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Syndinium
''Syndinium'' is a cosmopolitan genus of parasitic dinoflagellates that infest and kill marine planktonic species of copepods and radiolarians.Chatton, E. 1910: The existence of coelom Dinoflagellate parasites. The Syndinium in pelagic copepods. ''Comptes Rendus Hebdomadaires Des Seances De L Academie des Sciences''. 151: 654-656. ''Syndinium'' belongs to order Syndiniales, a candidate for the uncultured group I and II marine alveolates.Guillou, L., et al. 2008: Widespread occurrence and genetic diversity of marine parasitoids belonging to Syndiniales (Alveolata). Environ. Microbiol. 10(12): 3349-3365 The lifecycle of ''Syndinium'' is not well understood beyond the parasitic and zoospore stages.Skovgaard, A., Massana, R., Balagué, V., Saiz, E. 2005: Phylogenetic Position of the Copepod-Infesting Parasite ''Syndinium turbo'' (Dinoflagellata, Syndinea). Protist, 156(4): 413-423 History of research ''Syndinium'' was first described by French biologist Édouard Chatton in 1910 as p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syndiniophyceae
The Syndiniales are an order of early branching dinoflagellates (also known as Marine Alveolates, "MALVs"), found as parasites of crustaceans, fish, algae, cnidarians, and protists (ciliates, radiolarians, other dinoflagellates). The trophic form is often multinucleate, and ultimately divides to form motile spores, which have two flagella in typical dinoflagellate arrangement. They lack a theca and chloroplasts, and unlike all other orders, the nucleus is never a dinokaryon. A well-studied example is '' Amoebophrya'', which is a parasite of other dinoflagellates and may play a part in ending red tides. Several MALV groups have been assigned to Syndiniales; recent studies, however, show paraphyly of MALVs suggesting that only those groups that branch as sister to dinokaryotes ('core dinoflagellates') belong to Syndiniales. Taxonomy * Class Syndiniophyceae Loeblich III, 1976 ''Syndinearef> ** Order Syndiniales Loeblich III 1976 occidinales Chatton & Biecheler 1934*** Family ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eukaryota
The eukaryotes ( ) constitute the Domain (biology), domain of Eukaryota or Eukarya, organisms whose Cell (biology), cells have a membrane-bound cell nucleus, nucleus. All animals, plants, Fungus, fungi, seaweeds, and many unicellular organisms are eukaryotes. They constitute a major group of Outline of life forms, life forms alongside the two groups of prokaryotes: the Bacteria and the Archaea. Eukaryotes represent a small minority of the number of organisms, but given their generally much larger size, their collective global biomass is much larger than that of prokaryotes. The eukaryotes emerged within the archaeal Kingdom (biology), kingdom Asgard (Archaea), Promethearchaeati and its sole phylum Promethearchaeota. This implies that there are only Two-domain system, two domains of life, Bacteria and Archaea, with eukaryotes incorporated among the Archaea. Eukaryotes first emerged during the Paleoproterozoic, likely as Flagellated cell, flagellated cells. The leading evolutiona ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protist
A protist ( ) or protoctist is any eukaryotic organism that is not an animal, land plant, or fungus. Protists do not form a natural group, or clade, but are a paraphyletic grouping of all descendants of the last eukaryotic common ancestor excluding land plants, animals, and fungi. Protists were historically regarded as a separate taxonomic kingdom known as Protista or Protoctista. With the advent of phylogenetic analysis and electron microscopy studies, the use of Protista as a formal taxon was gradually abandoned. In modern classifications, protists are spread across several eukaryotic clades called supergroups, such as Archaeplastida ( photoautotrophs that includes land plants), SAR, Obazoa (which includes fungi and animals), Amoebozoa and " Excavata". Protists represent an extremely large genetic and ecological diversity in all environments, including extreme habitats. Their diversity, larger than for all other eukaryotes, has only been discovered in rece ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microtubule
Microtubules are polymers of tubulin that form part of the cytoskeleton and provide structure and shape to eukaryotic cells. Microtubules can be as long as 50 micrometres, as wide as 23 to 27 nanometer, nm and have an inner diameter between 11 and 15 nm. They are formed by the polymerization of a Protein dimer, dimer of two globular proteins, Tubulin#Eukaryotic, alpha and beta tubulin into #Structure, protofilaments that can then associate laterally to form a hollow tube, the microtubule. The most common form of a microtubule consists of 13 protofilaments in the tubular arrangement. Microtubules play an important role in a number of cellular processes. They are involved in maintaining the structure of the cell and, together with microfilaments and intermediate filaments, they form the cytoskeleton. They also make up the internal structure of cilia and flagella. They provide platforms for intracellular transport and are involved in a variety of cellular processes, in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinetochore
A kinetochore (, ) is a flared oblique-shaped protein structure associated with duplicated chromatids in eukaryotic cells where the spindle fibers, which can be thought of as the ropes pulling chromosomes apart, attach during cell division to pull sister chromatids apart. The kinetochore assembles on the centromere and links the chromosome to microtubule polymers from the mitotic spindle during mitosis and meiosis. The term kinetochore was first used in a footnote in a 1934 Cytology book by Lester W. Sharp and commonly accepted in 1936. Sharp's footnote reads: "The convenient term ''kinetochore'' (= movement place) has been suggested to the author by J. A. Moore", likely referring to John Alexander Moore who had joined Columbia University as a freshman in 1932. Monocentric organisms, including vertebrates, fungi, and most plants, have a single centromeric region on each chromosome which assembles a single, localized kinetochore. Holocentric organisms, such as nematodes a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinokaryon
A dinokaryon is a eukaryotic nucleus present in dinoflagellates in which the chromosomes are fibrillar in appearance (i.e. with unmasked DNA fibrils) and are more or less continuously condensed. The nuclear envelope does not break down during mitosis, which is thus termed closed mitosis Mitosis () is a part of the cell cycle in eukaryote, eukaryotic cells in which replicated chromosomes are separated into two new Cell nucleus, nuclei. Cell division by mitosis is an equational division which gives rise to genetically identic ..., or "dinomitosis". The mitotic spindle is extranuclear. Histones are absent. However, recent EST sequencing has revealed the presence of histones in one of the closest relative to dinoflagellates, '' Perkinsus marinus'' and an early-branching dinoflagellate, '' Hematodinium'' sp. However, histone-like proteins of bacterial origins are found in the coding regions at periphery of the dinokaryon's chromosomes. References Dinoflagellate bio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxyrrhis
''Oxyrrhis'' is a genus of heterotrophic dinoflagellate, the only genus in the family Oxyrrhinaceae. It inhabits a range of marine environments worldwide and is important in the food web dynamics of these ecosystems. It has the potential to be considered a model organism for the study of other protists. ''Oxyrrhis'' is an early-branching lineage and has long been described in literature as a monospecific genus, containing only ''Oxyrrhis marina''. Some recent molecular phylogenetic studies argue that ''Oxyrrhis'' comprises ''O. marina'' and ''O. maritima'' as distinct species, while other publications state that the two are genetically diverse lineages of the same species. The genus has previously been suggested to contain ''O. parasitica'' as a separate species, however the current consensus appears to exclude this, with ''Oxyrrhis'' being monospecific and containing ''O. marina'' and ''O. maritima'' as separate lineages of the type species. The genus is characterised by its elong ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gymnodinium
''Gymnodinium'' is a genus of dinoflagellates, a type of marine and freshwater plankton. It is one of the few naked dinoflagellates, or species lacking armor known as cellulosic plates. Since 2000, the species which had been considered to be part of ''Gymnodinium'' have been divided into several genera, based on the nature of the apical groove and partial LSU rDNA sequence data. '' Amphidinium'' was redefined later. Gymnodinium belong to red dinoflagellates that, in concentration, can cause red tides. The red tides produced by some ''Gymnodinium'', such as '' Gymnodinium catenatum'', are toxic and pose risks to marine and human life, including paralytic shellfish poisoning. Segregate genera *''Gymnodinium'' sensu stricto *'' Akashiwo'' *'' Amphidinium'' *'' Gyrodinium'' *'' Karenia'' *'' Karlodinium'' *'' Katodinium'' Former species ''Torodinium'' (with ''Torodinium robustum'' and the type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasmodium (life Cycle)
A plasmodium is a living structure of cytoplasm that contains many nuclei, rather than being divided into individual cells each with a single nucleus. Plasmodia are best known from slime molds, but are also found in parasitic Myxosporea, and some algae such as the Chlorarachniophyta. Structure A plasmodium is an amoeboid, multinucleate, and naked mass of cytoplasm that contains many diploid nuclei. The resulting structure, a coenocyte, is created by many nuclear divisions without the process of cytokinesis, which in other organisms pulls newlydivided cells apart. In some cases, the resulting structure is a syncytium, created by the fusion of cells after division. Under suitable conditions, a plasmodium may differentiate and form fruiting bodies bearing spores at their tips. Taxonomic distribution The term plasmodium, introduced by Leon Cienkowski, usually refers to the feeding stage of slime molds; these are macroscopic mycetozoans. The multinucleate developmental stage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
