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Yoshinaga N, Miyamoto T, Goto M, Tanaka A, Numata K. Phenylboronic Acid-Functionalized Micelles Dual-Targeting Boronic Acid Transporter and Polysaccharides for siRNA Delivery into Brown Algae. JACS AU 2024; 4:1385-1395. [PMID: 38665671 PMCID: PMC11040673 DOI: 10.1021/jacsau.3c00767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 02/05/2024] [Accepted: 02/20/2024] [Indexed: 04/28/2024]
Abstract
Brown algae play essential roles ecologically, practically, and evolutionarily because they maintain coastal areas, capture carbon dioxide, and produce valuable chemicals such as therapeutic drugs. To unlock their full potential, understanding the unique molecular biology of brown algae is imperative. Genetic engineering tools that regulate homeostasis in brown algae are essential for determining their biological mechanisms in detail. However, few methodologies have been developed to control gene expression due to the robust structural barriers of brown algae. To address this issue, we designed peptide-based, small interfering RNA (siRNA)-loaded micelles decorated with phenylboronic acid (PBA) ligands. The PBA ligands facilitated the cellular uptake of the micelles into a model brown alga, Ectocarpus siliculosus (E. Siliculosus), through chemical interaction with polysaccharides in the cell wall and biological recognition by boronic acid transporters on the plasma membrane. The micelles, featuring "kill two birds with one stone" ligands, effectively induced gene silencing related to auxin biosynthesis. As a result, the growth of E. siliculosus was temporarily inhibited without persistent genome editing. This study demonstrated the potential for exploring the characteristics of brown algae through a simple yet effective approach and presented a feasible system for delivering siRNA in brown algae.
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Affiliation(s)
- Naoto Yoshinaga
- Biomacromolecule
Research Team, RIKEN Center for Sustainable
Resource Science, Wako-shi, Saitama 351-0198, Japan
- Institute
for Advanced Biosciences, Keio University, Tsuruoka-shi, Yamagata 997-0017, Japan
| | - Takaaki Miyamoto
- Biomacromolecule
Research Team, RIKEN Center for Sustainable
Resource Science, Wako-shi, Saitama 351-0198, Japan
| | - Mami Goto
- Biomacromolecule
Research Team, RIKEN Center for Sustainable
Resource Science, Wako-shi, Saitama 351-0198, Japan
| | - Atsuko Tanaka
- Department
of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Nakagami-gun, Okinawa 903-0213, Japan
| | - Keiji Numata
- Biomacromolecule
Research Team, RIKEN Center for Sustainable
Resource Science, Wako-shi, Saitama 351-0198, Japan
- Institute
for Advanced Biosciences, Keio University, Tsuruoka-shi, Yamagata 997-0017, Japan
- Department
of Material Chemistry, Kyoto University, Kyoto-shi, Kyoto 606-8501, Japan
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2
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Beuder S, Braybrook SA. Brown algal cell walls and development. Semin Cell Dev Biol 2023; 134:103-111. [PMID: 35396168 DOI: 10.1016/j.semcdb.2022.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/17/2022] [Accepted: 03/04/2022] [Indexed: 10/18/2022]
Abstract
Brown algae are complex multicellular eukaryotes whose cells possess a cell wall, which is an important structure that regulates cell size and shape. Alginate and fucose-containing sulfated polysaccharides (FCSPs) are two carbohydrate types that have major roles in influencing the mechanical properties of the cell wall (i.e. increasing or decreasing wall stiffness), which in turn regulate cell expansion, division, adhesion, and other processes; however, how brown algal cell wall structure regulates its mechanical properties, and how this relationship influences cellular growth and organismal development, is not well-understood. This chapter is focused on reviewing what we currently know about how the roles of alginates and FCSPs in brown algal developmental processes, as well as how they influence the structural and mechanical properties of cell walls. Additionally, we discuss how brown algal mutants may be leveraged to learn more about the underlying mechanisms that regulate cell wall structure, mechanics, and developmental processes, and finally we propose questions to guide future research with the use of emerging technologies.
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Affiliation(s)
- Steven Beuder
- Department of Molecular, Cell, and Developmental Biology, UCLA, 610 Charles E Young Drive, Los Angeles, CA 90095, USA; California NanoSystems Institute, UCLA, 570 Westwood Plaza Building 114, Los Angeles, CA 90095, USA
| | - Siobhan A Braybrook
- Department of Molecular, Cell, and Developmental Biology, UCLA, 610 Charles E Young Drive, Los Angeles, CA 90095, USA; California NanoSystems Institute, UCLA, 570 Westwood Plaza Building 114, Los Angeles, CA 90095, USA; Molecular Biology Institute, UCLA, 611 Charles E. Young Drive, Los Angeles, CA 90095, USA.
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3
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Clerc T, Boscq S, Attia R, Kaminski Schierle GS, Charrier B, Läubli NF. Cultivation and Imaging of S. latissima Embryo Monolayered Cell Sheets Inside Microfluidic Devices. Bioengineering (Basel) 2022; 9:bioengineering9110718. [PMID: 36421119 PMCID: PMC9687954 DOI: 10.3390/bioengineering9110718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/08/2022] [Accepted: 11/17/2022] [Indexed: 11/23/2022] Open
Abstract
The culturing and investigation of individual marine specimens in lab environments is crucial to further our understanding of this highly complex ecosystem. However, the obtained results and their relevance are often limited by a lack of suitable experimental setups enabling controlled specimen growth in a natural environment while allowing for precise monitoring and in-depth observations. In this work, we explore the viability of a microfluidic device for the investigation of the growth of the alga Saccharina latissima to enable high-resolution imaging by confining the samples, which usually grow in 3D, to a single 2D plane. We evaluate the specimen’s health based on various factors such as its growth rate, cell shape, and major developmental steps with regard to the device’s operating parameters and flow conditions before demonstrating its compatibility with state-of-the-art microscopy imaging technologies such as the skeletonisation of the specimen through calcofluor white-based vital staining of its cell contours as well as the immunolocalisation of the specimen’s cell wall. Furthermore, by making use of the on-chip characterisation capabilities, we investigate the influence of altered environmental illuminations on the embryonic development using blue and red light. Finally, live tracking of fluorescent microspheres deposited on the surface of the embryo permits the quantitative characterisation of growth at various locations of the organism.
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Affiliation(s)
- Thomas Clerc
- Morphogenesis of Macroalgae, Laboratory of Integrative Biology of Marine Models, Station Biologique de Roscoff, CNRS, Sorbonne University, 29680 Roscoff, France
| | - Samuel Boscq
- Morphogenesis of Macroalgae, Laboratory of Integrative Biology of Marine Models, Station Biologique de Roscoff, CNRS, Sorbonne University, 29680 Roscoff, France
| | - Rafaele Attia
- Ecology of Marine Plankton, Laboratory of Adaptation and Diversity in the Marine Environment, Station Biologique de Roscoff, CNRS, Sorbonne University, 29680 Roscoff, France
| | - Gabriele S. Kaminski Schierle
- Molecular Neuroscience Group, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK
| | - Bénédicte Charrier
- Morphogenesis of Macroalgae, Laboratory of Integrative Biology of Marine Models, Station Biologique de Roscoff, CNRS, Sorbonne University, 29680 Roscoff, France
- Correspondence: (B.C.); (N.F.L.)
| | - Nino F. Läubli
- Molecular Neuroscience Group, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK
- Correspondence: (B.C.); (N.F.L.)
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4
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Ruiz-Trillo I, de Mendoza A. Towards understanding the origin of animal development. Development 2020; 147:147/23/dev192575. [PMID: 33272929 DOI: 10.1242/dev.192575] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Almost all animals undergo embryonic development, going from a single-celled zygote to a complex multicellular adult. We know that the patterning and morphogenetic processes involved in development are deeply conserved within the animal kingdom. However, the origins of these developmental processes are just beginning to be unveiled. Here, we focus on how the protist lineages sister to animals are reshaping our view of animal development. Most intriguingly, many of these protistan lineages display transient multicellular structures, which are governed by similar morphogenetic and gene regulatory processes as animal development. We discuss here two potential alternative scenarios to explain the origin of animal embryonic development: either it originated concomitantly at the onset of animals or it evolved from morphogenetic processes already present in their unicellular ancestors. We propose that an integrative study of several unicellular taxa closely related to animals will allow a more refined picture of how the last common ancestor of animals underwent embryonic development.
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Affiliation(s)
- Iñaki Ruiz-Trillo
- Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra), Passeig Marítim de la Barceloneta, 37-49, 08003 Barcelona, Spain .,Departament de Genètica, Microbiologia i Estadística, Institut de Recerca de la Biodiversitat, Universitat de Barcelona, Avinguda Diagonal 643, 08028 Barcelona, Spain.,ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain
| | - Alex de Mendoza
- Queen Mary University of London, School of Biological and Chemical Sciences, London E1 4DQ, UK
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5
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Poza AM, Santiañez WJE, Croce ME, Gauna MC, Kogame K, Parodi ER. Cryptic Haploid Stages in the Life Cycle of Leathesia marina (Chordariaceae, Phaeophyceae) Under In Vitro Culture. JOURNAL OF PHYCOLOGY 2020; 56:1349-1361. [PMID: 32463924 DOI: 10.1111/jpy.13034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Accepted: 05/17/2020] [Indexed: 06/11/2023]
Abstract
We evaluated the life cycle of Leathesia marina through molecular analyses, culture studies, morphological observations, and ploidy measurements. Macroscopic sporophytes were collected from two localities in Atlantic Patagonia and were cultured under long-day (LD) and short-day (SD) conditions. Molecular identification of the microscopic and macroscopic phases was performed through the cox3 and rbcL genes and the phylogeny was assessed on the basis of single gene and concatenated datasets. Nuclear ploidy of each phase was estimated from the DNA contents of individual nuclei through epifluorescence microscopy and flow cytometry. Molecular results confirmed the identity of the Argentinian specimens as L. marina and revealed their conspecificity with L. marina from New Zealand, Germany, and Japan. The sporophytic macrothalli (2n) released mitospores from plurilocular sporangia, which developed into globular microthalli (2n), morphologically similar to the sporophytes but not in size, constituting a generation of small diploid thalli, with a mean fluorescent nuclei cross-sectional area of 3.21 ± 0.7 μm2 . The unilocular sporangia released meiospores that developed two morphologically different types of microthalli: erect branched microthalli (n) with a nuclear area of 1.48 ± 0.07 µm2 that reproduces asexually, and prostrate branched microthalli (n) with a nuclear area of 1.24 ± 0.10 µm2 that reproduces sexually. The prostrate microthalli released gametes in LD conditions, which merged and produced macroscopic thalli with a nuclear cross-sectional area of 3.45 ± 0.09 µm2 . Flow cytometry confirmed that the erect and prostrate microthalli were haploid and that the globular microthalli and macrothalli were diploid.
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Affiliation(s)
- Ailen M Poza
- CONICET-Bahía Blanca, Instituto Argentino de Oceanografía (IADO), Camino Carrindanga 7.5 km, B8000FWB, Bahía Blanca, Argentina
| | - Wilfred John E Santiañez
- Department of Natural History Sciences, Graduate School of Science, Hokkaido University, Sapporo, 060-0810, Japan
- The Marine Science Institute, College of Science, University of the Philippines Diliman, Quezon City, 1101, Philippines
| | - M Emilia Croce
- CONICET-Bahía Blanca, Instituto Argentino de Oceanografía (IADO), Camino Carrindanga 7.5 km, B8000FWB, Bahía Blanca, Argentina
- Laboratorio de Ecología Acuática, Botánica Marina y Acuicultura, Depto. Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, San Juan 670, B8000FTN, Bahía Blanca, Argentina
| | - M Cecilia Gauna
- CONICET-Bahía Blanca, Instituto Argentino de Oceanografía (IADO), Camino Carrindanga 7.5 km, B8000FWB, Bahía Blanca, Argentina
- Laboratorio de Ecología Acuática, Botánica Marina y Acuicultura, Depto. Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, San Juan 670, B8000FTN, Bahía Blanca, Argentina
| | - Kazuhiro Kogame
- Department of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo, 060-0810, Japan
| | - Elisa R Parodi
- CONICET-Bahía Blanca, Instituto Argentino de Oceanografía (IADO), Camino Carrindanga 7.5 km, B8000FWB, Bahía Blanca, Argentina
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Siméon A, Kridi S, Kloareg B, Hervé C. Presence of Exogenous Sulfate Is Mandatory for Tip Growth in the Brown Alga Ectocarpus subulatus. FRONTIERS IN PLANT SCIENCE 2020; 11:1277. [PMID: 33013948 PMCID: PMC7461865 DOI: 10.3389/fpls.2020.01277] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 08/05/2020] [Indexed: 05/08/2023]
Abstract
Brown algae (Phaeophyceae) are multicellular photoautrophic organisms and the largest biomass producers in coastal regions. A variety of observations indicate that their extracellular matrix (ECM) is involved with screening of salts, development, cell fate selection, and defense responses. It is likely that these functionalities are related to its constitutive structures. The major components of the ECM of brown algae are β-glucans, alginates, and fucose-containing sulfated polysaccharides. The genus Ectocarpus comprises a wide range of species that have adapted to different environments, including isolates of Ectocarpus subulatus, a species highly resistant to low salinity. Previous studies on a freshwater strain of E. subulatus indicated that the sulfate remodeling of fucans is related to the external salt concentration. Here we show that the sulfate content of the surrounding medium is a key parameter influencing both the patterning of the alga and the occurrence of the BAM4 sulfated fucan epitope in walls of apical cells. These results indicate that sulfate uptake and incorporation in the sulfated fucans from apical cells is an essential parameter to sustain tip growth, and we discuss its influence on the architectural plasticity of Ectocarpus.
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7
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Coudert Y, Harris S, Charrier B. Design Principles of Branching Morphogenesis in Filamentous Organisms. Curr Biol 2019; 29:R1149-R1162. [PMID: 31689405 DOI: 10.1016/j.cub.2019.09.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The radiation of life on Earth was accompanied by the diversification of multicellular body plans in the eukaryotic kingdoms Animalia, Plantae, Fungi and Chromista. Branching forms are ubiquitous in nature and evolved repeatedly in the above lineages. The developmental and genetic basis of branch formation is well studied in the three-dimensional shoot and root systems of land plants, and in animal organs such as the lung, kidney, mammary gland, vasculature, etc. Notably, recent thought-provoking studies combining experimental analysis and computational modeling of branching patterns in whole animal organs have identified global patterning rules and proposed unifying principles of branching morphogenesis. Filamentous branching forms represent one of the simplest expressions of the multicellular body plan and constitute a key step in the evolution of morphological complexity. Similarities between simple and complex branching forms distantly related in evolution are compelling, raising the question whether shared mechanisms underlie their development. Here, we focus on filamentous branching organisms that represent major study models from three distinct eukaryotic kingdoms, including the moss Physcomitrella patens (Plantae), the brown alga Ectocarpus sp. (Chromista), and the ascomycetes Neurospora crassa and Aspergillus nidulans (Fungi), and bring to light developmental regulatory mechanisms and design principles common to these lineages. Throughout the review we explore how the regulatory mechanisms of branching morphogenesis identified in other models, and in particular animal organs, may inform our thinking on filamentous systems and thereby advance our understanding of the diverse strategies deployed across the eukaryotic tree of life to evolve similar forms.
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Affiliation(s)
- Yoan Coudert
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, INRIA, Lyon 69007, France.
| | - Steven Harris
- University of Manitoba, Department of Biological Sciences, Winnipeg, MB, Canada; Center for Plant Science Innovation and Department of Plant Pathology, University of Nebraska, Lincoln, NE, USA
| | - Bénédicte Charrier
- CNRS, Sorbonne Université, Laboratoire de Biologie Intégrative des Modèles Marins LBI2M, Station Biologique de Roscoff, Roscoff 29680, France
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8
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Rabillé H, Torode TA, Tesson B, Le Bail A, Billoud B, Rolland E, Le Panse S, Jam M, Charrier B. Alginates along the filament of the brown alga Ectocarpus help cells cope with stress. Sci Rep 2019; 9:12956. [PMID: 31506545 PMCID: PMC6736953 DOI: 10.1038/s41598-019-49427-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 08/23/2019] [Indexed: 11/29/2022] Open
Abstract
Ectocarpus is a filamentous brown alga, which cell wall is composed mainly of alginates and fucans (80%), two non-crystalline polysaccharide classes. Alginates are linear chains of epimers of 1,4-linked uronic acids, β-D-mannuronic acid (M) and α-L-guluronic acid (G). Previous physico-chemical studies showed that G-rich alginate gels are stiffer than M-rich alginate gels when prepared in vitro with calcium. In order to assess the possible role of alginates in Ectocarpus, we first immunolocalised M-rich or G-rich alginates using specific monoclonal antibodies along the filament. As a second step, we calculated the tensile stress experienced by the cell wall along the filament, and varied it with hypertonic or hypotonic solutions. As a third step, we measured the stiffness of the cell along the filament, using cell deformation measurements and atomic force microscopy. Overlapping of the three sets of data allowed to show that alginates co-localise with the stiffest and most stressed areas of the filament, namely the dome of the apical cell and the shanks of the central round cells. In addition, no major distinction between M-rich and G-rich alginate spatial patterns could be observed. Altogether, these results support that both M-rich and G-rich alginates play similar roles in stiffening the cell wall where the tensile stress is high and exposes cells to bursting, and that these roles are independent from cell growth and differentiation.
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Affiliation(s)
- Hervé Rabillé
- CNRS, Sorbonne Université, Laboratoire de Biologie Intégrative des Modèles Marins LBI2M, Station Biologique, Roscoff, France
| | - Thomas A Torode
- The Sainsbury Laboratory, University of Cambridge, Bateman Street, Cambridge, United Kingdom
| | - Benoit Tesson
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Aude Le Bail
- CNRS, Sorbonne Université, Laboratoire de Biologie Intégrative des Modèles Marins LBI2M, Station Biologique, Roscoff, France
- Department of Cell Biology, Friedrich-Alexander-University of Erlangen-Nürnberg, Erlangen, Germany
| | - Bernard Billoud
- CNRS, Sorbonne Université, Laboratoire de Biologie Intégrative des Modèles Marins LBI2M, Station Biologique, Roscoff, France
| | - Elodie Rolland
- CNRS, Sorbonne Université, Laboratoire de Biologie Intégrative des Modèles Marins LBI2M, Station Biologique, Roscoff, France
| | - Sophie Le Panse
- Platform Merimage, FR 2424, CNRS, Station Biologique, Roscoff, France
| | - Murielle Jam
- Marine Glycobiology team, UMR8227, CNRS-UPMC, Station Biologique, Roscoff, France
| | - Bénédicte Charrier
- CNRS, Sorbonne Université, Laboratoire de Biologie Intégrative des Modèles Marins LBI2M, Station Biologique, Roscoff, France.
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9
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Rabillé H, Billoud B, Tesson B, Le Panse S, Rolland É, Charrier B. The brown algal mode of tip growth: Keeping stress under control. PLoS Biol 2019; 17:e2005258. [PMID: 30640903 PMCID: PMC6347293 DOI: 10.1371/journal.pbio.2005258] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 01/25/2019] [Accepted: 12/20/2018] [Indexed: 01/09/2023] Open
Abstract
Tip growth has been studied in pollen tubes, root hairs, and fungal and oomycete hyphae and is the most widely distributed unidirectional growth process on the planet. It ensures spatial colonization, nutrient predation, fertilization, and symbiosis with growth speeds of up to 800 μm h-1. Although turgor-driven growth is intuitively conceivable, a closer examination of the physical processes at work in tip growth raises a paradox: growth occurs where biophysical forces are low, because of the increase in curvature in the tip. All tip-growing cells studied so far rely on the modulation of cell wall extensibility via the polarized excretion of cell wall-loosening compounds at the tip. Here, we used a series of quantitative measurements at the cellular level and a biophysical simulation approach to show that the brown alga Ectocarpus has an original tip-growth mechanism. In this alga, the establishment of a steep gradient in cell wall thickness can compensate for the variation in tip curvature, thereby modulating wall stress within the tip cell. Bootstrap analyses support the robustness of the process, and experiments with fluorescence recovery after photobleaching (FRAP) confirmed the active vesicle trafficking in the shanks of the apical cell, as inferred from the model. In response to auxin, biophysical measurements change in agreement with the model. Although we cannot strictly exclude the involvement of a gradient in mechanical properties in Ectocarpus morphogenesis, the viscoplastic model of cell wall mechanics strongly suggests that brown algae have evolved an alternative strategy of tip growth. This strategy is largely based on the control of cell wall thickness rather than fluctuations in cell wall mechanical properties.
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Affiliation(s)
- Hervé Rabillé
- CNRS, Sorbonne Université, Morphogenesis of Macro Algae, UMR8227, Station Biologique, Roscoff, France
| | - Bernard Billoud
- CNRS, Sorbonne Université, Morphogenesis of Macro Algae, UMR8227, Station Biologique, Roscoff, France
| | - Benoit Tesson
- SCRIPPS Institution of Oceanography, University of California, San Diego, San Diego, California, United States of America
| | - Sophie Le Panse
- MerImage platform, FR2424, CNRS, Sorbonne Université, Station Biologique, Roscoff, France
| | - Élodie Rolland
- CNRS, Sorbonne Université, Morphogenesis of Macro Algae, UMR8227, Station Biologique, Roscoff, France
| | - Bénédicte Charrier
- CNRS, Sorbonne Université, Morphogenesis of Macro Algae, UMR8227, Station Biologique, Roscoff, France
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10
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Jia F, Ben Amar M, Billoud B, Charrier B. Morphoelasticity in the development of brown alga Ectocarpus siliculosus: from cell rounding to branching. J R Soc Interface 2017; 14:20160596. [PMID: 28228537 PMCID: PMC5332559 DOI: 10.1098/rsif.2016.0596] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 01/27/2017] [Indexed: 11/29/2022] Open
Abstract
A biomechanical model is proposed for the growth of the brown alga Ectocarpus siliculosus Featuring ramified uniseriate filaments, this alga has two modes of growth: apical growth and intercalary growth with branching. Apical growth occurs upon the mitosis of a young cell at one extremity and leads to a new tip cell followed by a cylindrical cell, whereas branching mainly occurs when a cylindrical cell becomes rounded and swells, forming a spherical cell. Given the continuous interplay between cell growth and swelling, a poroelastic model combining osmotic pressure and volumetric growth is considered for the whole cell, cytoplasm and cell wall. The model recovers the morphogenetic transformations of mature cells: transformation of a cylindrical shape into spherical shape with a volumetric increase, and then lateral branching. Our simulations show that the poro-elastic model, including the Mooney-Rivlin approach for hyper-elastic materials, can correctly reproduce the observations. In particular, branching appears to be a plasticity effect due to the high level of tension created after the increase in volume of mature cells.
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Affiliation(s)
- Fei Jia
- School of Manufacturing Science and Engineering, Southwest University of Science and Technology, Sichuan 621010, People's Republic of China
| | - Martine Ben Amar
- Laboratoire de Physique Statistique, Ecole Normale Supérieure, PSL Research University, Sorbonne Universités UPMC Univ Paris 06, CNRS, 24 rue Lhomond, 75005 Paris, France
- Institut Universitaire de Cancérologie, Faculté de médecine, Université Pierre et Marie Curie-Paris 6, 91 Bd de l'Hôpital, 75013 Paris, France
| | - Bernard Billoud
- UMR8227 CNRS-UPMC, Station Biologique, Place George Teissier, 29680 Roscoff, France
| | - Bénédicte Charrier
- UMR8227 CNRS-UPMC, Station Biologique, Place George Teissier, 29680 Roscoff, France
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11
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Tapia JE, González B, Goulitquer S, Potin P, Correa JA. Microbiota Influences Morphology and Reproduction of the Brown Alga Ectocarpus sp. Front Microbiol 2016; 7:197. [PMID: 26941722 PMCID: PMC4765120 DOI: 10.3389/fmicb.2016.00197] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 02/05/2016] [Indexed: 01/06/2023] Open
Abstract
Associated microbiota play crucial roles in health and disease of higher organisms. For macroalgae, some associated bacteria exert beneficial effects on nutrition, morphogenesis and growth. However, current knowledge on macroalgae–microbiota interactions is mostly based on studies on green and red seaweeds. In this study, we report that when cultured under axenic conditions, the filamentous brown algal model Ectocarpus sp. loses its branched morphology and grows with a small ball-like appearance. Nine strains of periphytic bacteria isolated from Ectocarpus sp. unialgal cultures were identified by 16S rRNA sequencing, and assessed for their effect on morphology, reproduction and the metabolites secreted by axenic Ectocarpus sp. Six of these isolates restored morphology and reproduction features of axenic Ectocarpus sp. Bacteria-algae co-culture supernatants, but not the supernatant of the corresponding bacterium growing alone, also recovered morphology and reproduction of the alga. Furthermore, colonization of axenic Ectocarpus sp. with a single bacterial isolate impacted significantly the metabolites released by the alga. These results show that the branched typical morphology and the individuals produced by Ectocarpus sp. are strongly dependent on the presence of bacteria, while the bacterial effect on the algal exometabolome profile reflects the impact of bacteria on the whole physiology of this alga.
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Affiliation(s)
- Javier E Tapia
- CNRS, Université Pierre-et-Marie-Curie, UMI 3614, Biology and Ecology of Algae, Station Biologique de RoscoffRoscoff, France; Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de ChileSantiago, Chile
| | - Bernardo González
- Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez - Center of Applied Ecology and Sustainability Santiago, Chile
| | - Sophie Goulitquer
- MetaboMer Mass Spectrometry Core Facility, Université Pierre-et-Marie-Curie, CNRS, FR2424, Station Biologique de Roscoff Roscoff, France
| | - Philippe Potin
- Université Pierre-et-Marie-Curie, CNRS UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff Roscoff, France
| | - Juan A Correa
- CNRS, Université Pierre-et-Marie-Curie, UMI 3614, Biology and Ecology of Algae, Station Biologique de RoscoffRoscoff, France; Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de ChileSantiago, Chile
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12
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Lipinska AP, Ahmed S, Peters AF, Faugeron S, Cock JM, Coelho SM. Development of PCR-Based Markers to Determine the Sex of Kelps. PLoS One 2015; 10:e0140535. [PMID: 26496392 PMCID: PMC4619726 DOI: 10.1371/journal.pone.0140535] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 09/28/2015] [Indexed: 11/18/2022] Open
Abstract
Sex discriminating genetic markers are commonly used to facilitate breeding programs in economically and ecologically important animal and plant species. However, despite their considerable economic and ecological value, the development of sex markers for kelp species has been very limited. In this study, we used the recently described sequence of the sex determining region (SDR) of the brown algal model Ectocarpus to develop novel DNA-based sex-markers for three commercially relevant kelps: Laminaria digitata, Undaria pinnatifida and Macrocystis pyrifera. Markers were designed within nine protein coding genes of Ectocarpus male and female (U/V) sex chromosomes and tested on gametophytes of the three kelp species. Seven primer pairs corresponding to three loci in the Ectocarpus SDR amplified sex-specific bands in the three kelp species, yielding at least one male and one female marker for each species. Our work has generated the first male sex-specific markers for L. digitata and U. pinnatifida, as well as the first sex markers developed for the genus Macrocystis. The markers and methodology presented here will not only facilitate seaweed breeding programs but also represent useful tools for population and demography studies and provide a means to investigate the evolution of sex determination across this largely understudied eukaryotic group.
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Affiliation(s)
- Agnieszka P. Lipinska
- Sorbonne Université, UPMC Univ Paris 06, Algal Genetics Group, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff, France
- CNRS, Algal Genetics Group, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff, France
| | - Sophia Ahmed
- Sorbonne Université, UPMC Univ Paris 06, Algal Genetics Group, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff, France
- CNRS, Algal Genetics Group, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff, France
| | | | - Sylvain Faugeron
- Sorbonne Universités, UPMC University Paris 06, UMI 3614, Evolutionary Biology and Ecology of Algae, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff, France
- CNRS, Evolutionary Biology and Ecology of Algae, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff, France
- Centro de Conservación Marina and CeBiB, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - J. Mark Cock
- Sorbonne Université, UPMC Univ Paris 06, Algal Genetics Group, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff, France
- CNRS, Algal Genetics Group, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff, France
| | - Susana M. Coelho
- Sorbonne Université, UPMC Univ Paris 06, Algal Genetics Group, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff, France
- CNRS, Algal Genetics Group, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff, France
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13
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Charrier B, Rolland E, Gupta V, Reddy CRK. Production of genetically and developmentally modified seaweeds: exploiting the potential of artificial selection techniques. FRONTIERS IN PLANT SCIENCE 2015; 6:127. [PMID: 25852700 PMCID: PMC4362299 DOI: 10.3389/fpls.2015.00127] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 02/17/2015] [Indexed: 05/07/2023]
Abstract
Plant feedstock with specific, modified developmental features has been a quest for centuries. Since the development and spread of agriculture, there has been a desire for plants producing disproportionate-or more abundant and more nutritional-biomass that meet human needs better than their native counterparts. Seaweed aquaculture, targeted for human consumption and the production of various raw materials, is a rapidly expanding field and its stakeholders have increasing vested interest for cost-effective and lucrative seaweed cultivation processes. Thus, scientific research on seaweed development is particularly timely: the potential for expansion of seaweed cultivation depends on the sector's capacity to produce seaweeds with modified morphological features (e.g., thicker blades), higher growth rates or delayed (or even no) fertility. Here, we review the various technical approaches used to modify development in macroalgae, which have attracted little attention from developmental biologists to date. Because seaweed (or marine macroalgae) anatomy is much less complex than that of land plants and because seaweeds belong to three different eukaryotic phyla, the mechanisms controlling their morphogenesis are key to understanding their development. Here, we present efficient sources of developmentally and genetically modified seaweeds-somatic variants, artificial hybrids and mutants-as well as the future potential of these techniques.
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Affiliation(s)
- Bénédicte Charrier
- Centre National de la Recherche Scientifique, Sorbonne Université, UPMC Univ Paris 06, UMR 8227, Integrative Biology of Marine Models, Station Biologique de RoscoffRoscoff, France
| | - Elodie Rolland
- Centre National de la Recherche Scientifique, Sorbonne Université, UPMC Univ Paris 06, UMR 8227, Integrative Biology of Marine Models, Station Biologique de RoscoffRoscoff, France
| | - Vishal Gupta
- Seaweed Biology and Cultivation Group, Division of Marine Biotechnology and Ecology, CSIR-Central Salt and Marine Chemicals Research InstituteBhavnagar, India
| | - C. R. K. Reddy
- Seaweed Biology and Cultivation Group, Division of Marine Biotechnology and Ecology, CSIR-Central Salt and Marine Chemicals Research InstituteBhavnagar, India
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14
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Saint-Marcoux D, Billoud B, Langdale JA, Charrier B. Laser capture microdissection in Ectocarpus siliculosus: the pathway to cell-specific transcriptomics in brown algae. FRONTIERS IN PLANT SCIENCE 2015; 6:54. [PMID: 25713580 PMCID: PMC4322613 DOI: 10.3389/fpls.2015.00054] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 01/21/2015] [Indexed: 05/23/2023]
Abstract
Laser capture microdissection (LCM) facilitates the isolation of individual cells from tissue sections, and when combined with RNA amplification techniques, it is an extremely powerful tool for examining genome-wide expression profiles in specific cell-types. LCM has been widely used to address various biological questions in both animal and plant systems, however, no attempt has been made so far to transfer LCM technology to macroalgae. Macroalgae are a collection of widespread eukaryotes living in fresh and marine water. In line with the collective effort to promote molecular investigations of macroalgal biology, here we demonstrate the feasibility of using LCM and cell-specific transcriptomics to study development of the brown alga Ectocarpus siliculosus. We describe a workflow comprising cultivation and fixation of algae on glass slides, laser microdissection, and RNA amplification. To illustrate the effectiveness of the procedure, we show qPCR data and metrics obtained from cell-specific transcriptomes generated from both upright and prostrate filaments of Ectocarpus.
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Affiliation(s)
| | - Bernard Billoud
- CNRS, Sorbonne Université, UPMC Univ Paris 06, UMR 8227, Integrative Biology of Marine Models, Station Biologique de RoscoffRoscoff, France
| | | | - Bénédicte Charrier
- CNRS, Sorbonne Université, UPMC Univ Paris 06, UMR 8227, Integrative Biology of Marine Models, Station Biologique de RoscoffRoscoff, France
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15
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Billoud B, Nehr Z, Le Bail A, Charrier B. Computational prediction and experimental validation of microRNAs in the brown alga Ectocarpus siliculosus. Nucleic Acids Res 2014; 42:417-29. [PMID: 24078085 PMCID: PMC3874173 DOI: 10.1093/nar/gkt856] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 08/30/2013] [Accepted: 09/03/2013] [Indexed: 12/16/2022] Open
Abstract
We used an in silico approach to predict microRNAs (miRNAs) genome-wide in the brown alga Ectocarpus siliculosus. As brown algae are phylogenetically distant from both animals and land plants, our approach relied on features shared by all known organisms, excluding sequence conservation, genome localization and pattern of base-pairing with the target. We predicted between 500 and 1500 miRNAs candidates, depending on the values of the energetic parameters used to filter the potential precursors. Using quantitative polymerase chain reaction assays, we confirmed the existence of 22 miRNAs among 72 candidates tested, and of 8 predicted precursors. In addition, we compared the expression of miRNAs and their precursors in two life cycle states (sporophyte, gametophyte) and under salt stress. Several miRNA precursors, Argonaute and DICER messenger RNAs were differentially expressed in these conditions. Finally, we analyzed the gene organization and the target functions of the predicted candidates. This showed that E. siliculosus miRNA genes are, like plant miRNA genes, rarely clustered and, like animal miRNA genes, often located in introns. Among the predicted targets, several widely conserved functional domains are significantly overrepresented, like kinesin, nucleotide-binding/APAF-1, R proteins and CED-4 (NB-ARC) and tetratricopeptide repeats. The combination of computational and experimental approaches thus emphasizes the originality of molecular and cellular processes in brown algae.
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Affiliation(s)
- Bernard Billoud
- Université Pierre et Marie Curie (UPMC), UMR 7139 Végétaux marins et Biomolécules, Station Biologique, CS 90074, F29688, Roscoff, France and Centre National de la Recherche Scientifique (CNRS), UMR 7139 Végétaux marins et Biomolécules, Station Biologique, CS 90074, F29688, Roscoff, France
| | - Zofia Nehr
- Université Pierre et Marie Curie (UPMC), UMR 7139 Végétaux marins et Biomolécules, Station Biologique, CS 90074, F29688, Roscoff, France and Centre National de la Recherche Scientifique (CNRS), UMR 7139 Végétaux marins et Biomolécules, Station Biologique, CS 90074, F29688, Roscoff, France
| | - Aude Le Bail
- Université Pierre et Marie Curie (UPMC), UMR 7139 Végétaux marins et Biomolécules, Station Biologique, CS 90074, F29688, Roscoff, France and Centre National de la Recherche Scientifique (CNRS), UMR 7139 Végétaux marins et Biomolécules, Station Biologique, CS 90074, F29688, Roscoff, France
| | - Bénédicte Charrier
- Université Pierre et Marie Curie (UPMC), UMR 7139 Végétaux marins et Biomolécules, Station Biologique, CS 90074, F29688, Roscoff, France and Centre National de la Recherche Scientifique (CNRS), UMR 7139 Végétaux marins et Biomolécules, Station Biologique, CS 90074, F29688, Roscoff, France
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16
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Tesson B, Charrier B. Brown algal morphogenesis: atomic force microscopy as a tool to study the role of mechanical forces. FRONTIERS IN PLANT SCIENCE 2014; 5:471. [PMID: 25278949 PMCID: PMC4166355 DOI: 10.3389/fpls.2014.00471] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Accepted: 08/28/2014] [Indexed: 05/17/2023]
Abstract
Over the last few years, a growing interest has been directed toward the use of macroalgae as a source of energy, food and molecules for the cosmetic and pharmaceutical industries. Besides this, macroalgal development remains poorly understood compared to other multicellular organisms. Brown algae (Phaeophyceae) form a monophyletic lineage of usually large multicellular algae which evolved independently from land plants. In their environment, they are subjected to strong mechanical forces (current, waves, and tide), in response to which they modify rapidly and reversibly their morphology. Because of their specific cellular features (cell wall composition, cytoskeleton organization), deciphering how they cope with these forces might help discover new control mechanisms of cell wall softening and cellulose synthesis. Despite the current scarcity in knowledge on brown algal cell wall dynamics and protein composition, we will illustrate, in the light of methods adapted to Ectocarpus siliculosus, to what extent atomic force microscopy can contribute to advance this field of investigation.
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Affiliation(s)
- Benoit Tesson
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San DiegoLa Jolla, CA, USA
- *Correspondence: Benoit Tesson, Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0202, USA e-mail:
| | - Bénédicte Charrier
- Centre National de la Recherche Scientifique-Unités Mixtes de Recherche 8227 Integrative Biology of Marine Models, Station Biologique de RoscoffRoscoff, France
- Sorbonne Universités, Université Pierre-et-Marie-Curie, Unités Mixtes de Recherche 8227 Integrative Biology of Marine ModelsRoscoff, France
- Bénédicte Charrier, CNRS, UMR 8227 Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688 Roscoff cedex, France e-mail:
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17
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Herron MD, Rashidi A, Shelton DE, Driscoll WW. Cellular differentiation and individuality in the 'minor' multicellular taxa. Biol Rev Camb Philos Soc 2013; 88:844-61. [PMID: 23448295 PMCID: PMC4103886 DOI: 10.1111/brv.12031] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2012] [Revised: 01/30/2013] [Accepted: 02/05/2013] [Indexed: 01/07/2023]
Abstract
Biology needs a concept of individuality in order to distinguish organisms from parts of organisms and from groups of organisms, to count individuals and compare traits across taxa, and to distinguish growth from reproduction. Most of the proposed criteria for individuality were designed for 'unitary' or 'paradigm' organisms: contiguous, functionally and physiologically integrated, obligately sexually reproducing multicellular organisms with a germ line sequestered early in development. However, the vast majority of the diversity of life on Earth does not conform to all of these criteria. We consider the issue of individuality in the 'minor' multicellular taxa, which collectively span a large portion of the eukaryotic tree of life, reviewing their general features and focusing on a model species for each group. When the criteria designed for unitary organisms are applied to other groups, they often give conflicting answers or no answer at all to the question of whether or not a given unit is an individual. Complex life cycles, intimate bacterial symbioses, aggregative development, and strange genetic features complicate the picture. The great age of some of the groups considered shows that 'intermediate' forms, those with some but not all of the traits traditionally associated with individuality, cannot reasonably be considered ephemeral or assumed transitional. We discuss a handful of recent attempts to reconcile the many proposed criteria for individuality and to provide criteria that can be applied across all the domains of life. Finally, we argue that individuality should be defined without reference to any particular taxon and that understanding the emergence of new kinds of individuals requires recognizing individuality as a matter of degree.
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Affiliation(s)
- Matthew D. Herron
- Department of Ecology and Evolutionary Biology, University of Arizona, 1041 Lowell St, Tucson, AZ 85721, USA
| | | | - Deborah E. Shelton
- Department of Ecology and Evolutionary Biology, University of Arizona, 1041 Lowell St, Tucson, AZ 85721, USA
| | - William W. Driscoll
- Department of Ecology and Evolutionary Biology, University of Arizona, 1041 Lowell St, Tucson, AZ 85721, USA
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18
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Charrier B, Le Bail A, de Reviers B. Plant Proteus: brown algal morphological plasticity and underlying developmental mechanisms. TRENDS IN PLANT SCIENCE 2012; 17:468-77. [PMID: 22513108 DOI: 10.1016/j.tplants.2012.03.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 03/05/2012] [Accepted: 03/05/2012] [Indexed: 05/13/2023]
Abstract
Brown algae are multicellular photosynthetic marine organisms, ubiquitous on rocky intertidal shores at cold and temperate latitudes. Nevertheless, little is known about many aspects of their biology, particularly their development. Given their phylogenetic distance (1.6 billion years) from other plant organisms (land plants, and green and red algae), brown algae harbor a high, as-yet undiscovered diversity of biological mechanisms governing their development. They also show great morphological plasticity, responding to specific environmental constraints, such as sea currents, reduced light availability, grazer attacks, desiccation and UV exposure. Here, we show that brown algal morphogenesis is rather simple and flexible, and review recent genomic data on the cellular and molecular mechanisms known to date that can possibly account for this developmental strategy.
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Affiliation(s)
- Bénédicte Charrier
- Marine Biological Station, UMR7139 CNRS-UPMC 'Marine Plants and Biomolecules', Place Georges Teissier, 29682 Roscoff Cedex, France.
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19
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Coelho SM, Scornet D, Rousvoal S, Peters NT, Dartevelle L, Peters AF, Cock JM. Ectocarpus: a model organism for the brown algae. Cold Spring Harb Protoc 2012; 2012:193-8. [PMID: 22301644 DOI: 10.1101/pdb.emo065821] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The brown algae are an interesting group of organisms from several points of view. They are the dominant organisms in many coastal ecosystems, where they often form large, underwater forests. They also have an unusual evolutionary history, being members of the stramenopiles, which are very distantly related to well-studied animal and green plant models. As a consequence of this history, brown algae have evolved many novel features, for example in terms of their cell biology and metabolic pathways. They are also one of only a small number of eukaryotic groups to have independently evolved complex multicellularity. Despite these interesting features, the brown algae have remained a relatively poorly studied group. This situation has started to change over the last few years, however, with the emergence of the filamentous brown alga Ectocarpus as a model system that is amenable to the genomic and genetic approaches that have proved to be so powerful in more classical model organisms such as Drosophila and Arabidopsis.
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Affiliation(s)
- Susana M Coelho
- UPMC Université Paris 06, The Marine Plants and Biomolecules Laboratory, UMR 7139, Station Biologique de Roscoff, BP74, 29682 Roscoff Cedex, France
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20
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Nehr Z, Billoud B, Le Bail A, Charrier B. Space-time decoupling in the branching process in the mutant étoile of the filamentous brown alga Ectocarpus siliculosus. PLANT SIGNALING & BEHAVIOR 2011; 6:1889-92. [PMID: 22095146 PMCID: PMC3337172 DOI: 10.4161/psb.6.12.18054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Ectocarpus siliculosus is being developed as a model organism for brown algal genetics and genomics. Brown algae are phylogenetically distant from the other multicellular phyla (green lineage, red algae, fungi and metazoan) and therefore might offer the opportunity to study novel and alternative developmental processes that lead to the establishment of multicellularity. E. siliculosus develops as uniseriate filaments, thereby displaying one of the simplest architectures among multicellular organisms. The young sporophyte grows as a primary filament and then branching occurs, preferentially at the center of the filament. We recently described the first morphogenetic mutant étoile (etl) in a brown alga, produced by UVB mutagenesis in E. siliculosus. We showed that a single recessive mutation was responsible for a defect in both cell differentiation and the very early branching pattern (first and second branch emergences). Here, we supplement this study by reporting the branching defects observed subsequently, i.e. for the later stages corresponding to the emergence of up to the first six secondary filaments, and we show that the branching process is composed of at least two distinct components: time and position.
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Affiliation(s)
- Zofia Nehr
- UMR 7139 CNRS-UPMC; Station Biologique de Roscoff; Roscoff, France
| | - Bernard Billoud
- UMR 7139 CNRS-UPMC; Station Biologique de Roscoff; Roscoff, France
| | - Aude Le Bail
- UMR 7139 CNRS-UPMC; Station Biologique de Roscoff; Roscoff, France
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21
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Le Bail A, Billoud B, Le Panse S, Chenivesse S, Charrier B. ETOILE regulates developmental patterning in the filamentous brown alga Ectocarpus siliculosus. THE PLANT CELL 2011; 23:1666-78. [PMID: 21478443 PMCID: PMC3101566 DOI: 10.1105/tpc.110.081919] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2010] [Revised: 01/14/2011] [Accepted: 03/18/2011] [Indexed: 05/06/2023]
Abstract
Brown algae are multicellular marine organisms evolutionarily distant from both metazoans and land plants. The molecular or cellular mechanisms that govern the developmental patterning in brown algae are poorly characterized. Here, we report the first morphogenetic mutant, étoile (etl), produced in the brown algal model Ectocarpus siliculosus. Genetic, cellular, and morphometric analyses showed that a single recessive locus, ETL, regulates cell differentiation: etl cells display thickening of the extracellular matrix (ECM), and the elongated, apical, and actively dividing E cells are underrepresented. As a result of this defect, the overrepresentation of round, branch-initiating R cells in the etl mutant leads to the rapid induction of the branching process at the expense of the uniaxial growth in the primary filament. Computational modeling allowed the simulation of the etl mutant phenotype by including a modified response to the neighborhood information in the division rules used to specify wild-type development. Microarray experiments supported the hypothesis of a defect in cell-cell communication, as primarily Lin-Notch-domain transmembrane proteins, which share similarities with metazoan Notch proteins involved in binary cell differentiation were repressed in etl. Thus, our study highlights the role of the ECM and of novel transmembrane proteins in cell-cell communication during the establishment of the developmental pattern in this brown alga.
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Affiliation(s)
- Aude Le Bail
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7139 Végétaux Marins et Biomolécules, Station Biologique, F 29682 Roscoff, France
- Université Pierre et Marie Curie-Paris 6, Unité Mixte de Recherche 7139 Végétaux Marins et Biomolécules, Station Biologique, F 29682 Roscoff, France
| | - Bernard Billoud
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7139 Végétaux Marins et Biomolécules, Station Biologique, F 29682 Roscoff, France
- Université Pierre et Marie Curie-Paris 6, Unité Mixte de Recherche 7139 Végétaux Marins et Biomolécules, Station Biologique, F 29682 Roscoff, France
| | - Sophie Le Panse
- Plateforme d’Imagerie, Fédération de Recherche 2424, Centre National de la Recherche Scientifique, Station Biologique, Place Georges Teissier, 29682 Roscoff Cedex, France
| | - Sabine Chenivesse
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7139 Végétaux Marins et Biomolécules, Station Biologique, F 29682 Roscoff, France
- Université Pierre et Marie Curie-Paris 6, Unité Mixte de Recherche 7139 Végétaux Marins et Biomolécules, Station Biologique, F 29682 Roscoff, France
| | - Bénédicte Charrier
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7139 Végétaux Marins et Biomolécules, Station Biologique, F 29682 Roscoff, France
- Université Pierre et Marie Curie-Paris 6, Unité Mixte de Recherche 7139 Végétaux Marins et Biomolécules, Station Biologique, F 29682 Roscoff, France
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22
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Bothwell JH, Marie D, Peters AF, Cock JM, Coelho SM. Role of endoreduplication and apomeiosis during parthenogenetic reproduction in the model brown alga Ectocarpus. THE NEW PHYTOLOGIST 2010; 188:111-21. [PMID: 20618911 DOI: 10.1111/j.1469-8137.2010.03357.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
• The filamentous brown alga Ectocarpus has a complex life cycle, involving alternation between independent and morphologically distinct sporophyte and gametophyte generations. In addition to this basic haploid-diploid life cycle, gametes can germinate parthenogenetically to produce parthenosporophytes. This article addresses the question of how parthenosporophytes, which are derived from a haploid progenitor cell, are able to produce meiospores in unilocular sporangia, a process that normally involves a reductive meiotic division. • We used flow cytometry, multiphoton imaging, culture studies and a bioinformatics survey of the recently sequenced Ectocarpus genome to describe its life cycle under laboratory conditions and the nuclear DNA changes which accompany key developmental transitions. • Endoreduplication occurs during the first cell cycle in about one-third of parthenosporophytes. The production of meiospores by these diploid parthenosporophytes involves a meiotic division similar to that observed in zygote-derived sporophytes. By contrast, meiospore production in parthenosporophytes that fail to endoreduplicate occurs via a nonreductive apomeiotic event. • Our results highlight Ectocarpus's reproductive and developmental plasticity and are consistent with previous work showing that its life cycle transitions are controlled by genetic mechanisms and are independent of ploidy.
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Affiliation(s)
- John H Bothwell
- Queen's University Belfast, School of Biological Sciences, 97 Lisburn Road, Belfast, BT9 7BL, UK
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23
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Le Bail A, Billoud B, Kowalczyk N, Kowalczyk M, Gicquel M, Le Panse S, Stewart S, Scornet D, Cock JM, Ljung K, Charrier B. Auxin metabolism and function in the multicellular brown alga Ectocarpus siliculosus. PLANT PHYSIOLOGY 2010; 153:128-44. [PMID: 20200071 PMCID: PMC2862433 DOI: 10.1104/pp.109.149708] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2009] [Accepted: 02/17/2010] [Indexed: 05/20/2023]
Abstract
Ectocarpus siliculosus is a small brown alga that has recently been developed as a genetic model. Its thallus is filamentous, initially organized as a main primary filament composed of elongated cells and round cells, from which branches differentiate. Modeling of its early development suggests the involvement of very local positional information mediated by cell-cell recognition. However, this model also indicates that an additional mechanism is required to ensure proper organization of the branching pattern. In this paper, we show that auxin indole-3-acetic acid (IAA) is detectable in mature E. siliculosus organisms and that it is present mainly at the apices of the filaments in the early stages of development. An in silico survey of auxin biosynthesis, conjugation, response, and transport genes showed that mainly IAA biosynthesis genes from land plants have homologs in the E. siliculosus genome. In addition, application of exogenous auxins and 2,3,5-triiodobenzoic acid had different effects depending on the developmental stage of the organism, and we propose a model in which auxin is involved in the negative control of progression in the developmental program. Furthermore, we identified an auxin-inducible gene called EsGRP1 from a small-scale microarray experiment and showed that its expression in a series of morphogenetic mutants was positively correlated with both their elongated-to-round cell ratio and their progression in the developmental program. Altogether, these data suggest that IAA is used by the brown alga Ectocarpus to relay cell-cell positional information and induces a signaling pathway different from that known in land plants.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Bénédicte Charrier
- CNRS-Université Pierre et Marie Curie, UMR 7139 Marine Plants and Biomolecules (A.L.B., B.B., N.K., M.G., S.S., D.S., J.M.C., B.C.), and Platform of Cytology, CNRS FR2424 (S.L.P.), Station Biologique de Roscoff, 29682 Roscoff cedex, France; Department of Forest Genetics and Plant Physiology, Umeå Plant Science Centre, Swedish University for Agricultural Sciences, S–901 83 Umea, Sweden (M.K., K.L.)
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