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Kuwata K, Lum WM, Takahashi K, Benico G, Takahashi K, Lim PT, Leaw CP, Uchida H, Ozawa M, Matsushima R, Watanabe R, Suzuki T, Iwataki M. Phylogeny and ultrastructure of a non-toxigenic dinoflagellate Amphidoma fulgens sp. nov. (Amphidomataceae, Dinophyceae), with a wide distribution across Asian Pacific. HARMFUL ALGAE 2024; 138:102701. [PMID: 39244236 DOI: 10.1016/j.hal.2024.102701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 06/20/2024] [Accepted: 07/24/2024] [Indexed: 09/09/2024]
Abstract
Amphidoma languida, a marine thecate dinoflagellate that produces the lipophilic toxin azaspiracids (AZAs), is primarily found in the Atlantic. Although this species has not been recorded in the Asian Pacific, environmental DNAs related to Am. languida have been widely detected in the region by metabarcoding analysis. Their morphology and AZA production remain unclear. In this study, the morphology, ultrastructure, phylogeny, and AZA production of nine Amphidoma strains isolated from Japan, Malaysia, and Philippines were investigated. Phylogenetic trees inferred from rDNAs (SSU, ITS, and LSU rDNA) showed monophyly of the nine Pacific strains and were sister to the Am. languida clade, including the toxigenic strains from the Atlantic. Cells were ellipsoid, 8.7-16.7 µm in length and 7.4-14.0 µm in width, with a conspicuous apical pore complex. A large nucleus in the hyposome, parietal chloroplast with a spherical pyrenoid in the episome, and refractile bodies were observed. Thecal tabulation was typical of Amphidoma, Po, cp, X, 6', 6'', 6C, 5S, 6''', 2''''. A ventral pore was located on the anterior of 1' plate, beside the suture to 6' plate. The presence of a ventral depression, on the anterior of anterior sulcal plate, was different from Am. languida. A large antapical pore, containing approximately 10 small pores, was observed. Cells were apparently smaller than Am. trioculata, a species possessing three pores (ventral pore, ventral depression, and antapical pore). TEM showed the presence of crystalline structures, resembling guanine crystals, and cytoplasmic invaginations into the pyrenoid matrix. Flagellar apparatus lacking the striated root connective is similar to peridinioids and related dinoflagellates. AZAs were not detected from the Pacific strains by LC-MS/MS. This non-toxigenic Amphidoma species, here we propose as Amphidoma fulgens sp. nov., is widely distributed in the Asian Pacific. Moreover, molecular comparison also suggested that most of the environmental DNA sequences previously reported as Am. languida or related sequences from the Asian Pacific were attributable to Am. fulgens.
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Affiliation(s)
- Koyo Kuwata
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo, 113-8657, Japan
| | - Wai Mun Lum
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo, 113-8657, Japan; Fisheries Technology Institute, Japan Fisheries Research and Education Agency, 2-12-4 Fukuura, Kanazawa, Yokohama, Kanagawa, 236-8648, Japan
| | - Kazuya Takahashi
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo, 113-8657, Japan
| | - Garry Benico
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo, 113-8657, Japan; Department of Biological Sciences, College of Science, Central Luzon State University, Science City of Muñoz, Nueva Ecija, 3120, Philippines
| | - Kazutaka Takahashi
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo, 113-8657, Japan
| | - Po Teen Lim
- Bachok Marine Research Station, Institute of Ocean and Earth Sciences, University of Malaya, 16310, Bachok, Kelantan, Malaysia
| | - Chui Pin Leaw
- Bachok Marine Research Station, Institute of Ocean and Earth Sciences, University of Malaya, 16310, Bachok, Kelantan, Malaysia
| | - Hajime Uchida
- Fisheries Technology Institute, Japan Fisheries Research and Education Agency, 2-12-4 Fukuura, Kanazawa, Yokohama, Kanagawa, 236-8648, Japan
| | - Mayu Ozawa
- Fisheries Technology Institute, Japan Fisheries Research and Education Agency, 2-12-4 Fukuura, Kanazawa, Yokohama, Kanagawa, 236-8648, Japan
| | - Ryoji Matsushima
- Fisheries Technology Institute, Japan Fisheries Research and Education Agency, 2-12-4 Fukuura, Kanazawa, Yokohama, Kanagawa, 236-8648, Japan
| | - Ryuichi Watanabe
- Fisheries Technology Institute, Japan Fisheries Research and Education Agency, 2-12-4 Fukuura, Kanazawa, Yokohama, Kanagawa, 236-8648, Japan
| | - Toshiyuki Suzuki
- Fisheries Technology Institute, Japan Fisheries Research and Education Agency, 2-12-4 Fukuura, Kanazawa, Yokohama, Kanagawa, 236-8648, Japan
| | - Mitsunori Iwataki
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo, 113-8657, Japan.
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Persson A, Smith BC, Alix JH, Li Y, Holohan BA, Wikfors GH. Differences in Specific Mass Density Between Dinoflagellate Life Stages and Relevance to Accumulation by Hydrodynamic Processes. JOURNAL OF PHYCOLOGY 2021; 57:1492-1503. [PMID: 33960400 PMCID: PMC8596432 DOI: 10.1111/jpy.13181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 03/31/2021] [Indexed: 06/12/2023]
Abstract
One previously unstudied aspect of differences between sexual and asexual life stages in large-scale transport and accumulation is density (mass per unit volume) of cells in each life stage. The specific density was determined for Scrippsiella lachrymosa cells in medium with and without nitrogen (N) enrichment through density-gradient centrifugation. Growth medium without N addition is often called "encystment medium" when used for the purpose of resting cyst formation in cyst-forming dinoflagellates; mating gametes are usually seen after 2-3 days. Significant differences in specific density were found after 2 days in encystment medium simultaneously with the observation of typical gamete swimming behavior and mating. The specific density of cells in encystment medium was 1.06 g · cm-3 ; whereas, the specific density of cells in growth medium was 1.11 g · cm-3 . Cells in encystment medium were found to have significantly increased lipid content, reduced chlorophyll content, and reduced internal complexity. The findings may explain differential transport of less dense and chemotactically aggregating gametes into surface blooms in contrast to denser vegetative cells that perform daily vertical migration and do not aggregate. Passive accumulation of non-migrating gametes into layers in stagnant water also can be explained, as well as sinking of zygotes when the storage of highly dense starch increases. Resting cysts had a density of over 1.14 g · cm-3 and would sink to become part of the silt fraction of the sediment. We suggest that differences in behavior and buoyancy between sexual and asexual life stages cause differences in cell accumulation, and therefore large-scale, environmental transport could be directly dependent upon life-cycle transitions.
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Affiliation(s)
- Agneta Persson
- Department of Biological and Environmental SciencesGöteborg UniversityBox 461405 30GöteborgSweden
- Smedjebacksvägen 13SE‐771 90LudvikaSweden
| | - Barry C. Smith
- National Oceanic and Atmospheric AdministrationNational Marine Fisheries ServiceNortheast Fisheries Science CenterMilford Laboratory212 Rogers AvenueMilfordConnecticut06460USA
| | - Jennifer H. Alix
- National Oceanic and Atmospheric AdministrationNational Marine Fisheries ServiceNortheast Fisheries Science CenterMilford Laboratory212 Rogers AvenueMilfordConnecticut06460USA
| | - Yaqin Li
- National Oceanic and Atmospheric AdministrationNational Marine Fisheries ServiceNortheast Fisheries Science CenterMilford Laboratory212 Rogers AvenueMilfordConnecticut06460USA
| | - Bridget A. Holohan
- Department of Marine SciencesUniversity of Connecticut1080 Shennecossett RoadGrotonConnecticut06340USA
| | - Gary H. Wikfors
- National Oceanic and Atmospheric AdministrationNational Marine Fisheries ServiceNortheast Fisheries Science CenterMilford Laboratory212 Rogers AvenueMilfordConnecticut06460USA
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Barrett J, Girr P, Mackinder LCM. Pyrenoids: CO 2-fixing phase separated liquid organelles. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2021; 1868:118949. [PMID: 33421532 DOI: 10.1016/j.bbamcr.2021.118949] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 12/11/2020] [Accepted: 12/12/2020] [Indexed: 02/06/2023]
Abstract
Pyrenoids are non-membrane bound organelles found in chloroplasts of algae and hornwort plants that can be seen by light-microscopy. Pyrenoids are formed by liquid-liquid phase separation (LLPS) of Rubisco, the primary CO2 fixing enzyme, with an intrinsically disordered multivalent Rubisco-binding protein. Pyrenoids are the heart of algal and hornwort biophysical CO2 concentrating mechanisms, which accelerate photosynthesis and mediate about 30% of global carbon fixation. Even though LLPS may underlie the apparent convergent evolution of pyrenoids, our current molecular understanding of pyrenoid formation comes from a single example, the model alga Chlamydomonas reinhardtii. In this review, we summarise current knowledge about pyrenoid assembly, regulation and structural organization in Chlamydomonas and highlight evidence that LLPS is the general principle underlying pyrenoid formation across algal lineages and hornworts. Detailed understanding of the principles behind pyrenoid assembly, regulation and structural organization within diverse lineages will provide a fundamental understanding of this biogeochemically important organelle and help guide ongoing efforts to engineer pyrenoids into crops to increase photosynthetic performance and yields.2.
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Affiliation(s)
- James Barrett
- Department of Biology, University of York, York YO10 5DD, UK
| | - Philipp Girr
- Department of Biology, University of York, York YO10 5DD, UK
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Jantschke A, Pinkas I, Schertel A, Addadi L, Weiner S. Biomineralization pathways in calcifying dinoflagellates: Uptake, storage in MgCaP-rich bodies and formation of the shell. Acta Biomater 2020; 102:427-439. [PMID: 31785382 DOI: 10.1016/j.actbio.2019.11.042] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 10/17/2019] [Accepted: 11/22/2019] [Indexed: 10/25/2022]
Abstract
Little is known about shell formation of calcareous dinoflagellates, despite the fact that they are one of the major calcifying organisms of the phytoplankton. Here, calcitic cyst formation in two representative members of calcareous dinoflagellates is investigated using cryo-electron microscopy (cryo-SEM and cryo-FIB-SEM) in combination with micro-Raman and infrared spectroscopy. Only calcein-AM and not calcein enters these cells, indicating active uptake of calcium and other divalent cations. Multifunctional vacuoles containing crystalline inclusions are observed, and the crystals are identified as anhydrous guanine in the β-form. The same vacuolar enclosures contain dense magnesium-, calcium-, and phosphorous-rich mineral bodies. These bodies are presumably secreted into the outer matrix where calcite forms. Calcite formation occurs via multiple independent nucleation events, and the different crystals grow with preferred orientation into a dense reticular network that forms the mature calcitic shell. We suggest a biomineralization pathway for calcareous dinoflagellates that includes (1) active uptake of calcium through the membranes, (2) deposition of Mg2+- and Ca2+-ions inside disordered MgCaP-rich mineral bodies, (3) secretion of these bodies to the inter-membrane space, and (4) Formation and growth of calcite into a dense reticulate network. This study provides new insights into calcium uptake, storage and transport in calcifying dinoflagellates. STATEMENT OF SIGNIFICANCE: Little is known about the shell formation of calcareous dinoflagellates, despite the fact that they are one of the major calcifying organisms of the phytoplankton. We used state-of-the-art cryo-electron microscopy (cryo-SEM and cryo-FIB-SEM) in combination with micro-Raman spectroscopy to provide new insights into mineral formation in calcifying dinoflagellates. To date, intracellular crystalline calcite was assumed to be involved in calcite shell formation. Surprisingly, we identify these crystalline inclusions as anhydrous guanine suggesting that they are not involved in biomineralization. Instead, a key finding is that MgCaP-rich bodies are probably secreted into the outer matrix where the calcite shell is formed. We suggest that these bodies are an essential part of Ca-uptake, -storage and -transport and propose a new biomineralization model.
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Persson A, Smith BC, Cyronak T, Cooper E, DiTullio GR. Differences in pigmentation between life cycle stages in Scrippsiella lachrymosa (dinophyceae). JOURNAL OF PHYCOLOGY 2016; 52:64-74. [PMID: 26987089 DOI: 10.1111/jpy.12364] [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] [Received: 10/23/2014] [Accepted: 10/13/2015] [Indexed: 06/05/2023]
Abstract
Various life cycle stages of cyst-producing dinoflagellates often appear differently colored under the microscope; gametes appear paler while zygotes are darker in comparison to vegetative cells. To compare physiological and photochemical competency, the pigment composition of discrete life cycle stages was determined for the common resting cyst-producing dinoflagellate Scrippsiella lachrymosa. Vegetative cells had the highest cellular pigment content (25.2 ± 0.5 pg · cell(-1) ), whereas gamete pigment content was 22% lower. The pigment content of zygotes was 82% lower than vegetative cells, even though they appeared darker under the microscope. Zygotes of S. lachrymosa contained significantly higher cellular concentrations of β-carotene (0.65 ± 0.15 pg · cell(-1) ) than all other life stages. Photoprotective pigments and the de-epoxidation ratio of xanthophylls-cycle pigments in S. lachrymosa were significantly elevated in zygotes and cysts compared to other stages. This suggests a role for accessory pigments in combating intracellular oxidative stress during sexual reproduction or encystment. Resting cysts contained some pigments even though chloroplasts were not visible, suggesting that the brightly colored accumulation body contained photosynthetic pigments. The differences in pigmentation between life stages have implications for interpretation of pigment data from field samples when sampled during dinoflagellate blooms.
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Affiliation(s)
- Agneta Persson
- Department of Biological and Environmental Sciences, Göteborg University, Box 461, Göteborg, SE-405 30, Sweden
| | - Barry C Smith
- National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Northeast Fisheries Science Center, Milford Laboratory, 212 Rogers Avenue, Milford, Connecticut, 06460, USA
| | - Tyler Cyronak
- Hollings Marine Laboratory, College of Charleston, 331 Fort Johnson Rd, Charleston, South Carolina, 29412, USA
| | - Emily Cooper
- Hollings Marine Laboratory, College of Charleston, 331 Fort Johnson Rd, Charleston, South Carolina, 29412, USA
| | - Giacomo R DiTullio
- Hollings Marine Laboratory, College of Charleston, 331 Fort Johnson Rd, Charleston, South Carolina, 29412, USA
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