|
Perivitellins
Perivitellins are egg proteins found in the perivitelline fluid of many gastropods. They are multifunctional complexes providing the developing embryo with nutrition, protection from the environment, and defense against predators. Despite the central role perivitellins play in reproduction and development, there is little information about their role in gastropod Molluscs. Most studies of perivitellins have been performed in eggs of Ampullaridae, a family of freshwater snails (Caenogastropoda), notably the ''Pomacea'' genus, mostly those of ''Pomacea canaliculata'', ''Pomacea scalaris'' and ''Pomacea maculata''. Synthesis Perivitellins are almost exclusively synthesized in the albumen gland (also known as albumen gland-capsule gland complex or uterine gland), an accessory gland from the female reproductive system of gastropods. This has been experimentally confirmed for the perivitellins ovorubin (PcOvo) and PcPV2, which were only found in the albumen gland with no extra-gland ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scalarin
Scalarin (PsSC) is the most abundant perivitellin of the perivitelline fluid from ''Pomacea scalaris'' eggs. This glyco-lipo-caroteno protein is an approx. 380 kDa multimer combining multiple copies of six different 24-35 kDa subunits. As part of the petivitelline fluid, PsSC is probably playing a role as a nutrient source for the developing embryo in ''Pomacea scalaris'' eggs. As its orthologous ovorubin and PmPV1, this protein carries and stabilizes carotenoid pigments. As a consequence, this perivitellin absorbs light throughout the visible range, a characteristic related to a photoprotective role in these aerially deposited eggs. The presence on its structure of carotenoid pigments is also associated with protective antioxidative properties. Like most other studied perivitellins from ''Pomacea'' snails, PsSC is highly stable in a wide range of pH values and withstands gastrointestinal digestion, characteristics associated with an antinutritive defense system that deters ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PmPV1
''Pomacea maculata'' perivitellin-1 (PmPV1) is the most abundant perivitellin found in the perivitelline fluid from ''Pomacea maculata'' snail eggs. This glyco-lipo-caroteno protein is an approx. 294 kDa multimer of a combination of multiple copies of six different ~30 kDa subunits. PmPV1 account >60% of the total proteins found in the ''Pomacea maculata'' eggs. PmPV1 is an orthologous of ovorubin and scalarin, sharing most of the structural features with the former protein and cross-reacting with anti- ovorubin polyclonal antibodies. Like ovorubin and scalarin, PmPV1 is highly glycosylated (~13% w/w) and carries carotenoid pigments, indicating that this perivitellin would probably have the antioxidant, photoprotective, aposematic and water retention functions described for its orthologous. PmPV1 is a kinetically stable protein that, like most other studied perivitellins from ''Pomacea ''Pomacea'' is a genus of freshwater snails with gills and an operculum, aquatic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perivitelline Fluid
The perivitelline fluid is an extracellular fluid found in the eggs of most gastropods and constitutes the main source of nutrition and defense for their embryos. It replaces the egg yolk of other animals, which in snail eggs is reduced to non-nutritive proteinaceous granules with putative enzymatic function. During embryonic development the perivitelline fluid is ingested macropinocytotically by the embryos and the resulting phagosomes fuse with β-granules containing hydrolytic enzymes, which digest the perivitelline fluid components. Origin The perivitelline fluid is synthesized by the albumen gland of female snails (also known as albumen gland-capsule gland complex or uterine gland), an accessory gland from the reproductive tract. Fertilized oocytes enter the albumen gland and, on their way out, are coated with the perivitelline fluid. The amount of perivitelline fluid per egg vary considerably among species. However, the amount of perivitelline fluid per egg is constant wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perivitellin-2
Perivitellin-2 (PV2) is a pore-forming toxin present in the egg perivitelline fluid of the apple snails ''Pomacea maculata'' (PmPV2) and ''Pomacea canaliculata'' (PcPV2). This protein, called perivitellin, is massively acumulated in the eggs (~20 % total protein. As a toxin PV2 protects eggs from predators, but it also nourishes the developing snail embryos. Structure and stability These ~172-kDa proteins are dimers of AB toxins, each composed of a carbohydrate-binding protein of the tachylectin family (targeting module) disulfide-linked to a pore-forming protein of the Membrane Attack Complex and Perforin (MACPF) family (toxic unit). Like most other studied perivitellins from ''Pomacea'' snails, PV2s are highly stable in a wide range of pH values and withstand gastrointestinal digestion, characteristics associated with an antinutritive defense system that deters predation by lowering the nutritional value of the eggs. Functions As part of the perivitelline fluid, perivite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ovorubin
Ovorubin (PcOvo or PcPV1) is the most abundant perivitellin (>60 % total protein) of the perivitelline fluid from ''Pomacea canaliculata'' snail eggs. This glyco-lipo-caroteno protein complex is a approx. 300 kDa multimer of a combination of multiple copies of six different ~30 kDa subunits. Together with the other perivitellins from ''Pomacea canaliculata'' eggs, ovorubin serves a nutrient source for developing embryos, notably to the intermediate and late stages. Moreover, after hatching, the protein is still detected in the lumen of the digestive gland ready to be endocytosed, therefore, acting as a nutrient source for the newly hatched snail. Ovorubin contains carbohydrates and carotenoid pigments as main prosthetic groups, which are related to many physiological roles on ''Pomacea'' aerial egg-laying strategy. Given that carbohydrates tend to retain water, the high glycosylation of ovorubin (~17 % w/w) was proposed as an embryo defense against water loss. The carotenoid p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perivitelline Fluid
The perivitelline fluid is an extracellular fluid found in the eggs of most gastropods and constitutes the main source of nutrition and defense for their embryos. It replaces the egg yolk of other animals, which in snail eggs is reduced to non-nutritive proteinaceous granules with putative enzymatic function. During embryonic development the perivitelline fluid is ingested macropinocytotically by the embryos and the resulting phagosomes fuse with β-granules containing hydrolytic enzymes, which digest the perivitelline fluid components. Origin The perivitelline fluid is synthesized by the albumen gland of female snails (also known as albumen gland-capsule gland complex or uterine gland), an accessory gland from the reproductive tract. Fertilized oocytes enter the albumen gland and, on their way out, are coated with the perivitelline fluid. The amount of perivitelline fluid per egg vary considerably among species. However, the amount of perivitelline fluid per egg is constant wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pathogen
In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ. The term ''pathogen'' came into use in the 1880s. Typically, the term ''pathogen'' is used to describe an ''infectious'' microorganism or agent, such as a virus, bacterium, protozoan, prion, viroid, or fungus. Small animals, such as helminths and insects, can also cause or transmit disease. However, these animals are usually referred to as parasites rather than pathogens. The scientific study of microscopic organisms, including microscopic pathogenic organisms, is called microbiology, while parasitology refers to the scientific study of parasites and the organisms that host them. There are several pathways through which pathogens can invade a host. The principal pathways have different episodic time frames, but soil has the longest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mucous Membrane
A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It is mostly of endodermal origin and is continuous with the skin at body openings such as the eyes, eyelids, ears, inside the nose, inside the mouth, lips, the genital areas, the urethral opening and the anus. Some mucous membranes secrete mucus, a thick protective fluid. The function of the membrane is to stop pathogens and dirt from entering the body and to prevent bodily tissues from becoming dehydrated. Structure The mucosa is composed of one or more layers of epithelial cells that secrete mucus, and an underlying lamina propria of loose connective tissue. The type of cells and type of mucus secreted vary from organ to organ and each can differ along a given tract. Mucous membranes line the digestive, respiratory and reproductive trac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of 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 soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of 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, such as hydrogen sulphide and methane, to energy. Bacteria also live in symbiotic and parasitic relationsh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toxin
A toxin is a naturally occurring organic poison produced by metabolic activities of living cells or organisms. Toxins occur especially as a protein or conjugated protein. The term toxin was first used by organic chemist Ludwig Brieger (1849–1919) and is derived from the word toxic. Toxins can be small molecules, peptides, or proteins that are capable of causing disease on contact with or absorption by body tissues interacting with biological macromolecules such as enzymes or cellular receptors. Toxins vary greatly in their toxicity, ranging from usually minor (such as a bee sting) to potentially fatal even at extremely low doses (such as botulinum toxin). Toxins are largely secondary metabolites, which are organic compounds that are not directly involved in an organism's growth, development, or reproduction, instead often aiding it in matters of defense. Terminology Toxins are often distinguished from other chemical agents strictly based on their biological origin. Le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intraperitoneal Injection
Intraperitoneal injection or IP injection is the injection of a substance into the peritoneum (body cavity). It is more often applied to animals than to humans. In general, it is preferred when large amounts of blood replacement fluids are needed or when low blood pressure or other problems prevent the use of a suitable blood vessel for intravenous injection. In humans, the method is widely used to administer chemotherapy drugs to treat some cancers, particularly ovarian cancer. Although controversial, intraperitoneal use in ovarian cancer has been recommended as a standard of care. Fluids are injected intraperitoneally in infants, also used for peritoneal dialysis. Background Intraperitoneal injections are a way to administer therapeutics and drugs through a peritoneal route (body cavity). They are one of the few ways drugs can be administered through injection, and have uses in research involving animals, drug administration to treat ovarian cancers, and much more. Understanding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphate
In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid . The phosphate or orthophosphate ion is derived from phosphoric acid by the removal of three protons . Removal of one or two protons gives the dihydrogen phosphate ion and the hydrogen phosphate ion ion, respectively. These names are also used for salts of those anions, such as ammonium dihydrogen phosphate and trisodium phosphate. File:3-phosphoric-acid-3D-balls.png, Phosphoricacid File:2-dihydrogenphosphate-3D-balls.png, Dihydrogenphosphate File:1-hydrogenphosphate-3D-balls.png, Hydrogenphosphate File:0-phosphate-3D-balls.png, Phosphate In organic chemistry, phosphate or orthophosphate is an organophosphate, an ester of orthophosphoric acid of the form where one or more hydrogen atoms are replaced by organic groups. An example is trimethyl phosphate, . The term also refers to the triv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
