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EDNRB
Endothelin receptor type B, also known as ETB is a protein that in humans is encoded by the ''EDNRB'' gene. Function Endothelin receptor type B is a G protein-coupled receptor which activates a phosphatidylinositol-calcium second messenger system. Its ligand, endothelin, consists of a family of three potent vasoactive peptides: ET1, ET2, and ET3. A splice variant, named SVR, has been described; the sequence of the ETB-SVR receptor is identical to ETRB except for the intracellular C-terminal domain. While both splice variants bind ET1, they exhibit different responses upon binding which suggests that they may be functionally distinct. Regulation In melanocytic cells the EDNRB gene is regulated by the microphthalmia-associated transcription factor. Mutations in either gene are links to Waardenburg syndrome. Clinical significance The multigenic disorder, Hirschsprung disease type 2, is due to mutation in endothelin receptor type B gene. Animals In horses, a mutation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lethal White Syndrome
Lethal white syndrome (LWS), also called overo lethal white syndrome (OLWS), lethal white overo (LWO), and overo lethal white foal syndrome (OLWFS), is an autosomal genetic disorder most prevalent in the American Paint Horse. Affected foals are born after the full 11-month gestation and externally appear normal, though they have all-white or nearly all-white coats and blue eyes. However, internally, these foals have a nonfunctioning colon. Within a few hours, signs of colic appear; affected foals die within a few days. Because the death is often painful, such foals are often humanely euthanized once identified. The disease is particularly devastating because foals are born seemingly healthy after being carried to full term. The disease has a similar cause to Hirschsprung's disease in humans. A mutation in the middle of the endothelin receptor type B (''EDNRB'') gene causes lethal white syndrome when homozygous. Carriers, which are heterozygous—that is, have one copy o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waardenburg Syndrome
Waardenburg syndrome is a group of rare genetic conditions characterised by at least some degree of congenital hearing loss and pigmentation deficiencies, which can include bright blue eyes (or one blue eye and one brown eye), a white forelock or patches of light skin. These basic features constitute type 2 of the condition; in type 1, there is also a wider gap between the inner corners of the eyes called telecanthus, or dystopia canthorum. In type 3, which is rare, the arms and hands are also malformed, with permanent finger contractures or fused fingers, while in type 4, the person also has Hirschsprung's disease. There also exist at least two types (2E and PCWH) that can result in central nervous system (CNS) symptoms such as developmental delay and muscle tone abnormalities. The syndrome is caused by mutations in any of several genes that affect the division and migration of neural crest cells during embryonic development (though some of the genes involved also affect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hirschsprung Disease
Hirschsprung's disease (HD or HSCR) is a birth defect in which nerves are missing from parts of the intestine. The most prominent symptom is constipation. Other symptoms may include vomiting, abdominal pain, diarrhea and slow growth. Symptoms usually become apparent in the first two months of life. Complications may include enterocolitis, megacolon, bowel obstruction and intestinal perforation. The disorder may occur by itself or in association with other genetic disorders such as Down syndrome or Waardenburg syndrome. About half of isolated cases are linked to a specific genetic mutation, and about 20% occur within families. Some of these occur in an autosomal dominant manner. The cause of the remaining cases is unclear. If otherwise normal parents have one child with the condition, the next child has a 4% risk of being affected. The condition is divided into two main types, short-segment and long-segment, depending on how much of the bowel is affected. Rarely, the sma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endothelin Receptor
There are at least four known endothelin receptors, ETA, ETB1, ETB2 and ETC, all of which are G protein-coupled receptors whose activation result in elevation of intracellular-free calcium, which constricts the smooth muscles of the blood vessels, raising blood pressure, or relaxes the smooth muscles of the blood vessels, lowering blood pressure, among other functions. Physiological functions *ETA is a subtype for vasoconstriction These receptors are found in the smooth muscle tissue of blood vessels, and binding of endothelin to ETA increases vasoconstriction (contraction of the blood vessel walls) and the retention of sodium, leading to increased blood pressure. *ETB1 mediates vasodilation, When endothelin binds to ETB1 receptors, this leads to the release of nitric oxide (also called endothelium-derived relaxing factor), natriuresis and diuresis (the production and elimination of urine) and mechanisms that lower blood pressure. *ETB2 mediates vasoconstriction *ETC has yet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overo
Overo refers to several genetically unrelated pinto coloration patterns of white-over-dark body markings in horses, and is a term used by the American Paint Horse Association to classify a set of pinto patterns that are not tobiano. ''Overo'' is a Spanish word, originally meaning "like an egg".''American Paint Horse Association's Guide to Coat Color Genetics'' American Paint Horse Association, 2007. Accessed August 19, 2008 The most common usage refers to frame overo, but splashed white and [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microphthalmia-associated Transcription Factor
Microphthalmia-associated transcription factor also known as class E basic helix-loop-helix protein 32 or bHLHe32 is a protein that in humans is encoded by the ''MITF'' gene. MITF is a basic helix-loop-helix leucine zipper transcription factor involved in lineage-specific pathway regulation of many types of cells including melanocytes, osteoclasts, and mast cells. The term "lineage-specific", since it relates to MITF, means genes or traits that are only found in a certain cell type. Therefore, MITF may be involved in the rewiring of signaling cascades that are specifically required for the survival and physiological function of their normal cell precursors. MITF, together with transcription factor EB ( TFEB), TFE3 and TFEC, belong to a subfamily of related bHLHZip proteins, termed the MiT-TFE family of transcription factors. The factors are able to form stable DNA-binding homo- and heterodimers. The gene that encodes for MITF resides at the ''mi'' locus in mice, and its prot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melanocyte
Melanocytes are melanin-producing neural crest-derived cells located in the bottom layer (the stratum basale) of the skin's epidermis, the middle layer of the eye (the uvea), the inner ear, vaginal epithelium, meninges, bones, and heart. Melanin is a dark pigment primarily responsible for skin color. Once synthesized, melanin is contained in special organelles called melanosomes which can be transported to nearby keratinocytes to induce pigmentation. Thus darker skin tones have more melanosomes present than lighter skin tones. Functionally, melanin serves as protection against UV radiation. Melanocytes also have a role in the immune system. Function Through a process called melanogenesis, melanocytes produce melanin, which is a pigment found in the skin, eyes, hair, nasal cavity, and inner ear. This melanogenesis leads to a long-lasting pigmentation, which is in contrast to the pigmentation that originates from oxidation of already-existing melanin. There a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bosentan
Bosentan, sold under the brand name Tracleer and Safebo among others, is a dual endothelin receptor antagonist medication used in the treatment of pulmonary artery hypertension (PAH). Bosentan is available as film-coated tablets (62.5 mg or 125 mg) or as dispersable tablets for oral suspension (32 mg). Medical uses Bosentan is used to treat people with moderate pulmonary arterial hypertension and to reduce the number of digital ulcers — open wounds on especially on fingertips and less commonly the knuckles — in people with systemic scleroderma. Bosentan causes harm to fetuses and pregnant women must not take it, and women must not become pregnant while taking it (Pregnancy Category X). It may render hormonal contraceptives ineffective so other forms of birth control must be used. In the US it is only available from doctors who follow an FDA-mandated risk evaluation and mitigation strategy (REMS) with respect to risks to fetuses and its risks of causing liv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caveolin 1
Caveolin-1 is a protein that in humans is encoded by the ''CAV1'' gene. Function The scaffolding protein encoded by this gene is the main component of the caveolae plasma membranes found in most cell types. The protein links integrin subunits to the tyrosine kinase FYN, an initiating step in coupling integrins to the Ras-ERK pathway and promoting cell cycle progression. The gene is a tumor suppressor gene candidate and a negative regulator of the Ras-p42/44 MAP kinase cascade. CAV1 and CAV2 are located next to each other on chromosome 7 and express colocalizing proteins that form a stable hetero-oligomeric complex. By using alternative initiation codons in the same reading frame, two isoforms (alpha and beta) are encoded by a single transcript from this gene. Interactions Caveolin 1 has been shown to interact with heterotrimeric G proteins, Src tyrosine kinases ( Src, Lyn) and H-Ras, cholesterol, TGF beta receptor 1, endothelial NOS, androgen receptor, amyloid precursor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equine Coat Color
Horses exhibit a diverse array of coat colors and distinctive markings. A specialized vocabulary has evolved to describe them. While most horses remain the same color throughout life, a few, over the course of several years, will develop a different coat color from that with which they were born. Most white markings are present at birth, and the underlying skin color of a healthy horse does not change. Some Equine coat colors are also related to the breed of horse, like the Friesian breed for instance. The basic outline of equine coat color genetics has largely been resolved, and DNA tests to determine the likelihood that a horse will have offspring of a given color have been developed for some colors. Discussion, research, and even controversy continues about some of the details, particularly those surrounding spotting patterns, color sub-shades such as "sooty" or " flaxen", and markings. Basic coat colors The two basic pigment colors of horse hairs are pheomelanin ("red" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
