DOI: 10.1371/journal.pone.0295290] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Accepted: 11/17/2023] [Indexed: 12/23/2023] Open
Abstract
Platynereis dumerilii, a marine annelid, is a model animal that has gained popularity in various fields such as developmental biology, biological rhythms, nervous system organization and physiology, behaviour, reproductive biology, and epigenetic regulation. The transparency of P. dumerilii tissues at all developmental stages makes it easy to perform live microscopic imaging of all cell types. In addition, the slow-evolving genome of P. dumerilii and its phylogenetic position as a representative of the vast branch of Lophotrochozoans add to its evolutionary significance. Although P. dumerilii is amenable to transgenesis and CRISPR-Cas9 knockouts, its relatively long and indefinite life cycle, as well as its semelparous reproduction have been hindrances to its adoption as a reverse genetics model. To overcome this limitation, an adapted culturing method has been developed allowing much faster life cycling, with median reproductive age at 13-14 weeks instead of 25-35 weeks using the traditional protocol. A low worm density in boxes and a strictly controlled feeding regime are important factors for the rapid growth and health of the worms. This culture method has several advantages, such as being much more compact, not requiring air bubbling or an artificial moonlight regime for synchronized sexual maturation and necessitating only limited water change. A full protocol for worm care and handling is provided.
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Affiliation(s)
- Mathieu Legras
- Université de Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | - Giulia Ghisleni
- Université de Paris Cité, CNRS, Institut Jacques Monod, Paris, France
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milano, Italy
| | - Léna Regnard
- Université de Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | - Manon Dias
- Université de Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | - Rabouant Soilihi
- Université de Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | - Enzo Celmar
- Université de Paris Cité, CNRS, Institut Jacques Monod, Paris, France
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4
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Vöcking O, Macias-Muñoz A, Jaeger SJ, Oakley TH. Deep Diversity: Extensive Variation in the Components of Complex Visual Systems across Animals. Cells 2022; 11:cells11243966. [PMID: 36552730 PMCID: PMC9776813 DOI: 10.3390/cells11243966] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 11/19/2022] [Accepted: 12/02/2022] [Indexed: 12/13/2022] Open
Abstract
Understanding the molecular underpinnings of the evolution of complex (multi-part) systems is a fundamental topic in biology. One unanswered question is to what the extent do similar or different genes and regulatory interactions underlie similar complex systems across species? Animal eyes and phototransduction (light detection) are outstanding systems to investigate this question because some of the genetics underlying these traits are well characterized in model organisms. However, comparative studies using non-model organisms are also necessary to understand the diversity and evolution of these traits. Here, we compare the characteristics of photoreceptor cells, opsins, and phototransduction cascades in diverse taxa, with a particular focus on cnidarians. In contrast to the common theme of deep homology, whereby similar traits develop mainly using homologous genes, comparisons of visual systems, especially in non-model organisms, are beginning to highlight a "deep diversity" of underlying components, illustrating how variation can underlie similar complex systems across taxa. Although using candidate genes from model organisms across diversity was a good starting point to understand the evolution of complex systems, unbiased genome-wide comparisons and subsequent functional validation will be necessary to uncover unique genes that comprise the complex systems of non-model groups to better understand biodiversity and its evolution.
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Affiliation(s)
- Oliver Vöcking
- Department of Biology, University of Kentucky, Lexington, KY 40508, USA
| | - Aide Macias-Muñoz
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA 93106, USA
| | - Stuart J. Jaeger
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA 93106, USA
| | - Todd H. Oakley
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA 93106, USA
- Correspondence:
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5
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Poehn B, Krishnan S, Zurl M, Coric A, Rokvic D, Häfker NS, Jaenicke E, Arboleda E, Orel L, Raible F, Wolf E, Tessmar-Raible K. A Cryptochrome adopts distinct moon- and sunlight states and functions as sun- versus moonlight interpreter in monthly oscillator entrainment. Nat Commun 2022; 13:5220. [PMID: 36064778 PMCID: PMC9445029 DOI: 10.1038/s41467-022-32562-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Accepted: 08/05/2022] [Indexed: 11/24/2022] Open
Abstract
The moon's monthly cycle synchronizes reproduction in countless marine organisms. The mass-spawning bristle worm Platynereis dumerilii uses an endogenous monthly oscillator set by full moon to phase reproduction to specific days. But how do organisms recognize specific moon phases? We uncover that the light receptor L-Cryptochrome (L-Cry) discriminates between different moonlight durations, as well as between sun- and moonlight. A biochemical characterization of purified L-Cry protein, exposed to naturalistic sun- or moonlight, reveals the formation of distinct sun- and moonlight states characterized by different photoreduction- and recovery kinetics of L-Cry's co-factor Flavin Adenine Dinucleotide. In Platynereis, L-Cry's sun- versus moonlight states correlate with distinct subcellular localizations, indicating different signaling. In contrast, r-Opsin1, the most abundant ocular opsin, is not required for monthly oscillator entrainment. Our work reveals a photo-ecological concept for natural light interpretation involving a "valence interpreter" that provides entraining photoreceptor(s) with light source and moon phase information.
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Affiliation(s)
- Birgit Poehn
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria
- Research Platform "Rhythms of Life", University of Vienna, Vienna BioCenter, Dr. Bohr-Gasse 9/4, A-1030, Vienna, Austria
| | - Shruthi Krishnan
- Institute of Molecular Physiology (IMP), Johannes Gutenberg-University, Hanns-Dieter-Hüsch-Weg 17, 55128, Mainz, Germany
- Institute of Molecular Biology (IMB), Ackermannweg 4, 55128, Mainz, Germany
| | - Martin Zurl
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria
- Research Platform "Rhythms of Life", University of Vienna, Vienna BioCenter, Dr. Bohr-Gasse 9/4, A-1030, Vienna, Austria
| | - Aida Coric
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria
- Research Platform "Rhythms of Life", University of Vienna, Vienna BioCenter, Dr. Bohr-Gasse 9/4, A-1030, Vienna, Austria
| | - Dunja Rokvic
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria
- Research Platform "Rhythms of Life", University of Vienna, Vienna BioCenter, Dr. Bohr-Gasse 9/4, A-1030, Vienna, Austria
| | - N Sören Häfker
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria
- Research Platform "Rhythms of Life", University of Vienna, Vienna BioCenter, Dr. Bohr-Gasse 9/4, A-1030, Vienna, Austria
| | - Elmar Jaenicke
- Institute of Molecular Physiology (IMP), Johannes Gutenberg-University, Hanns-Dieter-Hüsch-Weg 17, 55128, Mainz, Germany
| | - Enrique Arboleda
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria
- Research Platform "Rhythms of Life", University of Vienna, Vienna BioCenter, Dr. Bohr-Gasse 9/4, A-1030, Vienna, Austria
- Institut de Génomique Fonctionnelle de Lyon (IGFL), École Normale Supérieure de Lyon, 32 avenue Tony Garnier, 69007, Lyon, France
| | - Lukas Orel
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria
- Research Platform "Rhythms of Life", University of Vienna, Vienna BioCenter, Dr. Bohr-Gasse 9/4, A-1030, Vienna, Austria
| | - Florian Raible
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria
- Research Platform "Rhythms of Life", University of Vienna, Vienna BioCenter, Dr. Bohr-Gasse 9/4, A-1030, Vienna, Austria
| | - Eva Wolf
- Institute of Molecular Physiology (IMP), Johannes Gutenberg-University, Hanns-Dieter-Hüsch-Weg 17, 55128, Mainz, Germany.
- Institute of Molecular Biology (IMB), Ackermannweg 4, 55128, Mainz, Germany.
| | - Kristin Tessmar-Raible
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria.
- Research Platform "Rhythms of Life", University of Vienna, Vienna BioCenter, Dr. Bohr-Gasse 9/4, A-1030, Vienna, Austria.
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany.
- Carl-von-Ossietzky University, Carl-von-Ossietzky-Straße 9-11, 26111, Oldenburg, Germany.
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6
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Two light sensors decode moonlight versus sunlight to adjust a plastic circadian/circalunidian clock to moon phase. Proc Natl Acad Sci U S A 2022; 119:e2115725119. [PMID: 35622889 PMCID: PMC9295771 DOI: 10.1073/pnas.2115725119] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The moon provides highly reliable time information to organisms. Whereas sunlight is known to set daily animal timing systems, mechanistic insight into the impact of moonlight on such systems remains scarce. We establish that the marine bristleworm Platynereis dumerilii times the precise hours of mass spawning by integrating lunar light information into a plastic daily timing system able to run with circadian (∼24 h) or circalunidian (∼24.8 h) periodicity. The correct interpretation of moonlight is mediated by the interplay of two light sensors: a cryptochrome and a melanopsin ortholog provide information on light valence and moonrise time, respectively. Besides its ecological relevance, our work provides a plausible explanation for long-standing observations of light intensity–dependent differences in circadian clock periods. Many species synchronize their physiology and behavior to specific hours. It is commonly assumed that sunlight acts as the main entrainment signal for ∼24-h clocks. However, the moon provides similarly regular time information. Consistently, a growing number of studies have reported correlations between diel behavior and lunidian cycles. Yet, mechanistic insight into the possible influences of the moon on ∼24-h timers remains scarce. We have explored the marine bristleworm Platynereis dumerilii to investigate the role of moonlight in the timing of daily behavior. We uncover that moonlight, besides its role in monthly timing, also schedules the exact hour of nocturnal swarming onset to the nights’ darkest times. Our work reveals that extended moonlight impacts on a plastic clock that exhibits <24 h (moonlit) or >24 h (no moon) periodicity. Abundance, light sensitivity, and genetic requirement indicate that the Platynereis light receptor molecule r-Opsin1 serves as a receptor that senses moonrise, whereas the cryptochrome protein L-Cry is required to discriminate the proper valence of nocturnal light as either moonlight or sunlight. Comparative experiments in Drosophila suggest that cryptochrome’s principle requirement for light valence interpretation is conserved. Its exact biochemical properties differ, however, between species with dissimilar timing ecology. Our work advances the molecular understanding of lunar impact on fundamental rhythmic processes, including those of marine mass spawners endangered by anthropogenic change.
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Abstract
Opsins, the protein moieties of animal visual photo-pigments, have emerged as moonlighting proteins with diverse, light-dependent and -independent physiological functions. This raises the need to revise some basic assumptions concerning opsin expression, structure, classification, and evolution.
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Affiliation(s)
- Roberto Feuda
- Department of Genetics and Genome Biology, University of Leicester, UK
| | - Anant K Menon
- Department of Biochemistry, Weill Cornell Medical College New York, USA
| | - Martin C Göpfert
- University of Göttingen, Department of Cellular Neurobiology, Germany
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8
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Purschke G, Vodopyanov S, Baller A, von Palubitzki T, Bartolomaeus T, Beckers P. Ultrastructure of cerebral eyes in Oweniidae and Chaetopteridae (Annelida) - implications for the evolution of eyes in Annelida. ZOOLOGICAL LETTERS 2022; 8:3. [PMID: 35078543 PMCID: PMC8787891 DOI: 10.1186/s40851-022-00188-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 10/23/2021] [Indexed: 06/14/2023]
Abstract
BACKGROUND Recent phylogenomic studies have revealed a robust, new hypothesis of annelid phylogeny. Most surprisingly, a few early branching lineages formed a basal grade, whereas the majority of taxa were categorized as monophyletic Pleistoannelida. Members of these basal groups show a comparatively simple organization lacking certain characters regarded to be annelid specific. Thus, the evolution of organ systems and the characteristics probably present in the last common annelid ancestor require reevaluation. With respect to light-sensitive organs, a pair of simple larval eyes is regarded as being present in their last common ancestor. However, the evolutionary origin and structure of adult eyes remain obscure. Typically, adult eyes are multicellular pigment cups or pinhole eyes with or without a lens comprising rhabdomeric photoreceptor cells (PRCs) and pigmented supportive cells (PSCs) in converse design. However, in the most basal lineages, eyes are only present in a few taxa, and thus far, their ultrastructure is unknown. RESULTS Ultrastructural investigations of members of Oweniidae and Chaetopteridae reveal a corresponding design of adult cerebral eyes and PRCs. The eyes in species of these groups are simple pigment spot eyes, either forming a flat patch or embedded in a tube-like invagination. They are part of the epidermis and comprise two cell types, PSCs and rhabdomeric PRCs. Both cell types bear microvilli and one more or less reduced cilium. However, the PRCs showed only a moderate increase in the apical membrane surface in the form of irregularly arranged microvilli intermingling with those of the PSCs; a densely arranged brush border of rhabdomeric microvilli was absent. Additionally, both cell types show certain characteristics elsewhere observable in typical epidermal supportive cells. CONCLUSIONS These findings shed new light on the evolutionary history of adult eyes in Annelida. Most likely, the adult eye of the annelid stem species was a pair of simple pigment spot eyes with only slightly specialized PSCs and PRCs being an integrative part of the epidermis. As is the case for the nuchal organs, typical pigment cup adult eyes presumably evolved later in the annelid phylogeny, namely, in the stem lineages of Amphinomida and Pleistoannelida.
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Affiliation(s)
- Günter Purschke
- Zoology and Developmental Biology, Department of Biology and Chemistry, Osnabrück University, Osnabrück, Germany.
| | - Stepan Vodopyanov
- Department of Invertebrate Zoology, Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
| | - Anjilie Baller
- Zoology and Developmental Biology, Department of Biology and Chemistry, Osnabrück University, Osnabrück, Germany
- Present address: Department of Biology, Faculty II, University of Vechta, Vechta, Germany
| | - Tim von Palubitzki
- Zoology and Developmental Biology, Department of Biology and Chemistry, Osnabrück University, Osnabrück, Germany
| | - Thomas Bartolomaeus
- Institute of Evolutionary Biology and Ecology, University of Bonn, Bonn, Germany
| | - Patrick Beckers
- Institute of Evolutionary Biology and Ecology, University of Bonn, Bonn, Germany
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9
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Ponz-Segrelles G, Ribeiro RP, Aguado MT. Monsters reveal patterns: bifurcated annelids and their implications for the study of development and evolution. Biol Rev Camb Philos Soc 2021; 97:896-922. [PMID: 34931440 DOI: 10.1111/brv.12826] [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: 06/24/2021] [Revised: 12/03/2021] [Accepted: 12/06/2021] [Indexed: 11/30/2022]
Abstract
During recent decades, the study of anatomical anomalies has been of great relevance for research on development and its evolution. Yet most animal groups have never been studied under this perspective. In annelids, one of the most common and remarkable anomalies is anteroposterior axis bifurcation, that is animals that have two or more heads and/or tails. Bifurcated annelids were first described in the 18th century and have been occasionally reported since then. However, these animals have rarely been considered other than curiosities, one-off anomalies, or monsters, and a condensed but comprehensive analysis of this phenomenon is lacking. Such an analysis of the existing knowledge is necessary for addressing the different patterns of annelid bifurcation, as well as to understand possible developmental mechanisms behind them and their evolution. In this review we summarize reports of annelid bifurcation published during the last 275 years and the wide variety of anatomies they present. Our survey reveals bifurcation as a widespread phenomenon found all over the annelid tree. Moreover, it also shows that bifurcations can be classified into different types according to anatomy (lateral versus dorsoventral) or developmental origin (embryonic versus postembryonic, the latter occurring in relation to regeneration, reproduction, or growth). Regarding embryos, three different types of bifurcation can be found: conjoined twins (in clitellates); Janus embryos (two posterior ends with a single head which shows duplicated structures); and duplicitas cruciata embryos (with anterior and posterior bifurcation with a 90° rotation). In adults, we show that while lateral bifurcation can result in well-integrated phenotypes, dorsoventral bifurcation cannot since it requires the discontinuity of at least some internal organs. The relevance of this distinction is highlighted in the case of the Ribbon Clade, a group of syllid annelids in which some species reproduce by collateral and successive gemmiparity (which involves dorsoventral bifurcation), while others grow by branching laterally. Although most known cases of bifurcation came from accidental findings in the wild or were unintentionally produced, experimental studies resulting in the induction of bifurcation of both embryos and adults are also reviewed. In embryos, these experimental studies show how mechanical or chemical disruption of the zygote can result in bifurcation. In adults, the ventral nervous system and the digestive tract seem to play a role in the induction of bifurcation. Based on the reviewed evidence, we argue that the long-forgotten study of annelid developmental anomalies should be incorporated into the growing field of annelid EvoDevo and examined with modern techniques and perspectives.
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Affiliation(s)
- Guillermo Ponz-Segrelles
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Darwin, 2, Madrid, 28049, Spain
| | - Rannyele P Ribeiro
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Darwin, 2, Madrid, 28049, Spain.,Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA, 02543, U.S.A
| | - M Teresa Aguado
- Biodiversitätsmuseum, Animal Evolution & Biodiversity, Georg-August-Universität Göttingen, Untere Karspüle 2, Göttingen, 37073, Germany
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10
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Transgenesis in the acoel worm Hofstenia miamia. Dev Cell 2021; 56:3160-3170.e4. [PMID: 34752780 DOI: 10.1016/j.devcel.2021.10.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 07/20/2021] [Accepted: 10/12/2021] [Indexed: 12/27/2022]
Abstract
The acoel worm Hofstenia miamia, which can replace tissue lost to injury via differentiation of a population of stem cells, has emerged as a new research organism for studying regeneration. To enhance the depth of mechanistic studies in this system, we devised a protocol for microinjection into embryonic cells that resulted in stable transgene integration into the genome and generated animals with tissue-specific fluorescent transgene expression in epidermis, gut, and muscle. We demonstrate that transgenic Hofstenia are amenable to the isolation of specific cell types, investigations of regeneration, tracking of photoconverted molecules, and live imaging. Further, our stable transgenic lines revealed insights into the biology of Hofstenia, including a high-resolution three-dimensional view of cell morphology and the organization of muscle as a cellular scaffold for other tissues. Our work positions Hofstenia as a powerful system with multiple toolkits for mechanistic investigations of development, whole-body regeneration, and stem cell biology.
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11
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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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12
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Revilla-i-Domingo R, Rajan VBV, Waldherr M, Prohaczka G, Musset H, Orel L, Gerrard E, Smolka M, Stockinger A, Farlik M, Lucas RJ, Raible F, Tessmar-Raible K. Characterization of cephalic and non-cephalic sensory cell types provides insight into joint photo- and mechanoreceptor evolution. eLife 2021; 10:e66144. [PMID: 34350831 PMCID: PMC8367381 DOI: 10.7554/elife.66144] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 08/04/2021] [Indexed: 12/11/2022] Open
Abstract
Rhabdomeric opsins (r-opsins) are light sensors in cephalic eye photoreceptors, but also function in additional sensory organs. This has prompted questions on the evolutionary relationship of these cell types, and if ancient r-opsins were non-photosensory. A molecular profiling approach in the marine bristleworm Platynereis dumerilii revealed shared and distinct features of cephalic and non-cephalic r-opsin1-expressing cells. Non-cephalic cells possess a full set of phototransduction components, but also a mechanosensory signature. Prompted by the latter, we investigated Platynereis putative mechanotransducer and found that nompc and pkd2.1 co-expressed with r-opsin1 in TRE cells by HCR RNA-FISH. To further assess the role of r-Opsin1 in these cells, we studied its signaling properties and unraveled that r-Opsin1 is a Gαq-coupled blue light receptor. Profiling of cells from r-opsin1 mutants versus wild-types, and a comparison under different light conditions reveals that in the non-cephalic cells light - mediated by r-Opsin1 - adjusts the expression level of a calcium transporter relevant for auditory mechanosensation in vertebrates. We establish a deep-learning-based quantitative behavioral analysis for animal trunk movements and identify a light- and r-Opsin-1-dependent fine-tuning of the worm's undulatory movements in headless trunks, which are known to require mechanosensory feedback. Our results provide new data on peripheral cell types of likely light sensory/mechanosensory nature. These results point towards a concept in which such a multisensory cell type evolved to allow for fine-tuning of mechanosensation by light. This implies that light-independent mechanosensory roles of r-opsins may have evolved secondarily.
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Affiliation(s)
- Roger Revilla-i-Domingo
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform "Single-Cell Regulation of Stem Cells", University of Vienna, Vienna BioCenterViennaAustria
| | - Vinoth Babu Veedin Rajan
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
| | - Monika Waldherr
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
| | - Günther Prohaczka
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
| | - Hugo Musset
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
| | - Lukas Orel
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
| | - Elliot Gerrard
- Division of Neuroscience & Experimental Psychology, University of ManchesterManchesterUnited Kingdom
| | - Moritz Smolka
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
- Center for Integrative Bioinformatics Vienna, Max Perutz Labs, University of Vienna and Medical University of ViennaViennaAustria
| | - Alexander Stockinger
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform "Single-Cell Regulation of Stem Cells", University of Vienna, Vienna BioCenterViennaAustria
| | - Matthias Farlik
- CeMM Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
- Department of Dermatology, Medical University of ViennaViennaAustria
| | - Robert J Lucas
- Division of Neuroscience & Experimental Psychology, University of ManchesterManchesterUnited Kingdom
| | - Florian Raible
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform "Single-Cell Regulation of Stem Cells", University of Vienna, Vienna BioCenterViennaAustria
| | - Kristin Tessmar-Raible
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
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13
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Discovery of a body-wide photosensory array that matures in an adult-like animal and mediates eye-brain-independent movement and arousal. Proc Natl Acad Sci U S A 2021; 118:2021426118. [PMID: 33941643 DOI: 10.1073/pnas.2021426118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The ability to respond to light has profoundly shaped life. Animals with eyes overwhelmingly rely on their visual circuits for mediating light-induced coordinated movements. Building on previously reported behaviors, we report the discovery of an organized, eye-independent (extraocular), body-wide photosensory framework that allows even a head-removed animal to move like an intact animal. Despite possessing sensitive cerebral eyes and a centralized brain that controls most behaviors, head-removed planarians show acute, coordinated ultraviolet-A (UV-A) aversive phototaxis. We find this eye-brain-independent phototaxis is mediated by two noncanonical rhabdomeric opsins, the first known function for this newly classified opsin-clade. We uncover a unique array of dual-opsin-expressing photoreceptor cells that line the periphery of animal body, are proximal to a body-wide nerve net, and mediate UV-A phototaxis by engaging multiple modes of locomotion. Unlike embryonically developing cerebral eyes that are functional when animals hatch, the body-wide photosensory array matures postembryonically in "adult-like animals." Notably, apart from head-removed phototaxis, the body-wide, extraocular sensory organization also impacts physiology of intact animals. Low-dose UV-A, but not visible light (ocular-stimulus), is able to arouse intact worms that have naturally cycled to an inactive/rest-like state. This wavelength selective, low-light arousal of resting animals is noncanonical-opsin dependent but eye independent. Our discovery of an autonomous, multifunctional, late-maturing, organized body-wide photosensory system establishes a paradigm in sensory biology and evolution of light sensing.
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14
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Tournière O, Dolan D, Richards GS, Sunagar K, Columbus-Shenkar YY, Moran Y, Rentzsch F. NvPOU4/Brain3 Functions as a Terminal Selector Gene in the Nervous System of the Cnidarian Nematostella vectensis. Cell Rep 2021; 30:4473-4489.e5. [PMID: 32234481 DOI: 10.1016/j.celrep.2020.03.031] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 01/08/2020] [Accepted: 03/11/2020] [Indexed: 12/27/2022] Open
Abstract
Terminal selectors are transcription factors that control the morphological, physiological, and molecular features that characterize distinct cell types. Here, we show that, in the sea anemone Nematostella vectensis, NvPOU4 is expressed in post-mitotic cells that give rise to a diverse set of neural cell types, including cnidocytes and NvElav1-expressing neurons. Morphological analyses of NvPOU4 mutants crossed to transgenic reporter lines show that the loss of NvPOU4 does not affect the initial specification of neural cells. Transcriptomes derived from the mutants and from different neural cell populations reveal that NvPOU4 is required for the execution of the terminal differentiation program of these neural cells. These findings suggest that POU4 genes have ancient functions as terminal selectors for morphologically and functionally disparate types of neurons and they provide experimental support for the relevance of terminal selectors for understanding the evolution of cell types.
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Affiliation(s)
- Océane Tournière
- Sars International Centre for Marine Molecular Biology, University of Bergen, 5006 Bergen, Norway
| | - David Dolan
- Computational Biology Unit, Department for Informatics, University of Bergen, 5006 Bergen, Norway
| | - Gemma Sian Richards
- Sars International Centre for Marine Molecular Biology, University of Bergen, 5006 Bergen, Norway
| | - Kartik Sunagar
- Department of Ecology, Evolution and Behaviour, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, 9190401 Jerusalem, Israel; Evolutionary Venomics Lab, Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560012, India
| | - Yaara Y Columbus-Shenkar
- Department of Ecology, Evolution and Behaviour, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, 9190401 Jerusalem, Israel
| | - Yehu Moran
- Department of Ecology, Evolution and Behaviour, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, 9190401 Jerusalem, Israel
| | - Fabian Rentzsch
- Sars International Centre for Marine Molecular Biology, University of Bergen, 5006 Bergen, Norway; Department for Biological Sciences, University of Bergen, 5006 Bergen, Norway.
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15
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Integration of ocular and non-ocular photosensory information in the brain of the terrestrial slug Limax. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2020; 206:907-919. [PMID: 33025057 DOI: 10.1007/s00359-020-01447-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 09/09/2020] [Accepted: 09/21/2020] [Indexed: 10/23/2022]
Abstract
In the terrestrial slugs Limax, most of the photosensory information is thought to be acquired by an eye located on the superior tentacles, by which the slugs avoid light. Recent studies, however, suggested that the brain also plays a role as a photosensor in their negative phototaxis behavior. In the present study, we investigated how the photosensory information acquired by the eye and brain is integrated. The visual pathway in the brain was traced by incorporating tracer molecules from the cut end of an optic nerve, and commissural interactions were found in optic neuropiles located in the lateral regions of the cerebral ganglia. A cluster of neuronal cell bodies located near the dorsal surface of the cerebral ganglion had connections with the contralateral optic neuropile via gap junctions. Some of these neuronal cell bodies were Opn5A-immunoreactive, and contained numerous photic vesicle-like structures. Light-induced spikes were recorded extracellularly from the dorsal surface of these neuronal clusters, and they were synchronous with the spikes recorded from the cut end of the cerebral commissure. This study suggests that both the light information from the eye and the contralateral cerebral ganglion are integrated in the optic neuropile.
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16
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Pende M, Vadiwala K, Schmidbaur H, Stockinger AW, Murawala P, Saghafi S, Dekens MPS, Becker K, Revilla-i-Domingo R, Papadopoulos SC, Zurl M, Pasierbek P, Simakov O, Tanaka EM, Raible F, Dodt HU. A versatile depigmentation, clearing, and labeling method for exploring nervous system diversity. SCIENCE ADVANCES 2020; 6:eaba0365. [PMID: 32523996 PMCID: PMC7259959 DOI: 10.1126/sciadv.aba0365] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 03/27/2020] [Indexed: 06/11/2023]
Abstract
Tissue clearing combined with deep imaging has emerged as a powerful alternative to classical histological techniques. Whereas current techniques have been optimized for imaging selected nonpigmented organs such as the mammalian brain, natural pigmentation remains challenging for most other biological specimens of larger volume. We have developed a fast DEpigmEntation-Plus-Clearing method (DEEP-Clear) that is easily incorporated in existing workflows and combines whole system labeling with a spectrum of detection techniques, ranging from immunohistochemistry to RNA in situ hybridization, labeling of proliferative cells (EdU labeling) and visualization of transgenic markers. With light-sheet imaging of whole animals and detailed confocal studies on pigmented organs, we provide unprecedented insight into eyes, whole nervous systems, and subcellular structures in animal models ranging from worms and squids to axolotls and zebrafish. DEEP-Clear thus paves the way for the exploration of species-rich clades and developmental stages that are largely inaccessible by regular imaging approaches.
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Affiliation(s)
- Marko Pende
- Department for Bioelectronics, FKE, Vienna University of Technology, Gußhausstraße 25-25A, building CH, 1040 Vienna, Austria
- Section for Bioelectronics, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
| | - Karim Vadiwala
- Max Perutz Labs and Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenter, Dr. Bohr-Gasse 9/4, 1030 Vienna, Austria
| | - Hannah Schmidbaur
- Department of Neuroscience and Development, University of Vienna, Althanstraße 14, 1090 Vienna, Austria
| | - Alexander W. Stockinger
- Max Perutz Labs and Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenter, Dr. Bohr-Gasse 9/4, 1030 Vienna, Austria
| | - Prayag Murawala
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter, Campus-Vienna-Biocenter 1, 1030 Vienna, Austria
| | - Saiedeh Saghafi
- Department for Bioelectronics, FKE, Vienna University of Technology, Gußhausstraße 25-25A, building CH, 1040 Vienna, Austria
| | - Marcus P. S. Dekens
- Max Perutz Labs and Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenter, Dr. Bohr-Gasse 9/4, 1030 Vienna, Austria
| | - Klaus Becker
- Department for Bioelectronics, FKE, Vienna University of Technology, Gußhausstraße 25-25A, building CH, 1040 Vienna, Austria
- Section for Bioelectronics, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
| | - Roger Revilla-i-Domingo
- Max Perutz Labs and Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenter, Dr. Bohr-Gasse 9/4, 1030 Vienna, Austria
| | - Sofia-Christina Papadopoulos
- Department for Bioelectronics, FKE, Vienna University of Technology, Gußhausstraße 25-25A, building CH, 1040 Vienna, Austria
| | - Martin Zurl
- Max Perutz Labs and Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenter, Dr. Bohr-Gasse 9/4, 1030 Vienna, Austria
| | - Pawel Pasierbek
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter, Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Oleg Simakov
- Department of Neuroscience and Development, University of Vienna, Althanstraße 14, 1090 Vienna, Austria
| | - Elly M. Tanaka
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter, Campus-Vienna-Biocenter 1, 1030 Vienna, Austria
| | - Florian Raible
- Max Perutz Labs and Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenter, Dr. Bohr-Gasse 9/4, 1030 Vienna, Austria
| | - Hans-Ulrich Dodt
- Department for Bioelectronics, FKE, Vienna University of Technology, Gußhausstraße 25-25A, building CH, 1040 Vienna, Austria
- Section for Bioelectronics, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
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17
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Yang Z, Zhang L, Hu J, Wang J, Bao Z, Wang S. The evo-devo of molluscs: Insights from a genomic perspective. Evol Dev 2020; 22:409-424. [PMID: 32291964 DOI: 10.1111/ede.12336] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Molluscs represent one of ancient and evolutionarily most successful groups of marine invertebrates, with a tremendous diversity of morphology, behavior, and lifestyle. Molluscs are excellent subjects for evo-devo studies; however, understanding of the evo-devo of molluscs has been largely hampered by incomplete fossil records and limited molecular data. Recent advancement of genomics and other technologies has greatly fueled the molluscan "evo-devo" field, and decoding of several molluscan genomes provides unprecedented insights into molluscan biology and evolution. Here, we review the recent progress of molluscan genome sequencing as well as novel insights gained from their genomes, by emphasizing how molluscan genomics enhances our understanding of the evo-devo of molluscs.
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Affiliation(s)
- Zhihui Yang
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Pilot Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Lingling Zhang
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Pilot Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Jingjie Hu
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Jing Wang
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Pilot Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Zhenmin Bao
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China.,Laboratory for Marine Fisheries Science and Food Production Processes, Pilot Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Shi Wang
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Pilot Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,The Sars-Fang Centre, Ocean University of China, Qingdao, China
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18
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Corazonin signaling integrates energy homeostasis and lunar phase to regulate aspects of growth and sexual maturation in Platynereis. Proc Natl Acad Sci U S A 2019; 117:1097-1106. [PMID: 31843923 PMCID: PMC6969523 DOI: 10.1073/pnas.1910262116] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Gonadotropin Releasing Hormone (GnRH) acts as a key regulator of sexual maturation in vertebrates, and is required for the integration of environmental stimuli to orchestrate breeding cycles. Whether this integrative function is conserved across phyla remains unclear. We characterized GnRH-type signaling systems in the marine worm Platynereis dumerilii, in which both metabolic state and lunar cycle regulate reproduction. We find gnrh-like (gnrhl) genes upregulated in sexually mature animals, after feeding, and in specific lunar phases. Animals in which the corazonin1/gnrhl1 gene has been disabled exhibit delays in growth, regeneration, and maturation. Molecular analyses reveal glycoprotein turnover/energy homeostasis as targets of CRZ1/GnRHL1. These findings point at an ancestral role of GnRH superfamily signaling in coordinating energy demands dictated by environmental and developmental cues. The molecular mechanisms by which animals integrate external stimuli with internal energy balance to regulate major developmental and reproductive events still remain enigmatic. We investigated this aspect in the marine bristleworm, Platynereis dumerilii, a species where sexual maturation is tightly regulated by both metabolic state and lunar cycle. Our specific focus was on ligands and receptors of the gonadotropin-releasing hormone (GnRH) superfamily. Members of this superfamily are key in triggering sexual maturation in vertebrates but also regulate reproductive processes and energy homeostasis in invertebrates. Here we show that 3 of the 4 gnrh-like (gnrhl) preprohormone genes are expressed in specific and distinct neuronal clusters in the Platynereis brain. Moreover, ligand–receptor interaction analyses reveal a single Platynereis corazonin receptor (CrzR) to be activated by CRZ1/GnRHL1, CRZ2/GnRHL2, and GnRHL3 (previously classified as AKH1), whereas 2 AKH-type hormone receptors (GnRHR1/AKHR1 and GnRHR2/AKHR2) respond only to a single ligand (GnRH2/GnRHL4). Crz1/gnrhl1 exhibits a particularly strong up-regulation in sexually mature animals, after feeding, and in specific lunar phases. Homozygous crz1/gnrhl1 knockout animals exhibit a significant delay in maturation, reduced growth, and attenuated regeneration. Through a combination of proteomics and gene expression analysis, we identify enzymes involved in carbohydrate metabolism as transcriptional targets of CRZ1/GnRHL1 signaling. Our data suggest that Platynereis CRZ1/GnRHL1 coordinates glycoprotein turnover and energy homeostasis with growth and sexual maturation, integrating both metabolic and developmental demands with the worm’s monthly cycle.
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19
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Kuehn E, Stockinger AW, Girard J, Raible F, Özpolat BD. A scalable culturing system for the marine annelid Platynereis dumerilii. PLoS One 2019; 14:e0226156. [PMID: 31805142 PMCID: PMC6894799 DOI: 10.1371/journal.pone.0226156] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 11/20/2019] [Indexed: 12/16/2022] Open
Abstract
Platynereis dumerilii is a marine segmented worm (annelid) with externally fertilized embryos and it can be cultured for the full life cycle in the laboratory. The accessibility of embryos and larvae combined with the breadth of the established molecular and functional techniques has made P. dumerilii an attractive model for studying development, cell lineages, cell type evolution, reproduction, regeneration, the nervous system, and behavior. Traditionally, these worms have been kept in rooms dedicated for their culture. This allows for the regulation of temperature and light cycles, which is critical to synchronizing sexual maturation. However, regulating the conditions of a whole room has limitations, especially if experiments require being able to change culturing conditions. Here we present scalable and flexible culture methods that provide ability to control the environmental conditions, and have a multi-purpose culture space. We provide a closed setup shelving design with proper light conditions necessary for P. dumerilii to mature. We also implemented a standardized method of feeding P. dumerilii cultures with powdered spirulina which relieves the ambiguity associated with using frozen spinach, and helps standardize nutrition conditions across experiments and across different labs. By using these methods, we were able to raise mature P. dumerilii, capable of spawning and producing viable embryos for experimentation and replenishing culture populations. These methods will allow for the further accessibility of P. dumerilii as a model system, and they can be adapted for other aquatic organisms.
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Affiliation(s)
- Emily Kuehn
- Marine Biological Laboratory, Woods Hole, Massachusetts, United States of America
| | | | - Jerome Girard
- Marine Biological Laboratory, Woods Hole, Massachusetts, United States of America
| | | | - B. Duygu Özpolat
- Marine Biological Laboratory, Woods Hole, Massachusetts, United States of America
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20
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Ultrastructure of pigmented eyes in Onuphidae and Eunicidae (Annelida: Errantia: Eunicida) and its importance in understanding the evolution of eyes in Annelida. ZOOMORPHOLOGY 2019. [DOI: 10.1007/s00435-019-00465-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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21
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Katana R, Guan C, Zanini D, Larsen ME, Giraldo D, Geurten BRH, Schmidt CF, Britt SG, Göpfert MC. Chromophore-Independent Roles of Opsin Apoproteins in Drosophila Mechanoreceptors. Curr Biol 2019; 29:2961-2969.e4. [PMID: 31447373 DOI: 10.1016/j.cub.2019.07.036] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 06/24/2019] [Accepted: 07/11/2019] [Indexed: 12/23/2022]
Abstract
Rhodopsins, the major light-detecting molecules of animal visual systems [1], consist of opsin apoproteins that covalently bind a retinal chromophore with a conserved lysine residue [1, 2]. In addition to capturing photons, this chromophore contributes to rhodopsin maturation [3, 4], trafficking [3, 4], and stabilization [5], and defects in chromophore synthesis and recycling can cause dysfunction of the retina and dystrophy [6-9]. Indications that opsin apoproteins alone might have biological roles have come from archaebacteria and platyhelminths, which present opsin-like proteins that lack the chromophore binding site and are deemed to function independently of light [10, 11]. Light-independent sensory roles have been documented for Drosophila opsins [12-15], yet also these unconventional opsin functions are thought to require chromophore binding [12, 13, 15]. Unconjugated opsin apoproteins act as phospholipid scramblases in mammalian photoreceptor disks [16], yet chromophore-independent roles of opsin apoproteins outside of eyes have, to the best of our knowledge, hitherto not been described. Drosophila chordotonal mechanoreceptors require opsins [13, 15], and we find that their function remains uncompromised by nutrient carotenoid depletion. Disrupting carotenoid uptake and cleavage also left the mechanoreceptors unaffected, and manipulating the chromophore attachment site of the fly's major visual opsin Rh1 impaired photoreceptor, but not mechanoreceptor, function. Notwithstanding this chromophore independence, some proteins that process and recycle the chromophore in the retina are also required in mechanoreceptors, including visual cycle components that recycle the chromophore upon its photoisomerization. Our results thus establish biological function for unconjugated opsin apoproteins outside of eyes and, in addition, document chromophore-independent roles for chromophore pathway components.
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Affiliation(s)
- Radoslaw Katana
- Department of Cellular Neurobiology, University of Göttingen, 37077 Göttingen, Germany
| | - Chonglin Guan
- Faculty of Physics, Third Institute of Physics - Biophysics, University of Göttingen, 37077 Göttingen, Germany
| | - Damiano Zanini
- Department of Cellular Neurobiology, University of Göttingen, 37077 Göttingen, Germany
| | - Matthew E Larsen
- Departments of Neurology and Ophthalmology, Dell Medical School, University of Texas at Austin, Austin, TX 78712, USA
| | - Diego Giraldo
- Department of Cellular Neurobiology, University of Göttingen, 37077 Göttingen, Germany
| | - Bart R H Geurten
- Department of Cellular Neurobiology, University of Göttingen, 37077 Göttingen, Germany
| | - Christoph F Schmidt
- Faculty of Physics, Third Institute of Physics - Biophysics, University of Göttingen, 37077 Göttingen, Germany; Department of Physics and Soft Matter Center, Duke University, Durham, NC 27708, USA
| | - Steven G Britt
- Departments of Neurology and Ophthalmology, Dell Medical School, University of Texas at Austin, Austin, TX 78712, USA
| | - Martin C Göpfert
- Department of Cellular Neurobiology, University of Göttingen, 37077 Göttingen, Germany.
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22
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Arboleda E, Zurl M, Waldherr M, Tessmar-Raible K. Differential Impacts of the Head on Platynereis dumerilii Peripheral Circadian Rhythms. Front Physiol 2019; 10:900. [PMID: 31354531 PMCID: PMC6638195 DOI: 10.3389/fphys.2019.00900] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 06/27/2019] [Indexed: 12/20/2022] Open
Abstract
The marine bristle worm Platynereis dumerilii is a useful functional model system for the study of the circadian clock and its interplay with others, e.g., circalunar clocks. The focus has so far been on the worm's head. However, behavioral and physiological cycles in other animals typically arise from the coordination of circadian clocks located in the brain and in peripheral tissues. Here, we focus on peripheral circadian rhythms and clocks, revisit and expand classical circadian work on the worm's chromatophores, investigate locomotion as read-out and include molecular analyses. We establish that different pieces of the trunk exhibit synchronized, robust oscillations of core circadian clock genes. These circadian core clock transcripts are under strong control of the light-dark cycle, quickly losing synchronized oscillation under constant darkness, irrespective of the absence or presence of heads. Different wavelengths are differently effective in controlling the peripheral molecular synchronization. We have previously shown that locomotor activity is under circadian clock control. Here, we show that upon decapitation worms exhibit strongly reduced activity levels. While still following the light-dark cycle, locomotor rhythmicity under constant darkness is less clear. We also observe the rhythmicity of pigments in the worm's individual chromatophores, confirming their circadian pattern. These size changes continue under constant darkness, but cannot be re-entrained by light upon decapitation. Our works thus provides the first basic characterization of the peripheral circadian clock of P. dumerilii. In the absence of the head, light is essential as a major synchronization cue for peripheral molecular and locomotor circadian rhythms, while circadian changes in chromatophore size can continue for several days in the absence of light/dark changes and the head. Thus, in Platynereis the dependence on the head depends on the type of peripheral rhythm studied. These data show that peripheral circadian rhythms and clocks should also be considered in "non-conventional" molecular model systems, i.e., outside Drosophila melanogaster, Danio rerio, and Mus musculus, and build a basic foundation for future investigations of interactions of clocks with different period lengths in marine organisms.
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Affiliation(s)
- Enrique Arboleda
- Max F. Perutz Laboratories, Vienna BioCenter, University of Vienna, Vienna, Austria
| | - Martin Zurl
- Max F. Perutz Laboratories, Vienna BioCenter, University of Vienna, Vienna, Austria
- Research Platform “Rhythms of Life”, Vienna BioCenter, University of Vienna, Vienna, Austria
| | - Monika Waldherr
- Max F. Perutz Laboratories, Vienna BioCenter, University of Vienna, Vienna, Austria
- Research Platform “Rhythms of Life”, Vienna BioCenter, University of Vienna, Vienna, Austria
| | - Kristin Tessmar-Raible
- Max F. Perutz Laboratories, Vienna BioCenter, University of Vienna, Vienna, Austria
- Research Platform “Rhythms of Life”, Vienna BioCenter, University of Vienna, Vienna, Austria
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23
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Neal S, de Jong DM, Seaver EC. CRISPR/CAS9 mutagenesis of a single r-opsin gene blocks phototaxis in a marine larva. Proc Biol Sci 2019; 286:20182491. [PMID: 31161907 PMCID: PMC6571462 DOI: 10.1098/rspb.2018.2491] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 05/09/2019] [Indexed: 11/17/2022] Open
Abstract
Many marine animals depend upon a larval phase of their life cycle to locate suitable habitat, and larvae use light detection to influence swimming behaviour and dispersal. Light detection is mediated by the opsin genes, which encode light-sensitive transmembrane proteins. Previous studies suggest that r-opsins in the eyes mediate locomotory behaviour in marine protostomes, but few have provided direct evidence through gene mutagenesis. Larvae of the marine annelid Capitella teleta have simple eyespots and are positively phototactic, although the molecular components that mediate this behaviour are unknown. Here, we characterize the spatio-temporal expression of the rhabdomeric opsin genes in C. teleta and show that a single rhabdomeric opsin gene, Ct-r-opsin1, is expressed in the larval photoreceptor cells. To investigate its function, Ct-r-opsin1 was disrupted using CRISPR/CAS9 mutagenesis. Polymerase chain reaction amplification and DNA sequencing demonstrated efficient editing of the Ct-r-opsin1 locus. In addition, the pattern of Ct-r-opsin1 expression in photoreceptor cells was altered. Notably, there was a significant decrease in larval phototaxis, although the eyespot photoreceptor cell and associated pigment cell formed normally and persisted in Ct-r-opsin1-mutant animals. The loss of phototaxis owing to mutations in Ct-r-opsin1 is similar to that observed when the entire photoreceptor and pigment cell are deleted, demonstrating that a single r-opsin gene is sufficient to mediate phototaxis in C. teleta. These results establish the feasibility of gene editing in animals like C. teleta, and extend previous work on the development, evolution and function of the C. teleta visual system . Our study represents one example of disruption of animal behaviour by gene editing through CRISPR/CAS9 mutagenesis, and has broad implications for performing genome editing studies in a wide variety of other understudied animals.
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Affiliation(s)
| | | | - E. C. Seaver
- Whitney Laboratory for Marine Bioscience, University of Florida, St Augustine, FL, 32080USA
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24
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Williams EA, Jékely G. Neuronal cell types in the annelid Platynereis dumerilii. Curr Opin Neurobiol 2019; 56:106-116. [DOI: 10.1016/j.conb.2018.12.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Revised: 12/14/2018] [Accepted: 12/17/2018] [Indexed: 02/08/2023]
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25
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Bernardo-Garcia FJ, Syed M, Jékely G, Sprecher SG. Glass confers rhabdomeric photoreceptor identity in Drosophila, but not across all metazoans. EvoDevo 2019; 10:4. [PMID: 30873275 PMCID: PMC6399963 DOI: 10.1186/s13227-019-0117-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 02/15/2019] [Indexed: 12/14/2022] Open
Abstract
Across metazoans, visual systems employ different types of photoreceptor neurons (PRs) to detect light. These include rhabdomeric PRs, which exist in distantly related phyla and possess an evolutionarily conserved phototransduction cascade. While the development of rhabdomeric PRs has been thoroughly studied in the fruit fly Drosophila melanogaster, we still know very little about how they form in other species. To investigate this question, we tested whether the transcription factor Glass, which is crucial for instructing rhabdomeric PR formation in Drosophila, may play a similar role in other metazoans. Glass homologues exist throughout the animal kingdom, indicating that this protein evolved prior to the metazoan radiation. Interestingly, our work indicates that glass is not expressed in rhabdomeric photoreceptors in the planarian Schmidtea mediterranea nor in the annelid Platynereis dumerilii. Combined with a comparative analysis of the Glass DNA-binding domain, our data suggest that the fate of rhabdomeric PRs is controlled by Glass-dependent and Glass-independent mechanisms in different animal clades.
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Affiliation(s)
- F Javier Bernardo-Garcia
- 1Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland.,2Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158 USA
| | - Maryam Syed
- 1Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Gáspár Jékely
- 3Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD UK
| | - Simon G Sprecher
- 1Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
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26
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Schlosser G. A Short History of Nearly Every Sense-The Evolutionary History of Vertebrate Sensory Cell Types. Integr Comp Biol 2019; 58:301-316. [PMID: 29741623 DOI: 10.1093/icb/icy024] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Evolving from filter feeding chordate ancestors, vertebrates adopted a more active life style. These ecological and behavioral changes went along with an elaboration of the vertebrate head including novel complex paired sense organs such as the eyes, inner ears, and olfactory epithelia. However, the photoreceptors, mechanoreceptors, and chemoreceptors used in these sense organs have a long evolutionary history and homologous cell types can be recognized in many other bilaterians or even cnidarians. After briefly introducing some of the major sensory cell types found in vertebrates, this review summarizes the phylogenetic distribution of sensory cell types in metazoans and presents a scenario for the evolutionary history of various sensory cell types involving several cell type diversification and fusion events. It is proposed that the evolution of novel cranial sense organs in vertebrates involved the redeployment of evolutionarily ancient sensory cell types for building larger and more complex sense organs.
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Affiliation(s)
- Gerhard Schlosser
- School of Natural Sciences and Regenerative Medicine Institute (REMEDI), National University of Ireland, Biomedical Sciences Building, Newcastle Road, Galway H91 TK33, Ireland
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27
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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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28
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Verasztó C, Gühmann M, Jia H, Rajan VBV, Bezares-Calderón LA, Piñeiro-Lopez C, Randel N, Shahidi R, Michiels NK, Yokoyama S, Tessmar-Raible K, Jékely G. Ciliary and rhabdomeric photoreceptor-cell circuits form a spectral depth gauge in marine zooplankton. eLife 2018; 7:36440. [PMID: 29809157 PMCID: PMC6019069 DOI: 10.7554/elife.36440] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 05/28/2018] [Indexed: 02/02/2023] Open
Abstract
Ciliary and rhabdomeric photoreceptor cells represent two main lines of photoreceptor-cell evolution in animals. The two cell types coexist in some animals, however how these cells functionally integrate is unknown. We used connectomics to map synaptic paths between ciliary and rhabdomeric photoreceptors in the planktonic larva of the annelid Platynereis and found that ciliary photoreceptors are presynaptic to the rhabdomeric circuit. The behaviors mediated by the ciliary and rhabdomeric cells also interact hierarchically. The ciliary photoreceptors are UV-sensitive and mediate downward swimming in non-directional UV light, a behavior absent in ciliary-opsin knockout larvae. UV avoidance overrides positive phototaxis mediated by the rhabdomeric eyes such that vertical swimming direction is determined by the ratio of blue/UV light. Since this ratio increases with depth, Platynereis larvae may use it as a depth gauge during vertical migration. Our results revealed a functional integration of ciliary and rhabdomeric photoreceptor cells in a zooplankton larva.
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Affiliation(s)
- Csaba Verasztó
- Max Planck Institute for Developmental Biology, Tübingen, Germany.,Living Systems Institute, University of Exeter, Exeter, United Kingdom
| | - Martin Gühmann
- Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Huiyong Jia
- Department of Biology, Emory University, Atlanta, United States
| | | | - Luis A Bezares-Calderón
- Max Planck Institute for Developmental Biology, Tübingen, Germany.,Living Systems Institute, University of Exeter, Exeter, United Kingdom
| | | | - Nadine Randel
- Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Réza Shahidi
- Max Planck Institute for Developmental Biology, Tübingen, Germany.,Living Systems Institute, University of Exeter, Exeter, United Kingdom
| | - Nico K Michiels
- Department of Biology, University of Tübingen, Tübingen, Germany
| | - Shozo Yokoyama
- Department of Biology, Emory University, Atlanta, United States
| | | | - Gáspár Jékely
- Max Planck Institute for Developmental Biology, Tübingen, Germany.,Living Systems Institute, University of Exeter, Exeter, United Kingdom
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29
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Ayers T, Tsukamoto H, Gühmann M, Veedin Rajan VB, Tessmar-Raible K. A G o-type opsin mediates the shadow reflex in the annelid Platynereis dumerilii. BMC Biol 2018; 16:41. [PMID: 29669554 PMCID: PMC5904973 DOI: 10.1186/s12915-018-0505-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 03/12/2018] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND The presence of photoreceptive molecules outside the eye is widespread among animals, yet their functions in the periphery are less well understood. Marine organisms, such as annelid worms, exhibit a 'shadow reflex', a defensive withdrawal behaviour triggered by a decrease in illumination. Herein, we examine the cellular and molecular underpinnings of this response, identifying a role for a photoreceptor molecule of the Go-opsin class in the shadow response of the marine bristle worm Platynereis dumerilii. RESULTS We found Pdu-Go-opsin1 expression in single specialised cells located in adult Platynereis head and trunk appendages, known as cirri. Using gene knock-out technology and ablation approaches, we show that the presence of Go-opsin1 and the cirri is necessary for the shadow reflex. Consistently, quantification of the shadow reflex reveals a chromatic dependence upon light of approximately 500 nm in wavelength, matching the photoexcitation characteristics of the Platynereis Go-opsin1. However, the loss of Go-opsin1 does not abolish the shadow reflex completely, suggesting the existence of a compensatory mechanism, possibly acting through a ciliary-type opsin, Pdu-c-opsin2, with a Lambdamax of approximately 490 nm. CONCLUSIONS We show that a Go-opsin is necessary for the shadow reflex in a marine annelid, describing a functional example for a peripherally expressed photoreceptor, and suggesting that, in different species, distinct opsins contribute to varying degrees to the shadow reflex.
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Affiliation(s)
- Thomas Ayers
- Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter, Dr. Bohr-Gasse 9/4, 1030, Vienna, Austria
| | - Hisao Tsukamoto
- Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, Okazaki, 444-8585, Japan
- Department of Structural Molecular Science, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Kanagawa, 240-0193, Japan
- Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Kawaguchi, Saitama, 332-0012, Japan
| | - Martin Gühmann
- Max Planck Institute for Developmental Biology, Paul-Ehrlich Straße 20, 72076, Tübingen, Germany
| | - Vinoth Babu Veedin Rajan
- Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter, Dr. Bohr-Gasse 9/4, 1030, Vienna, Austria
- Research Platform 'Rhythms of Life', University of Vienna, 1030, Vienna, Austria
| | - Kristin Tessmar-Raible
- Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter, Dr. Bohr-Gasse 9/4, 1030, Vienna, Austria.
- Research Platform 'Rhythms of Life', University of Vienna, 1030, Vienna, Austria.
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30
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Shettigar N, Joshi A, Dalmeida R, Gopalkrishna R, Chakravarthy A, Patnaik S, Mathew M, Palakodeti D, Gulyani A. Hierarchies in light sensing and dynamic interactions between ocular and extraocular sensory networks in a flatworm. SCIENCE ADVANCES 2017; 3:e1603025. [PMID: 28782018 PMCID: PMC5533540 DOI: 10.1126/sciadv.1603025] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 06/27/2017] [Indexed: 05/23/2023]
Abstract
Light sensing has independently evolved multiple times under diverse selective pressures but has been examined only in a handful among the millions of light-responsive organisms. Unsurprisingly, mechanistic insights into how differential light processing can cause distinct behavioral outputs are limited. We show how an organism can achieve complex light processing with a simple "eye" while also having independent but mutually interacting light sensing networks. Although planarian flatworms lack wavelength-specific eye photoreceptors, a 25 nm change in light wavelength is sufficient to completely switch their phototactic behavior. Quantitative photoassays, eye-brain confocal imaging, and RNA interference/knockdown studies reveal that flatworms are able to compare small differences in the amounts of light absorbed at the eyes through a single eye opsin and convert them into binary behavioral outputs. Because planarians can fully regenerate, eye-brain injury-regeneration studies showed that this acute light intensity sensing and processing are layered on simple light detection. Unlike intact worms, partially regenerated animals with eyes can sense light but cannot sense finer gradients. Planarians also show a "reflex-like," eye-independent (extraocular/whole-body) response to low ultraviolet A light, apart from the "processive" eye-brain-mediated (ocular) response. Competition experiments between ocular and extraocular sensory systems reveal dynamic interchanging hierarchies. In intact worms, cerebral ocular response can override the reflex-like extraocular response. However, injury-regeneration again offers a time window wherein both responses coexist, but the dominance of the ocular response is reversed. Overall, we demonstrate acute light intensity-based behavioral switching and two evolutionarily distinct but interacting light sensing networks in a regenerating organism.
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Affiliation(s)
- Nishan Shettigar
- Institute for Stem Cell Biology and Regenerative Medicine (inStem), National Centre for Biological Sciences, GKVK Post, Bangalore 560065, India
- Shanmugha Arts, Science, Technology and Research Academy (SASTRA) University, Tirumalaisamudram, Thanjavur 613401, India
| | - Asawari Joshi
- Institute for Stem Cell Biology and Regenerative Medicine (inStem), National Centre for Biological Sciences, GKVK Post, Bangalore 560065, India
| | - Rimple Dalmeida
- Institute for Stem Cell Biology and Regenerative Medicine (inStem), National Centre for Biological Sciences, GKVK Post, Bangalore 560065, India
- Shanmugha Arts, Science, Technology and Research Academy (SASTRA) University, Tirumalaisamudram, Thanjavur 613401, India
| | - Rohini Gopalkrishna
- Institute for Stem Cell Biology and Regenerative Medicine (inStem), National Centre for Biological Sciences, GKVK Post, Bangalore 560065, India
| | - Anirudh Chakravarthy
- Institute for Stem Cell Biology and Regenerative Medicine (inStem), National Centre for Biological Sciences, GKVK Post, Bangalore 560065, India
| | - Siddharth Patnaik
- Institute for Stem Cell Biology and Regenerative Medicine (inStem), National Centre for Biological Sciences, GKVK Post, Bangalore 560065, India
| | - Manoj Mathew
- National Centre for Biological Sciences, GKVK Post, Bangalore 560065, India
| | - Dasaradhi Palakodeti
- Institute for Stem Cell Biology and Regenerative Medicine (inStem), National Centre for Biological Sciences, GKVK Post, Bangalore 560065, India
| | - Akash Gulyani
- Institute for Stem Cell Biology and Regenerative Medicine (inStem), National Centre for Biological Sciences, GKVK Post, Bangalore 560065, India
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31
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Wang S, Zhang J, Jiao W, Li J, Xun X, Sun Y, Guo X, Huan P, Dong B, Zhang L, Hu X, Sun X, Wang J, Zhao C, Wang Y, Wang D, Huang X, Wang R, Lv J, Li Y, Zhang Z, Liu B, Lu W, Hui Y, Liang J, Zhou Z, Hou R, Li X, Liu Y, Li H, Ning X, Lin Y, Zhao L, Xing Q, Dou J, Li Y, Mao J, Guo H, Dou H, Li T, Mu C, Jiang W, Fu Q, Fu X, Miao Y, Liu J, Yu Q, Li R, Liao H, Li X, Kong Y, Jiang Z, Chourrout D, Li R, Bao Z. Scallop genome provides insights into evolution of bilaterian karyotype and development. Nat Ecol Evol 2017; 1:120. [PMID: 28812685 PMCID: PMC10970998 DOI: 10.1038/s41559-017-0120] [Citation(s) in RCA: 240] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 02/16/2017] [Indexed: 12/21/2022]
Abstract
Reconstructing the genomes of bilaterian ancestors is central to our understanding of animal evolution, where knowledge from ancient and/or slow-evolving bilaterian lineages is critical. Here we report a high-quality, chromosome-anchored reference genome for the scallop Patinopecten yessoensis, a bivalve mollusc that has a slow-evolving genome with many ancestral features. Chromosome-based macrosynteny analysis reveals a striking correspondence between the 19 scallop chromosomes and the 17 presumed ancestral bilaterian linkage groups at a level of conservation previously unseen, suggesting that the scallop may have a karyotype close to that of the bilaterian ancestor. Scallop Hox gene expression follows a new mode of subcluster temporal co-linearity that is possibly ancestral and may provide great potential in supporting diverse bilaterian body plans. Transcriptome analysis of scallop mantle eyes finds unexpected diversity in phototransduction cascades and a potentially ancient Pax2/5/8-dependent pathway for noncephalic eyes. The outstanding preservation of ancestral karyotype and developmental control makes the scallop genome a valuable resource for understanding early bilaterian evolution and biology.
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Affiliation(s)
- Shi Wang
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237 China
| | - Jinbo Zhang
- Novogene Bioinformatics Institute, Beijing, 100083 China
| | - Wenqian Jiao
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Ji Li
- Novogene Bioinformatics Institute, Beijing, 100083 China
| | - Xiaogang Xun
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Yan Sun
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Ximing Guo
- Department of Marine and Coastal Sciences, Haskin Shellfish Research Laboratory, Rutgers University, Port Norris, 08349 New Jersey USA
| | - Pin Huan
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071 China
| | - Bo Dong
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237 China
| | - Lingling Zhang
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Xiaoli Hu
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237 China
| | - Xiaoqing Sun
- Novogene Bioinformatics Institute, Beijing, 100083 China
| | - Jing Wang
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Chengtian Zhao
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
| | - Yangfan Wang
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Dawei Wang
- Novogene Bioinformatics Institute, Beijing, 100083 China
| | - Xiaoting Huang
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Ruijia Wang
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Jia Lv
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Yuli Li
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Zhifeng Zhang
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Baozhong Liu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071 China
| | - Wei Lu
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Yuanyuan Hui
- Novogene Bioinformatics Institute, Beijing, 100083 China
| | - Jun Liang
- Dalian Zhangzidao Group Co. Ltd, Dalian, 116001 China
| | - Zunchun Zhou
- Liaoning Key Lab of Marine Fishery Molecular Biology, Liaoning Ocean and Fisheries Science Research Institute, Dalian, 116023 China
| | - Rui Hou
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Xue Li
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Yunchao Liu
- Novogene Bioinformatics Institute, Beijing, 100083 China
| | - Hengde Li
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
- Key Laboratory of Aquatic Genomics, Ministry of Agriculture, Chinese Academy of Fishery Sciences, Beijing 100141, China
| | - Xianhui Ning
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Yu Lin
- Novogene Bioinformatics Institute, Beijing, 100083 China
| | - Liang Zhao
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Qiang Xing
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Jinzhuang Dou
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Yangping Li
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Junxia Mao
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Haobing Guo
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Huaiqian Dou
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Tianqi Li
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Chuang Mu
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Wenkai Jiang
- Novogene Bioinformatics Institute, Beijing, 100083 China
| | - Qiang Fu
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Xiaoteng Fu
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Yan Miao
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Jian Liu
- Novogene Bioinformatics Institute, Beijing, 100083 China
| | - Qian Yu
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Ruojiao Li
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Huan Liao
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Xuan Li
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Yifan Kong
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
| | - Zhi Jiang
- Novogene Bioinformatics Institute, Beijing, 100083 China
| | - Daniel Chourrout
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, N-5008 Norway
| | - Ruiqiang Li
- Novogene Bioinformatics Institute, Beijing, 100083 China
| | - Zhenmin Bao
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003 China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237 China
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Scherholz M, Redl E, Wollesen T, de Oliveira AL, Todt C, Wanninger A. Ancestral and novel roles of Pax family genes in mollusks. BMC Evol Biol 2017; 17:81. [PMID: 28302062 PMCID: PMC5356317 DOI: 10.1186/s12862-017-0919-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 02/18/2017] [Indexed: 01/31/2023] Open
Abstract
Background Pax genes are transcription factors with significant roles in cell fate specification and tissue differentiation during animal ontogeny. Most information on their tempo-spatial mode of expression is available from well-studied model organisms where the Pax-subfamilies Pax2/5/8, Pax6, and Paxα/β are mainly involved in the development of the central nervous system (CNS), the eyes, and other sensory organs. In certain taxa, Pax2/5/8 seems to be additionally involved in the development of excretion organs. Data on expression patterns in lophotrochozoans, and in particular in mollusks, are very scarce for all the above-mentioned Pax-subfamilies, which hampers reconstruction of their putative ancestral roles in bilaterian animals. Thus, we studied the developmental expression of Pax2/5/8, Pax6, and the lophotrochozoan-specific Paxβ in the worm-shaped mollusk Wirenia argentea, a member of Aplacophora that together with Polyplacophora forms the Aculifera, the proposed sister taxon to all primarily single-shelled mollusks (Conchifera). Results All investigated Pax genes are expressed in the developing cerebral ganglia and in the ventral nerve cords, but not in the lateral nerve cords of the tetraneural nervous system. Additionally, Pax2/5/8 is expressed in epidermal spicule-secreting or associated cells of the larval trunk and in the region of the developing protonephridia. We found no indication for an involvement of the investigated Pax genes in the development of larval or adult sensory organs of Wirenia argentea. Conclusions Pax2/5/8 seems to have a conserved role in the development of the CNS, whereas expression in the spicule-secreting tissues of aplacophorans and polyplacophorans suggests co-option in aculiferan skeletogenesis. The Pax6 expression pattern in Aculifera largely resembles the common bilaterian expression during CNS development. All data available on Paxβ expression argue for a common role in lophotrochozoan neurogenesis. Electronic supplementary material The online version of this article (doi:10.1186/s12862-017-0919-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Maik Scherholz
- Department of Integrative Zoology, Faculty of Life Sciences, University of Vienna, Althanstraße 14, 1090, Vienna, Austria
| | - Emanuel Redl
- Department of Integrative Zoology, Faculty of Life Sciences, University of Vienna, Althanstraße 14, 1090, Vienna, Austria
| | - Tim Wollesen
- Department of Integrative Zoology, Faculty of Life Sciences, University of Vienna, Althanstraße 14, 1090, Vienna, Austria
| | - André Luiz de Oliveira
- Department of Integrative Zoology, Faculty of Life Sciences, University of Vienna, Althanstraße 14, 1090, Vienna, Austria
| | - Christiane Todt
- University Museum of Bergen, University of Bergen, Allégaten 41, 5007, Bergen, Norway
| | - Andreas Wanninger
- Department of Integrative Zoology, Faculty of Life Sciences, University of Vienna, Althanstraße 14, 1090, Vienna, Austria.
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Structural analysis of the branchiae and dorsal cirri in Eurythoe complanata (Annelida, Amphinomida). ZOOMORPHOLOGY 2016. [DOI: 10.1007/s00435-016-0336-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Grillo M, Konstantinides N, Averof M. Old questions, new models: unraveling complex organ regeneration with new experimental approaches. Curr Opin Genet Dev 2016; 40:23-31. [DOI: 10.1016/j.gde.2016.05.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 05/12/2016] [Accepted: 05/13/2016] [Indexed: 10/21/2022]
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35
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Kelley JL, Davies WIL. The Biological Mechanisms and Behavioral Functions of Opsin-Based Light Detection by the Skin. Front Ecol Evol 2016. [DOI: 10.3389/fevo.2016.00106] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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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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Chou HC, Pruitt MM, Bastin BR, Schneider SQ. A transcriptional blueprint for a spiral-cleaving embryo. BMC Genomics 2016; 17:552. [PMID: 27496340 PMCID: PMC4974748 DOI: 10.1186/s12864-016-2860-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 06/29/2016] [Indexed: 01/29/2023] Open
Abstract
Background The spiral cleavage mode of early development is utilized in over one-third of all animal phyla and generates embryonic cells of different size, position, and fate through a conserved set of stereotypic and invariant asymmetric cell divisions. Despite the widespread use of spiral cleavage, regulatory and molecular features for any spiral-cleaving embryo are largely uncharted. To address this gap we use RNA-sequencing on the spiralian model Platynereis dumerilii to capture and quantify the first complete genome-wide transcriptional landscape of early spiral cleavage. Results RNA-sequencing datasets from seven stages in early Platynereis development, from the zygote to the protrochophore, are described here including the de novo assembly and annotation of ~17,200 Platynereis genes. Depth and quality of the RNA-sequencing datasets allow the identification of the temporal onset and level of transcription for each annotated gene, even if the expression is restricted to a single cell. Over 4000 transcripts are maternally contributed and cleared by the end of the early spiral cleavage phase. Small early waves of zygotic expression are followed by major waves of thousands of genes, demarcating the maternal to zygotic transition shortly after the completion of spiral cleavages in this annelid species. Conclusions Our comprehensive stage-specific transcriptional analysis of early embryonic stages in Platynereis elucidates the regulatory genome during early spiral embryogenesis and defines the maternal to zygotic transition in Platynereis embryos. This transcriptome assembly provides the first systems-level view of the transcriptional and regulatory landscape for a spiral-cleaving embryo. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2860-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hsien-Chao Chou
- Department of Genetics, Development and Cell Biology, Iowa State University, 503 Science Hall II, Ames, IA, 50011, USA.,Present Address: National Cancer Institute, US National Institutes of Health, Bethesda, Maryland, USA
| | - Margaret M Pruitt
- Department of Genetics, Development and Cell Biology, Iowa State University, 503 Science Hall II, Ames, IA, 50011, USA.,Present Address: Department of Pediatrics, University of Chicago, Chicago, IL, USA
| | - Benjamin R Bastin
- Department of Genetics, Development and Cell Biology, Iowa State University, 503 Science Hall II, Ames, IA, 50011, USA
| | - Stephan Q Schneider
- Department of Genetics, Development and Cell Biology, Iowa State University, 503 Science Hall II, Ames, IA, 50011, USA.
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Schumann I, Hering L, Mayer G. Immunolocalization of Arthropsin in the Onychophoran Euperipatoides rowelli (Peripatopsidae). Front Neuroanat 2016; 10:80. [PMID: 27540356 PMCID: PMC4972820 DOI: 10.3389/fnana.2016.00080] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 07/14/2016] [Indexed: 01/09/2023] Open
Abstract
Opsins are light-sensitive proteins that play a key role in animal vision and are related to the ancient photoreceptive molecule rhodopsin found in unicellular organisms. In general, opsins involved in vision comprise two major groups: the rhabdomeric (r-opsins) and the ciliary opsins (c-opsins). The functionality of opsins, which is dependent on their protein structure, may have changed during evolution. In arthropods, typically r-opsins are responsible for vision, whereas in vertebrates c-opsins are components of visual photoreceptors. Recently, an enigmatic r-opsin-like protein called arthropsin has been identified in various bilaterian taxa, including arthropods, lophotrochozoans, and chordates, by performing transcriptomic and genomic analyses. Since the role of arthropsin and its distribution within the body are unknown, we immunolocalized this protein in a representative of Onychophora – Euperipatoides rowelli – an ecdysozoan taxon which is regarded as one of the closest relatives of Arthropoda. Our data show that arthropsin is expressed in the central nervous system of E. rowelli, including the brain and the ventral nerve cords, but not in the eyes. These findings are consistent with previous results based on reverse transcription PCR in a closely related onychophoran species and suggest that arthropsin is a non-visual protein. Based on its distribution in the central brain region and the mushroom bodies, we speculate that the onychophoran arthropsin might be either a photosensitive molecule playing a role in the circadian clock, or a non-photosensitive protein involved in olfactory pathways, or both.
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Affiliation(s)
- Isabell Schumann
- Department of Zoology, Institute of Biology, University of Kassel, KasselGermany; Molecular Evolution and Animal Systematics, University of Leipzig, LeipzigGermany
| | - Lars Hering
- Department of Zoology, Institute of Biology, University of Kassel, Kassel Germany
| | - Georg Mayer
- Department of Zoology, Institute of Biology, University of Kassel, Kassel Germany
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Bok MJ, Capa M, Nilsson DE. Here, There and Everywhere: The Radiolar Eyes of Fan Worms (Annelida, Sabellidae). Integr Comp Biol 2016; 56:784-795. [PMID: 27453305 DOI: 10.1093/icb/icw089] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Fan worms (Annelida: Sabellidae) possess some of the strangest eyes in nature. Their eponymous fans are composed of two sets of radiolar tentacles that project from the head up out of the worm's protective tube into the water column. Primarily used for respiration and feeding, these radioles are also often involved in photoreception. They display a surprising diversity of eyes of varying levels of sophistication, ranging from scattered single ocelli to compound eyes with up to hundreds of facets. These photoreceptors could represent a relatively recent evolutionary development to cope with a sessile, tube-dwelling lifestyle, and the primary cerebral eyes (haplessly positioned within the tube most of the time) amount to little more than minute pigment cups with scant visual potential. The radiolar eyes on the other hand, appear to function as visual burglar alarms for detecting looming predators and eliciting a startle response for the worm to rapidly retreat within its fortified tube. Despite sometimes resembling arthropod compound eyes, the radiolar photoreceptors have many canonically vertebrate-like physiological characteristics. Considering the unusual and apparently recently evolved nature of the fan worm radiolar photoreceptors, these animals are an excellent case for examining the emergence of novel visual systems, the development of rudimentary visually guided behaviors, and the function of distributed sensory systems. Here, we review over 100 years of investigations into the anatomical diversity of sabellid radiolar photoreceptors and eyes in an evolutionary and functional context. We provide new information on radiolar eye structure in several species of fan worms, and we attempt to organize the various eye types and ocellar structures into meaningful hierarchies. We discuss the developmental, evolutionary, and functional significance of the radiolar eyes and highlight areas of future interest in deciphering their unique nature.
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Affiliation(s)
- Michael J Bok
- *Department of Biology, Lund Vision Group, Lund University, Lund, Sweden .,*Department of Biology, Lund Vision Group, Lund University, Lund, Sweden
| | - María Capa
- NTNU University Museum, Norwegian University of Science and Technology, Trondheim, Norway
| | - Dan-Eric Nilsson
- *Department of Biology, Lund Vision Group, Lund University, Lund, Sweden
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Ramirez MD, Oakley TH. Eye-independent, light-activated chromatophore expansion (LACE) and expression of phototransduction genes in the skin of Octopus bimaculoides. ACTA ACUST UNITED AC 2016; 218:1513-20. [PMID: 25994633 DOI: 10.1242/jeb.110908] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cephalopods are renowned for changing the color and pattern of their skin for both camouflage and communication. Yet, we do not fully understand how cephalopods control the pigmented chromatophore organs in their skin and change their body pattern. Although these changes primarily rely on eyesight, we found that light causes chromatophores to expand in excised pieces of Octopus bimaculoides skin. We call this behavior light-activated chromatophore expansion (or LACE). To uncover how octopus skin senses light, we used antibodies against r-opsin phototransduction proteins to identify sensory neurons that express r-opsin in the skin. We hypothesized that octopus LACE relies on the same r-opsin phototransduction cascade found in octopus eyes. By creating an action spectrum for the latency to LACE, we found that LACE occurred most quickly in response to blue light. We fit our action spectrum data to a standard opsin curve template and estimated the λmax of LACE to be 480 nm. Consistent with our hypothesis, the maximum sensitivity of the light sensors underlying LACE closely matches the known spectral sensitivity of opsin from octopus eyes. LACE in isolated preparations suggests that octopus skin is intrinsically light sensitive and that this dispersed light sense might contribute to their unique and novel patterning abilities. Finally, our data suggest that a common molecular mechanism for light detection in eyes may have been co-opted for light sensing in octopus skin and then used for LACE.
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Affiliation(s)
- M Desmond Ramirez
- Department of Ecology Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, CA 93106-6150, USA
| | - Todd H Oakley
- Department of Ecology Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, CA 93106-6150, USA
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Cvekl A, Callaerts P. PAX6: 25th anniversary and more to learn. Exp Eye Res 2016; 156:10-21. [PMID: 27126352 DOI: 10.1016/j.exer.2016.04.017] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 04/12/2016] [Accepted: 04/22/2016] [Indexed: 01/29/2023]
Abstract
The DNA-binding transcription factor PAX6 was cloned 25 years ago by multiple teams pursuing identification of human and mouse eye disease causing genes, cloning vertebrate homologues of pattern-forming regulatory genes identified in Drosophila, or abundant eye-specific transcripts. Since its discovery in 1991, genetic, cellular, molecular and evolutionary studies on Pax6 mushroomed in the mid 1990s leading to the transformative thinking regarding the genetic program orchestrating both early and late stages of eye morphogenesis as well as the origin and evolution of diverse visual systems. Since Pax6 is also expressed outside of the eye, namely in the central nervous system and pancreas, a number of important insights into the development and function of these organs have been amassed. In most recent years, genome-wide technologies utilizing massively parallel DNA sequencing have begun to provide unbiased insights into the regulatory hierarchies of specification, determination and differentiation of ocular cells and neurogenesis in general. This review is focused on major advancements in studies on mammalian eye development driven by studies of Pax6 genes in model organisms and future challenges to harness the technology-driven opportunities to reconstruct, step-by-step, the transition from naïve ectoderm, neuroepithelium and periocular mesenchyme/neural crest cells into the three-dimensional architecture of the eye.
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Affiliation(s)
- Ales Cvekl
- The Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; The Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA.
| | - Patrick Callaerts
- Laboratory of Behavioral and Developmental Genetics, K.U. Leuven, VIB, 3000, Leuven, Belgium.
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Ultrastructural differences in presumed photoreceptive organs and molecular data as a means for species discrimination in Polygordius (Annelida, Protodriliformia, Polygordiidae). ORG DIVERS EVOL 2016. [DOI: 10.1007/s13127-016-0272-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Vöcking O, Kourtesis I, Hausen H. Posterior eyespots in larval chitons have a molecular identity similar to anterior cerebral eyes in other bilaterians. EvoDevo 2015; 6:40. [PMID: 26702352 PMCID: PMC4689004 DOI: 10.1186/s13227-015-0036-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 11/19/2015] [Indexed: 11/17/2022] Open
Abstract
Background Development of cerebral eyes is generally based on fine-tuned networks and closely intertwined with the formation of brain and head. Consistently and best studied in insects and vertebrates, many signaling pathways relaying the activity of eye developmental factors to positional information in the head region are characterized. Though known from several organisms, photoreceptors developing outside the head region are much less studied and the course of their development, relation to cerebral eyes and evolutionary origin is in most cases unknown. To explore how position influences development of otherwise similar photoreceptors, we analyzed the molecular characteristics of photoreceptors we discovered at the very anterior, the posttrochal mid-body and posterior body region of larval Leptochiton asellus, a representative of the chiton subgroup of mollusks. Results Irrespective of their position, all found photoreceptors exhibit a molecular signature highly similar to cerebral eye photoreceptors of related animals. All photoreceptors employ the same subtype of visual pigments (r-opsin), and the same key elements for phototransduction such as GNAq, trpC and arrestin and intracellular r-opsin transport such as rip11 and myosinV as described from other protostome cerebral eyes. Several transcription factors commonly involved in cerebral eye and brain development such as six1/2, eya, dachshund, lhx2/9 and prox are also expressed by all found photoreceptor cells, only pax6 being restricted to the anterior most cells. Coexpression of pax6 and MITF in photoreceptor-associated shielding pigment cells present at the mid-body position matches the common situation in cerebral eye retinal pigment epithelium specification and differentiation. Notably, all photoreceptors, even the posterior ones, further express clear anterior markers such as foxq2, irx, otx, and six3/6 (only the latter absent in the most posterior photoreceptors), which play important roles in the early patterning of the anterior neurogenic area throughout the animal kingdom. Conclusions Our data suggest that anterior eyes with brain-associated development can indeed be subject to heterotopic replication to developmentally distinct and even posterior body regions. Retention of the transcriptional activity of a broad set of eye developmental factors and common anterior markers suggests a mode of eye development induction, which is largely independent of body regionalization. Electronic supplementary material The online version of this article (doi:10.1186/s13227-015-0036-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Oliver Vöcking
- 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
| | - Ioannis Kourtesis
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate 55, 5008 Bergen, Norway
| | - Harald Hausen
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate 55, 5008 Bergen, Norway
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Shahidi R, Williams EA, Conzelmann M, Asadulina A, Verasztó C, Jasek S, Bezares-Calderón LA, Jékely G. A serial multiplex immunogold labeling method for identifying peptidergic neurons in connectomes. eLife 2015; 4. [PMID: 26670546 PMCID: PMC4749568 DOI: 10.7554/elife.11147] [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: 08/26/2015] [Accepted: 11/27/2015] [Indexed: 02/07/2023] Open
Abstract
Electron microscopy-based connectomics aims to comprehensively map synaptic connections in neural tissue. However, current approaches are limited in their capacity to directly assign molecular identities to neurons. Here, we use serial multiplex immunogold labeling (siGOLD) and serial-section transmission electron microscopy (ssTEM) to identify multiple peptidergic neurons in a connectome. The high immunogenicity of neuropeptides and their broad distribution along axons, allowed us to identify distinct neurons by immunolabeling small subsets of sections within larger series. We demonstrate the scalability of siGOLD by using 11 neuropeptide antibodies on a full-body larval ssTEM dataset of the annelid Platynereis. We also reconstruct a peptidergic circuitry comprising the sensory nuchal organs, found by siGOLD to express pigment-dispersing factor, a circadian neuropeptide. Our approach enables the direct overlaying of chemical neuromodulatory maps onto synaptic connectomic maps in the study of nervous systems. DOI:http://dx.doi.org/10.7554/eLife.11147.001 In the nervous system, cells called neurons connect to each other to form large “neural” networks. The most powerful method that is currently available for tracing neurons and mapping the connections between them is called electron microscopy. This requires slicing brain tissue into ultrathin sections, which are then imaged one by one. However, while electron microscopy provides highly detailed information about the structure of the connections between neurons, it does not reveal which molecules the neurons use to communicate with each other. To address this question, Shahidi et al. have developed a new approach called ‘siGOLD’. Unlike previous approaches, siGOLD allows signal molecules inside cells to be labeled with protein tags called antibodies without compromising the ability to examine the tissue with electron microscopy. The technique was developed using the larvae of a marine worm called Platynereis. A single larva was sliced into 5000 sections thin enough to view under an electron microscope, and 150 of these were selected to represent the entire body. Because neurons are typically long and thin, individual neurons usually spanned multiple slices. To identify the neurons, Shahidi et al. then applied an antibody that recognizes a specific signal molecule to a subset of the slices. The antibodies were labeled with gold particles, which show up as black dots under the electron microscope. Because the molecules recognized by the antibodies are present all along the neuron, and because individual neurons extend over multiple slices, it was possible to trace single neurons by labeling only a small number of slices. Repeating this process in different subsets of slices with antibodies that bind to different signal molecules allowed entire neural circuits to be mapped. In the future, Shahidi et al.’s approach could be adapted to study neural networks in other organisms such as flies, fish and mice. DOI:http://dx.doi.org/10.7554/eLife.11147.002
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Affiliation(s)
- Réza Shahidi
- Max-Planck-Institute for Developmental Biology, Tübingen, Germany
| | | | | | - Albina Asadulina
- Max-Planck-Institute for Developmental Biology, Tübingen, Germany
| | - Csaba Verasztó
- Max-Planck-Institute for Developmental Biology, Tübingen, Germany
| | - Sanja Jasek
- Max-Planck-Institute for Developmental Biology, Tübingen, Germany
| | | | - Gáspár Jékely
- Max-Planck-Institute for Developmental Biology, Tübingen, Germany
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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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47
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High-throughput spatial mapping of single-cell RNA-seq data to tissue of origin. Nat Biotechnol 2015; 33:503-9. [PMID: 25867922 DOI: 10.1038/nbt.3209] [Citation(s) in RCA: 278] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 03/13/2015] [Indexed: 01/12/2023]
Abstract
Understanding cell type identity in a multicellular organism requires the integration of gene expression profiles from individual cells with their spatial location in a particular tissue. Current technologies allow whole-transcriptome sequencing of spatially identified cells but lack the throughput needed to characterize complex tissues. Here we present a high-throughput method to identify the spatial origin of cells assayed by single-cell RNA-sequencing within a tissue of interest. Our approach is based on comparing complete, specificity-weighted mRNA profiles of a cell with positional gene expression profiles derived from a gene expression atlas. We show that this method allocates cells to precise locations in the brain of the marine annelid Platynereis dumerilii with a success rate of 81%. Our method is applicable to any system that has a reference gene expression database of sufficiently high resolution.
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Perry KJ, Henry JQ. CRISPR/Cas9-mediated genome modification in the mollusc, Crepidula fornicata. Genesis 2015; 53:237-44. [PMID: 25529990 DOI: 10.1002/dvg.22843] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 12/12/2014] [Accepted: 12/17/2014] [Indexed: 12/20/2022]
Abstract
The discovery and application of the CRISPR/Cas9 genome editing method has greatly enhanced the ease with which transgenic manipulation can occur. We applied this technology to the mollusc, Crepidula fornicata, and have successfully created transgenic embryos expressing mCherry fused to endogenous β-catenin. Specific integration of the fluorescent reporter was achieved by homologous recombination with a β-catenin-specific donor DNA containing the mCherry coding sequence. This fluorescent gene knock-in strategy permits in vivo observations of β-catenin expression during embryonic development and represents the first demonstration of CRISPR/Cas9-mediated transgenesis in the Lophotrochozoa superphylum. The CRISPR/Cas9 method is a powerful and economical tool for genome modification and presents an option for analysis of gene expression in not only major model systems, but also in those more diverse species that may not have been amenable to the classic methods of transgenesis. This approach will allow one to generate transgenic lines of snails for future studies.
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Affiliation(s)
- Kimberly J Perry
- Department of Cell and Developmental Biology, University of Illinois, Urbana, Illinois, 61801
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Gilles AF, Averof M. Functional genetics for all: engineered nucleases, CRISPR and the gene editing revolution. EvoDevo 2014; 5:43. [PMID: 25699168 PMCID: PMC4332929 DOI: 10.1186/2041-9139-5-43] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 10/03/2014] [Indexed: 12/26/2022] Open
Abstract
Developmental biology, as all experimental science, is empowered by technological advances. The availability of genetic tools in some species - designated as model organisms - has driven their use as major platforms for understanding development, physiology and behavior. Extending these tools to a wider range of species determines whether (and how) we can experimentally approach developmental diversity and evolution. During the last two decades, comparative developmental biology (evo-devo) was marked by the introduction of gene knockdown and deep sequencing technologies that are applicable to a wide range of species. These approaches allowed us to test the developmental role of specific genes in diverse species, to study biological processes that are not accessible in established models and, in some cases, to conduct genome-wide screens that overcome the limitations of the candidate gene approach. The recent discovery of CRISPR/Cas as a means of precise alterations into the genome promises to revolutionize developmental genetics. In this review we describe the development of gene editing tools, from zinc-finger nucleases to TALENs and CRISPR, and examine their application in gene targeting, their limitations and the opportunities they present for evo-devo. We outline their use in gene knock-out and knock-in approaches, and in manipulating gene functions by directing molecular effectors to specific sites in the genome. The ease-of-use and efficiency of CRISPR in diverse species provide an opportunity to close the technology gap that exists between established model organisms and emerging genetically-tractable species.
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Affiliation(s)
- Anna F Gilles
- Institut de Génomique Fonctionnelle de Lyon (IGFL), École Normale Supérieure de Lyon, 46 Allée d'Italie, Lyon, 69364 France ; BMIC graduate programme and Université Claude Bernard - Lyon 1, Lyon, France
| | - Michalis Averof
- Institut de Génomique Fonctionnelle de Lyon (IGFL), École Normale Supérieure de Lyon, 46 Allée d'Italie, Lyon, 69364 France ; Centre National de la Recherche Scientifique (CNRS), Lyon, France
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50
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Wollesen T, McDougall C, Degnan BM, Wanninger A. POU genes are expressed during the formation of individual ganglia of the cephalopod central nervous system. EvoDevo 2014; 5:41. [PMID: 25908957 PMCID: PMC4407788 DOI: 10.1186/2041-9139-5-41] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 09/29/2014] [Indexed: 11/18/2022] Open
Abstract
Background Among the Lophotrochozoa, cephalopods possess the highest degree of central nervous system (CNS) centralization and complexity. Although the anatomy of the developing cephalopod CNS has been investigated, the developmental mechanisms underlying brain development and evolution are unknown. POU genes encode key transcription factors controlling nervous system development in a range of bilaterian species, including lophotrochozoans. In this study, we investigate the expression of POU genes during early development of the pygmy squid Idiosepius notoides and make comparisons with other bilaterians to reveal whether these genes have conserved or divergent roles during CNS development in this species. Results POU2, POU3, POU4 and POU6 orthologs were identified in transcriptomes derived from developmental stages and adult brain tissue of I. notoides. All four POU gene orthologs are expressed in different spatiotemporal combinations in the early embryo. Ino-POU2 is expressed in the gills and the palliovisceral, pedal, and optic ganglia of stage 19 to 20 embryos, whereas the cerebral and palliovisceral ganglia express Ino-POU3. Ino-POU4 is expressed in the optic and palliovisceral ganglia and the arms/intrabrachial ganglia of stage 19 to 20 individuals. Ino-POU6 is expressed in the palliovisceral ganglia during early development. In stage 25 embryos expression domains include the intrabrachial ganglia (Ino-POU3) and the pedal ganglia (Ino-POU6). All four POU genes are strongly expressed in large areas of the brain of stage 24 to 26 individuals. Expression could not be detected in late prehatching embryos (approximately stage 27 to 30). Conclusions The expression of four POU genes in unique spatiotemporal combinations during early neurogenesis and sensory organ development of I. notoides suggests that they fulfill distinct tasks during early brain development. Comparisons with other bilaterian species reveal that POU gene expression is associated with anteriormost neural structures, even between animals for which these structures are unlikely to be homologous. Within lophotrochozoans, POU3 and POU4 are the only two genes that have been comparatively investigated. Their expression patterns are broadly similar, indicating that the increased complexity of the cephalopod brain is likely due to other unknown factors.
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Affiliation(s)
- Tim Wollesen
- Department of Integrative Zoology, Faculty of Sciences, University of Vienna, Althanstr. 14, 1090 Vienna, Austria
| | - Carmel McDougall
- School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072 Australia
| | - 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, Althanstr. 14, 1090 Vienna, Austria
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