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67-478: CPEB is involved in closed-loop regulation of mRNAs that keeps them inactive. The closed-loop structure between the 3'UTR and 5'UTR inhibits translation. This has been observed in Xenopus laevis in which eIF4E bound to the 5' cap interacts with Maskin bound to CPEB on the 3' UTR creating translationally inactive transcripts . This translational inhibition is lifted once CPEB is phosphorylated , displacing

134-523: A cell-free environment which allows easier manipulation. The first vertebrate ever to be cloned was an African clawed frog in 1962, an experiment for which Sir John Gurdon was awarded the Nobel Prize in Physiology or Medicine in 2012 "for the discovery that mature cells can be reprogrammed to become pluripotent". Additionally, four female African clawed frogs and stored sperm were present on

201-426: A concerted effort to remove this species to ensure the survival of other indigenous species. Huntingtin 3IO6 , 3IOU , 3LRH , 4FE8 , 4FEB , 4FEC , 4FED , 2LD0 , 2LD2 , 3IO4 , 3IOR , 3IOT , 3IOV , 3IOW , 4RAV 3064 15194 ENSG00000197386 ENSMUSG00000029104 P42858 P42859 NM_002111 NM_001388492 NM_010414 NP_002102 NP_034544 Huntingtin (Htt)

268-490: A coping mechanism—and not simply a pathogenic mechanism—to stem neuronal death by decreasing the amount of diffuse huntingtin. This process is particularly likely to occur in the striatum (a part of the brain that coordinates movement) primarily, and the frontal cortex (a part of the brain that controls thinking and emotions). People with 36 to 40 CAG repeats may or may not develop the signs and symptoms of Huntington disease, while people with more than 40 repeats will develop

335-527: A cysteine-histidine region that is reminiscent of a zinc finger." The zinc finger region and RRMs are necessary for RNA bind. It was found that CPEB bound to other metals than zinc destroyed RNA binding, but the binding would be restored if supplemented with zinc. Proteins lacking any of the RRMs were also shown to be less efficient in binding RNA. Not all of the regions are the same across the different forms of CPEB. The amino terminus can differ substantially across

402-460: A form of programmed cell death . The huntingtin protein is required for normal development before birth . It is expressed in many tissues in the body, with the highest levels of expression seen in the brain. The 5'-end (five prime end) of the HTT gene has a sequence of three DNA bases, cytosine-adenine-guanine (CAG), coding for the amino acid glutamine , that is repeated multiple times. This region

469-459: A harmful invasive species. They can travel short distances to other bodies of water, and some have even been documented to survive mild freezes. They have been shown to devastate native populations of frogs and other creatures by eating their young. In 2003, Xenopus laevis frogs were discovered in a pond at San Francisco 's Golden Gate Park . Much debate now exists in the area on how to exterminate these creatures and keep them from spreading. It

536-494: A knockdown of CPEB, they bypassed the M1 crisis stage of senescence. This bypass is required for cellular transformation. Reduced CPEB levels also affected the rate at which cell division occurred, slowing down the process until the cells ceased to divide. In mice, reduced CPEB levels caused cells to become immortal. A senescence-like phenotype recurred when CPEB was introduced into early passage cells, but not late passage cells. Senescence

603-541: A more comprehensive discussion of the use of these frogs in biomedical research, see Xenopus . Xenopus laevis is also notable for its use in the first widely used method of pregnancy testing . In the 1930s, two South African researchers, Hillel Shapiro and Harry Zwarenstein, students of Lancelot Hogben at the University of Cape Town , discovered that the urine from pregnant women would induce oocyte production in X. laevis within 8–12 hours of injection. This

670-458: A more pronounced cloaca and have hip-like bulges above their rear legs where their eggs are internally located. Both males and females have a cloaca , which is a chamber through which digestive and urinary wastes pass and through which the reproductive systems also empty. The cloaca empties by way of the vent which in reptiles and amphibians is a single opening for all three systems. African clawed frogs are fully aquatic and will rarely leave

737-516: A mottled greenish-grey-brown in color, sometimes with yellowish botches, and with a pale white-cream belly. African clawed frogs have been frequently sold as pets, and are sometimes misidentified as African dwarf frogs . Albino clawed frogs are common and sold as animals for laboratories . Amphibians reproduce by fertilizing eggs outside of the female's body (see frog reproduction ). Of the seven amplexus modes (positions in which frogs mate), these frogs are found breeding in inguinal amplexus, where

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804-457: A neuronal-specific microexon together with a new molecular signature of global polyadenine tail shortening..." In idiopathic autism spectrum disorder individuals, CPEB4 is greatly decreased and showed significant splicing alterations. An equivalent isoform imbalance in mice mimics changes of autism spectrum disorder genes, which causes similar neuroanatomical, electrophysiological, and behavioral phenotype expression. Gene regulation of CPEB proteins

871-631: A permit in the following US states: Arizona, California, Kentucky, Louisiana, New Jersey, North Carolina, Oregon, Vermont, Virginia, Hawaii, Nevada, and Washington state. However, it is legal to own Xenopus laevis in New Brunswick (Canada) and Ohio. Feral colonies of Xenopus laevis exist in South Wales , United Kingdom . In Yunnan , China there is a population of albino clawed frogs in Lake Kunming , along with another invasive:

938-474: A role in the formation of long-term memory . It has been suggested that "both memory storage and its underlying synaptic plasticity are mediated by the increase in. . .CPEB." CPEBs are responsible for the polyadenine tail length in oocytes during oogenesis . In Xenopus and mice oocytes, CPEB has been noted to control oocyte growth. Regulation of follicle development has been noted specifically in mice. CPEB regulates oocyte development and follicle development in

1005-467: Is a scaffolding protein in the ATM oxidative DNA damage response complex. Mutant huntingtin (mHtt) plays a key role in mitochondrial dysfunction involving the inhibition of mitochondrial electron transport , higher levels of reactive oxygen species and increased oxidative stress . The promotion of oxidative damage to DNA may contribute to Huntington's disease pathology. Huntington's disease (HD)

1072-561: Is able to fit into their mouths. Being aquatic, clawed frogs use their sense of smell and their lateral line to detect prey rather than eyesight like other frogs. However, clawed frogs can still see using their eyes and will stalk prey or watch predators by sticking their heads out of the water. Clawed frogs will dig through substrate to unearth worms and other food. Unlike other frogs, they have no tongue to extend to catch food, so clawed frogs use their hands to grab food and shovel it into their mouths. These frogs are particularly cannibalistic;

1139-441: Is also proposed as a target for gene therapy.. Fragile X syndrome and Huntington's disease are two such disorders and diseases where CPEB regulation has been used to attempt recovery of brain function. There is not a cure for either of these afflictions, but translation dysfunction of CPEB proteins can be a cause for either. When modeling fragile X syndrome in mice, CPEB1 gene mutations reduced pathological processes associated with

1206-473: Is called a trinucleotide repeat . The usual CAG repeat count is between seven and 35 repeats. The HTT gene is located on the short arm (p) of chromosome 4 at position 16.3, from base pair 3,074,510 to base pair 3,243,960. The function of huntingtin (Htt) is not well understood but it is involved in axonal transport . Huntingtin is essential for development, and its absence is lethal in mice. The protein has no sequence homology with other proteins and

1273-492: Is caused by a mutated form of the huntingtin gene, where excessive (more than 36) CAG repeats result in formation of an unstable protein. These expanded repeats lead to production of a huntingtin protein that contains an abnormally long polyglutamine tract at the N-terminus. This makes it part of a class of neurodegenerative disorders known as trinucleotide repeat disorders or polyglutamine disorders. The key sequence which

1340-632: Is considered a more viable model for genetics, although gene editing protocols have now been perfected for. Roger Wolcott Sperry used X. laevis for his famous experiments describing the development of the visual system. These experiments led to the formulation of the chemoaffinity hypothesis . X. laevis have been used as a model organism in vertebrae cardiogenesis, human congenital heart defects, and in GWAS studies of congenital heart defects. Xenopus oocytes provide an important expression system for molecular biology . By injecting DNA or mRNA into

1407-647: Is considered an irreversible process, but the CPEB-induced senescence-like phenotype can possibly refute that. CPEB is thus shown to regulate senescence, as well as mediate immortalization in cells. Drosophila Orb2 binds to genes implicated in long-term memory. An isoform of CPEB found in the neurons of the sea slug Aplysia californica , as well as in Drosophila , mice, and humans, contains an N-terminal domain not found in other isoforms that shows high sequence similarity to prion proteins. Experiments with

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1474-643: Is found in Huntington's disease is a trinucleotide repeat expansion of glutamine residues beginning at the 18th amino acid. In unaffected individuals, this contains between 9 and 35 glutamine residues with no adverse effects. However, 36 or more residues produce an erroneous mutant form of Htt, (mHtt). Reduced penetrance is found in counts 36–39. Enzymes in the cell often cut this elongated protein into fragments. The protein fragments form abnormal clumps, known as neuronal intranuclear inclusions (NIIs), inside nerve cells, and may attract other, normal proteins into

1541-410: Is highly expressed in neurons and testes in humans and rodents. Huntingtin upregulates the expression of brain-derived neurotrophic factor (BDNF) at the transcription level, but the mechanism by which huntingtin regulates gene expression has not been determined. From immunohistochemistry , electron microscopy , and subcellular fractionation studies of the molecule, it has been found that huntingtin

1608-1040: Is primarily associated with vesicles and microtubules . These appear to indicate a functional role in cytoskeletal anchoring or transport of mitochondria . The Htt protein is involved in vesicle trafficking as it interacts with HIP1, a clathrin -binding protein, to mediate endocytosis , the trafficking of materials into a cell. Huntingtin has also been shown to have a role in the establishment in epithelial polarity through its interaction with RAB11A . Huntingtin has been found to interact directly with at least 19 other proteins , of which six are used for transcription, four for transport, three for cell signalling, and six others of unknown function (HIP5, HIP11, HIP13, HIP15, HIP16, and CGI-125). Over 100 interacting proteins have been found, such as huntingtin-associated protein 1 (HAP1) and huntingtin interacting protein 1 (HIP1), these were typically found using two-hybrid screening and confirmed using immunoprecipitation . Huntingtin has also been shown to interact with: Huntingtin

1675-468: Is the protein coded for in humans by the HTT gene , also known as the IT15 ("interesting transcript 15") gene. Mutated HTT is the cause of Huntington's disease (HD), and has been investigated for this role and also for its involvement in long-term memory storage. It is variable in its structure, as the many polymorphisms of the gene can lead to variable numbers of glutamine residues present in

1742-486: Is unknown if these frogs entered the San Francisco ecosystem through intentional release or escape into the wild. San Francisco officials drained Lily Pond and fenced off the area to prevent the frogs from escaping to other ponds in the hopes they starve to death. Due to incidents in which these frogs were released and allowed to escape into the wild, African clawed frogs are illegal to own, transport or sell without

1809-493: The platanna ) is a species of African aquatic frog of the family Pipidae . Its name is derived from the short black claws on its feet. The word Xenopus means 'strange foot' and laevis means 'smooth'. The species is found throughout much of Sub-Saharan Africa ( Nigeria and Sudan to South Africa ), and in isolated, introduced populations in North America, South America, Europe, and Asia. All species of

1876-486: The American bullfrog . Because this population is albino, it suggests that the clawed frogs originated from the pet trade or a laboratory. The African clawed frog may be an important vector and the initial source of Batrachochytrium dendrobatidis , a chytrid fungus that has been implicated in the drastic decline in amphibian populations in many parts of the world. Unlike in many other amphibian species (including

1943-533: The Aplysia isoform expressed in yeast reveal that CPEB has a key property associated with prions: it can cause other proteins to assume alternate protein conformations that are heritable in successive generations of yeast cells. Furthermore, the functional RNA-binding form of the CPEB protein may be the prion-like state. These observations have led to the suggestion that long-lasting bistable prionlike proteins play

2010-476: The Space Shuttle Endeavour when it was launched into space on mission STS-47 on September 12, 1992, so that scientists could test whether reproduction and development could occur normally in zero gravity. Xenopus laevis also serves as an ideal model system for the study of the mechanisms of apoptosis. In fact, iodine and thyroxine stimulate the spectacular apoptosis of the cells of

2077-444: The dictyate stage through phosphorylation and dephosphorylation. During pachytene, CPEB is phosphorylated, which controls polyadenylation and translation of mRNAs. An experiment was conducted to determine how CPEB affected development by inhibiting the protein in mice. It was found that CPEB regulates Gdf9 , a growth factor necessary for follicle development. Without CPEB, Gdf9 had a shortened polyadenine tail and reduced expression. It

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2144-717: The mediobasal hypothalamus , then it stimulates seasonal testicular growth; if peripherally, then testicular regression and cold-season thermogenesis. These observations are regarded as widely applicable across vertebrate thyroid systems. The lipidomics of Xenopus oocytes have been studied by Tian et al 2014 and Phan et al 2015. In X. laevis , epigenetic methylation changes in neural-developmental genes associated with aging are analogous to aging related epigenetic changes in mammalian species. This finding suggests that, during their evolutionary divergence, patterns of epigenetic changes in neural-development genes during aging have been conserved between frogs and mammals C. In

2211-481: The oocyte . Translation of proteins can be blocked or splicing of pre-mRNA can be modified by injection of Morpholino antisense oligos into the oocyte (for distribution throughout the embryo) or early embryo (for distribution only into daughter cells of the injected cell). Extracts from the eggs of X. laevis frogs are also commonly used for biochemical studies of DNA replication and repair, as these extracts fully support DNA replication and other related processes in

2278-515: The Maskin binding site, allowing for the polymerization of the PolyA tail , which can recruit the translational machinery by means of PABP . However, is important to note that this mechanism has been under great scrutiny. CPEB has been shown to shuttle between the nucleus and cytoplasm . In the nuclei of different organisms, it was found that CPEB helps guide the path of mRNA in the cytoplasm. CPEB

2345-568: The National Institutes of Health. The work rapidly expanded to include de novo reconstruction of X. laevis transcripts, in collaboration with groups around the world donating Illumina Hi-Seq RNA sequencing datasets. Genome sequencing by the Rokhsar and Harland groups (UC Berkeley) and by Taira and collaborators (University of Tokyo, Japan) gave a major boost to the project, which, with additional contributions from investigators in

2412-496: The Netherlands, Korea, Canada and Australia, led to publication of the genome sequence and its characterization in 2016. X. laevis oocytes are often used as an easy model for the artificially induced expression of transgenes . For example, they are commonly used when studying chloroquine resistance produced by specialized transporter mutants. Even so the foreign expression tissue may itself confer some alterations to

2479-514: The closely related western clawed frog ) where this chytrid fungus causes the disease Chytridiomycosis , it does not appear to affect the African clawed frog, making it an effective carrier. Invasive: The African clawed frog is considered invasive by the Centre of Invasive biology from Stellenbosh University with this species even going as far as predating on other species. There has even been

2546-462: The clumps. The characteristic presence of these clumps in patients was thought to contribute to the development of Huntington disease. However, later research raised questions about the role of the inclusions (clumps) by showing the presence of visible NIIs extended the life of neurons and acted to reduce intracellular mutant huntingtin in neighboring neurons. One confounding factor is that different types of aggregates are now recognised to be formed by

2613-401: The disorder during a normal lifetime. When there are more than 60 CAG repeats, the person develops a severe form of HD known as juvenile HD . Therefore, the number of CAG (the sequence coding for the amino acid glutamine) repeats influences the age of onset of the disease. No case of HD has been diagnosed with a count less than 36. As the altered gene is passed from one generation to the next,

2680-530: The disorder. A decrease in CPEB1 restored the balance of mRNA translation, which can be achieved by manipulating levels of miRNAs. For Huntington's disease, a study on a Drosophila cell culture showed that the Drosophila Orb2A protein was absorbed on the surface of Huntingtin gene (Htt) aggregates . The aggregates lead to a protein synthesis imbalance, cell decay, and neuron death. The absorption of

2747-510: The expression, and so findings may or may not be entirely identical to native expression: For example, iron has been found by Bakouh et al 2017 to be an important substrate for one such transporter in X. l. oocytes, but as of 2020 iron is merely presumptively involved in native expression of the same gene. Xenbase is the Model Organism Database (MOD) for both Xenopus laevis and Xenopus tropicalis . Xenbase hosts

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2814-427: The family Pipidae are tongueless, toothless and completely aquatic. They use their hands to shove food in their mouths and down their throats and a hyobranchial pump to draw or suck things in their mouth. Pipidae have powerful legs for swimming and lunging after food. They also use the claws on their feet to tear pieces of large food. They have no external eardrums, but instead subcutaneous cartilaginous disks that serve

2881-550: The full details and release information regarding the current v10 Xenopus laevis genome released in 2022. The clawed frog have been kept as pets and research subjects since as early as the 1950s. They are extremely hardy and long lived, having been known to live up to 20 or even 30 years in captivity. African clawed frogs are frequently mislabeled as African dwarf frogs in pet stores. Identifiable differences are: African clawed frogs are voracious predators and easily adapt to many habitats. For this reason, they can easily become

2948-615: The larval gills, tail and fins in amphibians metamorphosis , and stimulate the evolution of their nervous system transforming the aquatic, vegetarian tadpole into the terrestrial, carnivorous frog. Stem cells of this frog were used to create xenobots . Early work on sequencing of the X. laevis genome was started when the Wallingford and Marcotte labs obtained funding from the Texas Institute for Drug and Diagnostic Development (TI3D), in conjunction with projects funded by

3015-425: The male clasps the female in front of the female's back legs until eggs are laid, and the male fertilizes the egg mass with the release of sperm. African clawed frogs are highly adaptable and will lay their eggs whenever conditions allow it. During wet rainy seasons they will travel to other ponds or puddles of water to search for food and new ponds. During times of drought, the clawed frogs can burrow themselves into

3082-444: The male. This frog has smooth slippery skin which is multicolored on its back with blotches of olive gray or brown. The underside is creamy white with a yellow tinge. Male and female frogs can be easily distinguished through the following differences. Male frogs are small and slim, while females are larger and more rotund. Males have black patches on their hands and arms which aid in grabbing onto females during amplexus. Females have

3149-474: The mud, becoming dormant for up to a year. Xenopus laevis have been known to survive 15 or more years in the wild and 25–30 years in captivity. They shed their skin every season, and eat their own shed skin. Although lacking a vocal sac , the males make a mating call of alternating long and short trills, by contracting the intrinsic laryngeal muscles . Females also answer vocally, signaling either acceptance (a rapping sound) or rejection (slow ticking) of

3216-426: The mutant protein, including protein deposits that are too small to be recognised as visible deposits in the above-mentioned studies. The likelihood of neuronal death remains difficult to predict. Likely multiple factors are important, including: (1) the length of CAG repeats in the huntingtin gene and (2) the neuron's exposure to diffuse intracellular mutant huntingtin protein. NIIs (protein clumping) can be helpful as

3283-444: The oocyte or developing embryo, scientists can study the protein products in a controlled system. This allows rapid functional expression of manipulated DNAs (or mRNA ). This is particularly useful in electrophysiology , where the ease of recording from the oocyte makes expression of membrane channels attractive. One challenge of oocyte work is eliminating native proteins that might confound results, such as membrane channels native to

3350-629: The protein caused a partial reduction of the lethality of the Htt aggregates. The aggregates did not decrease, but protein synthesis balance was restored in the cells. However, CPEB sequestration translation dysfunction is not a definite cause of Huntington's disease symptoms in humans. Other RNA binding proteins could be other possible targets for translation dysfunction in patients with this disease. CPEB has been found to help regulate cellular senescence through modulating p53 mRNA polyadenylation-induced translation. When human skin and lung cells were put under

3417-399: The protein. In its wild-type (normal) form, the polymorphic locus contains 6-35 glutamine residues. However, in individuals affected by Huntington's disease (an autosomal dominant genetic disorder ), the polymorphic locus contains more than 36 glutamine residues (highest reported repeat length is about 250). Its commonly used name is derived from this disease; previously, the IT15 label

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3484-512: The proteins. The prion-like isoform of CPEB found in Aplysia californica, Drosophila, mice, and humans is an example of such differentiation. This isoform is prion-like due to the presence of polyglutamine- or polyalanine-rich domains at the N-terminus. A misstep in the process of translation with CPEB can lead to possible adverse affects on neurological development. Risk genes for autism spectrum disorder were found in brains where "...CPEB4 transcript isoform imbalance due to decreased inclusion of

3551-416: The same function. They use their sensitive fingers and sense of smell to find food. Pipidae are scavengers and will eat almost anything living, dying, or dead and any type of organic waste. It is considered an invasive species in several countries , including across Europe. These frogs are plentiful in ponds and rivers within the south-eastern portion of Sub-Saharan Africa. They are aquatic and are often

3618-629: The second contains CPEB2 - CPEB4. The general CPE that CPEBs bind to has a canonical UUUUAU sequence, which all four of the proteins can recognize. However, CPEB1 can only recognize CPEs with the canonical sequence, while the second group of CPEB2–4 can also bind to variants of the CPE, known as G-variants due to their sequence difference (UUUUGU). This suggests that CPEB2–4 has other targets that it can hit in addition to CPEB1 targets. The CPEB structure consists of "...an amino-terminal port with no obvious functional motif, two RNA recognition motifs (RRMS), and

3685-751: The stomach contents of feral clawed frogs in California have revealed large amounts of the frog's larvae. Clawed frog larvae are filter feeders and collect nutrients from plankton, allowing adult frogs that consume the tadpoles to have access to these nutrients. This allows clawed frogs to survive in areas that have little to no other food sources. Clawed frogs are nocturnal and most reproductive activity and feeding occurs after dark. Male clawed frogs are very promiscuous and will grab onto other males and even other species of frogs. Male frogs that are grasped will make release calls and attempt to break free. If not feeding, clawed frogs will just sit motionless on top of

3752-590: The substrate or floating, legs splayed below, at the waters surface with their nostrils and eyes sticking out. The clawed frog liver responds to low temperatures by increasing production of type II iodothyronine deiodinase through increased food intake . This in turn spurs the thyroid to increase T 3 to increase body temperature . (This T 3 increase also induces germ cell apoptosis , mediated through genes left over from tadpole metamorphosis.) The effects of provocation of T hormone release are broadly differentiated by where it starts: If centrally, within

3819-561: The super short generation time , or genetic simplicity generally desired in genetic model organisms , it is an important model organism in developmental biology , cell biology , toxicology and neurobiology . X. laevis takes 1 to 2 years to reach sexual maturity and, like most of its genus, it is tetraploid . It does have a large and easily manipulated embryo , however. The ease of manipulation in amphibian embryos has given them an important place in historical and modern developmental biology. A related species, Xenopus tropicalis ,

3886-401: The translation regulation. CPEB can also refer to the family of proteins. There are four proteins in the protein family: This protein family can be divided into two subfamilies. The groups are separated by their ..specific properties in target/motif recognition, large-order complex co-factors, and dynamic properties and regulation during cell cycle." The first subfamily contains only CPEB1 and

3953-676: The water except to migrate to new water bodies during droughts or other disturbances. Clawed frogs have powerful legs that help them move quickly both underwater and on land. Feral clawed frogs in South Wales have been found to travel up to 2 kilometres (1.2 mi) between locations. The feet of Xenopus species have three black claws on the last three digits. These claws are used to rip apart food and scratch predators. Clawed frogs are carnivores and will eat both living and dead prey including fish, tadpoles, crustaceans, annelids, arthropods, and more. Clawed frogs will try to consume anything that

4020-654: The wide breadth of Xenopus research stems from the additional fact that cell-free extracts made from Xenopus are a premier in vitro system for studies of fundamental aspects of cell and molecular biology. Thus, Xenopus is the only vertebrate model system that allows for high-throughput in vivo analyses of gene function and high-throughput biochemistry. Xenopus oocytes are a leading system in their own right for studies of various systems, including ion transport and channel physiology. Xanthos et al 2001 uses oocytes to uncover T-box expression earlier than previously found in vertebrates. Although X. laevis does not have

4087-555: The wild - Found at higher densities in artificial water bodies such as ponds, dams and irrigation canals, rather than in natural lagoons or streams or rivers. - There is no evidence of predation on native anurans, but rather on their own larvae. - They face predation from native birds. Cause of concerns from African clawed frogs - They are reaching both lower and higher altitudes than formerly estimated. - They are able to migrate overland to colonise other water bodies, causing ecological disruption and spreading diseases. X. laevis in

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4154-472: The wild are commonly infected by various parasites , including monogeneans in the urinary bladder . Xenopus embryos and eggs are a popular model system for a wide variety of biological studies, in part because they have the potential to lay eggs throughout the year. This animal is widely used because of its powerful combination of experimental tractability and close evolutionary relationship with humans, at least compared to many model organisms. For

4221-614: The wild, X. laevis are native to wetlands , ponds, and lakes across arid/semiarid regions of Sub-Saharan Africa . X. laevis and X. muelleri occur along the western boundary of the Great African Rift . The people of the sub-Saharan are generally very familiar with this frog, and some cultures use it as a source of protein, an aphrodisiac , or as fertility medicine . Two historic outbreaks of priapism have been linked to consumption of frog legs from frogs that ate insects containing cantharidin . African clawed frogs in

4288-508: Was also found that progressive oocyte loss and infertility arose from the knockdown of CPEB in oocytes, which resembles premature ovarian failure syndrome in humans. CPEB has been shown to interact with the following proteins: This protein -related article is a stub . You can help Misplaced Pages by expanding it . Xenopus laevis X. boiei Wagler 1827 The African clawed frog ( Xenopus laevis ), also known as simply xenopus , African clawed toad , African claw-toed frog or

4355-496: Was commonly used. The mass of huntingtin protein is dependent largely on the number of glutamine residues it has; the predicted mass is around 350  kDa . Normal huntingtin is generally accepted to be 3144 amino acids in size. The exact function of this protein is not known, but it plays an important role in nerve cells . Within cells, huntingtin may or may not be involved in signaling, transporting materials, binding proteins and other structures, and protecting against apoptosis ,

4422-401: Was found to be almost exclusively in the c plasm in stage VI Xenopus oocytes. However, a further study on this topic found that there is a substantial amount of CPEB in the nucleus. CPEB can bind with CPE-containing mRNAs in the nucleus, which forces tight translational regulation in the cytoplasm. CPEBs bound to these mRNAs were found to have wer translation efficiency, which is indicative of

4489-528: Was used as a simple and reliable test up through to the 1960s. In the late 1940s, Carlos Galli Mainini found in separate studies that male specimens of Xenopus and Bufo could be used to indicate pregnancy Today, commercially available hCG is injected into Xenopus males and females to induce mating behavior and to breed these frogs in captivity at any time of the year. Xenopus has long been an important tool for in vivo studies in molecular, cell, and developmental biology of vertebrate animals. However,

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