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Kinetoplast
A kinetoplast is a network of circular DNA (called kDNA) inside a mitochondrion that contains many copies of the mitochondrial genome. The most common kinetoplast structure is a disk, but they have been observed in other arrangements. Kinetoplasts are only found in Excavata of the class Kinetoplastida. The variation in the structures of kinetoplasts may reflect phylogenic relationships between kinetoplastids. A kinetoplast is usually adjacent to the organism's flagellum, flagellar basal body, suggesting that it is bound to some components of the cytoskeleton. In ''Trypanosoma brucei'' this cytoskeletal connection is called the tripartite attachment complex and includes the protein p166. ''Trypanosoma'' In trypanosoma, trypanosomes, a group of flagellated protozoans, the kinetoplast exists as a dense granule of DNA within the mitochondrion. ''Trypanosoma brucei'', the parasite which causes African trypanosomiasis (African sleeping sickness), is an example of a trypanosome with a kine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinetoplastida
Kinetoplastida (or Kinetoplastea, as a class) is a group of flagellated protists belonging to the phylum Euglenozoa, and characterised by the presence of a distinctive organelle called the kinetoplast (hence the name), a granule containing a large mass of DNA. The group includes a number of parasites responsible for serious diseases in humans and other animals, as well as various forms found in soil and aquatic environments. The organisms are commonly referred to as "kinetoplastids" or "kinetoplasts". The kinetoplastids were first defined by Bronislaw M. Honigberg in 1963 as the members of the flagellated protozoans. They are traditionally divided into the biflagellate Bodonidae and uniflagellate Trypanosomatidae; the former appears to be paraphyletic to the latter. One family of kinetoplastids, the trypanosomatids, is notable as it includes several genera which are exclusively parasitic. ''Bodo'' is a typical genus within kinetoplastida, which also includes various common f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimastigella Trypaniformis
''Dimastigella'' /(daɪˈmæstɪˌd͡ʒɛlə)/ is a biflagellate genus from the larger class Kinetoplastea. This class is identifiable by the presence of complex mitochondrial DNA structures known as kinetoplast DNA (kDNA). kDNA is composed of fewer, larger maxicircles, and smaller and more numerous minicircles, each containing different types of genetic informationDimastigella has been found in a variety of environments including as a free-living flagellate in soils and in the gut of termites. The type species, ''Dimastigella trypaniformis'' was first described very briefly by Sandon in 1928 in his study of the different soil protozoa. The genus ''Dimastigella'' currently contains only two species, ''D. trypaniformis'', and ''D. mimosa'' which was described by Frovlov et al. in 1996. Habitat and ecology ''D. trypaniformis'' can be found in a variety of different environments, including in carbonate-rich soils, loam plots, compost, freshwater and in the gut of termites. ''D. t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trypanosoma Brucei
''Trypanosoma brucei'' is a species of parasitic Kinetoplastida, kinetoplastid belonging to the genus ''Trypanosoma'' that is present in sub-Saharan Africa. Unlike other protozoan parasites that normally infect blood and tissue cells, it is exclusively extracellular and inhabits the blood plasma and body fluids. It causes deadly vector-borne diseases: African trypanosomiasis or sleeping sickness in humans, and animal trypanosomiasis or ''nagana'' in cattle and horses. It is a species complex grouped into three subspecies: ''T. b. brucei'', ''T. b. gambiense'' and ''T. b. rhodesiense''. The first is a parasite of non-human mammals and causes ''nagana'', while the latter two are zoonotic infecting both humans and animals and cause African trypanosomiasis. ''T. brucei'' is transmitted between mammal hosts by an insect Vector (epidemiology), vector belonging to different species of tsetse fly (''Glossina''). Transmission occurs by biting during the insect's blood meal. The parasites ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
African Trypanosomiasis
African trypanosomiasis is an insect-borne parasitic infection of humans and other animals. Human African trypanosomiasis (HAT), also known as African sleeping sickness or simply sleeping sickness, is caused by the species ''Trypanosoma brucei''. Humans are infected by two types, ''Trypanosoma brucei gambiense'' (TbG) and ''Trypanosoma brucei rhodesiense'' (TbR). TbG causes over 92% of reported cases. Both are usually transmitted by the bite of an infected tsetse fly and are most common in rural areas. Initially, the first stage of the disease is characterized by fevers, headaches, itchiness, and joint pains, beginning one to three weeks after the bite. Weeks to months later, the second stage begins with confusion, poor coordination, numbness, and trouble sleeping. Diagnosis involves detecting the parasite in a blood smear or lymph node fluid. A lumbar puncture is often needed to tell the difference between first- and second-stage disease. Prevention of severe disease in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bodo Saltans
''Bodo saltans'' (alternatively known as ''Pleuromonas jaculans'') is a free-living nonparasitic species of kinetoplastid flagellated phagotrophic protozoa that feed on bacteria. ''Bodo saltans'' cells have been reported in freshwater and marine environments. ''Bodo saltans'' is a single-celled bean-shaped organism 4 to 5 micrometers in length. It has two flagella: a short anterior projecting flagellum and a longer posterior-projecting flagellum without hairs (acronematic) that extends beyond the length of the cell. ''B. saltans'' secures itself to the substrate of its aquatic habitat by the tip of a posterior flagellum. Flexing of the posterior flagellum results in a twitching, jumping movement that is characteristic of this species. This type of movement appears similar to the undulating membrane of the sexually-transmitted pathogen ''Trichomonas vaginalis'' and can result in a false-positive diagnosis in cases where ''B. saltans'' is a contaminant in test samples, especially ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guide RNA
Guide RNA (gRNA) or single guide RNA (sgRNA) is a short sequence of RNA that functions as a guide for the Cas9-endonuclease or other Cas-proteins that cut the double-stranded DNA and thereby can be used for gene editing. In bacteria and archaea, gRNAs are a part of the CRISPR-Cas system that serves as an adaptive immune defense that protects the organism from viruses. Here the short gRNAs serve as detectors of foreign DNA and direct the Cas-enzymes that degrades the foreign nucleic acid. History The RNA editing guide RNA was discovered in 1990 by B. Blum, N. Bakalara, and L. Simpson through Northern Blot Hybridization in the mitochondrial maxicircle DNA of the eukaryotic parasite Leishmania tarentolae. Subsequent research throughout the mid-2000s and the following years explored the structure and function of gRNA and the CRISPR-Cas system. A significant breakthrough occurred in 2012 when it was discovered that gRNA could guide the Cas9 endonuclease to introduce target-specific cu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trypanosoma
''Trypanosoma'' is a genus of kinetoplastids (class Trypanosomatidae), a monophyletic group of unicellular parasitic flagellate protozoa. Trypanosoma is part of the phylum Euglenozoa. The name is derived from the Ancient Greek ''trypano-'' (borer) and ''soma'' (body) because of their corkscrew-like motion. Most trypanosomes are heteroxenous (requiring more than one obligatory host to complete life cycle) and most are transmitted via a vector. The majority of species are transmitted by blood-feeding invertebrates, but there are different mechanisms among the varying species. '' Trypanosoma equiperdum'' is spread between horses and other equine species by sexual contact. They are generally found in the intestine of their invertebrate host, but normally occupy the bloodstream or an intracellular environment in the vertebrate host. Trypanosomes infect a variety of hosts and cause various diseases, including the fatal human diseases sleeping sickness, caused by '' Trypanosoma br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minicircles
Minicircles are small (~4 kb) circular replicons. They occur naturally in some eukaryotic organelle genomes. In the mitochondria-derived kinetoplast of trypanosomes, minicircles encode guide RNAs for RNA editing. In ''Amphidinium'', the chloroplast genome is made of minicircles that encode chloroplast proteins. ''In vitro'' experimentally-derived minicircles Minicircles are small (~4kb) circular plasmid derivatives that have been freed from all prokaryotic vector parts. They have been applied as transgene carriers for the genetic modification of mammalian cells, with the advantage that, since they contain no bacterial DNA sequences, they are less likely to be perceived as foreign and destroyed. (Typical transgene delivery methods involve plasmids, which contain foreign DNA.) The smaller size of minicircles also extends their cloning capacity and facilitates their delivery into cells. Their preparation usually follows a two-step procedure: * production of a 'parental plasmid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flagellum
A flagellum (; : flagella) (Latin for 'whip' or 'scourge') is a hair-like appendage that protrudes from certain plant and animal sperm cells, from fungal spores ( zoospores), and from a wide range of microorganisms to provide motility. Many protists with flagella are known as flagellates. A microorganism may have from one to many flagella. A gram-negative bacterium '' Helicobacter pylori'', for example, uses its flagella to propel itself through the stomach to reach the mucous lining where it may colonise the epithelium and potentially cause gastritis, and ulcers – a risk factor for stomach cancer. In some swarming bacteria, the flagellum can also function as a sensory organelle, being sensitive to wetness outside the cell. Across the three domains of Bacteria, Archaea, and Eukaryota, the flagellum has a different structure, protein composition, and mechanism of propulsion but shares the same function of providing motility. The Latin word means " whip" to describe its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crithidia Fasciculata
''Crithidia fasciculata'' is a species of parasitic excavates. ''C. fasciculata'', like other species of ''Crithidia'' have a single host life cycle with insect host, in the case of ''C. fasciculata'' this is the mosquito. ''C. fasciculata'' have low host species specificity and can infect many species of mosquito. Life cycle ''C. fasciculata'' is found in two morphologically different life cycle stages – the free swimming choanomastigote form, which has a long external flagellum for motility, and the attached, immotile, amastigote form in the mosquito gut. Amastigotes excreted in the faeces contaminate the mosquito habitat; contamination of flowers during nectar feeding is common. Transmission of ''C fasciculata'' primarily occurs when amastigotes, washed into standing water, are ingested by mosquito larvae. The amastigotes are typically found in the rectum of a larva. Each molt of the larva results in loss of infection, but it is generally quickly re-acquired from the envir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chain Mail
Mail (sometimes spelled maille and, since the 18th century, colloquially referred to as chain mail, chainmail or chain-mail) is a type of armour consisting of small metal rings linked together in a pattern to form a mesh. It was in common military use between the 3rd century BC and the 16th century AD in Europe, while it continued to be used militarily in Asia, Africa, and the Middle East as late as the 18th century. Even today it is still in use in industries such as Butcher, butchery and as protection against the powerful bites of creatures such as sharks. A coat of this armour is often called a hauberk or sometimes a byrnie. History The earliest examples of surviving mail were found in the Carpathian Basin at a burial in Horný Jatov, Slovakia dated in the 3rd century BC, and in a chieftain's burial located in Ciumești, Romania. Its invention is commonly credited to the Celts, [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
