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Wallaceina Raviniae
''Crithidia brevicula'' is a species of parasitic flagellate protist belonging to the family Trypanosomatidae. It is a monoxenous parasite of insects. Other one-host trypanosomatids from hemipteran and dipteran insects have been traditionally placed in the same genus or others like ''Wallaceina'', '' Blastocrithidia'', '' Leptomonas'', '' Herpetomonas'', and '' Rhynchoidomonas''. ''Wallaceina'' was characterized by endomastigote morphological forms, whereas epimastigotes and opisthomastigotes were features of the genera ''Blastocrithidia'' and ''Herpetomonas'', respectively. Later comparison and phylogenetic analysis of 18S ribosomal RNA and glycosomal glyceraldehyde-3-phosphatedehydrogenase sequences of trypanosomatid taxa revealed that ''Wallaceina'' is polyphyletic. Its species have been reassigned either to ''C. brevicula'' (for ''Wallaceina brevicula'', ''W. inconstans'', ''W. vicina'', and ''W. podlipaevi'') or to a newly proposed genus '' Wallacemonas'' (for ''Wallac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trypanosomatidae
Trypanosomatida is a group of kinetoplastid unicellular organisms distinguished by having only a single flagellum. The name is derived from the Greek ''trypano'' (borer) and ''soma'' (body) because of the corkscrew-like motion of some trypanosomatid species. All members are exclusively parasitic, found primarily in insects. A few genera have life-cycles involving a secondary host, which may be a vertebrate, invertebrate or plant. These include several species that cause major diseases in humans. Some trypanosomatida are intracellular parasites, with the important exception of ''Trypanosoma brucei''. Medical importance The three major human diseases caused by trypanosomatids are; African trypanosomiasis (sleeping sickness, caused by ''Trypanosoma brucei'' and transmitted by tsetse flies), South American trypanosomiasis (Chagas disease, caused by '' T. cruzi'' and transmitted by triatomine bugs), and leishmaniasis (a set of trypanosomal diseases caused by various species of ''Le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
18S Ribosomal RNA
18S ribosomal RNA (abbreviated 18S rRNA) is a part of the ribosomal RNA in eukaryotes. It is a component of the Eukaryotic small ribosomal subunit (40S) and the cytosolic homologue of both the 12S ribosomal RNA, 12S rRNA in mitochondria and the 16S ribosomal RNA, 16S rRNA in plastids and prokaryotes. Similar to the prokaryotic 16S rRNA, the genes of the 18S ribosomal RNA have been widely used for Phylogenetics, phylogenetic studies and biodiversity screening of eukaryotes. Research history Along with the 28S ribosomal RNA, 28S and 5.8S ribosomal RNA, 5.8S rRNA in eukaryotes, the 18S rRNA was early identified as integral structural element of ribosomes which were first characterized by their sedimentation properties and named according to measured Svedberg, Svedberg units. Given its ubiquitous presence in eukaryotic life, the evolution of the 18S rRNA was soon proposed as marker for phylogenetics, phylogenetic studies to resolve the evolution of eukaryotes. Structure and function ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptomonad
The cryptomonads (or cryptophytes) are a superclass of algae, most of which have plastids. They are traditionally considered a division of algae among phycologists, under the name of Cryptophyta. They are common in freshwater, and also occur in marine and brackish habitats. Each cell is around 10–50 μm in size and flattened in shape, with an anterior groove or pocket. At the edge of the pocket there are typically two slightly unequal flagella. Some may exhibit mixotrophy. They are classified as superclass Cryptomonada, which is divided into two classes: heterotrophic Goniomonadea and phototrophic Cryptophyceae. The two groups are united under three shared morphological characteristics: presence of a periplast, ejectisomes with secondary scroll, and mitochondrial cristae with flat tubules. Genetic studies as early as 1994 also supported the hypothesis that ''Goniomonas'' was sister to Cryptophyceae. A study in 2018 found strong evidence that the common ancestor of Crypto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proteomonas
Geminigeraceae is a family of cryptophytes containing the five genera '' Geminigera'', '' Guillardia'', ''Hanusia'', ''Proteomonas'' and ''Teleaulax''. They are characterised by chloroplasts containing Cr-phycoerythrin 545, and an inner periplast component (IPC) comprising "a sheet or a sheet and multiple plates if diplomorphic". The nucleomorphs are never in the pyrenoid Pyrenoids are sub-cellular phase-separated micro-compartments found in chloroplasts of many algae,Giordano, M., Beardall, J., & Raven, J. A. (2005). CO2 concentrating mechanisms in algae: mechanisms, environmental modulation, and evolution. ''An ..., and there is never a scalariform furrow. The cells do, however, have a long, keeled rhizostyle with lamellae (wings). References Cryptomonads Cryptista families Algae families {{Cryptomonad-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyphyletic
A polyphyletic group is an assemblage that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies, which are explained as a result of convergent evolution. The arrangement of the members of a polyphyletic group is called a polyphyly .. [Source for pronunciation.] It is contrasted with monophyly and paraphyly. For example, the biological characteristic of warm-bloodedness evolved separately in the ancestors of mammals and the ancestors of birds; "warm-blooded animals" is therefore a polyphyletic grouping. Other examples of polyphyletic groups are algae, C4 photosynthesis, C4 photosynthetic plants, and Xenarthra#Evolutionary relationships, edentates. Many taxonomists aim to avoid homoplasies in grouping taxa together, with a goal to identify and eliminate groups that are found to be polyphyletic. This is often the stimulus for major re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GAPDH
Glyceraldehyde 3-phosphate dehydrogenase (abbreviated GAPDH) () is an enzyme of about 37kDa that catalyzes the sixth step of glycolysis and thus serves to break down glucose for energy and carbon molecules. In addition to this long established metabolic function, GAPDH has recently been implicated in several non-metabolic processes, including transcription activation, initiation of apoptosis, ER-to-Golgi vesicle shuttling, and fast axonal, or axoplasmic transport. In sperm, a testis-specific isoenzyme GAPDHS is expressed. Structure Under normal cellular conditions, cytoplasmic GAPDH exists primarily as a tetramer. This form is composed of four identical 37-kDa subunits containing a single catalytic thiol group each and critical to the enzyme's catalytic function. Nuclear GAPDH has increased isoelectric point (pI) of pH 8.3–8.7. Of note, the cysteine residue C152 in the enzyme's active site is required for the induction of apoptosis by oxidative stress. Notably, post- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycosome
The glycosome is a membrane A membrane is a selective barrier; it allows some things to pass through but stops others. Such things may be molecules, ions, or other small particles. Membranes can be generally classified into synthetic membranes and biological membranes. Bi ...-enclosed organelle that contains the glycolysis, glycolytic enzymes. The term was first used by Scott and Still in 1968 after they realized that the glycogen in the cell was not static but rather a dynamic molecule. It is found in a few species of protozoa including the Kinetoplastida which include the suborders Trypanosomatida and Bodonina, most notably in the human pathogenic trypanosomes, which can cause African trypanosomiasis, sleeping sickness, Chagas's disease, and leishmaniasis. The organelle is bounded by a single membrane and contains a dense proteinaceous matrix. It is believed to have evolved from the peroxisome. This has been verified by work done on Leishmania genetics. The glycosome is curre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetic
In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical data and observed heritable traits of DNA sequences, protein amino acid sequences, and morphology. The results are a phylogenetic tree—a diagram depicting the hypothetical relationships among the organisms, reflecting their inferred evolutionary history. The tips of a phylogenetic tree represent the observed entities, which can be living taxa or fossils. A phylogenetic diagram can be rooted or unrooted. A rooted tree diagram indicates the hypothetical common ancestor of the taxa represented on the tree. An unrooted tree diagram (a network) makes no assumption about directionality of character state transformation, and does not show the origin or "root" of the taxa in question. In addition to their use for inferring phylogenetic pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoxenous Development
Monoxenous development, or monoxeny, characterizes a parasite whose development is restricted to a single host species. The etymology of the terms monoxeny / monoxenous derives from the two ancient Greek words (), meaning "unique", and (), meaning "foreign". In a monoxenous life cycle, the parasitic species may be strictly host specific (using only a single host species, such as gregarines) or not (e.g. ''Eimeria'', ''Coccidia Coccidia (Coccidiasina) are a subclass of microscopic, spore-forming, single-celled obligate intracellular parasites belonging to the apicomplexan class Conoidasida. As obligate intracellular parasites, they must live and reproduce within a ...''). References External links xeno-, xen- word info Parasitism {{parasite-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trypanosomatida
Trypanosomatida is a group of kinetoplastid unicellular organisms distinguished by having only a single flagellum. The name is derived from the Greek ''trypano'' (borer) and ''soma'' (body) because of the corkscrew-like motion of some trypanosomatid species. All members are exclusively parasitic, found primarily in insects. A few genera have life-cycles involving a secondary host, which may be a vertebrate, invertebrate or plant. These include several species that cause major diseases in humans. Some trypanosomatida are intracellular parasites, with the important exception of ''Trypanosoma brucei''. Medical importance The three major human diseases caused by trypanosomatids are; African trypanosomiasis (African trypanosomiasis, sleeping sickness, caused by ''Trypanosoma brucei'' and transmitted by Tsetse fly, tsetse flies), South American trypanosomiasis (Chagas disease, caused by ''Trypanosoma cruzi, T. cruzi'' and transmitted by Triatominae, triatomine bugs), and leishmanias ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
