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Apicomplexa
The Apicomplexa (also called Apicomplexia; single: apicomplexan) are organisms of a large phylum of mainly parasitic alveolates. Most possess a unique form of organelle structure that comprises a type of non-photosynthetic plastid called an apicoplastwith an apical complex membrane. The organelle's apical shape is an adaptation that the apicomplexan applies in penetrating a host cell. The Apicomplexa are unicellular and spore-forming. Most are obligate endoparasites of animals, except '' Nephromyces'', a symbiont in marine animals, originally classified as a chytrid fungus, and the Chromerida, some of which are photosynthetic partners of corals. Motile structures such as flagella or pseudopods are present only in certain gamete stages. The Apicomplexa are a diverse group that includes organisms such as the coccidia, gregarines, piroplasms, haemogregarines, and plasmodia. Diseases caused by Apicomplexa include: * Babesiosis ('' Babesia'') * Malaria (''Plasmodium'') * Cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromerida
Chrompodellids are a phylum of single-celled protists belonging to the Alveolata supergroup. It comprises two different polyphyletic groups of flagellates: the colpodellids, phagotrophic predators, and the chromerids, photosynthetic algae that live as symbionts of corals. These groups were independently discovered and described, but molecular phylogenetic analyses demonstrated that they are intermingled in a clade that is the closest relative to Apicomplexa, and they became collectively known as chrompodellids. Due to the history of their research, they are variously known in biological classification as Chromerida or Colpodellida ( ICZN)/Colpodellales ( ICN). Description and life cycle Chrompodellids are a phylum of unicellular protists containing two functionally different groups: the photosynthetic "chromerids" and the predatory phagotrophic "colpodellids". Like other Alveolata, they present tubular mitochondrial cristae and highly flattened cortical alveoli with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nephromyces
''Nephromyces'' is a genus of apicomplexans that are symbionts of the ascidian genus '' Molgula'' (sea grapes). Systematics ''Nephromyces'' was first described in 1888 by Alfred Mathieu Giard as a chytrid fungus, because of its filamentous cells. He formally named three species, each corresponding to a different species of the host animal. Molecular phylogenetics later showed that ''Nephromyces'' are not actually fungi, but instead constitute a group within the Apicomplexa that is related to the Piroplasmida. Species of ''Nephromyces'' * ''Nephromyces molgularum'' Giard, 1888 * ''Nephromyces rosocovitanus'' Giard, 1888 * ''Nephromyces sorokini'' Giard, 1888 Description ''Nephromyces'' is found in the lumen of the renal sac of its host animals. The renal sac is a closed, fluid-filled structure that is derived from the epicardium during development. There are different cell types (at least seven in ''Nephromyces'' from '' Molgula manhattensis'') which appear to be dif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 an animal cell. Coccidian parasites infect the intestinal tracts of animals, and are the largest group of apicomplexan protozoa. Infection with these parasites is known as coccidiosis. Coccidia can infect all mammals, some birds, some fish, some reptiles, and some amphibians. Most species of coccidia are species-specific in their host. An exception is '' Toxoplasma gondii'', which can infect all mammals, although it can only undergo sexual reproduction in cats. Depending on the species of coccidia, infection can cause fever, vomiting, diarrhea, muscle pain, and nervous system effects and changes to behavior, and may lead to death. Healthy adults may recover without medication—but those who are immunocompromised or young almost certainly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coccidiasina
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 an animal cell. Coccidian parasites infect the intestinal tracts of animals, and are the largest group of apicomplexan protozoa. Infection with these parasites is known as coccidiosis. Coccidia can infect all mammals, some birds, some fish, some reptiles, and some amphibians. Most species of coccidia are species-specific in their host. An exception is ''Toxoplasma gondii'', which can infect all mammals, although it can only undergo sexual reproduction in cats. Depending on the species of coccidia, infection can cause fever, vomiting, diarrhea, muscle pain, and nervous system effects and changes to behavior, and may lead to death. Healthy adults may recover without medication—but those who are immunocompromised or young almost certainly req ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 an animal cell. Coccidian parasites infect the intestinal tracts of animals, and are the largest group of apicomplexan protozoa. Infection with these parasites is known as coccidiosis. Coccidia can infect all mammals, some birds, some fish, some reptiles, and some amphibians. Most species of coccidia are species-specific in their host. An exception is '' Toxoplasma gondii'', which can infect all mammals, although it can only undergo sexual reproduction in cats. Depending on the species of coccidia, infection can cause fever, vomiting, diarrhea, muscle pain, and nervous system effects and changes to behavior, and may lead to death. Healthy adults may recover without medication—but those who are immunocompromised or young almost certainly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasmodium
''Plasmodium'' is a genus of unicellular eukaryotes that are obligate parasites of vertebrates and insects. The life cycles of ''Plasmodium'' species involve development in a Hematophagy, blood-feeding insect host (biology), host which then injects parasites into a vertebrate host during a blood meal. Parasites grow within a vertebrate body tissue (often the liver) before entering the bloodstream to infect red blood cells. The ensuing destruction of host red blood cells can result in malaria. During this infection, some parasites are picked up by a blood-feeding insect (mosquitoes in majority cases), continuing the life cycle. ''Plasmodium'' is a member of the phylum Apicomplexa, a large group of parasitic eukaryotes. Within Apicomplexa, ''Plasmodium'' is in the order Haemosporida and family Plasmodiidae. Over 200 species of ''Plasmodium'' have been described, many of which have been subdivided into 14 subgenera based on parasite morphology and host range. Evolutionary relations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gregarinia
The gregarines are a group of Apicomplexan alveolates, classified as the Gregarinasina or Gregarinia. The large (roughly half a millimeter) parasites inhabit the intestines of many invertebrates. They are not found in any vertebrates. Gregarines are closely related to both '' Toxoplasma'' and ''Plasmodium'', which cause toxoplasmosis and malaria, respectively. Both protists use protein complexes similar to those that are formed by the gregarines for gliding motility and for invading target cells. This makes the gregarines excellent models for studying gliding motility, with the goal of developing treatment options for both toxoplasmosis and malaria. Thousands of different species of gregarine are expected to be found in insects, and 99% of these gregarine species still need to be described. Each insect species can be the host of multiple gregarine species. One of the most-studied gregarines is '' Gregarina garnhami''. In general, gregarines are regarded as a very successful group ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasmodiidae
The Plasmodiidae are a family of apicomplexan parasites, including the type genus ''Plasmodium'', which is responsible for malaria. This family was erected in 1903 by Mesnil and is one of the four families in the order Haemospororida. Diagnostic criteria The diagnostic criteria of the Plasmodiidae are: * Macrogametes and microgamonts develop independently * Meiosis is absent * Microgametocyte produces eight flagellated microgametes * Zygote is motile (known as an ookinete) * Conoid present in ookinete stage only * Sporozoites naked in oocyst (that is without a sporocyst) * Sporozoites have three walls * Heteroxenous: merogony and gamogony occur in vertebrate host, and fertilization and sporogony in definitive host (a blood-sucking insect) * Hemozoin pigment is produced Taxonomy The family Plasmodiidae has three sister taxa in the order Haemospororida: the families Garniidae, Haemoproteidae, and Leucocytozoidae. The Haemoproteidae and the Plasmodiidae both pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plastid
A plastid is a membrane-bound organelle found in the Cell (biology), cells of plants, algae, and some other eukaryotic organisms. Plastids are considered to be intracellular endosymbiotic cyanobacteria. Examples of plastids include chloroplasts (used for photosynthesis); chromoplasts (used for synthesis and storage of pigments); leucoplasts (non-pigmented plastids, some of which can cellular differentiation, differentiate); and apicoplasts (non-photosynthetic plastids of apicomplexa derived from secondary endosymbiosis). A permanent primary endosymbiosis event occurred about 1.5 billion years ago in the Archaeplastida cladeEmbryophyte, land plants, red algae, green algae and glaucophytesprobably with a cyanobiont, a symbiotic cyanobacteria related to the genus ''Gloeomargarita lithophora, Gloeomargarita''. Another primary endosymbiosis event occurred later, between 140 and 90 million years ago, in the photosynthetic plastids ''Paulinella'' amoeboids of the cyanobacteria genera '' ... [...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] |
