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1
Edwards, Lucy E. "Dinoflagellates". Notes for a Short Course: Studies in Geology 18 (1987): 34–61. http://dx.doi.org/10.1017/s0271164800001494.
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Dinoflagellates are single-celled organisms of the Division Pyrrhophyta. Most people, although not familiar with dinoflagellates, are familiar with their effects. Bioluminescent dinoflagellates cause a sparkling of the sea at night as the waves break, and certain dinoflagellates may produce blooms called “red tides,” which poison marine life or which cause toxins to accumulate in shellfish, poisoning those who eat them. The Old Testament (Exodus 7:20–21) and the writings of the ancient Greeks refer to red water and the killing of fish. The Red Sea may have gotten its name from dinoflagellate blooms.
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Janouškovec, Jan, Gregory S. Gavelis, Fabien Burki, Donna Dinh, Tsvetan R. Bachvaroff, Sebastian G. Gornik, Kelley J. Bright i in. "Major transitions in dinoflagellate evolution unveiled by phylotranscriptomics". Proceedings of the National Academy of Sciences 114, nr 2 (27.12.2016): E171—E180. http://dx.doi.org/10.1073/pnas.1614842114.
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Dinoflagellates are key species in marine environments, but they remain poorly understood in part because of their large, complex genomes, unique molecular biology, and unresolved in-group relationships. We created a taxonomically representative dataset of dinoflagellate transcriptomes and used this to infer a strongly supported phylogeny to map major morphological and molecular transitions in dinoflagellate evolution. Our results show an early-branching position of Noctiluca, monophyly of thecate (plate-bearing) dinoflagellates, and paraphyly of athecate ones. This represents unambiguous phylogenetic evidence for a single origin of the group’s cellulosic theca, which we show coincided with a radiation of cellulases implicated in cell division. By integrating dinoflagellate molecular, fossil, and biogeochemical evidence, we propose a revised model for the evolution of thecal tabulations and suggest that the late acquisition of dinosterol in the group is inconsistent with dinoflagellates being the source of this biomarker in pre-Mesozoic strata. Three distantly related, fundamentally nonphotosynthetic dinoflagellates, Noctiluca, Oxyrrhis, and Dinophysis, contain cryptic plastidial metabolisms and lack alternative cytosolic pathways, suggesting that all free-living dinoflagellates are metabolically dependent on plastids. This finding led us to propose general mechanisms of dependency on plastid organelles in eukaryotes that have lost photosynthesis; it also suggests that the evolutionary origin of bioluminescence in nonphotosynthetic dinoflagellates may be linked to plastidic tetrapyrrole biosynthesis. Finally, we use our phylogenetic framework to show that dinoflagellate nuclei have recruited DNA-binding proteins in three distinct evolutionary waves, which included two independent acquisitions of bacterial histone-like proteins.
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Gornik, Sebastian G., Ian Hu, Imen Lassadi i Ross F. Waller. "The Biochemistry and Evolution of the Dinoflagellate Nucleus". Microorganisms 7, nr 8 (8.08.2019): 245. http://dx.doi.org/10.3390/microorganisms7080245.
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Dinoflagellates are known to possess a highly aberrant nucleus—the so-called dinokaryon—that exhibits a multitude of exceptional biological features. These include: (1) Permanently condensed chromosomes; (2) DNA in a cholesteric liquid crystalline state, (3) extremely large DNA content (up to 200 pg); and, perhaps most strikingly, (4) a deficit of histones—the canonical building blocks of all eukaryotic chromatin. Dinoflagellates belong to the Alveolata clade (dinoflagellates, apicomplexans, and ciliates) and, therefore, the biological oddities observed in dinoflagellate nuclei are derived character states. Understanding the sequence of changes that led to the dinokaryon has been difficult in the past with poor resolution of dinoflagellate phylogeny. Moreover, lack of knowledge of their molecular composition has constrained our understanding of the molecular properties of these derived nuclei. However, recent advances in the resolution of the phylogeny of dinoflagellates, particularly of the early branching taxa; the realization that divergent histone genes are present; and the discovery of dinoflagellate-specific nuclear proteins that were acquired early in dinoflagellate evolution have all thrown new light nature and evolution of the dinokaryon.
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Siqueiros Beltrones, David A. "Infección de Ceratium furca por el dinoflagelado parásito Amoebophrya ceratii (Amoebophryidae) en el Pacífico mexicano". Acta Botanica Mexicana, nr 65 (1.10.2003): 1. http://dx.doi.org/10.21829/abm65.2003.958.
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Parasitism within dinoflagellates is a widespread and well-documented phenomenon. Parasitic dinoflagellates of the genus Amoebophrya commonly infect free-living toxic, and non-toxic dinoflagellates species which may cause harmful red tides. Infections of Ceratium furca by A. ceratii were observed in red tides samples collected in the northwest coast of Baja California between 30°01'05'' N, 115°51'16'' W and 31°09'33'' N, 116°31'09'' W. This is the first record of this particular parasitic dinoflagellate in Mexican Pacific waters. There were mainly three dinoflagellate species causing this particular seawater discoloration: a Gymnodinium-like dinoflagellate, Ceratium furca, and Akashiwo sanguinea. These reached concentrations as high as 560 000, 762 600, and 395 400 cells L-1, respectively. During the bloom, surface water temperature ranged between 13 and 17°C. Seawater salinity ranged from 33.2 to 33.8 psu. About 1.5% of the individuals of C. furca observed were infected by the intracellular parasite dinoflagellate Amoebophrya ceratii. This parasite was observed mainly inside specimens of Ceratium furca and very few specimens of Ceratium macroceros. In general, individuals of C. furca were partially or totally deformed. Infections by A. ceratii could delay or inhibit the dinoflagellate blooms as infected dinoflagellates become reproductively incompetent.
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Deng, Yunyan, Kui Wang, Zhangxi Hu i Ying-Zhong Tang. "Abundant Species Diversity and Essential Functions of Bacterial Communities Associated with Dinoflagellates as Revealed from Metabarcoding Sequencing for Laboratory-Raised Clonal Cultures". International Journal of Environmental Research and Public Health 19, nr 8 (7.04.2022): 4446. http://dx.doi.org/10.3390/ijerph19084446.
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Interactions between algae and bacteria represent an important inter-organism association in aquatic environments, which often have cascading bottom-up influences on ecosystem-scale processes. Despite the increasing recognition of linkages between bacterioplankton and dynamics of dinoflagellate blooms in the field, knowledge about the forms and functions of dinoflagellate-bacteria associations remains elusive, mainly due to the ephemeral and variable conditions in the field. In this study, we characterized the bacterial community associated with laboratory cultures of 144 harmful algal strains, including 130 dinoflagellates (covering all major taxonomic orders of dinoflagellates) and 14 non-dinoflagellates, via high-throughput sequencing for 16S rRNA gene amplicons. A total of 4577 features belonging to bacteria kingdom comprising of 24 phyla, 55 classes, 134 orders, 273 families, 716 genera, and 1104 species were recovered from the algal culture collection, and 3 phyla (Proteobacteria, Bacteroidetes, and Firmicutes) were universally present in all the culture samples. Bacterial communities in dinoflagellates cultures exhibited remarkable conservation across different algal strains, which were dominated by a relatively small number of taxa, most notably the γ-proteobacteria Methylophaga, Marinobacter and Alteromonas. Although the bacterial community composition between dinoflagellates and non-dinoflagellate groups did not show significant difference in general, dinoflagellates harbored a large number of unique features (up to 3811) with relatively low individual abundance and enriched in the potential methylotrophs Methylophaga. While the bacterial assemblages associated with thecate and athecate dinoflagellates displayed no general difference in species composition and functional groups, athecate dinoflagellates appeared to accommodate more aerobic cellulolytic members of Actinobacteria, implying a more possible reliance on cellulose utilization as energy source. The extensive co-occurrence discovered here implied that the relationships between these algal species and the bacterial consortia could be viewed as either bilaterally beneficial (i.e., mutualism) or unilaterally beneficial at least to one party but virtually harmless to the other party (i.e., commensalism), whereas both scenarios support a long-term and stable co-existence rather than an exclusion of one or the other. Our results demonstrated that dinoflagellates-associated bacterial communities were similar in composition, with enrichment of potential uncultured methylotrophs to one-carbon compounds. This work enriches the knowledge about the fundamental functions of bacteria consortia associated with the phycospheres of dinoflagellates and other HABs-forming microalgae.
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Ok, Jin Hee, Hae Jin Jeong, Hee Chang Kang, Ji Hyun You, Sang Ah Park, Se Hee Eom, Jin Kyeong Kang i Yeong Du Yoo. "Protists in hypoxic waters of Jinhae Bay and Masan Bay, Korea, based on metabarcoding analyses: emphasizing surviving dinoflagellates". Algae 38, nr 4 (15.12.2023): 265–81. http://dx.doi.org/10.4490/algae.2023.38.12.6.
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Hypoxia can indeed impact the survival of protists, which play a crucial role in marine ecosystems. To better understand the protistan community structure and species that can thrive in hypoxic waters, we collected samples from both the surface and bottom waters during the hypoxic period in Jinhae and Masan Bays and the non-hypoxic period in Jinhae Bay. Subsequently, we utilized metabarcoding techniques to identify the protistan species. During hypoxia, with dissolved oxygen concentrations of 0.8 mg L<sup>-1</sup> in Jinhae Bay and 1.8 mg L<sup>-1</sup> in Masan Bay within the bottom waters, the phylum Dinoflagellata exhibited the highest amplicon sequence variants richness among the identified protist phyla. Following the Dinoflagellata, Ochrophyta and Ciliophora also displayed notable presence. In hypoxic waters of Jinhae and Masan Bays, we identified a total of 36 dinoflagellate species that exhibited various trophic modes. These included one autotrophic species, 14 mixotrophic species, 9 phototrophic species with undetermined trophic modes (either autotrophic or mixotrophic), 2 kleptoplastidic species, and 10 heterotrophic species. Furthermore, the hypoxic bottom water exhibited a greater number of heterotrophic dinoflagellate species compared to the non-hypoxic surface water within the same water column or the non-hypoxic bottom water. Therefore, feeding by mixotrophic and heterotrophic dinoflagellates may be partially responsible for their dominance in terms of the number of species surviving in hypoxic waters. This study not only introduces the initial documentation of 26 dinoflagellate species surviving in hypoxic conditions but also establishes a foundation for a more comprehensive understanding of the ecophysiology of dinoflagellates in hypoxic marine environments.
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Huynh, Thi Ngoc Duyen, Thi Minh Hue Tran, Thi Le Van Tran, Tan Luom Phan, Tam Vinh Nguyen, Ngoc Lam Nguyen i Nhu Hai Doan-. "Dinoflagellate composition and environmental conditions in the Xuan Dai Bay, South-Central Vietnam". Vietnam Journal of Marine Science and Technology 24, nr 2 (21.05.2024): 153–66. http://dx.doi.org/10.15625/1859-3097/18610.
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The dinoflagellate community was investigated in association with environmental factors using a data set in April 2021 and April 2022 in Xuan Dai Bay, South-Central Viet Nam. Environmental variables, including physical parameters and dissolved inorganic nutrients, were measured in April 2022. Seventy-three dinoflagellate taxa were identified for Xuan Dai Bay. There was a significant difference in the number and abundance of dinoflagellates between two parts of the bay, the upper and lower bay. The study showed that dinoflagellates favored an area with good water exchange and were less affected by aquaculture activities. Principal component analysis (PCA) was used to explore the relative abundances of different phytoplankton groups, their diversity indices, and environmental variables at the surface and bottom layers of the two parts of the bay. The results showed that dinoflagellates correlated to physical parameters (e.g., PAR, salinity, temperature) at the surface layer and nutrients at the bottom layer. Dinoflagellates and diatoms are mixotrophic and strongly correlated at the bottom layer in Xuan Dai Bay. This strong relationship in the bay was because of the dominance of a heterotrophic genus, Protoperidinium. The present study provided characteristics of the dinoflagellates in Xuan Dai Bay and the possible impacts of environmental parameters on their abundance. The results can be used for further studies and possibly managing of dinoflagellate blooms in coastal waters.
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Verma, Arjun, Abanti Barua, Rendy Ruvindy, Henna Savela, Penelope A. Ajani i Shauna A. Murray. "The Genetic Basis of Toxin Biosynthesis in Dinoflagellates". Microorganisms 7, nr 8 (29.07.2019): 222. http://dx.doi.org/10.3390/microorganisms7080222.
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In marine ecosystems, dinoflagellates can become highly abundant and even dominant at times, despite their comparatively slow growth rates. One factor that may play a role in their ecological success is the production of complex secondary metabolite compounds that can have anti-predator, allelopathic, or other toxic effects on marine organisms, and also cause seafood poisoning in humans. Our knowledge about the genes involved in toxin biosynthesis in dinoflagellates is currently limited due to the complex genomic features of these organisms. Most recently, the sequencing of dinoflagellate transcriptomes has provided us with valuable insights into the biosynthesis of polyketide and alkaloid-based toxin molecules in dinoflagellate species. This review synthesizes the recent progress that has been made in understanding the evolution, biosynthetic pathways, and gene regulation in dinoflagellates with the aid of transcriptomic and other molecular genetic tools, and provides a pathway for future studies of dinoflagellates in this exciting omics era.
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Mestry, C. M., A. D. Adsul, A. S. Pawase, M. S. Sawant, R. A. Pawar i G. S. Ghode. "Monthly Variations of Dinoflagellates in Relation to the Water Parameters Along Purnagad Estuary, Ratnagiri, Maharashtra, India". International Journal of Environment and Climate Change 14, nr 5 (28.05.2024): 395–403. http://dx.doi.org/10.9734/ijecc/2024/v14i54199.
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Water samples were collected from Purnagad estuary, southwest coast of India. The monthly surface water sampling was carried out during high tide to find out the variations in physicochemical parameters and distribution of dinoflagellates. Samples were collected for one year period during 2022–2023. Dinoflagellates and water quality parameters were investigated to changes of dinoflagellates community. Variation in atmospheric temperature 21.9 - 37.2 0C, water temperatures varied from 25.4 - 37 0C, salinity varied from 0-37.6 psu, pH ranges between 7-8.8, dissolved oxygen 3.2-10.8 mgl-1, nitrate varied from 0.1747 - 0.1796 mgl-1, nitrite concentration varied from 0.0076 - 0.0228 mgl-1, phosphate values varied from 0.1038 mgl-1 to 0.3899 mgl-1, Silicate was varied from 0.0050 - 0.6031 mgl-1. A quantitative approach was employed, involving the collection of quantitative data through field sampling and laboratory analysis. During the study 22 species of dinoflagellates were encountered among which Ceratium fusus was dominant. Relatively high density and diversity of dinoflagellates were discovered in May as compared to the other months. Temperature showed a positive correlation with the dinoflagellate community showing its importance in dinoflagellate growth.
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Bryantseva, Yu V. "Dinoflagellates of the Crimean Peninsula and its coastal waters". Algologia 30, nr 4 (grudzień 2020): 341–58. http://dx.doi.org/10.15407/alg30.04.341.
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The article is devoted to the generalization of the existing information concerning dinoflagellates of the Crimea. A list of dinoflagellate species of continental waters of the peninsula and the Crimean coast (Black and Azov seas) of Ukraine was compiled. It is based on the analysis of literature and original data obtained in 1987, 1992-1993 and 2011 in the Black Sea. The list of dinoflagellata species of Crimea includes 196 species (206 infraspecific taxa) belonging to 64 genera, 36 families, 15 orders and 3 classes. Eighteen species have been recorded in the fresh and salt water bodies and mud volcanoes of the least studied continental part of Crimea; half of them were also found in marine waters. Dinoflagellates of the Azov coast of Crimea and the Kerch Strait are similar in number of species, but differ significantly in composition (26 and 31 species, respectively; only 13 (25%) of them are common). The greatest number of species of dinoflagellates found on the Black Sea coast of Crimea. It is almost half of all species known for the Black Sea (196 and 447, respectively). To compare the species richness of dinoflagellates from different regions of the Crimea, survey data covering all areas in a short period of time are of great importance. A total of 74 species of dinoflagellates belonging to 3 classes, 11 orders, 22 families and 30 genera were found off the coast of Crimea. The most species-rich genera are Protoperidinium Bergh (17), Dinophysis Ehrenb. (8), Gymnodinium F.Stein (7) and Prorocentrum Ehrenb. (6). Based on the analysis of original and literature data and the criterion of similarity of the species composition of Crimean dinoflagellates, it’s division into five algofloristic regions is proposed: the western Black Sea coast of Crimea (from Karkinitsky Bay to Cape Aya); southeastern (from Ayia to Takil), Kerch Strait, Azov coast of Crimea and land (which, in turn, is divided into steppe and mountainous Crimean regions). It is in compliance with the algofloristic zoning of Ukraine.
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Nagasaki, K., Y. Tomaru, Y. Shirai, Y. Takao i H. Mizumoto. "Dinoflagellate-infecting viruses". Journal of the Marine Biological Association of the United Kingdom 86, nr 3 (10.04.2006): 469–74. http://dx.doi.org/10.1017/s0025315406013361.
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Dinoflagellates (Dinophyceae) are considered to be one of the most abundant and diverse groups of phytoplankton; however, the viral impact on dinoflagellates was not studied until recently. This review shows the present information concerning the viruses infecting dinoflagellates and the ecology relationships between the host and the virus. So far, two viruses have been isolated and characterized: a large DNA virus (HcV: Heterocapsa circularisquama virus) and a small RNA virus (HcRNAV: H. circularisquama RNA virus); both of which are infectious to the harmful bloom-forming dinoflagellate H. circularisquama.In the present review, we mainly discuss the relationship between HcRNAV and H. circularisquama from the viewpoint of physiology, ecology and genetics. It will help clarify the viral impact on dinoflagellate populations in marine environments to understand the host/parasite ecology.
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Mardones, Jorge I., Ana Flores-Leñero, Marco Pinto-Torres, Javier Paredes-Mella i Sebastián Fuentes-Alburquenque. "Mitigation of Marine Dinoflagellates Using Hydrogen Peroxide (H2O2) Increases Toxicity towards Epithelial Gill Cells". Microorganisms 11, nr 1 (28.12.2022): 83. http://dx.doi.org/10.3390/microorganisms11010083.
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Hydrogen peroxide (H2O2) has been shown to efficiently remove toxic microalgae from enclosed ballast waters and brackish lakes. In this study, in vitro experiments were conducted to assess the side effects of mitigating toxic and non-toxic dinoflagellates with H2O2. Five H2O2 concentrations (50 to 1000 ppm) were used to control the cell abundances of the toxic dinoflagellates Alexandrium catenella and Karenia selliformis and the non-toxic dinoflagellates Lepidodinium chlorophorum and Prorocentrum micans. Photosynthetic efficiency and staining dye measurements showed the high efficiency of H2O2 for mitigating all dinoflagellate species at only 50 ppm. In a bioassay carried out to test cytotoxicity using the cell line RTgill-W1, control experiments (only H2O2) showed cytotoxicity in a concentration- and time- (0 to 24 h) dependent manner. The toxic dinoflagellates, especially K. selliformis, showed basal cytotoxicity that increased with the application of hydrogen peroxide. Unexpectedly, the application of a low H2O2 concentration increased toxicity, even when mitigating non-toxic dinoflagellates. This study suggests that the fatty acid composition of toxic and non-toxic dinoflagellate species can yield toxic aldehyde cocktails after lipoperoxidation with H2O2 that can persist in water for days with different half-lives. Further studies are needed to understand the role of lipoperoxidation products as acute mediators of disease and death in aquatic environments.
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Li, Chongping, i Joseph Tin Yum Wong. "DNA Damage Response Pathways in Dinoflagellates". Microorganisms 7, nr 7 (5.07.2019): 191. http://dx.doi.org/10.3390/microorganisms7070191.
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Dinoflagellates are a general group of phytoplankton, ubiquitous in aquatic environments. Most dinoflagellates are non-obligate autotrophs, subjected to potential physical and chemical DNA-damaging agents, including UV irradiation, in the euphotic zone. Delay of cell cycles by irradiation, as part of DNA damage responses (DDRs), could potentially lead to growth inhibition, contributing to major errors in the estimation of primary productivity and interpretations of photo-inhibition. Their liquid crystalline chromosomes (LCCs) have large amount of abnormal bases, restricted placement of coding sequences at the chromosomes periphery, and tandem repeat-encoded genes. These chromosome characteristics, their large genome sizes, as well as the lack of architectural nucleosomes, likely contribute to possible differential responses to DNA damage agents. In this study, we sought potential dinoflagellate orthologues of eukaryotic DNA damage repair pathways, and the linking pathway with cell-cycle control in three dinoflagellate species. It appeared that major orthologues in photoreactivation, base excision repair, nucleotide excision repair, mismatch repair, double-strand break repair and homologous recombination repair are well represented in dinoflagellate genomes. Future studies should address possible differential DNA damage responses of dinoflagellates over other planktonic groups, especially in relation to possible shift of life-cycle transitions in responses to UV irradiation. This may have a potential role in the persistence of dinoflagellate red tides with the advent of climatic change.
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Sprecher, Brittany N., Huan Zhang i Senjie Lin. "Nuclear Gene Transformation in the Dinoflagellate Oxyrrhis marina". Microorganisms 8, nr 1 (16.01.2020): 126. http://dx.doi.org/10.3390/microorganisms8010126.
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The lack of a robust gene transformation tool that allows proper expression of foreign genes and functional testing for the vast number of nuclear genes in dinoflagellates has greatly hampered our understanding of the fundamental biology in this ecologically important and evolutionarily unique lineage of microeukaryotes. Here, we report the development of a dinoflagellate expression vector containing various DNA elements from phylogenetically separate dinoflagellate lineages, an electroporation protocol, and successful expression of introduced genes in an early branching dinoflagellate, Oxyrrhis marina. This protocol, involving the use of Lonza’s Nucleofector and a codon-optimized antibiotic resistance gene, has been successfully used to produce consistent results in several independent experiments for O. marina. It is anticipated that this protocol will be adaptable for other dinoflagellates and will allow characterization of many novel dinoflagellate genes.
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Riaz, Sadaf, Zhenghong Sui, Zeeshan Niaz, Sohrab Khan, Yuan Liu i Haoxin Liu. "Distinctive Nuclear Features of Dinoflagellates with A Particular Focus on Histone and Histone-Replacement Proteins". Microorganisms 6, nr 4 (14.12.2018): 128. http://dx.doi.org/10.3390/microorganisms6040128.
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Dinoflagellates are important eukaryotic microorganisms that play critical roles as producers and grazers, and cause harmful algal blooms. The unusual nuclei of dinoflagellates “dinokaryon” have led researchers to investigate their enigmatic nuclear features. Their nuclei are unusual in terms of their permanently condensed nucleosome-less chromatin, immense genome, low protein to DNA ratio, guanine-cytosine rich methylated DNA, and unique mitosis process. Furthermore, dinoflagellates are the only known group of eukaryotes that apparently lack histone proteins. Over the course of evolution, dinoflagellates have recruited other proteins, e.g., histone-like proteins (HLPs), from bacteria and dinoflagellates/viral nucleoproteins (DVNPs) from viruses as histone substitutes. Expression diversity of these nucleoproteins has greatly influenced the chromatin structure and gene expression regulation in dinoflagellates. Histone replacement proteins (HLPs and DVNPs) are hypothesized to perform a few similar roles as histone proteins do in other eukaryotes, i.e., gene expression regulation and repairing DNA. However, their role in bulk packaging of DNA is not significant as low amounts of proteins are associated with the gigantic genome. This review intends to summarize the discoveries encompassing unique nuclear features of dinoflagellates, particularly focusing on histone and histone replacement proteins. In addition, a comprehensive view of the evolution of dinoflagellate nuclei is presented.
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Herawati, E. Y., R. Valina, C. A. F. Dini, V. Cahyani, R. I. Khasanah, E. N. Wiratno i P. D. Samuel. "Abundance and composition analysis of dinoflagellates in Mayangan and Binor Coastal Area, Probolinggo, East Java, Indonesia". IOP Conference Series: Earth and Environmental Science 1191, nr 1 (1.05.2023): 012001. http://dx.doi.org/10.1088/1755-1315/1191/1/012001.
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Abstract Dinoflagellates are one of the phytoplankton groups that an important role as primary producers in waters. However, in very abundant conditions (blooming) it can be dangerous for ecosystems and aquatic biota. This study aims to determine the composition and abundance of harmful dinoflagellates and environmental factors that influence the presence of dinoflagellates in coastal area of Mayangan and Binor, Probolinggo Regency, East Java. The method used in this study is a survey method by determining the sample point by purposive sampling. The research was conducted in March 2022. The result showed that the abundance of dinoflagellates in Mayangan waters 255 – 1511 cells/mL consisting of 10 genera namely Alexandrium, Ceratium, Dinophysis, Gambierdiscus, Glenodinium, Gymnodinium, Ostreopsis, Peridinium, Phyrodinium, and Prorocentrum. The abundance of dinoflagellates in Binor waters 716 – 2536 cells/mL consisting of 10 genera namely Alexandrium, Amphydinium, Bysmatrum, Cochlodinium, Gambierdiscus, Glenodinium, Gymnodinium, Peridinium, Protoperidinium, and Scrippsiella. The highest genus in Mayangan waters Ceratium 18% and Binor waters Protoperidinium 21%. The abundance of dinoflagellates in the Mayangan and Binor waters has no potential for blooming, but the presence of the dinoflagellate genus in the waters can still endanger coastal ecosystems because it can produce toxins. The presence of dinoflagellates is influenced by environmental factors such as salinity, nitrate, and phosphate.
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Zhang, Yong, Jin-Zhu Su, Yu-Ping Su, Hong Lin, Yang-Chun Xu, Balaji P. Barathan, Wan-Ning Zheng i Kai G. Schulz. "Spatial Distribution of Phytoplankton Community Composition and Their Correlations with Environmental Drivers in Taiwan Strait of Southeast China". Diversity 12, nr 11 (18.11.2020): 433. http://dx.doi.org/10.3390/d12110433.
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Large-scale dinoflagellate blooms have appeared in recent decades in the Taiwan Strait, Southeast China. To study spatial variability of phytoplankton community composition, physical and chemical environmental drivers in surface seawater of the Taiwan Strait, we conducted cruises in May and July 2019. Cell numbers of dinoflagellates were significantly higher than that of diatoms in most sampling stations during the cruise in May, whereas diatoms were the major contributor to autotrophic biomass in July. Phytoplankton community shifted from a dinoflagellate- and diatom-dominated system in May to diatom dominance in July. The dominant phytoplankton species (genera) were the harmful algal bloom dinoflagellates Prorocentrum donghaiense and Scrippsiella trochoidea and the diatoms Coscinodiscus in May, and Rhizosolenia, Pseudo-nitzschia, and Guinardia in July. Cell densities of dinoflagellates and P. donghaiense reduced exponentially with increasing seawater temperature and salinity and decreasing dissolved inorganic nitrogen (DIN) concentrations. Based on the results of our work and previous studies, it becomes obvious that harmful dinoflagellate blooms are likely to be a major component of the planktonic food web in the Taiwan Strait at a temperature of 17.0–23.0 °C, a salinity of 29.0–33.0 psu, and a DIN concentration higher than 2.0 μmol L–1.
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Widiarti, Riani, Murtiningsih, Suwarti, Ahmad Mutaqin i Gud Elina Kurnia. "THE POTENTIALLY TOXIC BENTHIC DINOFLAGELLATES ON MACROALGAE AT THE REEF FLAT OF SERIBU ISLANDS, NORTH JAKARTA - INDONESIA". Marine Research in Indonesia 33, nr 1 (14.05.2018): 91–94. http://dx.doi.org/10.14203/mri.v33i1.462.
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The Ciguatera Fish Poisoning (CFP) causing microorganisms were observed at the reef flat of Penjaliran Barat Islands and Pramuka Islands District, Seribu Island National Park, North Jakarta, Indonesia. Of the samples collected, four potentially toxic benthic dinoflagellates species were found, which are Gambierdiscus toxicus, Prorocentrum concavum, Prorocentrum lima, and Ostreopsis lenticularis. The dinoflagellates were found attached on the brown macroalgae Padina and Sargassum. Most of the benthic dinoflagellates from both locations were found in Pramuka Islands District, the inhabitated islands where human activities which could damage the coral reef areas were relatively high. Beside the macroalgae substrate preference of each dinoflagellate species, several environmental factors were also obtained in this research.
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Prol, María Jesús, Cástor Guisande, Aldo Barreiro, Beatriz Míguez, Pablo de la Iglesia, Adriano Villar, Ana Gago-Martínez i María Pilar Combarro. "Evaluation of the production of paralytic shellfish poisoning toxins by extracellular bacteria isolated from the toxic dinoflagellateAlexandrium minutum". Canadian Journal of Microbiology 55, nr 8 (sierpień 2009): 943–54. http://dx.doi.org/10.1139/w09-047.
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The purpose of the study was to determine if paralytic shellfish poisoning (PSP) toxins are present in extracellular bacteria isolated from a toxic strain of the dinoflagellate Alexandrium minutum . A quantitative analysis was carried out of viable culturable bacteria attached to the surface of dinoflagellates and of bacteria present in dinoflagellate culture medium. A numerical taxonomy study was undertaken for presumptive identification of bacteria attached to the surface of dinoflagellates. Members of the following genera were detected on the cell surface of A. minutum: Cellulophaga , Marinomonas , Pseudoalteromonas , and Vibrio . The presence of intracellular PSP toxins in bacteria isolated from the cell surface of dinoflagellates was analysed by high-performance liquid chromatography with fluorescence detection (HPLC–FLD). Compounds that eluted at the same time as the standards of the PSP toxins GTX-2, GTX-3, GTX-4, dcGTX-2, and dcGTX-3 were present in some of the bacterial cell extracts. Natural fluorescent bacterial compounds, coeluting with some PSP toxins, were also detected. The results obtained showed that the fluorescent compounds, identified as putative PSP toxins by HPLC–FLD, did not correspond to any PSP analogue. This allowed us to reject the hypothesis that extracellular bacteria attached to the surface of dinoflagellates produce PSP toxins.
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Fulco, V. Karin. "Harmful effects of the toxic dinoflagellate Alexandrium tamarense on the tintinnids Favella taraikaensis and Eutintinnus sp." Journal of the Marine Biological Association of the United Kingdom 87, nr 5 (październik 2007): 1085–88. http://dx.doi.org/10.1017/s002531540705374x.
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The effects of the exposure of two tintinnids (Favella taraikaensis and Eutintinnus sp.) to the toxic dinoflagellate Alexandrium tamarense were studied, using the non-toxic dinoflagellate Scrippsiella trochoidea as a control. The tintinnid F. taraikaensis showed backward swimming and cellular lysis after a few minutes in the presence of the toxic dinoflagellate A. tamarense in high concentration (280–700 cells ml-1). At low concentrations of A. tamarense (30–120 cells ml-1) no swimming alterations were observed, but cellular lysis occurred after 48 hours. No changes in the swimming patterns were observed when Eutintinnus sp. was exposed to either toxic dinoflagellates or cell-free filtrate, or when F. taraikaensis was exposed to cell-free filtrate. However, both tintinnids suffered cellular lysis after 48 hours of exposure. Favella taraikaensis and Eutintinnus sp. remained healthy after preying on the non-toxic S. trochoidea for 48 hours. In selectivity experiments, F. taraikaensis avoided cells of the toxic dinoflagellates during the dark phase. Our results suggest that tintinnids could play a regulatory role when the toxic blooms are initiating and the toxic cell concentrations remain still low in the northern Patagonian gulfs of Argentina. Since tintinnids are affected by substances released by A. tamarense, predation on dinoflagellates would not occur during the peak of the bloom.
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Akbar, Muhamad Afiq, Nurul Yuziana Mohd Yusof, Noor Idayu Tahir, Asmat Ahmad, Gires Usup, Fathul Karim Sahrani i Hamidun Bunawan. "Biosynthesis of Saxitoxin in Marine Dinoflagellates: An Omics Perspective". Marine Drugs 18, nr 2 (5.02.2020): 103. http://dx.doi.org/10.3390/md18020103.
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Saxitoxin is an alkaloid neurotoxin originally isolated from the clam Saxidomus giganteus in 1957. This group of neurotoxins is produced by several species of freshwater cyanobacteria and marine dinoflagellates. The saxitoxin biosynthesis pathway was described for the first time in the 1980s and, since then, it was studied in more than seven cyanobacterial genera, comprising 26 genes that form a cluster ranging from 25.7 kb to 35 kb in sequence length. Due to the complexity of the genomic landscape, saxitoxin biosynthesis in dinoflagellates remains unknown. In order to reveal and understand the dynamics of the activity in such impressive unicellular organisms with a complex genome, a strategy that can carefully engage them in a systems view is necessary. Advances in omics technology (the collective tools of biological sciences) facilitated high-throughput studies of the genome, transcriptome, proteome, and metabolome of dinoflagellates. The omics approach was utilized to address saxitoxin-producing dinoflagellates in response to environmental stresses to improve understanding of dinoflagellates gene–environment interactions. Therefore, in this review, the progress in understanding dinoflagellate saxitoxin biosynthesis using an omics approach is emphasized. Further potential applications of metabolomics and genomics to unravel novel insights into saxitoxin biosynthesis in dinoflagellates are also reviewed.
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Deng, Yunyan, Fengting Li, Zhangxi Hu, Caixia Yue i Ying Zhong Tang. "The Implication Inferred from the Expression of Small Heat-Shock Protein Genes in Dinoflagellate Resting Cysts Buried in Marine Sediment". Diversity 13, nr 10 (27.09.2021): 471. http://dx.doi.org/10.3390/d13100471.
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Dinoflagellates are unicellular eukaryotic microalgae, occupying pivotal niches in aquatic ecosystems with great ecological, biological, and economic significance. Small heat shock proteins (sHsps) are the most omnipresent, but the least conserved, family of molecular chaperones found in all domains of life. Although their common name (small Hsp) implies to exclusively stress their heat shock-responsive function, many sHsps in fact engage in a variety of physiological processes, from cell growth and proliferation to embryogenesis, development, differentiation, apoptosis, and even to human disease prevention. Recent years have greatly expanded our understanding of sHsps in higher plants; however, comprehensive study aiming to delineate the composition and expression pattern of dinoflagellate sHsp gene family has not yet been performed. In this study, we constructed dinoflagellate-specific environmental cDNA library from marine sediment and sequenced using the third-generation sequencing technique. Screening of sHsp genes from the library returned 13 entries with complete coding regions, which were considered to be transcriptionally activated in the natural community of dinoflagellate resting cysts. All the 13 dinoflagellate sHsps consisted of a solely characteristic α-crystallin domain, covering 88–123 amino acid residues with the typical A-X-X-X-N-G-V-L motif, flanked by variable N- and C-terminal extensions. Multiple alignment revealed considerable amino acid divergence (~26.7% average similarity) among them. An unexpected close relationship was revealed between dinoflagellate and green algal sHsps in the phylogenetic tree, seemingly reflecting a close evolutionary relationship of these sHsps themselves. We confirmed that sHsp mRNAs are expressed during dormancy of the resting cyst assemblages of dinoflagellates that were buried in marine sediment, which raised the possibility that the sHsp expression is part of the machinery of maintaining the dormancy or/and the adaptation to ambient conditions of dinoflagellate resting cysts. Our results, although preliminary, gained an important glance on the universal presence of sHsps in dinoflagellates and their active expressions in the assemblage of resting cysts that were buried in the marine sediment. The essentiality of sHsps functioning in resting cysts necessitate more intensive and extensive investigations on all possible functions of Hsps in dinoflagellates, a group of protists with vital ecological and biological importance.
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Godhe, Anna, Maria E. Asplund, Karolina Härnström, V. Saravanan, Anuj Tyagi i Indrani Karunasagar. "Quantification of Diatom and Dinoflagellate Biomasses in Coastal Marine Seawater Samples by Real-Time PCR". Applied and Environmental Microbiology 74, nr 23 (10.10.2008): 7174–82. http://dx.doi.org/10.1128/aem.01298-08.
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ABSTRACT Two real-time PCR assays targeting the small-subunit (SSU) ribosomal DNA (rDNA) were designed to assess the proportional biomass of diatoms and dinoflagellates in marine coastal water. The reverse primer for the diatom assay was designed to be class specific, and the dinoflagellate-specific reverse primer was obtained from the literature. For both targets, we used universal eukaryotic SSU rDNA forward primers. Specificity was confirmed by using a BLAST search and by amplification of cultures of various phytoplankton taxa. Reaction conditions were optimized for each primer set with linearized plasmids from cloned SSU rDNA fragments. The number of SSU rDNA copies per cell was estimated for six species of diatoms and nine species of dinoflagellates; these were significantly correlated to the biovolumes of the cells. Nineteen field samples were collected along the Swedish west coast and subjected to the two real-time PCR assays. The linear regression of the proportion of SSU rDNA copies of dinoflagellate and diatom origin versus the proportion of dinoflagellate and diatom biovolumes or biomass per liter was significant. For diatoms, linear regression of the number of SSU rDNA copies versus biovolume or biomass per liter was significant, but no such significant correlation was detected in the field samples for dinoflagellates. The method described will be useful for estimating the proportion of dinoflagellate versus diatom biovolume or biomass and the absolute diatom biovolume or biomass in various aquatic disciplines.
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Frommlet, Jörg C., Maria L. Sousa, Artur Alves, Sandra I. Vieira, David J. Suggett i João Serôdio. "Coral symbiotic algae calcifyex hospitein partnership with bacteria". Proceedings of the National Academy of Sciences 112, nr 19 (27.04.2015): 6158–63. http://dx.doi.org/10.1073/pnas.1420991112.
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Dinoflagellates of the genusSymbiodiniumare commonly recognized as invertebrate endosymbionts that are of central importance for the functioning of coral reef ecosystems. However, the endosymbiotic phase withinSymbiodiniumlife history is inherently tied to a more cryptic free-living (ex hospite) phase that remains largely unexplored. Here we show that free-livingSymbiodiniumspp. in culture commonly form calcifying bacterial–algal communities that produce aragonitic spherulites and encase the dinoflagellates as endolithic cells. This process is driven bySymbiodiniumphotosynthesis but occurs only in partnership with bacteria. Our findings not only place dinoflagellates on the map of microbial–algal organomineralization processes but also point toward an endolithic phase in theSymbiodiniumlife history, a phenomenon that may provide new perspectives on the biology and ecology ofSymbiodiniumspp. and the evolutionary history of the coral–dinoflagellate symbiosis.
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Bi, Wang i Zhang. "Omics Analysis for Dinoflagellates Biology Research". Microorganisms 7, nr 9 (23.08.2019): 288. http://dx.doi.org/10.3390/microorganisms7090288.
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Dinoflagellates are important primary producers for marine ecosystems and are also responsible for certain essential components in human foods. However, they are also notorious for their ability to form harmful algal blooms, and cause shellfish poisoning. Although much work has been devoted to dinoflagellates in recent decades, our understanding of them at a molecular level is still limited owing to some of their challenging biological properties, such as large genome size, permanently condensed liquid-crystalline chromosomes, and the 10-fold lower ratio of protein to DNA than other eukaryotic species. In recent years, omics technologies, such as genomics, transcriptomics, proteomics, and metabolomics, have been applied to the study of marine dinoflagellates and have uncovered many new physiological and metabolic characteristics of dinoflagellates. In this article, we review recent application of omics technologies in revealing some of the unusual features of dinoflagellate genomes and molecular mechanisms relevant to their biology, including the mechanism of harmful algal bloom formations, toxin biosynthesis, symbiosis, lipid biosynthesis, as well as species identification and evolution. We also discuss the challenges and provide prospective further study directions and applications of dinoflagellates.
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Boisnoir, Aurélie, Pierre-Yves Pascal, Sophie Marro i Rodolphe Lémée. "First spatial distribution of potentially toxic benthic dinoflagellates in the Lesser Antilles (Guadeloupe and Martinique), Caribbean Sea". Botanica Marina 62, nr 4 (27.08.2019): 309–22. http://dx.doi.org/10.1515/bot-2018-0002.
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Abstract For the first time, distribution and abundances (cells per gram of fresh macrophyte weight) of potentially toxic benthic dinoflagellates were studied around Guadeloupe (20 sites) and Martinique (six sites) islands (Lesser Antilles, Caribbean Sea). Benthic dinoflagellates were identified at the genus level and cell counts were undertaken on different host species of macroalgae and seagrasses. Abundance values of potentially toxic benthic dinoflagellates were one order of magnitude higher in Guadeloupe than in Martinique. The highest abundances of benthic dinoflagellates were found in the northern part of Guadeloupe Island, while their distribution was more homogeneous in Martinique. Ostreopsis was the dominant genus in Guadeloupe and Martinique. Regarding biotic substrate preferences, Phaeophyceae hosted the highest total abundances of benthic dinoflagellates on both islands, while the lowest total abundances were observed on Ulvophyceae in Guadeloupe and Florideophyceae in Martinique. The genus Gambierdiscus, known as the causal agent of the ciguatera fish poisoning (CFP), developed on all macrophyte groups on both islands without showing any preferences towards biotic substrates. The presence of this potentially harmful dinoflagellate genus in both islands could explain the existence of local cases of CFP in Guadeloupe and Martinique islands.
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Hwang, Jinik, Hee Woong Kang, Seung Joo Moon, Jun-Ho Hyung, Eun Sun Lee i Jaeyeon Park. "Metagenomic Analysis of the Species Composition and Seasonal Distribution of Marine Dinoflagellate Communities in Four Korean Coastal Regions". Microorganisms 10, nr 7 (19.07.2022): 1459. http://dx.doi.org/10.3390/microorganisms10071459.
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Biomonitoring of dinoflagellate communities in marine ecosystems is essential for efficient water quality management and limiting ecosystem disturbances. Current identification and monitoring of toxic dinoflagellates, which cause harmful algal blooms, primarily involves light or scanning electron microscopy; however, these techniques are limited in their ability to monitor dinoflagellates and plankton, leaving an incomplete analysis. In this study, we analyzed the species composition and seasonal distribution of the dinoflagellate communities in four Korean coastal regions using 18S rRNA amplicon sequencing. The results showed significantly high diversity in the dinoflagellate communities in all regions and seasons. Furthermore, we found seasonally dominant species and causative species of harmful algal blooms (Cochlodinium sp., Alexandrium sp., Dinophysis sp., and Gymnodinium sp.). Moreover, dominant species were classified by region and season according to the difference in geographical and environmental parameters. The molecular analysis of the dinoflagellate community based on metagenomics revealed more diverse species compositions that could not be identified by microscopy and revealed potentially harmful or recently introduced dinoflagellate species. In conclusion, metagenomic analysis of dinoflagellate communities was more precise and obtained results faster than microscopic analysis, and could improve the existing monitoring techniques for community analysis.
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Chen, Antony K., Michael I. Latz, Peter Sobolewski i John A. Frangos. "Evidence for the role of G-proteins in flow stimulation of dinoflagellate bioluminescence". American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 292, nr 5 (maj 2007): R2020—R2027. http://dx.doi.org/10.1152/ajpregu.00649.2006.
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Luminescent dinoflagellates respond to flow by the production of light. The primary mechanotransduction event is unknown, although downstream events include a calcium flux in the cytoplasm, a self-propagating action potential across the vacuole membrane, and a proton flux into the cytoplasm that activates the luminescent chemistry. Given the role of GTP-binding (G) proteins in the mechanotransduction of flow by nonmarine cells and the presence of G-proteins in dinoflagellates, it was hypothesized that flow-stimulated dinoflagellate bioluminescence involves mechanotransduction by G-proteins. In the present study, osmotic swelling of cells of the dinoflagellate Lingulodinium polyedrum was used as a drug delivery system to introduce GDPβS, an inhibitor of G-protein activation. Osmotically swollen cells produced higher levels of flow-stimulated bioluminescence at a lower threshold of shear stress, indicating they were more flow sensitive. GDPβS inhibited flow-stimulated bioluminescence in osmotically swollen cells and in cells that were restored to the isosmotic condition following hypoosmotic treatment with GDPβS. These results provide evidence that G-proteins are involved in the mechanotransduction of flow in dinoflagellates and suggest that G-protein involvement in mechanotransduction may be a fundamental evolutionary adaptation.
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Reñé, A., M. Hoppenrath, G. Reboul, D. Moreira i P. López-García. "Composition and temporal dynamics of sand-dwelling dinoflagellate communities from three Mediterranean beaches". Aquatic Microbial Ecology 86 (8.04.2021): 85–98. http://dx.doi.org/10.3354/ame01960.
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Compared to plankton, benthic communities are thought to be heterogeneous among sites and more stable through time; however, benthic protists in general, and sand-dwelling dinoflagellates in particular, have been scarcely studied, and their diversity remains mostly unknown. To test those claims, we studied the diversity, structure and temporal dynamics of benthic dinoflagellate communities in sandy sediments obtained from 3 NW Mediterranean Sea coastal locations during temperate spring and warm summer months. After separating protist cells from the substrate using the seawater-ice method, high-throughput amplicon sequencing of the V4 18S rRNA gene region followed by the analysis of amplicon sequence variants (ASVs) showed similar richness, alpha-diversity, and community composition among sand-dwelling dinoflagellates at the 3 locations. Dinoflagellates affiliating with the Thoracosphaeraceae or Gymnodiniales sensu stricto were highly represented. In contrast, other well-known dinoflagellate taxa, such as Gonyaulacales or Dinophysales, were poorly represented or absent. Dinoflagellate communities showed significant differences between the 2 studied seasons, mainly driven by water temperature. Samples from temperate months had higher diversity and were more dissimilar, while samples from warmer months showed lower diversity and higher similarity. Some species were always present in the community, others only appeared sporadically, and some others showed clear differences between seasons. Our results suggest that large-scale changes (pointing to seasonality) prevail over spatial heterogeneity in shaping community composition. The 3 studied locations had a similar dinoflagellate community composed of sand-dwelling taxa, with many representatives of undescribed species, highlighting the need to further study the diversity of the benthic compartment.
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Wang, Yanfei, i Kathryn J. Coyne. "Metabolomic Insights of the Effects of Bacterial Algicide IRI-160AA on Dinoflagellate Karlodinium veneficum". Metabolites 12, nr 4 (1.04.2022): 317. http://dx.doi.org/10.3390/metabo12040317.
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Shewanella sp. IRI-160 is an algicidal bacterium that secretes an algicide, IRI-160AA. This algicide specifically targets dinoflagellates, while having no adverse effects on other algal species tested. Dinoflagellates exposed to IRI-160AA exhibited increased production of reactive oxygen species (ROS), DNA damage, and cell cycle arrest, implying a programmed pathway leading to cell death (PCD). Here, a metabolomic analysis was conducted on dinoflagellate Karlodinium veneficum and a control cryptophyte species Rhodomonas exposed to IRI-160AA to investigate the cellular mechanisms behind the physiological effects and the specificity of this algicide. Results of this research supported previous observations about physiological responses to the algicide. A suite of metabolites was identified that increased in the cell pellets of K. veneficum but not in Rhodomonas, including oxidative stress biomarkers, antioxidants, and compounds involved in DNA damage and PCD. Overall, the results of this study illustrated the metabolomic mechanisms underlying the algicidal effects of IRI-160AA on dinoflagellates. This research also provided insights and future directions for studies on the cellular response of dinoflagellates exposed to antagonistic bacteria in the environment.
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Gómez, Fernando, i Alf Skovgaard. "A Parasite of Marine Rotifers: A New Lineage of Dinokaryotic Dinoflagellates (Dinophyceae)". Journal of Marine Biology 2015 (2015): 1–5. http://dx.doi.org/10.1155/2015/614609.
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Dinoflagellate infections have been reported for different protistan and animal hosts. We report, for the first time, the association between a dinoflagellate parasite and a rotifer host, tentativelySynchaetasp. (Rotifera), collected from the port of Valencia, NW Mediterranean Sea. The rotifer contained a sporangium with 100–200 thecate dinospores that develop synchronically through palintomic sporogenesis. This undescribed dinoflagellate forms a new and divergent fast-evolved lineage that branches among the dinokaryotic dinoflagellates.
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Linacre, Lorena, Citlalli Sánchez-Robles, Uriel Mirabal-Gómez, J. Rubén Lara-Lara i Carmen Bazán-Guzmán. "Cell carbon content and biomass assessments of dinoflagellates and diatoms in the oceanic ecosystem of the Southern Gulf of Mexico". PLOS ONE 16, nr 2 (17.02.2021): e0247071. http://dx.doi.org/10.1371/journal.pone.0247071.
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This study assessed the cell carbon content and biomass for genera of dinoflagellates and diatoms in the oceanic ecosystem of the Southern Gulf of Mexico. Carbon content estimates were based on biovolume calculations derived from linear dimension measurements of individual cells and the approximate geometric body shape of each genus. Then, biomass assessments were performed for both groups in two gulf regions (Perdido and Coatzacoalcos) using these carbon content factors and cell abundances. After four seasonal cruises, 11,817 cells of dinoflagellates and 3,412 cells of diatoms were analyzed. Diverse body shapes and cell sizes were observed among 46 dinoflagellate genera and 37 diatom genera. Nano-cells of dinoflagellates (68% <20 μm) and micro-cells of diatoms (77% 20–200 μm, mostly 50–75 μm) were predominant. According to this cell-size structure, on average, diatoms contained 40% more carbon per cell than dinoflagellates. Contrasting carbon content estimates were observed within the genera of both microalgae. Large carbon averages (>10,000 pg C cell-1) were attributed to Gonyaulacal and some occasional genera of dinoflagellates (e.g., Pyrocystis and Noctiluca) and centric diatoms. In contrast, values up to 3 orders of magnitude lower were found for Peridinial and Gymnodinial dinoflagellates and pennate diatoms. Based on these carbon content estimates, which can be considered representative for most of this oceanic ecosystem, seasonal and regional differences were found in the biomass assessments conducted for these functional groups. Overall, dinoflagellates (mostly low-carbon Gymnodinales) had larger depth-integrated biomass than diatoms (mainly rich-carbon centric forms) within the euphotic zone. An exception to it was the late-summer cruise at the Coatzacoalcos region when a surface bloom of centric diatoms was observed in stations influenced by river runoff. This work contributes useful reference information for future ecological studies and models for understanding the biogeochemical functioning of this open-ocean ecosystem.
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Dorrell, Richard G., i Christopher J. Howe. "Integration of plastids with their hosts: Lessons learned from dinoflagellates". Proceedings of the National Academy of Sciences 112, nr 33 (20.05.2015): 10247–54. http://dx.doi.org/10.1073/pnas.1421380112.
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After their endosymbiotic acquisition, plastids become intimately connected with the biology of their host. For example, genes essential for plastid function may be relocated from the genomes of plastids to the host nucleus, and pathways may evolve within the host to support the plastid. In this review, we consider the different degrees of integration observed in dinoflagellates and their associated plastids, which have been acquired through multiple different endosymbiotic events. Most dinoflagellate species possess plastids that contain the pigment peridinin and show extreme reduction and integration with the host biology. In some species, these plastids have been replaced through serial endosymbiosis with plastids derived from a different phylogenetic derivation, of which some have become intimately connected with the biology of the host whereas others have not. We discuss in particular the evolution of the fucoxanthin-containing dinoflagellates, which have adapted pathways retained from the ancestral peridinin plastid symbiosis for transcript processing in their current, serially acquired plastids. Finally, we consider why such a diversity of different degrees of integration between host and plastid is observed in different dinoflagellates and how dinoflagellates may thus inform our broader understanding of plastid evolution and function.
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Perin, Luíza S., Gabriela V. Moraes, Gabriela A. Galeazzo i Anderson G. Oliveira. "Bioluminescent Dinoflagellates as a Bioassay for Toxicity Assessment". International Journal of Molecular Sciences 23, nr 21 (27.10.2022): 13012. http://dx.doi.org/10.3390/ijms232113012.
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Dinoflagellates bioluminescence mechanism depends upon a luciferin–luciferase reaction that promotes blue light emission (480 nm) in specialized luminogenic organelles called scintillons. The scintillons contain luciferin, luciferase and, in some cases, a luciferin-binding protein (LBP), which prevents luciferin from non-enzymatic oxidation in vivo. Even though dinoflagellate bioluminescence has been studied since the 1950s, there is still a lack of mechanistic understanding on whether the light emission process involves a peroxidic intermediate or not. Still, bioassays employing luminous dinoflagellates, usually from Gonyaulax or Pyrocystis genus, can be used to assess the toxicity of metals or organic compounds. In these dinoflagellates, the response to toxicity is observed as a change in luminescence, which is linked to cellular respiration. As a result, these changes can be used to calculate a percentage of light inhibition that correlates directly with toxicity. This current approach, which lies in between fast bacterial assays and more complex toxicity tests involving vertebrates and invertebrates, can provide a valuable tool for detecting certain pollutants, e.g., metals, in marine sediment and seawater. Thus, the present review focuses on how the dinoflagellates bioluminescence can be applied to evaluate the risks caused by contaminants in the marine environment.
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Head, Martin J. "Dinoflagellates, Sporomorphs, and Other Palynomorphs from the Upper Pliocene St. Erth Beds of Cornwall, Southwestern England". Journal of Paleontology 67, S31 (maj 1993): 1–62. http://dx.doi.org/10.1017/s0022336000061126.
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Palynological analysis of the highly fossiliferous marine clays of the St. Erth Beds of Cornwall has revealed the presence of dinoflagellates, acritarchs and prasinophytes, scolecodonts, microforaminiferal linings, freshwater? invertebrates, freshwater algal spores, embryophyte spores and pollen, fungal spores, and plant cuticles. These groups are documented here and several, including the dinoflagellates, are reported from the St. Erth Beds for the first time.The marine clays were deposited in warm, shallow waters of an inlet or embayment during a probable high stand in sea level. They are generally held to be of late Pliocene age, planktonic foraminiferal evidence placing them at between 1.9 and 2.1 Ma (late late Pliocene). Dinoflagellates are consistent with a late Pliocene age. Spores and pollen, if not reworked, suggest placement no higher than the lower part of the Tiglian Stage (upper Pliocene) of The Netherlands.Analysis of all palynological groups permits terrestrial and marine climates to be evaluated independently. The spore-pollen assemblage has some thermophilic elements but mainly reflects a cool-temperate terrestrial climate. In contrast, dinoflagellates—dominated by gymnodinialean? and protoperidinioid cysts—indicate warm inner neritic waters and present some evidence for subtropical to tropical conditions with winter sea-surface temperatures above 15°. Increased influence of the Gulf Stream during the late Pliocene, perhaps superimposed upon a phase of global warming, is hypothesized to explain these differentially elevated marine temperatures.The St. Erth inlet was not markedly brackish or hypersaline judging from the dinoflagellates, but rare freshwater algal spores attest either to some freshwater input or redeposition from sandy soils during marine incursion. High abundance of scolecodonts, about 1,500 to 2,000 per gram dry weight of sediment, allows speculation that the inlet hosted a thriving association of latest Pliocene marine annelid worms.A species of algae incertae sedis,Halodinium scopaeum, and three species of dinoflagellate,Algidasphaeridium?euaxum, Sumatradinium pliocenicum, andTrinovantedinium sterthense, are proposed as new. The dinoflagellate genusSelenopemphixBenedek, 1972, is emended herein.QuinquecuspisHarland, 1977, is now validated by the transfer ofTrinovantedinium concretumReid, 1978, toQuinquecuspisHarland, 1977, asQ. concretan. comb.
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Lin, Senjie, Huan Zhang, Yubo Hou, Yunyun Zhuang i Lilibeth Miranda. "High-Level Diversity of Dinoflagellates in the Natural Environment, Revealed by Assessment of Mitochondrial cox1 and cob Genes for Dinoflagellate DNA Barcoding". Applied and Environmental Microbiology 75, nr 5 (29.12.2008): 1279–90. http://dx.doi.org/10.1128/aem.01578-08.
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ABSTRACT DNA barcoding is a diagnostic technique for species identification using a short, standardized DNA. An effective DNA barcoding marker would be very helpful for unraveling the poorly understood species diversity of dinoflagellates in the natural environment. In this study, the potential utility for DNA barcoding of mitochondrial cytochrome c oxidase 1 (cox1) and cytochrome b (cob) was assessed. Among several primer sets examined, the one amplifying a 385-bp cob fragment was most effective for dinoflagellates. This short cob fragment is easy to sequence and yet possess reasonable taxon resolution. While the lack of a uniform gap between interspecific and intraspecific distances poses difficulties in establishing a phylum-wide species-discriminating distance threshold, the variability of cob allows recognition of species within particular lineages. The potential of this cob fragment as a dinoflagellate species marker was further tested by applying it to an analysis of the dinoflagellate assemblages in Long Island Sound (LIS) and Mirror Lake in Connecticut. In LIS, a highly diverse assemblage of dinoflagellates was detected. Some taxa can be identified to the species and some to the genus level, including a taxon distinctly related to the bipolar species Polarella glacialis, and the large number of others cannot be clearly identified, due to the inadequate database. In Mirror Lake, a Ceratium species and an unresolved taxon were detected, exhibiting a temporal transition from one to the other. We demonstrate that this 385-bp cob fragment is promising for lineage-wise dinoflagellate species identification, given an adequate database.
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Dodge, John D. "A Seasonal Analysis of the Armoured Dinoflagellates of Loch Eriboll, North Scotland". Journal of the Marine Biological Association of the United Kingdom 75, nr 1 (luty 1995): 219–33. http://dx.doi.org/10.1017/s0025315400015320.
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The armoured planktonic dinoflagellates present at a site adjacent to a floating fish-farm in Loch Eriboll, North Scotland, were studied by surface net-sampling, mainly at two-weekly intervals, over a period of four years 1990–1993. A total of 62 species was recorded. Some dinoflagellates were present at all times of the year but they reached their lowest numbers in May, during the spring diatom bloom, and their highest numbers in mid-summer. There was usually a seasonal pattern in which the most abundant dinoflagellate during the early summer was the heterotrophic species Protoperidinium ovatum, and this was followed in the later summer by the autotroph Ceratium fusus. In 1993 the pattern was rather different, with Gonyaulax species abundant in June and, later in the year, both Protoperidinium cerasus and P. excentricum having periods of abundance. Potential toxin-producing dinoflagellates, Alexandrium tamarense (PSP) and Dinophysis acuminata (DSP), were found in small numbers.
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Miller, Todd R., i Robert Belas. "Dimethylsulfoniopropionate Metabolism by Pfiesteria-Associated Roseobacter spp." Applied and Environmental Microbiology 70, nr 6 (czerwiec 2004): 3383–91. http://dx.doi.org/10.1128/aem.70.6.3383-3391.2004.
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ABSTRACT The Roseobacter clade of marine bacteria is often found associated with dinoflagellates, one of the major producers of dimethylsulfoniopropionate (DMSP). In this study, we tested the hypothesis that Roseobacter species have developed a physiological relationship with DMSP-producing dinoflagellates mediated by the metabolism of DMSP. DMSP was measured in Pfiesteria and Pfiesteria-like (Cryptoperidiniopsis) dinoflagellates, and the identities and metabolic potentials of the associated Roseobacter species to degrade DMSP were determined. Both Pfiesteria piscicida and Pfiesteria shumwayae produce DMSP with an average intracellular concentration of 3.8 μM. Cultures of P. piscicida or Cryptoperidiniopsis sp. that included both the dinoflagellates and their associated bacteria rapidly catabolized 200 μM DMSP (within 30 h), and the rate of catabolism was much higher for P. piscicida cultures than for P. shumwayae cultures. The community of bacteria from P. piscicida and Cryptoperidiniopsis cultures degraded DMSP with the production of dimethylsulfide (DMS) and acrylate, followed by 3-methylmercaptopropionate (MMPA) and methanethiol (MeSH). Four DMSP-degrading bacteria were isolated from the P. piscicida cultures and found to be taxonomically related to Roseobacter species. All four isolates produced MMPA from DMSP. Two of the strains also produced MeSH and DMS, indicating that they are capable of utilizing both the lyase and demethylation pathways. The diverse metabolism of DMSP by the dinoflagellate-associated Roseobacter spp. offers evidence consistent with a hypothesis that these bacteria benefit from association with DMSP-producing dinoflagellates.
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Riding, James B., Robert A. Fensome, Marie-Odile Soyer-Gobillard i Linda K. Medlin. "A Review of the Dinoflagellates and Their Evolution from Fossils to Modern". Journal of Marine Science and Engineering 11, nr 1 (20.12.2022): 1. http://dx.doi.org/10.3390/jmse11010001.
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Molecular clock and biogeochemical evidence indicate that the dinoflagellate lineage diverged at around 650 Ma. Unequivocal dinoflagellate cysts/zygotes appeared during the Triassic. These biotas were badly affected by the end-Triassic extinction and recovery from this was relatively slow. During the early Middle Jurassic, the family Gonyaulacaceae underwent an explosive diversification event and taxonomic richness steadily increased throughout the rest of the Jurassic. The entire Cretaceous also recorded increases in diversity. This trend reversed during the Oligocene, probably caused by global cooling. Marine cyst-forming peridiniaceans declined substantially through the Oligocene and Neogene, but protoperidiniaceans continued to diversify. Modern taxa, as evidenced by the molecular tree, comprise three major clades: the first two are composed largely of parasitic forms, marine alveolates of unknown identity and the Syndiniales; free-living dinoflagellates form the third clade, which diverges rapidly and bears short branch lengths with no real support for branching order. This suggests that morphological divergence preceded molecular divergence because, as the fossil record indicates, major groups appeared at different ages. Unique features of the dinoflagellates helped the group take on a predominant role in the marine phytoplankton. Living in marine or fresh water, dinoflagellates have demonstrated innovative capacities that have enabled them to live among the phytoplankton or benthos as autotrophic, heterotrophic, mixotrophic free-living organisms or symbiotic and/or as parasitic forms.
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McIntyre, David J. "Campanian to Paleocene dinoflagellate assemblages from the Turtle Mountain core hole, Manitoba, western Canada". Canadian Journal of Earth Sciences 36, nr 5 (1.05.1999): 769–74. http://dx.doi.org/10.1139/e98-011.
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Dinoflagellate assemblages from the Turtle Mountain core hole provide evidence for the Paleocene age of the Turtle Mountain Formation and confirm that the Boissevain Formation and the Coulter Member of the Pierre Formation are Maastrichtian. Evidence from dinoflagellates suggests that the Odonah Member of the Pierre Formation is late Campanian. The dinoflagellate assemblages indicate that nearshore shallow marine conditions were present at times during deposition of all the formations.
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Orr, Russell J. S., Anke Stüken, Shauna A. Murray i Kjetill S. Jakobsen. "Evolutionary Acquisition and Loss of Saxitoxin Biosynthesis in Dinoflagellates: the Second “Core” Gene,sxtG". Applied and Environmental Microbiology 79, nr 7 (18.01.2013): 2128–36. http://dx.doi.org/10.1128/aem.03279-12.
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ABSTRACTSaxitoxin and its derivatives are potent neurotoxins produced by several cyanobacteria and dinoflagellate species. SxtA is the initial enzyme in the biosynthesis of saxitoxin. The dinoflagellate full mRNA and partial genomic sequences have previously been characterized, and it appears thatsxtAoriginated in dinoflagellates through a horizontal gene transfer from a bacterium. So far, little is known about the remaining genes involved in this pathway in dinoflagellates. Here we characterizesxtG, an amidinotransferase enzyme gene that putatively encodes the second step in saxitoxin biosynthesis. In this study, the entiresxtGtranscripts fromAlexandrium fundyenseCCMP1719 andAlexandrium minutumCCMP113 were amplified and sequenced. The transcripts contained typical dinoflagellate spliced leader sequences and eukaryotic poly(A) tails. In addition, partialsxtGtranscript fragments were amplified from four additionalAlexandriumspecies andGymnodinium catenatum. The phylogenetic inference of dinoflagellatesxtG, congruent withsxtA, revealed a bacterial origin. However, it is not known ifsxtGwas acquired independently ofsxtA. Amplification and sequencing of the corresponding genomicsxtGregion revealed noncanonical introns. These introns show a high interspecies and low intraspecies variance, suggesting multiple independent acquisitions and losses. UnlikesxtA,sxtGwas also amplified fromAlexandriumspecies not known to synthesize saxitoxin. However, amplification was not observed for 22 non-saxitoxin-producing dinoflagellate species other than those of the genusAlexandriumorG. catenatum. This result strengthens our hypothesis that saxitoxin synthesis has been secondarily lost in conjunction withsxtAfor some descendant species.
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Buckland-Nicks, J., D. J. Garbary i T. E. Reimchen. "Haidadinium ichthyophilum gen.nov. et sp.nov. (Phytodiniales, Dinophyceae), a freshwater ectoparasite on stickleback (Gastetosteus aculeatus) from the Queen Charlotte Islands, Canada". Canadian Journal of Botany 75, nr 11 (1.11.1997): 1936–40. http://dx.doi.org/10.1139/b97-905.
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The dinoflagellate Haidadinium ichthyophilum gen.nov. et sp.nov. is associated with the threespine stickleback, Gasterosteus aculeatus L., in freshwater. This new genus differs from all previously described dinoflagellates in the morphology and ultrastructure of its complex life history stages and in the ecology of its interaction with G. aculeatus. Distinguishing characters included (i) the absence of thecal plates and the occurrence of chloroplastes in the short-lived swarmer (=dinospore) stage; (ii) the development of four distinct amoeboid stages including a spheroidal, rolling amoeba unknown in any other species; and (iii) the fact that this dinoflagellate causes epithelial hyperplasia in the stickleback and does not result in massive fish kills. Haidadinium ichthyophilum is known only from two acidic lakes in the Queen Charlotte Islands, British Columbia, Canada. Haidadinium is tentatively assigned to the family Phytodiniaceae of the order Phytodiniales. Key words: dinoflagellates, Dinophyceae, Gasterosteus, Haidadinium ichthyophilum gen.nov. et sp.nov., Queen Charlotte Islands, Phytodiniales, symbiosis, taxonomy, ultrastructure.
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Schiøler, Poul. "Dinoflagellate cysts and acritarchs from the Oligocene–Lower Miocene interval of the Alma-1X well, Danish North Sea". Journal of Micropalaeontology 24, nr 1 (1.05.2005): 1–37. http://dx.doi.org/10.1144/jm.24.1.1.
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Abstract. This palynological study of cuttings samples from the Lark Formation in the Danish North Sea well Alma-1X documents for the first time in the public domain the succession of last occurrences of dinoflagellate cysts and acritarchs in the Oligocene–Lower Miocene interval of the Central North Sea. The distribution of dinoflagellates and acritarchs in the well demonstrates the potential for the development of a detailed subdivision of the Oligocene–Lower Miocene in the Central North Sea, based on the first downhole occurrences of key taxa. Five regional intra-Lark Formation seismic and petrophysical log markers can be dated with precision using dinoflagellate biostratigraphy. Four new species and one new subspecies of dinoflagellates are described from the study interval: Amphorosphaeridium? almae sp. nov., Filisphaera pachyderma sp. nov., Pentadinium corium sp. nov., Spiniferites pseudofurcatus verrucosus ssp. nov. and Thalassiphora rota sp. nov. Pseudospiniferites manumii Lund, 2002 is emended and transferred to the genus Spiniferites.
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Thomsen, E., i C. Heilmann Clausen. "The Danian-Selandian boundary at Svejstrup with remarks on the biostratigraphy of the boundary in western Denmark". Bulletin of the Geological Society of Denmark 33 (28.02.1985): 341–62. http://dx.doi.org/10.37570/bgsd-1984-33-28.
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The Danian-Selandian boundary at Svejstrup is characterized by an abrupt facies change from a pure limestone to a terrigeneous marl. The top of the Danian limestone is an intensively burrowed abrasion surface. The Sel:indian deposits are initiated by a conglomerate of glauconitized and phosphatized limestone pebbles. Although the boundary at Svejstrup is very similar to the nearby section at Hvalklse, the time interval included in the hiatus at Svejstrup is greater than at Hvall0se. The coccoliths and dinoflagellates indicate different ages for the top of the Danian. It is also shown that the Danian sequences in the Harre and the Viborg 1 borings include strata younger than in any previously described Danian sections. At both of these localities a number of coccoliths and a dinoflagellate, Spinidinium densispinatum, hitherto only recorded from the Selandian, occur in the Danian limestone. The top of the Danian at Harre and Viborg 1 is of upper NP4 or lower NP5 age. The calcareous nannofossils of the lower Selandian are completely dominated by reworked Cretaceous forms, whereas reworked dinoflagellates are extremely rare. This difference is probably due to oxidation of the Cretaceous dinoflagellates during reworking. Two new species of dinoflagellates from the Paleocene are described.
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Dale, Barrie. "Paleontological Evidence for Dinoflagellates and Ciliates as Early Eukaryotes". Journal of Marine Science and Engineering 11, nr 3 (28.02.2023): 533. http://dx.doi.org/10.3390/jmse11030533.
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Molecular trees and geochemical markers suggest the divergence of dinoflagellates as early eukaryotes (~650 million years ago), but the traditional fossil record of cysts (dinocysts) starts during the Triassic (~230 million years ago). A re-evaluation of the pre-Triassic record shows that many acritarchs (microfossils of uncertain affinities) are dinocysts representing “missing” fossil evidence. Traditional diagnostic criteria for dinocysts, based on morphologic comparisons with motile stages, are biased towards thecate species. The approach proposed here, based on the more natural comparison with living cysts, includes athecate species. Many living cysts of athecate species would be “acritarchs” if found as fossils, and many earlier acritarchs would be accepted as dinoflagellate cysts if found living. The earliest acritarchs represent an innovation with profound implications for evolution: a cell wall of sporopollenin-like material enabling survival from microbial attack, in a then microbial-dominated world. Related cell wall material most likely evolved as protection for crucial stages in sexual reproduction (e.g., cysts in ciliates and dinoflagellates, and spores and pollen in algae and plants). Ciliates and dinoflagellates may have evolved in response to extreme climatic conditions in the Cryogenian, where a robust resting cyst would be advantageous. Thecate dinoflagellates most likely evolved from athecate forms, possibly in response to predatory pressure.
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Wang, Da-Zhi, Cheng Li, Zhang-Xian Xie, Hong-Po Dong, Lin Lin i Hua-Sheng Hong. "Homology-Driven Proteomics of Dinoflagellates with Unsequenced Genomes Using MALDI-TOF/TOF and AutomatedDe NovoSequencing". Evidence-Based Complementary and Alternative Medicine 2011 (2011): 1–16. http://dx.doi.org/10.1155/2011/471020.
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This study developed a multilayered, gel-based, and underivatized strategy forde novoprotein sequence analysis of unsequenced dinoflagellates using a MALDI-TOF/TOF mass spectrometer with the assistance of DeNovo Explorer software. MASCOT was applied as the first layer screen to identify either known or unknown proteins sharing identical peptides presented in a database. Once the confident identifications were removed after searching against the NCBInr database, the remainder was searched against the dinoflagellate expressed sequence tag database. In the last layer, those borderline and nonconfident hits were further subjected tode novointerpretation using DeNovo Explorer software. Thede novosequences passing a reliability filter were subsequently submitted to nonredundant MS-BLAST search. Using this layer identification method, 216 protein spots representing 158 unique proteins out of 220 selected protein spots fromAlexandrium tamarense, a dinoflagellate with unsequenced genome, were confidently or tentatively identified by database searching. These proteins were involved in various intracellular physiological activities. This study is the first effort to develop a completely automated approach to identify proteins from unsequenced dinoflagellate databases and establishes a preliminary protein database for various physiological studies of dinoflagellates in the future.
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Haq, Saddef, Benjamin L. Oyler, Ernest Williams, Mohd M. Khan, David R. Goodlett, Tsvetan Bachvaroff i Allen R. Place. "Investigating A Multi-Domain Polyketide Synthase in Amphidinium carterae". Marine Drugs 21, nr 8 (27.07.2023): 425. http://dx.doi.org/10.3390/md21080425.
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Dinoflagellates are unicellular organisms that are implicated in harmful algal blooms (HABs) caused by potent toxins that are produced through polyketide synthase (PKS) pathways. However, the exact mechanisms of toxin synthesis are unknown due to a lack of genomic segregation of fat, toxins, and other PKS-based pathways. To better understand the underlying mechanisms, the actions and expression of the PKS proteins were investigated using the toxic dinoflagellate Amphidinium carterae as a model. Cerulenin, a known ketosynthase inhibitor, was shown to reduce acetate incorporation into all fat classes with the toxins amphidinol and sulpho-amphidinol. The mass spectrometry analysis of cerulenin-reacted synthetic peptides derived from ketosynthase domains of A. carterae multimodular PKS transcripts demonstrated a strong covalent bond that could be localized using collision-induced dissociation. One multi-modular PKS sequence present in all dinoflagellates surveyed to date was found to lack an AT domain in toxin-producing species, indicating trans-acting domains, and was shown by Western blotting to be post-transcriptionally processed. These results demonstrate how toxin synthesis in dinoflagellates can be differentiated from fat synthesis despite common underlying pathway.
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Bryantseva, Yu V. "Current information on the diversity of dinoflagellates of Ukraine". Algologia 32, nr 1 (marzec 2022): 53–67. http://dx.doi.org/10.15407/alg32.01.053.
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Present current information on the diversity of Dinoflagellata in Ukraine. The study of the species composition of microalgae in modern climate change remains relevant. Dinoflagellates, especially luminous species, are sensitive to anomalies in the warm Black Sea and can serve as a convenient indicator of the state of aquatic ecosystems due to the rapid response to external influences. The use of electron microscopy, as well as molecular genetic research methods over the past 10 years have made it possible to observe significant changes in the taxonomic system of the Miozoa division of the superclass Dinoflagellata. Based on the analysis of 204 literature sources and revision of the taxonomic composition of dinoflagellates of Ukraine, according to the international database AlgaeBase, it is established that the current list of Dinoflagellates of Ukraine includes 370 species (397 watts), belonging to 3 classes, 14 orders, 45 families and 98 genera. The number of species found in Ukraine is an order of magnitude lower than that currently known for Miozoa in the world (3636), and their distribution by order almost coincides and is very uneven: 3 orders include 63% of currently known species and 71% found in Ukraine. The most diverse in Ukraine are the orders Peridiniales (121 species, 32.4%), Gymnodiniales (82, 22%) and Gonyaulacales (61, 16.4%). Analysis of the distribution of dinoflagellates in the territorial waters of Ukraine by main algae-floristic areas confirmed that most of them live in marine waters (273, 55%), which is twice as large as terrestrial (128, 26%) and a significant proportion occurs in estuaries – 92, 19%). Among the species found on land, the largest number is attributed to the Dnieper–Black Sea (108 taxa) and Carpathian-Danube algae sub-provinces (71) due to the fact that they include contact zones of the main rivers of Ukraine and the Black Sea–Azov waters. Over the last decade, the species composition of dinoflagellates of Ukraine and their taxonomy have undergone significant changes. The number of species, orders and genera has increased, but as a result of the fact that some species have been renamed, the actual number of new species and WWT has increased by 85 units and one species has been described as new to science. But the species diversity of some dinoflagellates regions of Ukraine remains insufficiently studied, and some of them require additional research.
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Bravo, Isabel, Francisco Rodríguez, Isabel Ramilo i Julio Afonso-Carrillo. "Epibenthic Harmful Marine Dinoflagellates from Fuerteventura (Canary Islands), with Special Reference to the Ciguatoxin-Producing Gambierdiscus". Journal of Marine Science and Engineering 8, nr 11 (12.11.2020): 909. http://dx.doi.org/10.3390/jmse8110909.
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The relationship between the ciguatoxin-producer benthic dinoflagellate Gambierdiscus and other epibenthic dinoflagellates in the Canary Islands was examined in macrophyte samples obtained from two locations of Fuerteventura Island in September 2016. The genera examined included Coolia, Gambierdiscus, Ostreopsis, Prorocentrum, Scrippsiella, Sinophysis, and Vulcanodinium. Distinct assemblages among these benthic dinoflagellates and preferential macroalgal communities were observed. Vulcanodinium showed the highest cell concentrations (81.6 × 103 cells gr−1 wet weight macrophyte), followed by Ostreopsis (25.2 × 103 cells gr−1 wet weight macrophyte). These two species were most represented at a station (Playitas) characterized by turfy Rhodophytes. In turn, Gambierdiscus (3.8 × 103 cells gr−1 wet weight macrophyte) and Sinophysis (2.6 × 103 cells gr−1 wet weight macrophyte) were mostly found in a second station (Cotillo) dominated by Rhodophytes and Phaeophytes. The influence of macrophyte’s thallus architecture on the abundance of dinoflagellates was observed. Filamentous morphotypes followed by macroalgae arranged in entangled clumps presented more richness of epiphytic dinoflagellates. Morphometric analysis was applied to Gambierdiscus specimens. By large, G. excentricus was the most abundant species and G. australes occupied the second place. The toxigenic potential of some of the genera/species distributed in the benthic habitats of the Canary coasts, together with the already known presence of ciguatera in the region, merits future studies on possible transmission of their toxins in the marine food chain.
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Zhang, Shu-Fei, Yong Zhang, Lin Lin i Da-Zhi Wang. "iTRAQ-Based Quantitative Proteomic Analysis of a Toxigenic Dinoflagellate Alexandrium catenella at Different Stages of Toxin Biosynthesis during the Cell Cycle". Marine Drugs 16, nr 12 (7.12.2018): 491. http://dx.doi.org/10.3390/md16120491.
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Paralytic shellfish toxins (PSTs) are a group of potent neurotoxic alkaloids that are produced mainly by marine dinoflagellates. PST biosynthesis in dinoflagellates is a discontinuous process that is coupled to the cell cycle. However, little is known about the molecular mechanism underlying this association. Here, we compared global protein expression profiles of a toxigenic dinoflagellate, Alexandrium catenella, collected at four different stages of toxin biosynthesis during the cell cycle, using an isobaric tags for relative and absolute quantification (iTRAQ)-based quantitative proteomic approach. The results showed that toxin biosynthesis occurred mainly in the G1 phase, especially the late G1 phase. In total, 7232 proteins were confidently identified, and 210 proteins exhibited differential expression among the four stages. Proteins involved in protein translation and photosynthetic pigment biosynthesis were significantly upregulated during toxin biosynthesis, indicating close associations among the three processes. Nine toxin-related proteins were detected, and two core toxin biosynthesis proteins, namely, sxtA and sxtI, were identified for the first time in dinoflagellates. Among these proteins, sxtI and ompR were significantly downregulated when toxin biosynthesis stopped, indicating that they played important roles in the regulation of PST biosynthesis. Our study provides new insights into toxin biosynthesis in marine dinoflagellates: nitrogen balance among different biological processes regulates toxin biosynthesis, and that glutamate might play a key modulatory role.