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Progressive Retinal Atrophy
Progressive retinal atrophy (PRA) is a group of genetic diseases seen in certain breeds of dogs and, more rarely, cats. Similar to retinitis pigmentosa in humans, it is characterized by the bilateral degeneration of the retina, causing progressive vision loss culminating in blindness. The condition in nearly all breeds is inherited as an autosomal recessive trait, with the exception of the Siberian Husky (inherited as an X chromosome linked trait) and the Bullmastiff (inherited as an autosomal dominant trait). There is no treatment. Types of PRA In general, PRAs are characterised by initial loss of rod photoreceptor cell function followed by that of the cones and for this reason night blindness is the first significant clinical sign for most dogs affected with PRA. As other retinal disorders, PRA can be divided into either dysplastic disease, where the cells develop abnormally, and degenerative, where the cells develop normally but then degenerate during the dog's lifetime. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetics
Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar working in the 19th century in Brno, was the first to study genetics scientifically. Mendel studied "trait inheritance", patterns in the way traits are handed down from parents to offspring over time. He observed that organisms (pea plants) inherit traits by way of discrete "units of inheritance". This term, still used today, is a somewhat ambiguous definition of what is referred to as a gene. Trait inheritance and molecular inheritance mechanisms of genes are still primary principles of genetics in the 21st century, but modern genetics has expanded to study the function and behavior of genes. Gene structure and function, variation, and distribution are studied within the context of the cell, the organism (e.g. dominance), and within the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphodiesterase
A phosphodiesterase (PDE) is an enzyme that breaks a phosphodiester bond. Usually, ''phosphodiesterase'' refers to cyclic nucleotide phosphodiesterases, which have great clinical significance and are described below. However, there are many other families of phosphodiesterases, including phospholipases C and D, autotaxin, sphingomyelin phosphodiesterase, DNases, RNases, and restriction endonucleases (which all break the phosphodiester backbone of DNA or RNA), as well as numerous less-well-characterized small-molecule phosphodiesterases. The cyclic nucleotide phosphodiesterases comprise a group of enzymes that degrade the phosphodiester bond in the second messenger molecules cAMP and cGMP. They regulate the localization, duration, and amplitude of cyclic nucleotide signaling within subcellular domains. PDEs are therefore important regulators of signal transduction mediated by these second messenger molecules. History These multiple forms (isoforms or subtypes) of ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poodle
The Poodle, called the Pudel in German and the Caniche in French, is a breed of water dog. The breed is divided into four varieties based on size, the Standard Poodle, Medium Poodle, Miniature Poodle and Toy Poodle, although the Medium Poodle variety is not universally recognised. They have a distinctive thick, curly coat, and come in many colors, with only solid ones recognized by breed registries. While a reasonably healthy breed, they are prone to sebaceous adenitis and Addison's disease among other genetic disorders. The Poodle most likely originated in Germany, although the Fédération Cynologique Internationale and a minority of cynologists believe it originated in France. Similar dogs date back to at least the 17th century, and it was first recognized by a kennel club in 1874. The Standard Poodle was originally used by wildfowl hunters to retrieve game from water. The smaller varieties of the breed were bred from in France, where they were once commonly used as circus p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosome
A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are the histones. These proteins, aided by chaperone proteins, bind to and condense the DNA molecule to maintain its integrity. These chromosomes display a complex three-dimensional structure, which plays a significant role in transcriptional regulation. Chromosomes are normally visible under a light microscope only during the metaphase of cell division (where all chromosomes are aligned in the center of the cell in their condensed form). Before this happens, each chromosome is duplicated ( S phase), and both copies are joined by a centromere, resulting either in an X-shaped structure (pictured above), if the centromere is located equatorially, or a two-arm structure, if the centromere is located distally. The joined copies are now c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glen Of Imaal Terrier
The Glen of Imaal Terrier ( gle, Brocaire Uí Mháil) is a breed of dog of the terrier category and one of four Irish terrier breeds. It is sometimes called the Irish Glen of Imaal Terrier or the Wicklow Terrier, and the name of the breed is often shortened by fanciers to just Glen. The breed originates in, and is named for, the Glen of Imaal in County Wicklow, Ireland. It was recognised first by the Irish Kennel Club in 1934 and most recently by the American Kennel Club in 2004. The Canadian Kennel Club voted to fully recognize Glens in 2017 after the breed spent years on the Miscellaneous list; approval by Agriculture Canada is pending. Reportedly, the Glen's history began during the reign of Elizabeth I, who hired French and Hessian mercenaries to put down a rebellion in Ireland. After the conflict, many of these soldiers settled in the Wicklow area. They brought with them their low-slung hounds, which they bred with the local terrier stock, eventually developing a di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemeralopia
Hemeralopia (from Greek ''ημέρα'' hemera, "day", and ''αλαός'' alaos, "blindness") is the inability to see clearly in bright light and is the exact opposite of nyctalopia (night blindness), the inability to see clearly in low light. Hemera was the Greek goddess of day, and Nyx was the goddess of night. However, it has been used in an opposite sense by many non-English-speaking doctors. It can be described as insufficient adaptation to bright light. It is also called "heliophobia" and "day blindness". In hemeralopia, daytime vision gets worse, characterised by photoaversion (dislike/avoidance of light) rather than photophobia (eye discomfort/pain in light), which is typical of inflammations of eye. Nighttime vision largely remains unchanged due to the use of rods as opposed to cones (during the day), which are affected by hemeralopia and in turn degrade the daytime optical response. Hence, many patients feel they see better at dusk than in daytime. Causes Hemeralopia is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alaskan Malamute
The Alaskan Malamute () is a large breed of dog that was originally bred for its strength and endurance to haul heavy freight as a sled dog and hound. It is similar to other arctic breeds such as the husky, the spitz, the Greenland Dog, Canadian Eskimo Dog, the Siberian Husky, and the Samoyed. Lineage Although it is believed that the first dogs arrived in the Americas 12,000 years ago, people and their dogs did not settle in the Arctic until the Paleo-Eskimo people 4,500 years ago, followed by the Thule people 1,000 years ago, with both originating from Siberia. Malamutes were thought to be bred by the Malimiut Inupiaq people of Alaska's Norton Sound region. The Malamute has been identified as a basal breed that predates the emergence of the modern breeds in the 19th century. A study in 2013 showed that the Alaskan Malamute has a similar east Asian origin to, but is not clearly related to, the Greenland Dog and the Canadian Eskimo Dog, but contains a possible admixture ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belgian Shepherd Dog
The Belgian Shepherd (also known as the Belgian Sheepdog, Belgian Malinois, or the Chien de Berger Belge) is a breed of medium-sized herding dog from Belgium. While predominantly considered a single breed, it is bred in four distinct varieties based on coat type and colour; the long-haired black Groenendael, the rough-haired fawn Laekenois, the short-haired fawn Malinois, and the long-haired fawn Tervuren; in the United States the American Kennel Club considers the four varieties to be separate breeds. The breed descends from a common type of shepherd dog found throughout Western Europe that includes such modern breeds as the Bouvier des Ardennes, Dutch Shepherd and German Shepherd. A common sight in the service of Belgian shepherds for centuries, it was not until the end of the 19th century that a breed club was formed and attempts were made to standardise the breed. In addition to its historical role as a herding dog, Belgian Shepherds have been used as assistance dogs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miniature Schnauzer
The Miniature Schnauzer is a breed of small dog of the Schnauzer type that originated in Germany in the mid-to-late 19th century. Miniature Schnauzers may have been developed from the smallest specimens of the Standard Schnauzer, or crosses between the standard and one or more smaller breeds such as the Affenpinscher, Miniature Pinscher, and Poodles, as farmers bred a small dog that was an efficient ratting dog. They are described as "spunky" but aloof dogs, with good guarding tendencies without some guard dogs' predisposition to bite. Miniature Schnauzers are recognized in four colors internationally: solid black, black and silver, salt and pepper, and white. It is the most popular Schnauzer breed, and remains one of the most popular worldwide, primarily for its temperament and relatively small size. As of 2020 it is the 19th most popular breed in the U.S. History The earliest records surrounding the development of the Standard Schnauzer in Germany come from the late 19th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norwegian Elkhound
The Norwegian Elkhound is one of the Northern Spitz-type breeds of dog and is the National Dog of Norway. The Elkhound has served as a hunter, guardian, herder, and defender. It is known for its courage in tracking and hunting elk and other large game, such as bears or wolves. The Norwegian Elkhound was first presented at a dog exhibition in Norway in 1877. The AKC breed name "Norwegian Elkhound" is a mistranslation from its original Norwegian name , meaning "Norwegian moose dog". In Norwegian "elg" means "moose" and "hund" means "dog," as it does in many other Germanic languages. It is Spitz breed, not a "hound" dog. The breed's object in the hunt is to independently track down and hold the moose at bay—jumping in and out toward the moose, distracting its attention, while signaling to the hunters by barking very loudly—until the hunter who follows the sound can arrive to shoot it. The dog will only bark while the moose is stationary, but it can also slowly dri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardigan Welsh Corgi
The Cardigan Welsh Corgi (; Welsh for "dwarf dog") is one of two separate dog breeds known as Welsh Corgis that originated in Wales; the other is the Pembroke Welsh Corgi. It is one of the oldest breeds of the British Isles. Cardigan Welsh Corgis are known to be an extremely loyal dog breed. They are also versatile and can live in a variety of settings. History Pembroke and Cardigan Welsh Corgis were originally listed as one breed by The Kennel Club in Britain in 1925, but were declared separate breeds in 1935. The Corgi Club was founded in December 1925 in Carmarthen in South Wales. It is reported that the local members favored the Pembroke breed, so a club for Cardigan enthusiasts was founded a year later (1926). Both groups have worked hard to ensure the appearance and type of breed are standardized through careful selective breeding. Pembrokes and Cardigans were officially recognized by the Kennel Club in 1928 and were lumped together under the heading Welsh Corgis. In 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collie
Collies form a distinctive type of herding dogs, including many related landraces and standardized breeds. The type originated in Scotland and Northern England. Collies are medium-sized, fairly lightly-built dogs, with pointed snouts. Many types have a distinctive white color over the shoulders. Collies are very active and agile, and most types of collies have a very strong herding instinct. Collie breeds have spread through many parts of the world (especially Australia and North America), and have diversified into many varieties, sometimes mixed with other dog types. Some collie breeds have remained as working dogs for herding cattle, sheep, and other livestock, while others are kept as pets, show dogs or for dog sports, in which they display great agility, stamina and trainability. While the American Kennel Club has a breed they call "collie", in fact ''collie dogs'' are a distinctive type of herding dog inclusive of many related landraces and formal breeds. There a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
