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43-491: (Redirected from Heavy Chain ) Heavy chain may refer to: Immunoglobulin heavy chain , a subunit of antibodies Heavy-chain antibody , an antibody composed of heavy chains only Heavy chain disease , a disease affecting antibody heavy chain production Myosin heavy chain , a subunit of myosin II Myosin-heavy-chain kinase , an enzyme that catalyses

86-685: A clade sister to Cervidae . According to the study, Cervidae diverged from the Bovidae-Moschidae clade 27 to 28 million years ago. The following cladogram is based on a large-scale genome ruminant genome sequence study from 2019: Tragulidae [REDACTED] Antilocapridae [REDACTED] Giraffidae [REDACTED] Cervidae [REDACTED] Bovidae [REDACTED] Moschidae [REDACTED] Hofmann and Stewart divided ruminants into three major categories based on their feed type and feeding habits: concentrate selectors, intermediate types, and grass/roughage eaters, with

129-447: A global warming potential of 86 compared to CO 2 over a 20-year period. As a by-product of consuming cellulose, cattle belch out methane, there-by returning that carbon sequestered by plants back into the atmosphere. After about 10 to 12 years, that methane is broken down and converted back to CO 2 . Once converted to CO 2 , plants can again perform photosynthesis and fix that carbon back into cellulose. From here, cattle can eat

172-487: A cow. The role of saliva is to provide ample fluid for rumen fermentation and to act as a buffering agent. Rumen fermentation produces large amounts of organic acids, thus maintaining the appropriate pH of rumen fluids is a critical factor in rumen fermentation. After digesta passes through the rumen, the omasum absorbs excess fluid so that digestive enzymes and acid in the abomasum are not diluted. Tannins are phenolic compounds that are commonly found in plants. Found in

215-427: A light chain. Pre-B lymphocytes can synthesize heavy chain in the absence of light chain, which then can allow the heavy chain to bind to a heavy-chain binding protein. There are five types of mammalian immunoglobulin heavy chain: γ, δ, α, μ and ε. They define classes of immunoglobulins: IgG , IgD , IgA , IgM and IgE , respectively. Each heavy chain has two regions: Cows, specifically Bos taurus , show

258-457: A series of immunoglobulin domains , usually with one variable domain (V H ) that is important for binding antigen and several constant domains (C H 1, C H 2, etc.). Production of a viable heavy chain is a key step in B cell maturation. If the heavy chain is able to bind to a surrogate light chain and move to the plasma membrane, then the developing B cell can begin producing its light chain. The heavy chain does not always have to bind to

301-415: A simple single-chambered stomach. Being hindgut fermenters , these animals ferment cellulose in an enlarged cecum . In smaller hindgut fermenters of the order Lagomorpha (rabbits, hares, and pikas), and Caviomorph rodents ( Guinea pigs , capybaras , etc.), material from the cecum is formed into cecotropes , passed through the large intestine, expelled and subsequently reingested to absorb nutrients in

344-470: A three-compartment stomach instead of four like ruminants. The Hippopotamidae (comprising hippopotamuses ) are well-known examples. Pseudoruminants, like traditional ruminants, are foregut fermentors and most ruminate or chew cud . However, their anatomy and method of digestion differs significantly from that of a four-chambered ruminant. Monogastric herbivores , such as rhinoceroses , horses , guinea pigs , and rabbits , are not ruminants, as they have

387-497: A variation on the general mammalian theme in which the heavy chain CDR H3 region has adapted to produce a divergent repertoire of antibodies which present a "stalk and knob" antigen interaction surface instead of the more familiar bivalent tip surface. The bovine CDR is unusually long and contains unique sequence attributes which support the production of paired cysteine residues during somatic hypermutation . Thus, where in humans

430-461: A warm, moist, anaerobic environment with a temperature range of 37.7 to 42.2 °C (99.9 to 108.0 °F) and a pH between 6.0 and 6.4. Without the help of microbes, ruminants would not be able to use nutrients from forages. The food is mixed with saliva and separates into layers of solid and liquid material. Solids clump together to form the cud or bolus . The cud is then regurgitated and chewed to completely mix it with saliva and to break down

473-628: A wide range of climates (from tropic to arctic) and habitats (from open plains to forests). The population of domestic ruminants is greater than 3.5 billion, with cattle, sheep, and goats accounting for about 95% of the total population. Goats were domesticated in the Near East circa 8000 BC. Most other species were domesticated by 2500 BC., either in the Near East or southern Asia. Ruminating animals have various physiological features that enable them to survive in nature. One feature of ruminants

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516-431: Is a heavy-chain antibody , an antibody lacking light chains, and can be used to produce single-domain antibodies , which are essentially the variable domain (V NAR ) of an IgNAR. Shark single domain antibodies (V NAR s) to tumor or viral antigens can be isolated from a large naïve nurse shark V NAR library using phage display technology . IgW has now also been found in the group of lobe finned fishes including

559-570: Is a stem-based definition for Ruminantiamorpha, and is more inclusive than the crown group Ruminantia. As a crown group, Ruminantia only includes the last common ancestor of all extant (living) ruminants and their descendants (living or extinct ), whereas Ruminantiamorpha, as a stem group, also includes more basal extinct ruminant ancestors that are more closely related to living ruminants than to other members of Artiodactyla. When considering only living taxa ( neontology ), this makes Ruminantiamorpha and Ruminantia synonymous , and only Ruminantia

602-413: Is different from Wikidata All article disambiguation pages All disambiguation pages Immunoglobulin heavy chain A typical antibody is composed of two immunoglobulin (Ig) heavy chains and two Ig light chains . Several different types of heavy chain exist that define the class or isotype of an antibody. These heavy chain types vary between different animals. All heavy chains contain

645-531: Is estimated to contain 10–50 billion bacteria and 1 million protozoa, as well as several yeasts and fungi. Since the environment inside a rumen is anaerobic , most of these microbial species are obligate or facultative anaerobes that can decompose complex plant material, such as cellulose , hemicellulose , starch , and proteins . The hydrolysis of cellulose results in sugars, which are further fermented to acetate, lactate, propionate, butyrate, carbon dioxide, and methane . As bacteria conduct fermentation in

688-408: Is the large ruminal storage capacity that gives them the ability to consume feed rapidly and complete the chewing process later. This is known as rumination, which consists of the regurgitation of feed, rechewing, resalivation, and reswallowing. Rumination reduces particle size, which enhances microbial function and allows the digesta to pass more easily through the digestive tract. Vertebrates lack

731-439: Is their continuously growing teeth. During grazing, the silica content in forage causes abrasion of the teeth. This is compensated for by continuous tooth growth throughout the ruminant's life, as opposed to humans or other nonruminants, whose teeth stop growing after a particular age. Most ruminants do not have upper incisors; instead, they have a thick dental pad to thoroughly chew plant-based food. Another feature of ruminants

774-938: Is used. Thus, Ruminantiamorpha is only used in the context of paleontology . Accordingly, Spaulding grouped some genera of the extinct family Anthracotheriidae within Ruminantiamorpha (but not in Ruminantia), but placed others within Ruminantiamorpha's sister clade, Cetancodontamorpha . Ruminantia's placement within Artiodactyla can be represented in the following cladogram : Tylopoda (camels) [REDACTED]   Suina (pigs) [REDACTED]   Tragulidae (mouse deer) [REDACTED]   Pecora (horn bearers) [REDACTED]   Hippopotamidae (hippopotamuses) [REDACTED]   Cetacea (whales) [REDACTED] Within Ruminantia,

817-456: Is very important because it provides liquid for the microbial population, recirculates nitrogen and minerals, and acts as a buffer for the rumen pH. The type of feed the animal consumes affects the amount of saliva that is produced. Though the rumen and reticulum have different names, they have very similar tissue layers and textures, making it difficult to visually separate them. They also perform similar tasks. Together, these chambers are called

860-556: The Tragulidae (mouse deer) are considered the most basal family, with the remaining ruminants classified as belonging to the infraorder Pecora . Until the beginning of the 21st century it was understood that the family Moschidae (musk deer) was sister to Cervidae . However, a 2003 phylogenetic study by Alexandre Hassanin (of National Museum of Natural History, France ) and colleagues, based on mitochondrial and nuclear analyses, revealed that Moschidae and Bovidae form

903-410: The (one's) cud' is to reflect or meditate. In psychology, "rumination" refers to a pattern of thinking, and is unrelated to digestive physiology. Methane is produced by a type of archaea , called methanogens , as described above within the rumen, and this methane is released to the atmosphere. The rumen is the major site of methane production in ruminants. Methane is a strong greenhouse gas with

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946-401: The U.S., and 22% of the total U.S. methane emissions . The meat from domestically raised ruminants has a higher carbon equivalent footprint than other meats or vegetarian sources of protein based on a global meta-analysis of lifecycle assessment studies. Methane production by meat animals, principally ruminants, is estimated 15–20% global production of methane, unless the animals were hunted in

989-442: The ability to hydrolyse the beta [1–4] glycosidic bond of plant cellulose due to the lack of the enzyme cellulase . Thus, ruminants completely depend on the microbial flora, present in the rumen or hindgut, to digest cellulose. Digestion of food in the rumen is primarily carried out by the rumen microflora, which contains dense populations of several species of bacteria , protozoa , sometimes yeasts and other fungi – 1 ml of rumen

1032-419: The abomasum. This is the gastric compartment of the ruminant stomach. The abomasum is the direct equivalent of the monogastric stomach, and digesta is digested here in much the same way. This compartment releases acids and enzymes that further digest the material passing through. This is also where the ruminant digests the microbes produced in the rumen. Digesta is finally moved into the small intestine , where

1075-516: The absorption of nutrients by reducing the populations of proteolytic rumen bacteria. Very high levels of tannin intake can produce toxicity that can even cause death. Animals that normally consume tannin-rich plants can develop defensive mechanisms against tannins, such as the strategic deployment of lipids and extracellular polysaccharides that have a high affinity to binding to tannins. Some ruminants (goats, deer, elk, moose) are able to consume food high in tannins (leaves, twigs, bark) due to

1118-463: The assumption that feeding habits in ruminants cause morphological differences in their digestive systems, including salivary glands, rumen size, and rumen papillae. However, Woodall found that there is little correlation between the fiber content of a ruminant's diet and morphological characteristics, meaning that the categorical divisions of ruminants by Hofmann and Stewart warrant further research. Also, some mammals are pseudoruminants , which have

1161-447: The cecotropes. The primary difference between ruminants and nonruminants is that ruminants' stomachs have four compartments: The first two chambers are the rumen and the reticulum. These two compartments make up the fermentation vat and are the major site of microbial activity. Fermentation is crucial to digestion because it breaks down complex carbohydrates, such as cellulose, and enables the animal to use them. Microbes function best in

1204-510: The coelacanth and lungfish. The IgW1 and IgW2 in coelacanth has a usual (VD)n-Jn-C structure as well as having a large number of constant domains. Frogs can synthesize IgX and IgY. Ruminant Ruminants are herbivorous grazing or browsing artiodactyls belonging to the suborder Ruminantia that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microbial actions. The process, which takes place in

1247-400: The digestion and absorption of nutrients occurs. The small intestine is the main site of nutrient absorption. The surface area of the digesta is greatly increased here because of the villi that are in the small intestine. This increased surface area allows for greater nutrient absorption. Microbes produced in the reticulorumen are also digested in the small intestine. After the small intestine is

1290-484: The early Miocene . Ruminantia is a crown group of ruminants within the order Artiodactyla , cladistically defined by Spaulding et al. as "the least inclusive clade that includes Bos taurus (cow) and Tragulus napu (mouse deer)". Ruminantiamorpha is a higher-level clade of artiodactyls, cladistically defined by Spaulding et al. as "Ruminantia plus all extinct taxa more closely related to extant members of Ruminantia than to any other living species." This

1333-786: The front part of the digestive system and therefore is called foregut fermentation , typically requires the fermented ingesta (known as cud ) to be regurgitated and chewed again. The process of rechewing the cud to further break down plant matter and stimulate digestion is called rumination . The word "ruminant" comes from the Latin ruminare , which means "to chew over again". The roughly 200 species of ruminants include both domestic and wild species. Ruminating mammals include cattle , all domesticated and wild bovines , goats , sheep , giraffes , deer , gazelles , and antelopes . It has also been suggested that notoungulates also relied on rumination, as opposed to other atlantogenatans that rely on

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1376-418: The large intestine. The major roles here are breaking down mainly fiber by fermentation with microbes, absorption of water (ions and minerals) and other fermented products, and also expelling waste. Fermentation continues in the large intestine in the same way as in the reticulorumen. Only small amounts of glucose are absorbed from dietary carbohydrates. Most dietary carbohydrates are fermented into VFAs in

1419-623: The leaf, bud, seed, root, and stem tissues, tannins are widely distributed in many different species of plants. Tannins are separated into two classes: hydrolysable tannins and condensed tannins . Depending on their concentration and nature, either class can have adverse or beneficial effects. Tannins can be beneficial, having been shown to increase milk production, wool growth, ovulation rate, and lambing percentage, as well as reducing bloat risk and reducing internal parasite burdens. Tannins can be toxic to ruminants, in that they precipitate proteins, making them unavailable for digestion, and they inhibit

1462-516: The more typical hindgut fermentation , though this is not entirely certain. Ruminants represent the most diverse group of living ungulates . The suborder Ruminantia includes six different families: Tragulidae , Giraffidae , Antilocapridae , Cervidae , Moschidae , and Bovidae . The first fossil ruminants appeared in the Early Eocene and were small, likely omnivorous, forest-dwellers. Artiodactyls with cranial appendages first occur in

1505-628: The most primitive animals that are able to make antibodies like those described for mammals. However, fish do not have the same repertoire of antibodies that mammals possess. Three distinct Ig heavy chains have so far been identified in bony fish . Similar to the situation observed for bony fish, three distinct Ig heavy chain isotypes have been identified in cartilaginous fish . With the exception of μ, these Ig heavy chain isotypes appear to be unique to cartilaginous fish. The resulting antibodies are designated IgW (also called IgX or IgNARC) and IgNAR ( immunoglobulin new antigen receptor ). The latter type

1548-460: The particle size. Smaller particle size allows for increased nutrient absorption. Fiber, especially cellulose and hemicellulose , is primarily broken down in these chambers by microbes (mostly bacteria , as well as some protozoa , fungi , and yeast ) into the three volatile fatty acids (VFAs): acetic acid , propionic acid , and butyric acid . Protein and nonstructural carbohydrate ( pectin , sugars , and starches ) are also fermented. Saliva

1591-487: The phosphorylation of myosin heavy chains Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title Heavy chain . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Heavy_chain&oldid=716693766 " Category : Disambiguation pages Hidden categories: Short description

1634-430: The plants and the cycle begins once again. In essence, the methane belched from cattle is not adding new carbon to the atmosphere. Rather it is part of the natural cycling of carbon through the biogenic carbon cycle . In 2010, enteric fermentation accounted for 43% of the total greenhouse gas emissions from all agricultural activity in the world, 26% of the total greenhouse gas emissions from agricultural activity in

1677-568: The presence in their saliva of tannin-binding proteins. The Law of Moses in the Bible allowed the eating of some mammals that had cloven hooves (i.e. members of the order Artiodactyla ) and "that chew the cud", a stipulation preserved to this day in Jewish dietary laws . The verb 'to ruminate' has been extended metaphorically to mean to ponder thoughtfully or to meditate on some topic. Similarly, ideas may be 'chewed on' or 'digested'. 'Chew

1720-408: The reticulorumen. The degraded digesta, which is now in the lower liquid part of the reticulorumen, then passes into the next chamber, the omasum. This chamber controls what is able to pass into the abomasum. It keeps the particle size as small as possible in order to pass into the abomasum. The omasum also absorbs volatile fatty acids and ammonia. After this, the digesta is moved to the true stomach,

1763-541: The rumen, they consume about 10% of the carbon, 60% of the phosphorus, and 80% of the nitrogen that the ruminant ingests. To reclaim these nutrients, the ruminant then digests the bacteria in the abomasum . The enzyme lysozyme has adapted to facilitate digestion of bacteria in the ruminant abomasum. Pancreatic ribonuclease also degrades bacterial RNA in the ruminant small intestine as a source of nitrogen. During grazing, ruminants produce large amounts of saliva – estimates range from 100 to 150 litres of saliva per day for

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1806-654: The rumen. The glucose needed as energy for the brain and for lactose and milk fat in milk production, as well as other uses, comes from nonsugar sources, such as the VFA propionate, glycerol, lactate, and protein. The VFA propionate is used for around 70% of the glucose and glycogen produced and protein for another 20% (50% under starvation conditions). Wild ruminants number at least 75 million and are native to all continents except Antarctica and Australia. Nearly 90% of all species are found in Eurasia and Africa. Species inhabit

1849-490: The somatic hypermutation step targets the V(D)J recombination process, the target in cows is on the creation of diverse disulfide bonds and the generation of unique sets of loops which interact with antigen. A speculated evolutionary driver for this variation is the presence of a vastly more diverse microbial environment in the digestive system of the cow as a consequence of their being ruminants . Jawed fish appear to be

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