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Trophosome
A trophosome is a highly vascularised organ found in some animals that houses symbiotic bacteria that provide food for their host. Trophosomes are contained by the coelom of tube worms (family Siboglinidae, e.g. the giant tube worm ''Riftia pachyptila'') and in the body of symbiotic flatworms of the genus ''Paracatenula''. Organization Initially, the trophosome in Frenulata, frenulates and vestimentiferans, which are now classified as members of the Siboglinidae, had been identified as a mesodermal tissue. The discovery of bacteria inside the trophosomal tissue only occurred in 1981 when the ultrastructure of trophosome of several frenulate species and of ''Sclerolinum brattstromi'' was studied. The bacteriocytes and Symbiosis, symbionts composed of 70.5% and 24.1% of the trophosome's volume respectively. Generally, trophosome extends over the entire trunk region between the two longitudinal blood vessels from immediately posterior to the ventral ciliary band of the forepart to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paracatenula
''Paracatenula'' is a genus of millimeter sized free-living Marine biology, marine gutless Catenulida, catenulid flatworms. ''Paracatenula'' spp. are found worldwide in warm temperate to tropical subtidal sediments. They are part of the Interstitial water, interstitial meiofauna of sandy sediments. Adult ''Paracatenula'' lack a mouth and a Gut (anatomy), gut and are associated with intracellular Symbiosis, symbiotic alphaproteobacteria of the genus Candidatus Riegeria, ''Candidatus'' Riegeria. The symbionts are housed in bacteriocytes in a specialized organ, the trophosome (Greek ‘food’). ''Ca.'' Riegeria can make up half of the worms' biomass. The Mutualism (biology), beneficial symbiosis with the autotroph, carbon dioxide fixing and chemotroph, sulfur-oxidizing endosymbionts allows the marine flatworm to live in oligotroph, nutrient poor environments. The symbionts ''not only'' provide the nutrition but also maintain the primary energy reserves in the symbiosis. Diversit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symbiosome Membrane
A symbiosome is a specialised compartment in a host cell that houses an endosymbiont in a symbiotic relationship. The term was first used in 1983 to describe the vacuole structure in the symbiosis between the animal host the '' Hydra'', and the endosymbiont ''Chlorella''. Symbiosomes are also seen in other cnidaria-dinoflagellate symbioses, including those found in coral-algal symbioses. In 1989 the concept was applied to the similar structure found in the nitrogen-fixing root nodules of certain plants. The symbiosome in the root nodules has been much more successfully researched due in part to the complexity of isolating the symbiosome membrane in animal hosts. The symbiosome in a root nodule cell in a plant is an organelle-like structure that has formed in a symbiotic relationship with nitrogen-fixing bacteria. The plant symbiosome is unique to those plants that produce root nodules. The majority of such symbioses are made between legumes and diazotrophic ''Rhizobia'' bacteria. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frenulata
Frenulata, "beard worms", is a clade of Siboglinidae, "tube worms". They are one of four lineages with numerous species. They may be the most basal clade in the family. Despite being the first tube worms to be encountered and described, they remain the least studied group. This is because of their slender shape, they often get destroyed as a result of being caught as bycatch or poor preservation. They are found primarily in deep, muddy sediments, cold seeps, and anoxic firth sediments. Anatomy Frenulata are typically long and slender, they have been described as "thread-like". They typically range from 0.1–3 mm in diameter. Like other Siboglinidae, they have distinct segments: a plume, a vestimentum, and a trophosome. The vestimentum is used to retract the organism in and out of its tube. The trophosome is unique to tube worms. It was found to house bacterial symbiotes in ''Riftia.'' Like other tube worms, they lack a digestive tract. In order to survive, it holds endosy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteria
Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit the air, soil, water, Hot spring, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria play a vital role in many stages of the nutrient cycle by recycling nutrients and the nitrogen fixation, fixation of nitrogen from the Earth's atmosphere, atmosphere. The nutrient cycle includes the decomposition of cadaver, dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peritoneum
The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs, and is composed of a layer of mesothelium supported by a thin layer of connective tissue. This peritoneal lining of the cavity supports many of the abdomen#Contents, abdominal organs and serves as a conduit for their blood vessels, lymphatic vessels, and nerves. The abdominal cavity (the space bounded by the vertebrae, abdominal muscles, Thoracic diaphragm, diaphragm, and pelvic floor) is different from the intraperitoneal space (located within the abdominal cavity but wrapped in peritoneum). The structures within the intraperitoneal space are called "intraperitoneal" (e.g., the stomach and intestines), the structures in the abdominal cavity that are located behind the intraperitoneal space are called "retroperitoneal" (e.g., the kidneys), and those structures below the intrape ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Ultrastructure Of The Trophosome Region
''The'' is a grammatical article in English, denoting nouns that are already or about to be mentioned, under discussion, implied or otherwise presumed familiar to listeners, readers, or speakers. It is the definite article in English. ''The'' is the most frequently used word in the English language; studies and analyses of texts have found it to account for seven percent of all printed English-language words. It is derived from gendered articles in Old English which combined in Middle English and now has a single form used with nouns of any gender. The word can be used with both singular and plural nouns, and with a noun that starts with any letter. This is different from many other languages, which have different forms of the definite article for different genders or numbers. Pronunciation In most dialects, "the" is pronounced as (with the voiced dental fricative followed by a schwa) when followed by a consonant sound, and as (homophone of the archaic pronoun ''thee'') ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterial Cell Wall
A cell wall is a structural layer that surrounds some cell types, found immediately outside the cell membrane. It can be tough, flexible, and sometimes rigid. Primarily, it provides the cell with structural support, shape, protection, and functions as a selective barrier. Another vital role of the cell wall is to help the cell withstand osmotic pressure and mechanical stress. While absent in many eukaryotes, including animals, cell walls are prevalent in other organisms such as fungi, algae and plants, and are commonly found in most prokaryotes, with the exception of mollicute bacteria. The composition of cell walls varies across taxonomic groups, species, cell type, and the cell cycle. In land plants, the primary cell wall comprises polysaccharides like cellulose, hemicelluloses, and pectin. Often, other polymers such as lignin, suberin or cutin are anchored to or embedded in plant cell walls. Algae exhibit cell walls composed of glycoproteins and polysaccharides, such as carr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-negative Bacteria
Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the Crystal violet, crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists of a thin peptidoglycan gram-negative cell wall, cell wall sandwiched between an inner (Cytoplasm, cytoplasmic) Cell membrane, membrane and an Bacterial outer membrane, outer membrane. These bacteria are found in all environments that support life on Earth. Within this category, notable species include the model organism ''Escherichia coli'', along with various pathogenic bacteria, such as ''Pseudomonas aeruginosa'', ''Chlamydia trachomatis'', and ''Yersinia pestis''. They pose significant challenges in the medical field due to their outer membrane, which acts as a protective barrier against numerous Antibiotic, antibiotics (including penicillin), Detergent, detergents that would normally damage the inner cell membrane, and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Membrane
The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of a cell from the outside environment (the extracellular space). The cell membrane consists of a lipid bilayer, made up of two layers of phospholipids with cholesterols (a lipid component) interspersed between them, maintaining appropriate membrane fluidity at various temperatures. The membrane also contains membrane proteins, including integral proteins that span the membrane and serve as membrane transporters, and peripheral proteins that loosely attach to the outer (peripheral) side of the cell membrane, acting as enzymes to facilitate interaction with the cell's environment. Glycolipids embedded in the outer lipid layer serve a similar purpose. The cell membrane controls the movement of substances in and out of a cell, being selectively permeable to ions and organic mole ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Wall
A cell wall is a structural layer that surrounds some Cell type, cell types, found immediately outside the cell membrane. It can be tough, flexible, and sometimes rigid. Primarily, it provides the cell with structural support, shape, protection, and functions as a selective barrier. Another vital role of the cell wall is to help the cell withstand osmotic pressure and mechanical stress. While absent in many eukaryotes, including animals, cell walls are prevalent in other organisms such as fungi, algae and plants, and are commonly found in most Prokaryote, prokaryotes, with the exception of Mollicutes, mollicute bacteria. The composition of cell walls varies across taxonomic groups, species, cell type, and the cell cycle. In Embryophyte, land plants, the primary cell wall comprises Polysaccharide, polysaccharides like cellulose, hemicelluloses, and pectin. Often, other Polymer, polymers such as lignin, suberin or cutin are anchored to or embedded in plant cell walls. Algae exhibit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Nucleus
The cell nucleus (; : nuclei) is a membrane-bound organelle found in eukaryote, eukaryotic cell (biology), cells. Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have #Anucleated_cells, no nuclei, and a few others including osteoclasts have Multinucleate, many. The main structures making up the nucleus are the nuclear envelope, a double membrane that encloses the entire organelle and isolates its contents from the cellular cytoplasm; and the nuclear matrix, a network within the nucleus that adds mechanical support. The cell nucleus contains nearly all of the cell's genome. Nuclear DNA is often organized into multiple chromosomes – long strands of DNA dotted with various proteins, such as histones, that protect and organize the DNA. The genes within these chromosomes are Nuclear organization, structured in such a way to promote cell function. The nucleus maintains the integrity of genes and controls the activities of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rough Endoplasmic Reticulum
The endoplasmic reticulum (ER) is a part of a transportation system of the eukaryotic cell, and has many other important functions such as protein folding. The word endoplasmic means "within the cytoplasm", and reticulum is Latin for "little net". It is a type of organelle made up of two subunits – rough endoplasmic reticulum (RER), and smooth endoplasmic reticulum (SER). The endoplasmic reticulum is found in most eukaryotic cells and forms an interconnected network of flattened, membrane-enclosed sacs known as cisternae (in the RER), and tubular structures in the SER. The membranes of the ER are continuous with the outer nuclear membrane. The endoplasmic reticulum is not found in red blood cells, or spermatozoa. There are two types of ER that share many of the same proteins and engage in certain common activities such as the synthesis of certain lipids and cholesterol. Different types of cells contain different ratios of the two types of ER depending on the activities of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
