146-683: The Scottsdale Arabian Horse Show is the world's largest Arabian horse show , held annually in Scottsdale, Arizona . Beginning in 1955, the show has grown from 50 horses and a dozen trainers/owners to more than 2200 horses and over 1300 owners. Called the "Super Bowl of the Arabian World", it represents the first leg in the Arabian Triple Crown, the other two major competitions being the Canadian and U.S. National Arabian Championships. In addition to
292-527: A broad forehead, large eyes, large nostrils, and small muzzles. Most display a distinctive concave, or "dished" profile. Many Arabians also have a slight forehead bulge between their eyes, called the jibbah by the Bedouin , that adds additional sinus capacity, believed to have helped the Arabian horse in its native dry desert climate. Another breed characteristic is an arched neck with a large, well-set windpipe set on
438-489: A broad, short back, all of which give the breed physical strength comparable to many taller animals. Thus, even a smaller Arabian can carry a heavy rider. For tasks where the sheer weight of the horse matters, such as farm work done by a draft horse , any lighter-weight horse is at a disadvantage. However, for most purposes, the Arabian is a strong and hardy light horse breed able to carry any type of rider in most equestrian pursuits. For centuries, Arabian horses lived in
584-445: A buffer to recruit or titrate ions or antibiotics. Extracellular DNA acts as a functional extracellular matrix component in the biofilms of several bacterial species. It may act as a recognition factor to regulate the attachment and dispersal of specific cell types in the biofilm; it may contribute to biofilm formation; and it may contribute to the biofilm's physical strength and resistance to biological stress. Cell-free fetal DNA
730-459: A cell makes up its genome ; the human genome has approximately 3 billion base pairs of DNA arranged into 46 chromosomes. The information carried by DNA is held in the sequence of pieces of DNA called genes . Transmission of genetic information in genes is achieved via complementary base pairing. For example, in transcription, when a cell uses the information in a gene, the DNA sequence is copied into
876-656: A common maternal ancestry. Fiery war horses with dished faces and high-carried tails were popular artistic subjects in Ancient Egypt and Mesopotamia , often depicted pulling chariots in war or for hunting. Horses with oriental characteristics appear in later artwork as far north as that of Ancient Greece and the Roman Empire . While this type of horse was not called an "Arabian" in the Ancient Near East until later, these proto-Arabians shared many characteristics with
1022-445: A complementary RNA sequence through the attraction between the DNA and the correct RNA nucleotides. Usually, this RNA copy is then used to make a matching protein sequence in a process called translation , which depends on the same interaction between RNA nucleotides. In an alternative fashion, a cell may copy its genetic information in a process called DNA replication . The details of these functions are covered in other articles; here
1168-416: A cooperative relationship with humans, created a horse breed that is good-natured, quick to learn, and willing to please. The Arabian also developed the high spirit and alertness needed in a horse used for raiding and war . This combination of willingness and sensitivity requires modern Arabian horse owners to handle their horses with competence and respect. The Arabian is a versatile breed. Arabians dominate
1314-525: A deep, well-angled hip and well laid-back shoulder. Within the breed, there are variations. Some individuals have wider, more powerfully muscled hindquarters suitable for intense bursts of activity in events such as reining , while others have longer, leaner muscling better suited for long stretches of flatwork such as endurance riding or horse racing . Most have a compact body with a short back. Arabians usually have dense, strong bone, and good hoof walls. They are especially noted for their endurance, and
1460-492: A double helix can thus be pulled apart like a zipper, either by a mechanical force or high temperature . As a result of this base pair complementarity, all the information in the double-stranded sequence of a DNA helix is duplicated on each strand, which is vital in DNA replication. This reversible and specific interaction between complementary base pairs is critical for all the functions of DNA in organisms. Most DNA molecules are actually two polymer strands, bound together in
1606-643: A foundation sire of the Orlov trotter . Orlov then provided Arabian horses to Catherine the Great , who in 1772 owned 12 pure Arabian stallions and 10 mares. By 1889 two members of the Russian nobility, Count Stroganov and Prince Nikolai Borisovich Shcherbatov , established Arabian stud farms to meet the continued need to breed Arabians as a source of pure bloodstock. In Poland, notable imports from Arabia included those of Prince Hieronymous Sanguszko (1743–1812), who founded
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#17330853508041752-428: A full set of the mitochondrial genes. Each human mitochondrion contains, on average, approximately 5 such mtDNA molecules. Each human cell contains approximately 100 mitochondria, giving a total number of mtDNA molecules per human cell of approximately 500. However, the amount of mitochondria per cell also varies by cell type, and an egg cell can contain 100,000 mitochondria, corresponding to up to 1,500,000 copies of
1898-484: A gray does. There is pictorial evidence from pottery and tombs in Ancient Egypt suggesting that spotting patterns may have existed on ancestral Arabian-type horses in antiquity. Nonetheless, purebred Arabians today do not carry genes for pinto or Leopard complex ("Appaloosa") spotting patterns, except for sabino . Spotting or excess white was believed by many breeders to be a mark of impurity until DNA testing for verification of parentage became standard. For
2044-439: A helical fashion by noncovalent bonds; this double-stranded (dsDNA) structure is maintained largely by the intrastrand base stacking interactions, which are strongest for G,C stacks. The two strands can come apart—a process known as melting—to form two single-stranded DNA (ssDNA) molecules. Melting occurs at high temperatures, low salt and high pH (low pH also melts DNA, but since DNA is unstable due to acid depurination, low pH
2190-571: A higher number is also possible but this would be against the natural principle of least effort . The phosphate groups of DNA give it similar acidic properties to phosphoric acid and it can be considered as a strong acid . It will be fully ionized at a normal cellular pH, releasing protons which leave behind negative charges on the phosphate groups. These negative charges protect DNA from breakdown by hydrolysis by repelling nucleophiles which could hydrolyze it. Pure DNA extracted from cells forms white, stringy clumps. The expression of genes
2336-412: A horse running free with accompanying music); and Western Pleasure as well as a youth division for most classes. The top prize of the show is "Scottsdale Supreme Halter Champion". This prize is given both to a mare and a stallion champion. Crowds at the event have exceeded 200,000. In 2015, over 320,000 visitors attended the 11 days of the event, with an additional 450,000 viewers around the world over
2482-625: A live television feed. A unique feature of the show is the user-friendly instructions which allow spectators to better understand the scoring system of the judges. The event brings about $ 52 million to the Scottsdale economy. In 2013, the WestWorld facility underwent a $ 47 million facelift, which included indoor air-conditioned arenas. In January 2015, the City of Scottsdale's WestWorld and The Arabian Horse Association of Arizona entered into an agreement to hold
2628-400: A long journey through the desert, Muhammad turned his herd of horses loose to race to an oasis for a desperately needed drink of water. Before the herd reached the water, Muhammad called for the horses to return to him. Only five mares responded. Because they faithfully returned to their master, though desperate with thirst, these mares became his favorites and were called Al Khamsa , meaning,
2774-667: A long-standing puzzle known as the " C-value enigma ". However, some DNA sequences that do not code protein may still encode functional non-coding RNA molecules, which are involved in the regulation of gene expression . Some noncoding DNA sequences play structural roles in chromosomes. Telomeres and centromeres typically contain few genes but are important for the function and stability of chromosomes. An abundant form of noncoding DNA in humans are pseudogenes , which are copies of genes that have been disabled by mutation. These sequences are usually just molecular fossils , although they can occasionally serve as raw genetic material for
2920-409: A narrower, deeper major groove. The A form occurs under non-physiological conditions in partly dehydrated samples of DNA, while in the cell it may be produced in hybrid pairings of DNA and RNA strands, and in enzyme-DNA complexes. Segments of DNA where the bases have been chemically modified by methylation may undergo a larger change in conformation and adopt the Z form . Here, the strands turn about
3066-414: A permanent home, naming it Paradise Park, and it remained there for many years before moving to its present location, WestWorld . The Arabian Horse Association of Arizona, with Ed Tweed as their president, sponsored the first show, which was then called the "All-Arabian Horse Show". It is the largest Arabian horse show in the world, and one of the largest breed shows in the world. The show is sanctioned by
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#17330853508043212-431: A process called translation . Within eukaryotic cells, DNA is organized into long structures called chromosomes . Before typical cell division , these chromosomes are duplicated in the process of DNA replication, providing a complete set of chromosomes for each daughter cell. Eukaryotic organisms ( animals , plants , fungi and protists ) store most of their DNA inside the cell nucleus as nuclear DNA , and some in
3358-442: A radius of 10 Å (1.0 nm). According to another study, when measured in a different solution, the DNA chain measured 22–26 Å (2.2–2.6 nm) wide, and one nucleotide unit measured 3.3 Å (0.33 nm) long. The buoyant density of most DNA is 1.7g/cm . DNA does not usually exist as a single strand, but instead as a pair of strands that are held tightly together. These two long strands coil around each other, in
3504-536: A refined, clean throatlatch . This structure of the poll and throatlatch was called the mitbah or mitbeh by the Bedouin. In the ideal Arabian, it is long, allowing flexibility in the bridle and room for the windpipe. Other distinctive features are a relatively long, level croup , or top of the hindquarters, and naturally high tail carriage. The USEF breed standard requires Arabians to have solid bone and standard correct equine conformation . Well-bred Arabians have
3650-407: A relatively horizontal croup and a properly angled pelvis as well as good croup length and depth to the hip (determined by the length of the pelvis), that allows agility and impulsion. A misconception confuses the topline of the croup with the angle of the "hip" (the pelvis or ilium ), leading some to assert that Arabians have a flat pelvis angle and cannot use their hindquarters properly. However,
3796-596: A result, many European monarchs began to support large breeding establishments that crossed Arabians on local stock, one example being Knyszyna , the royal stud of Polish king Zygmunt II August , and another the Imperial Russian Stud of Peter the Great . European horse breeders also obtained Arabian stock directly from the desert or via trade with the Ottomans. In Russia, Count Alexey Orlov obtained many Arabians, including Smetanka , an Arabian stallion who became
3942-416: A second protein when read in the opposite direction along the other strand. In bacteria , this overlap may be involved in the regulation of gene transcription, while in viruses, overlapping genes increase the amount of information that can be encoded within the small viral genome. DNA can be twisted like a rope in a process called DNA supercoiling . With DNA in its "relaxed" state, a strand usually circles
4088-445: A simple TTAGGG sequence. These guanine-rich sequences may stabilize chromosome ends by forming structures of stacked sets of four-base units, rather than the usual base pairs found in other DNA molecules. Here, four guanine bases, known as a guanine tetrad , form a flat plate. These flat four-base units then stack on top of each other to form a stable G-quadruplex structure. These structures are stabilized by hydrogen bonding between
4234-501: A stallion, Zad el-Raheb or Zad-el-Rakib ("Gift to the Rider"), to the Banu Azd people when they came to pay tribute to the king. This legendary stallion was said to be faster than the zebra and the gazelle, and every hunt with him was successful, thus when he was put to stud, he became a founding sire of legend. Yet another creation myth puts the origin of the Arabian in the time of Ishmael ,
4380-473: A supply of cavalry horses, and Ottoman nobles, such as Muhammad Ali of Egypt also collected pure, desert-bred Arabian horses. El Naseri, or Al-Nasir Muhammad , Sultan of Egypt (1290–1342) imported and bred numerous Arabians in Egypt. A stud farm record was made of his purchases describing many of the horses as well as their abilities, and was deposited in his library, becoming a source for later study. Through
4526-460: A time, horses with belly spots and other white markings deemed excessive were discouraged from registration and excess white was sometimes penalized in the show ring. Purebred Arabians never carry dilution genes . Therefore, purebreds cannot be colors such as dun , cremello , palomino or buckskin . To produce horses with some Arabian characteristics but coat colors not found in purebreds, they have to be crossbred with other breeds. Though
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4672-590: Is a clearinghouse for information on these conditions. Additional information is available from the World Arabian Horse Association (WAHO). Recent trends in halter breeding have given rise to Arabian horses with extremely concave features, raising concerns that the trait is detrimental to the animal's welfare. Comparisons have been made to a similar trend with some dog breeds, where show judging awarding certain features has led to breeders seeking an ever more exaggerated form, with little concern as to
4818-437: Is actually the action of rabicano genetics. Unlike a genetic roan, rabicano is a partial roan-like pattern; the horse does not have intermingled white and solid hairs over the entire body, only on the midsection and flanks, the head and legs are solid-colored. Some people also confuse a young gray horse with a roan because of the intermixed hair colors common to both. However, a roan does not consistently lighten with age, while
4964-447: Is called intercalation . Most intercalators are aromatic and planar molecules; examples include ethidium bromide , acridines , daunomycin , and doxorubicin . For an intercalator to fit between base pairs, the bases must separate, distorting the DNA strands by unwinding of the double helix. This inhibits both transcription and DNA replication, causing toxicity and mutations. As a result, DNA intercalators may be carcinogens , and in
5110-435: Is called a polynucleotide . The backbone of the DNA strand is made from alternating phosphate and sugar groups. The sugar in DNA is 2-deoxyribose , which is a pentose (five- carbon ) sugar. The sugars are joined by phosphate groups that form phosphodiester bonds between the third and fifth carbon atoms of adjacent sugar rings. These are known as the 3′-end (three prime end), and 5′-end (five prime end) carbons,
5256-468: Is characterized by white markings such as "high white" above the knees and hocks , irregular spotting on the legs, belly and face, white markings that extend beyond the eyes or under the chin and jaw, and sometimes lacy or roaned edges. The genetic mechanism that produces sabino patterning in Arabians is now thought to be a form of dominant white, and more than one gene may be involved. However, studies at
5402-445: Is composed of one of four nitrogen-containing nucleobases ( cytosine [C], guanine [G], adenine [A] or thymine [T]), a sugar called deoxyribose , and a phosphate group . The nucleotides are joined to one another in a chain by covalent bonds (known as the phosphodiester linkage ) between the sugar of one nucleotide and the phosphate of the next, resulting in an alternating sugar-phosphate backbone . The nitrogenous bases of
5548-434: Is dependent on ionic strength and the concentration of DNA. As a result, it is both the percentage of GC base pairs and the overall length of a DNA double helix that determines the strength of the association between the two strands of DNA. Long DNA helices with a high GC -content have more strongly interacting strands, while short helices with high AT content have more weakly interacting strands. In biology, parts of
5694-411: Is influenced by how the DNA is packaged in chromosomes, in a structure called chromatin . Base modifications can be involved in packaging, with regions that have low or no gene expression usually containing high levels of methylation of cytosine bases. DNA packaging and its influence on gene expression can also occur by covalent modifications of the histone protein core around which DNA is wrapped in
5840-432: Is introduced by enzymes called topoisomerases . These enzymes are also needed to relieve the twisting stresses introduced into DNA strands during processes such as transcription and DNA replication . DNA exists in many possible conformations that include A-DNA , B-DNA , and Z-DNA forms, although only B-DNA and Z-DNA have been directly observed in functional organisms. The conformation that DNA adopts depends on
5986-487: Is more difficult to train a "hot-blooded" horse. Though most Arabians have a natural tendency to cooperate with humans, when treated badly, like any horse, they can become excessively nervous or anxious, but seldom become vicious unless seriously spoiled or subjected to extreme abuse. At the other end of the spectrum, romantic myths are sometimes told about Arabian horses that give them near-divine characteristics. The Arabian Horse Association registers purebred horses with
Scottsdale Arabian Horse Show - Misplaced Pages Continue
6132-422: Is nothing special about the four natural nucleobases that evolved on Earth. On the other hand, DNA is tightly related to RNA which does not only act as a transcript of DNA but also performs as molecular machines many tasks in cells. For this purpose it has to fold into a structure. It has been shown that to allow to create all possible structures at least four bases are required for the corresponding RNA , while
6278-514: Is rarely used). The stability of the dsDNA form depends not only on the GC -content (% G,C basepairs) but also on sequence (since stacking is sequence specific) and also length (longer molecules are more stable). The stability can be measured in various ways; a common way is the melting temperature (also called T m value), which is the temperature at which 50% of the double-strand molecules are converted to single-strand molecules; melting temperature
6424-428: Is recreated by an enzyme called DNA polymerase . This enzyme makes the complementary strand by finding the correct base through complementary base pairing and bonding it onto the original strand. As DNA polymerases can only extend a DNA strand in a 5′ to 3′ direction, different mechanisms are used to copy the antiparallel strands of the double helix. In this way, the base on the old strand dictates which base appears on
6570-564: Is that this development occurred in the Nejd plateau in central Arabia. Other scholars, noting that horses were common in the Fertile Crescent but rare in the Arabian peninsula prior to the rise of Islam , theorize that the breed as it is known today only developed in large numbers when the conversion of the Persians to Islam in the 7th century brought knowledge of horse breeding and horsemanship to
6716-428: Is the sequence of these four nucleobases along the backbone that encodes genetic information. RNA strands are created using DNA strands as a template in a process called transcription , where DNA bases are exchanged for their corresponding bases except in the case of thymine (T), for which RNA substitutes uracil (U). Under the genetic code , these RNA strands specify the sequence of amino acids within proteins in
6862-516: Is the largest human chromosome with approximately 220 million base pairs , and would be 85 mm long if straightened. In eukaryotes , in addition to nuclear DNA , there is also mitochondrial DNA (mtDNA) which encodes certain proteins used by the mitochondria. The mtDNA is usually relatively small in comparison to the nuclear DNA. For example, the human mitochondrial DNA forms closed circular molecules, each of which contains 16,569 DNA base pairs, with each such molecule normally containing
7008-486: Is to allow the cell to replicate chromosome ends using the enzyme telomerase , as the enzymes that normally replicate DNA cannot copy the extreme 3′ ends of chromosomes. These specialized chromosome caps also help protect the DNA ends, and stop the DNA repair systems in the cell from treating them as damage to be corrected. In human cells , telomeres are usually lengths of single-stranded DNA containing several thousand repeats of
7154-612: The Arabian Peninsula . With a distinctive head shape and high tail carriage, the Arabian is one of the most easily recognizable horse breeds in the world. It is also one of the oldest modern breeds. Although modern DNA cannot trace breed purity in the modern population beyond 200 years, there is archaeological evidence of horses in the Middle East with landrace characteristics that resemble modern Arabians dating back 3,500 years. Throughout history, Arabian horses have spread around
7300-568: The Barb horse of North Africa. More Arabian horses were introduced to North Africa as a result of the migration of Banu Hilal . Arabian horses also spread to the rest of the world via the Ottoman Empire , which rose in 1299. Though it never fully dominated the heart of the Arabian Peninsula , this Turkish empire obtained many Arabian horses through trade, diplomacy and war. The Ottomans encouraged formation of private stud farms in order to ensure
7446-657: The DNA sequence . Mutagens include oxidizing agents , alkylating agents and also high-energy electromagnetic radiation such as ultraviolet light and X-rays . The type of DNA damage produced depends on the type of mutagen. For example, UV light can damage DNA by producing thymine dimers , which are cross-links between pyrimidine bases. On the other hand, oxidants such as free radicals or hydrogen peroxide produce multiple forms of damage, including base modifications, particularly of guanosine, and double-strand breaks. A typical human cell contains about 150,000 bases that have suffered oxidative damage. Of these oxidative lesions,
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#17330853508047592-539: The Ice Age . This hypothesis has gained renewed attention following a 2010 discovery of artifacts dated between 6590 and 7250 BCE in Al-Magar , in southwestern Saudi Arabia, that appeared to portray horses. The proto-Arabian horse may have been domesticated by the people of the Arabian Peninsula known today as the Bedouin , some time after they learned to use the camel, approximately 4,000–5,000 years ago. One theory
7738-693: The Marwari horse of India, the Barb of North Africa, the Akhal-Teke of western Asia and the now-extinct Turkoman Horse . There are different theories about where the ancestors of the Arabian originally lived. Most evidence suggests the proto-Arabian came from the area along the northern edge of the Fertile Crescent . Another hypothesis suggests the southwestern corner of the Arabian peninsula, in modern-day Yemen , where three now-dry riverbeds indicate good natural pastures existed long ago, perhaps as far back as
7884-547: The United States Equestrian Federation and the Arabian Horse Association . Called the "Super Bowl of the Arabian world", 2015 version marked the 60th anniversary of the show. The Diamond Jubilee of the event featured more than 2250 horses, and over $ 1 million in prize money, with over 1300 farms represented. The overall prize money increased to $ 3 million in 2021. It is the first of three legs of
8030-529: The University of California, Davis indicate that Arabians do not appear to carry the autosomal dominant gene "SB1" or sabino 1 , that often produces bold spotting and some completely white horses in other breeds. The inheritance patterns observed in sabino-like Arabians also do not follow the same mode of inheritance as sabino 1 . There are very few Arabians registered as roan , and according to researcher D. Phillip Sponenberg, roaning in purebred Arabians
8176-406: The amino-acid sequences of proteins is determined by the rules of translation , known collectively as the genetic code . The genetic code consists of three-letter 'words' called codons formed from a sequence of three nucleotides (e.g. ACT, CAG, TTT). In transcription, the codons of a gene are copied into messenger RNA by RNA polymerase . This RNA copy is then decoded by a ribosome that reads
8322-420: The mitochondria as mitochondrial DNA or in chloroplasts as chloroplast DNA . In contrast, prokaryotes ( bacteria and archaea ) store their DNA only in the cytoplasm , in circular chromosomes . Within eukaryotic chromosomes, chromatin proteins, such as histones , compact and organize DNA. These compacting structures guide the interactions between DNA and other proteins, helping control which parts of
8468-543: The "Arabian Triple Crown", the other two being the Canadian National Arabian Championship and the U.S. Nationals. As of 2015, the show consisted of competition in multiple divisions: Mounted Native Costume; Breeding/Halter ; Dressage ; Driving ; working western ( Reining , cutting , Working cow horse ), English Pleasure (including show hack , park horse, and country English pleasure); Hunter / Jumper and hunter under saddle ; Liberty (featuring
8614-419: The 3′ and 5′ carbons along the sugar-phosphate backbone confers directionality (sometimes called polarity) to each DNA strand. In a nucleic acid double helix , the direction of the nucleotides in one strand is opposite to their direction in the other strand: the strands are antiparallel . The asymmetric ends of DNA strands are said to have a directionality of five prime end (5′ ), and three prime end (3′), with
8760-588: The 5′ end having a terminal phosphate group and the 3′ end a terminal hydroxyl group. One major difference between DNA and RNA is the sugar, with the 2-deoxyribose in DNA being replaced by the related pentose sugar ribose in RNA. The DNA double helix is stabilized primarily by two forces: hydrogen bonds between nucleotides and base-stacking interactions among aromatic nucleobases. The four bases found in DNA are adenine ( A ), cytosine ( C ), guanine ( G ) and thymine ( T ). These four bases are attached to
8906-499: The Arabian came from a separate subspecies of horse, known as equus caballus pumpelli . However, others, including Gladys Brown Edwards, a noted Arabian researcher, stated that the "dry" oriental horses of the desert, from which the modern Arabian developed, were Equus ferus caballus with specific landrace characteristics based on the environments in which they lived, rather than being a separate subspecies. Horses with similar, though not identical, physical characteristics include
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#17330853508049052-554: The Arabian horse spread across the known world of the time, and became recognized as a distinct, named breed. It played a significant role in the History of the Middle East and of Islam. By 630, Muslim influence expanded across the Middle East and North Africa, by 711 Muslim warriors had reached Spain, and they controlled most of the Iberian Peninsula by 720. Their war horses were of various oriental types, including both Arabians and
9198-572: The Bedouin developed several sub-types or strains of Arabian horse, each with unique characteristics, and traced through the maternal line only. According to the Arabian Horse Association , the five primary strains were known as the Keheilan, Seglawi, Abeyan, Hamdani and Hadban. Carl Raswan , a promoter and writer about Arabian horses from the middle of the 20th century, held the belief that there were only three strains, Kehilan, Seglawi and Muniqi. Raswan felt that these strains represented body "types" of
9344-589: The Bedouin. The oldest depictions in the Arabian Peninsula of horses that are clearly domesticated date no earlier than 1800-2000 BCE. Regardless of origin, climate and culture ultimately created the Arabian. The desert environment required a domesticated horse to cooperate with humans to survive; humans were the only providers of food and water in certain areas, and even hardy Arabian horses needed far more water than camels in order to survive (most horses can only live about 72 hours without water). Where there
9490-435: The DNA are transcribed. DNA is a long polymer made from repeating units called nucleotides . The structure of DNA is dynamic along its length, being capable of coiling into tight loops and other shapes. In all species it is composed of two helical chains, bound to each other by hydrogen bonds . Both chains are coiled around the same axis, and have the same pitch of 34 ångströms (3.4 nm ). The pair of chains have
9636-453: The DNA double helix that need to separate easily, such as the TATAAT Pribnow box in some promoters , tend to have a high AT content, making the strands easier to pull apart. In the laboratory, the strength of this interaction can be measured by finding the melting temperature T m necessary to break half of the hydrogen bonds. When all the base pairs in a DNA double helix melt,
9782-456: The Ottomans reached Vienna , where they were stopped by the Polish and Hungarian armies, who captured these horses from the defeated Ottoman cavalry . Some of these animals provided foundation bloodstock for the major studs of eastern Europe. With the rise of light cavalry, the stamina and agility of horses with Arabian blood gave an enormous military advantage to any army who possessed them. As
9928-543: The Ottomans, Arabian horses were often sold, traded, or given as diplomatic gifts to Europeans and, later, to Americans. Historically, Egyptian breeders imported horses bred in the deserts of Palestine and the Arabian peninsula as the source of their foundation bloodstock . By the time that the Ottoman Empire dominated Egypt, the political elites of the region still recognized the need for quality bloodstock for both war and for horse racing , and some continued to return to
10074-549: The Prussian cavalry mounts were superior in endurance to those of the British, and credited Arabian bloodlines for this superiority. DNA Deoxyribonucleic acid ( / d iː ˈ ɒ k s ɪ ˌ r aɪ b oʊ nj uː ˌ k l iː ɪ k , - ˌ k l eɪ -/ ; DNA ) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix . The polymer carries genetic instructions for
10220-401: The RNA sequence by base-pairing the messenger RNA to transfer RNA , which carries amino acids. Since there are 4 bases in 3-letter combinations, there are 64 possible codons (4 combinations). These encode the twenty standard amino acids , giving most amino acids more than one possible codon. There are also three 'stop' or 'nonsense' codons signifying the end of the coding region; these are
10366-570: The Royal Agricultural Society (RAS) in 1908, which is known today as the Egyptian Agricultural Organization (EAO). RAS representatives traveled to England during the 1920s and purchased eighteen descendants of the original Blunt exports from Lady Wentworth at Crabbet Park, and brought them to Egypt in order to restore bloodlines had been lost. Other than several horses purchased by Henry Babson for importation to
10512-575: The Slawuta stud. Poland's first state-run Arabian stud farm, Janów Podlaski , was established by the decree of Alexander I of Russia in 1817, and by 1850, the great stud farms of Poland were well-established, including Antoniny, owned by the Polish Count Potocki (who had married into the Sanguszko family); later notable as the farm that produced the stallion Skowronek . The 18th century marked
10658-716: The South Wind: "I want to make a creature out of you. Condense." Then from the material condensed from the wind, he made a kamayt -colored animal (a bay or burnt chestnut ) and said: "I call you Horse; I make you Arabian and I give you the chestnut color of the ant; I have hung happiness from the forelock which hangs between your eyes; you shall be the Lord of the other animals. Men shall follow you wherever you go; you shall be as good for flight as for pursuit; you shall fly without wings; riches shall be on your back and fortune shall come through your meditation." Arabians are thought to be one of
10804-488: The TAG, TAA, and TGA codons, (UAG, UAA, and UGA on the mRNA). Cell division is essential for an organism to grow, but, when a cell divides, it must replicate the DNA in its genome so that the two daughter cells have the same genetic information as their parent. The double-stranded structure of DNA provides a simple mechanism for DNA replication . Here, the two strands are separated and then each strand's complementary DNA sequence
10950-607: The United States in the 1930s, and one other small group exported to the US in 1947, relatively few Egyptian-bred Arabian horses were exported until the overthrow of King Farouk I in 1952. Many of the private stud farms of the princes were then confiscated and the animals taken over by the EAO. In the 1960s and 1970s, as oil development brought more foreign investors to Egypt, some of whom were horse fanciers, Arabians were exported to Germany and to
11096-584: The United States, as well as to the former Soviet Union. Today, the designation "Straight Egyptian" or "Egyptian Arabian" is popular with some Arabian breeders, and the modern Egyptian-bred Arabian is an outcross used to add refinement in some breeding programs. Probably the earliest horses with Arabian bloodlines to enter Europe came indirectly, through Spain and France. Others would have arrived with returning Crusaders —beginning in 1095, European armies invaded Palestine and many knights returned home with Arabian horses as spoils of war. Later, as knights and
11242-566: The Wind" to the first Arabian horse. Finally, a Bedouin story states that Allah created the Arabian horse from the south wind and exclaimed, "I create thee, Oh Arabian. To thy forelock, I bind Victory in battle. On thy back, I set a rich spoil and a Treasure in thy loins. I establish thee as one of the Glories of the Earth... I give thee flight without wings." Other versions of the story claim Allah said to
11388-442: The axis of the double helix once every 10.4 base pairs, but if the DNA is twisted the strands become more tightly or more loosely wound. If the DNA is twisted in the direction of the helix, this is positive supercoiling, and the bases are held more tightly together. If they are twisted in the opposite direction, this is negative supercoiling, and the bases come apart more easily. In nature, most DNA has slight negative supercoiling that
11534-554: The breed, with the Kehilan being "masculine", the Seglawi being "feminine" and the Muniqi being "speedy". There were also lesser strains, sub-strains, and regional variations in strain names. Therefore, many Arabian horses were not only Asil , of pure blood, but also bred to be pure in strain, with crossbreeding between strains discouraged, though not forbidden, by some tribes. Purity of bloodline
11680-431: The breeding of their camels, Saluki dogs, and their own family or tribal history. Eventually, written records began to be kept; the first written pedigrees in the Middle East that specifically used the term "Arabian" date to 1330 AD. As important as strain was to the Bedouin, modern studies of mitochondrial DNA suggest that Arabian horses alive today with records stating descent from a given strain may not actually share
11826-407: The canonical bases plus uracil. Twin helical strands form the DNA backbone. Another double helix may be found tracing the spaces, or grooves, between the strands. These voids are adjacent to the base pairs and may provide a binding site . As the strands are not symmetrically located with respect to each other, the grooves are unequally sized. The major groove is 22 ångströms (2.2 nm) wide, while
11972-467: The case of thalidomide, a teratogen . Others such as benzo[ a ]pyrene diol epoxide and aflatoxin form DNA adducts that induce errors in replication. Nevertheless, due to their ability to inhibit DNA transcription and replication, other similar toxins are also used in chemotherapy to inhibit rapidly growing cancer cells. DNA usually occurs as linear chromosomes in eukaryotes , and circular chromosomes in prokaryotes . The set of chromosomes in
12118-581: The cell (see below) , but the major and minor grooves are always named to reflect the differences in width that would be seen if the DNA was twisted back into the ordinary B form . In a DNA double helix, each type of nucleobase on one strand bonds with just one type of nucleobase on the other strand. This is called complementary base pairing . Purines form hydrogen bonds to pyrimidines, with adenine bonding only to thymine in two hydrogen bonds, and cytosine bonding only to guanine in three hydrogen bonds. This arrangement of two nucleotides binding together across
12264-619: The chromatin structure or else by remodeling carried out by chromatin remodeling complexes (see Chromatin remodeling ). There is, further, crosstalk between DNA methylation and histone modification, so they can coordinately affect chromatin and gene expression. For one example, cytosine methylation produces 5-methylcytosine , which is important for X-inactivation of chromosomes. The average level of methylation varies between organisms—the worm Caenorhabditis elegans lacks cytosine methylation, while vertebrates have higher levels, with up to 1% of their DNA containing 5-methylcytosine. Despite
12410-458: The coat colors bay , gray , chestnut , black , and roan . Bay, gray and chestnut are the most common; black is less common. The classic roan gene does not appear to exist in Arabians; rather, Arabians registered by breeders as "roan" are usually expressing rabicano or, sometimes, sabino patterns with roan features. All Arabians, no matter their coat color , have black skin, except under white markings . Black skin provided protection from
12556-545: The competition, the show acts as a fundraiser for the Arabian Horse Association of Arizona, which has donated millions of dollars to charity from the proceeds of the show. The first show was held in 1955 at the Arizona Biltmore Hotel, and was composed of approximately 50 horses from twelve farms. Anne McCormick , one of the founders, donated 150 acres of her ranch in Scottsdale so that the show could have
12702-476: The conditions found in cells, it is not a well-defined conformation but a family of related DNA conformations that occur at the high hydration levels present in cells. Their corresponding X-ray diffraction and scattering patterns are characteristic of molecular paracrystals with a significant degree of disorder. Compared to B-DNA, the A-DNA form is a wider right-handed spiral, with a shallow, wide minor groove and
12848-405: The creation of new genes through the process of gene duplication and divergence . A gene is a sequence of DNA that contains genetic information and can influence the phenotype of an organism. Within a gene, the sequence of bases along a DNA strand defines a messenger RNA sequence, which then defines one or more protein sequences. The relationship between the nucleotide sequences of genes and
12994-456: The croup is formed by the sacral vertebrae. The hip angle is determined by the attachment of the ilium to the spine, the structure and length of the femur , and other aspects of hindquarter anatomy, which is not correlated to the topline of the sacrum. Thus, the Arabian has conformation typical of other horse breeds built for speed and distance, such as the Thoroughbred , where the angle of
13140-449: The cytoplasm called the nucleoid . The genetic information in a genome is held within genes, and the complete set of this information in an organism is called its genotype . A gene is a unit of heredity and is a region of DNA that influences a particular characteristic in an organism. Genes contain an open reading frame that can be transcribed, and regulatory sequences such as promoters and enhancers , which control transcription of
13286-560: The desert in close association with humans. For shelter and protection from theft, prized war mares were sometimes kept in their owner's tent, close to children and everyday family life. Only horses with a naturally good disposition were allowed to reproduce, with the result that Arabians today have a good temperament that, among other examples, makes them one of the few breeds where the United States Equestrian Federation rules allow children to exhibit stallions in nearly all show ring classes, including those limited to riders under 18. On
13432-480: The deserts to obtain pure-blooded Arabians. One of the most famous was Muhammad Ali of Egypt , also known as Muhammad Ali Pasha, who established an extensive stud farm in the 19th century. After his death, some of his stock was bred on by Abbas I of Egypt , also known as Abbas Pasha. However, after Abbas Pasha was assassinated in 1854, his heir, El Hami Pasha, sold most of his horses, often for crossbreeding, and gave away many others as diplomatic gifts. A remnant of
13578-489: The development, functioning, growth and reproduction of all known organisms and many viruses . DNA and ribonucleic acid (RNA) are nucleic acids . Alongside proteins , lipids and complex carbohydrates ( polysaccharides ), nucleic acids are one of the four major types of macromolecules that are essential for all known forms of life . The two DNA strands are known as polynucleotides as they are composed of simpler monomeric units called nucleotides . Each nucleotide
13724-475: The discipline of endurance riding and compete today in many other fields of equestrian sport. They are one of the top ten most popular horse breeds in the world. They are now found worldwide, including the United States and Canada, the United Kingdom, Australia, continental Europe, South America (especially Brazil), and their land of origin, the Middle East. Arabian horses have refined, wedge-shaped heads,
13870-405: The double helix (from six-carbon ring to six-carbon ring) is called a Watson-Crick base pair. DNA with high GC-content is more stable than DNA with low GC -content. A Hoogsteen base pair (hydrogen bonding the 6-carbon ring to the 5-carbon ring) is a rare variation of base-pairing. As hydrogen bonds are not covalent , they can be broken and rejoined relatively easily. The two strands of DNA in
14016-442: The edges of the bases and chelation of a metal ion in the centre of each four-base unit. Other structures can also be formed, with the central set of four bases coming from either a single strand folded around the bases, or several different parallel strands, each contributing one base to the central structure. In addition to these stacked structures, telomeres also form large loop structures called telomere loops, or T-loops. Here,
14162-481: The end of an otherwise complementary double-strand of DNA. However, branched DNA can occur if a third strand of DNA is introduced and contains adjoining regions able to hybridize with the frayed regions of the pre-existing double-strand. Although the simplest example of branched DNA involves only three strands of DNA, complexes involving additional strands and multiple branches are also possible. Branched DNA can be used in nanotechnology to construct geometric shapes, see
14308-456: The establishment of most of the great Arabian studs of Europe, dedicated to preserving "pure" Arabian bloodstock. The Prussians set up a royal stud in 1732, originally intended to provide horses for the royal stables, and other studs were established to breed animals for other uses, including mounts for the Prussian army. The foundation of these breeding programs was the crossing of Arabians on native horses; by 1873 some English observers felt that
14454-546: The five . These mares became the legendary founders of the five "strains" of the Arabian horse. Although the Al Khamsa are generally considered fictional horses of legend, some breeders today claim the modern Bedouin Arabian actually descended from these mares. Another origin tale claims that King Solomon was given a pure Arabian-type mare named Safanad ("the pure") by the Queen of Sheba . A different version says that Solomon gave
14600-418: The focus is on the interactions between DNA and other molecules that mediate the function of the genome. Genomic DNA is tightly and orderly packed in the process called DNA condensation , to fit the small available volumes of the cell. In eukaryotes, DNA is located in the cell nucleus , with small amounts in mitochondria and chloroplasts . In prokaryotes, the DNA is held within an irregularly shaped body in
14746-448: The functions of these RNAs are not entirely clear. One proposal is that antisense RNAs are involved in regulating gene expression through RNA-RNA base pairing. A few DNA sequences in prokaryotes and eukaryotes, and more in plasmids and viruses , blur the distinction between sense and antisense strands by having overlapping genes . In these cases, some DNA sequences do double duty, encoding one protein when read along one strand, and
14892-494: The heavy, armored war horses who carried them became obsolete, Arabian horses and their descendants were used to develop faster, agile light cavalry horses that were used in warfare into the 20th century. Another major infusion of Arabian horses into Europe occurred when the Ottoman Turks sent 300,000 horsemen into Hungary in 1522, many of whom were mounted on pure-blooded Arabians, captured during raids into Arabia. By 1529,
15038-448: The helical axis in a left-handed spiral, the opposite of the more common B form. These unusual structures can be recognized by specific Z-DNA binding proteins and may be involved in the regulation of transcription. For many years, exobiologists have proposed the existence of a shadow biosphere , a postulated microbial biosphere of Earth that uses radically different biochemical and molecular processes than currently known life. One of
15184-577: The herd was obtained by Ali Pasha Sherif , who then went back to the desert to bring in new bloodstock. At its peak, the stud of Ali Pasha Sherif had over 400 purebred Arabians. Unfortunately, an epidemic of African horse sickness in the 1870s that killed thousands of horses throughout Egypt decimated much of his herd, wiping out several irreplaceable bloodlines. Late in his life, he sold several horses to Wilfred and Lady Anne Blunt , who exported them to Crabbet Park Stud in England. After his death, Lady Anne
15330-448: The hydration level, DNA sequence, the amount and direction of supercoiling, chemical modifications of the bases, the type and concentration of metal ions , and the presence of polyamines in solution. The first published reports of A-DNA X-ray diffraction patterns —and also B-DNA—used analyses based on Patterson functions that provided only a limited amount of structural information for oriented fibers of DNA. An alternative analysis
15476-427: The hydrolytic activities of cellular water, etc., also occur frequently. Although most of these damages are repaired, in any cell some DNA damage may remain despite the action of repair processes. These remaining DNA damages accumulate with age in mammalian postmitotic tissues. This accumulation appears to be an important underlying cause of aging. Many mutagens fit into the space between two adjacent base pairs, this
15622-504: The ilium is more oblique than that of the croup. Thus, the hip angle is not necessarily correlated to the topline of the croup. Horses bred to gallop need a good length of croup and good length of hip for proper attachment of muscles, and so unlike angle, length of hip and croup do go together as a rule. The breed standard stated by the United States Equestrian Federation , describes Arabians as standing between 14.1 to 15.1 hands (57 to 61 inches, 145 to 155 cm) tall, "with
15768-412: The importance of 5-methylcytosine, it can deaminate to leave a thymine base, so methylated cytosines are particularly prone to mutations . Other base modifications include adenine methylation in bacteria, the presence of 5-hydroxymethylcytosine in the brain , and the glycosylation of uracil to produce the "J-base" in kinetoplastids . DNA can be damaged by many sorts of mutagens , which change
15914-425: The inherent function of the animal. Some veterinarians speculate that an extremely concave face is detrimental to a horse's breathing, but the issue has not been formally studied. Arabian horses are the topic of many myths and legends. One origin story tells how Muhammad chose his foundation mares by a test of their courage and loyalty. While there are several variants on the tale, a common version states that after
16060-444: The intense desert sun. Although many Arabians appear to have a "white" hair coat, they are not genetically "white". This color is usually created by the natural action of the gray gene , and virtually all white-looking Arabians are actually grays. A specialized colorization seen in some older gray Arabians is the so-called "bloody-shoulder", which is a particular type of "flea-bitten" gray with localized aggregations of pigment on
16206-441: The minor groove is 12 Å (1.2 nm) in width. Due to the larger width of the major groove, the edges of the bases are more accessible in the major groove than in the minor groove. As a result, proteins such as transcription factors that can bind to specific sequences in double-stranded DNA usually make contact with the sides of the bases exposed in the major groove. This situation varies in unusual conformations of DNA within
16352-516: The mitochondrial genome (constituting up to 90% of the DNA of the cell). A DNA sequence is called a "sense" sequence if it is the same as that of a messenger RNA copy that is translated into protein. The sequence on the opposite strand is called the "antisense" sequence. Both sense and antisense sequences can exist on different parts of the same strand of DNA (i.e. both strands can contain both sense and antisense sequences). In both prokaryotes and eukaryotes, antisense RNA sequences are produced, but
16498-640: The modern Arabian, including speed, endurance, and refinement. For example, a horse skeleton unearthed in the Sinai peninsula , dated to 1700 BC and probably brought by the Hyksos invaders, is considered the earliest physical evidence of the horse in Ancient Egypt . This horse had a wedge-shaped head, large eye sockets and small muzzle, all characteristics of the Arabian horse. Following the Hijra in AD 622 (also sometimes spelled Hegira),
16644-406: The modern Arabian. Horses with these features appeared in rock paintings and inscriptions in the Arabian Peninsula dating back 3500 years. In ancient history throughout the Ancient Near East , horses with refined heads and high-carried tails were depicted in artwork, particularly that of Ancient Egypt in the 16th century BC. Some 20th-century scholars of the Arabian horse once theorized that
16790-477: The most dangerous are double-strand breaks, as these are difficult to repair and can produce point mutations , insertions , deletions from the DNA sequence, and chromosomal translocations . These mutations can cause cancer . Because of inherent limits in the DNA repair mechanisms, if humans lived long enough, they would all eventually develop cancer. DNA damages that are naturally occurring , due to normal cellular processes that produce reactive oxygen species,
16936-464: The new strand, and the cell ends up with a perfect copy of its DNA. Naked extracellular DNA (eDNA), most of it released by cell death, is nearly ubiquitous in the environment. Its concentration in soil may be as high as 2 μg/L, and its concentration in natural aquatic environments may be as high at 88 μg/L. Various possible functions have been proposed for eDNA: it may be involved in horizontal gene transfer ; it may provide nutrients; and it may act as
17082-509: The non-Arabian parent was a carrier. There are six known genetic disorders in Arabian horses. Two are inevitably fatal, two are not inherently fatal but are disabling and usually result in euthanasia of the affected animal; the remaining conditions can usually be treated. Three are thought to be autosomal recessive conditions, which means that the flawed gene is not sex-linked and has to come from both parents for an affected foal to be born. One may be an autosomal dominant . Arabians are not
17228-447: The occasional individual over or under". Thus, all Arabians, regardless of height, are classified as "horses", even though 14.2 hands (58 inches, 147 cm) is the traditional cutoff height between a horse and a pony . A common myth is that Arabians are not strong because they are relatively small and refined. However, the Arabian horse is noted for a greater density of bone than other breeds, short cannons , sound feet, and
17374-457: The oldest human-developed horse breeds in the world. Recent genetic studies of mitochondrial DNA in Arabian horses of Polish and American breeding suggest that the modern breed has heterogeneous origins with ten haplogroups . The modern concept of breed purity in the modern population cannot be traced beyond 200 years. The progenitor stock, the Oriental subtype , had characteristics similar to
17520-474: The only breed of horse to have problems with inherited diseases; partbred Arabians may inherit deleterious genetics from other breeds. Genetic diseases that can occur in purebred Arabians, or in partbreds with Arabian ancestry in both parents, are the following: The Arabian Horse Association in the United States has created a foundation that supports research efforts to uncover the roots of genetic diseases. The organization F.O.A.L. (Fight Off Arabian Lethals)
17666-454: The open reading frame. In many species , only a small fraction of the total sequence of the genome encodes protein. For example, only about 1.5% of the human genome consists of protein-coding exons , with over 50% of human DNA consisting of non-coding repetitive sequences . The reasons for the presence of so much noncoding DNA in eukaryotic genomes and the extraordinary differences in genome size , or C-value , among species, represent
17812-569: The other hand, the Arabian is also classified as a "hot-blooded" breed, a category that includes other refined, spirited horses bred for speed, such as the Akhal-Teke , the Barb , and the Thoroughbred. Like other hot-bloods, Arabians' sensitivity and intelligence enable quick learning and greater communication with their riders; however, their intelligence also allows them to learn bad habits as quickly as good ones, and they do not tolerate inept or abusive training practices. Some sources claim that it
17958-428: The place of thymine in RNA and differs from thymine by lacking a methyl group on its ring. In addition to RNA and DNA, many artificial nucleic acid analogues have been created to study the properties of nucleic acids, or for use in biotechnology. Modified bases occur in DNA. The first of these recognized was 5-methylcytosine , which was found in the genome of Mycobacterium tuberculosis in 1925. The reason for
18104-449: The position of the fighters. A good disposition was also critical; prized war mares were often brought inside family tents to prevent theft and for protection from weather and predators. Though appearance was not necessarily a survival factor, the Bedouin bred for refinement and beauty in their horses as well as for more practical features. For centuries, the Bedouin tracked the ancestry of each horse through an oral tradition . Horses of
18250-530: The presence of these noncanonical bases in bacterial viruses ( bacteriophages ) is to avoid the restriction enzymes present in bacteria. This enzyme system acts at least in part as a molecular immune system protecting bacteria from infection by viruses. Modifications of the bases cytosine and adenine, the more common and modified DNA bases, play vital roles in the epigenetic control of gene expression in plants and animals. A number of noncanonical bases are known to occur in DNA. Most of these are modifications of
18396-412: The prime symbol being used to distinguish these carbon atoms from those of the base to which the deoxyribose forms a glycosidic bond . Therefore, any DNA strand normally has one end at which there is a phosphate group attached to the 5′ carbon of a ribose (the 5′ phosphoryl) and another end at which there is a free hydroxyl group attached to the 3′ carbon of a ribose (the 3′ hydroxyl). The orientation of
18542-504: The prizes for the competitors, the show is also a fundraiser for charities. Since its inception, the show has raised millions of dollars for such organizations as the Cox Charities and the March of Dimes . Arabian (horse) The Arabian or Arab horse ( Arabic : الحصان العربي [alħisˤaːn alʕarabijj] , DMG al-ḥiṣān al-ʿarabī ) is a breed of horse with historic roots on
18688-466: The proposals was the existence of lifeforms that use arsenic instead of phosphorus in DNA . A report in 2010 of the possibility in the bacterium GFAJ-1 was announced, though the research was disputed, and evidence suggests the bacterium actively prevents the incorporation of arsenic into the DNA backbone and other biomolecules. At the ends of the linear chromosomes are specialized regions of DNA called telomeres . The main function of these regions
18834-484: The purebred Arabian produces a limited range of potential colors, they do not appear to carry any color-based lethal disorders such as the frame overo gene ("O") that can produce lethal white syndrome (LWS). Because purebred Arabians cannot produce LWS foals , Arabian mares were used as a non-affected population in some of the studies seeking the gene that caused the condition in other breeds. Nonetheless, partbred Arabian offspring can, in some cases, carry these genes if
18980-426: The purest blood were known as Asil and crossbreeding with non- Asil horses was forbidden. Mares were the most valued, both for riding and breeding, and pedigree families were traced through the female line. The Bedouin did not believe in gelding male horses, and considered stallions too intractable to be good war horses, thus they kept very few colts , selling most, and culling those of poor quality. Over time,
19126-409: The same biological information . This information is replicated when the two strands separate. A large part of DNA (more than 98% for humans) is non-coding , meaning that these sections do not serve as patterns for protein sequences . The two strands of DNA run in opposite directions to each other and are thus antiparallel . Attached to each sugar is one of four types of nucleobases (or bases ). It
19272-432: The section on uses in technology below. Several artificial nucleobases have been synthesized, and successfully incorporated in the eight-base DNA analogue named Hachimoji DNA . Dubbed S, B, P, and Z, these artificial bases are capable of bonding with each other in a predictable way (S–B and P–Z), maintain the double helix structure of DNA, and be transcribed to RNA. Their existence could be seen as an indication that there
19418-473: The shape of a double helix . The nucleotide contains both a segment of the backbone of the molecule (which holds the chain together) and a nucleobase (which interacts with the other DNA strand in the helix). A nucleobase linked to a sugar is called a nucleoside , and a base linked to a sugar and to one or more phosphate groups is called a nucleotide . A biopolymer comprising multiple linked nucleotides (as in DNA)
19564-552: The shoulder. There are a very few Arabians registered as "white" defined as having a white coat, pink skin and dark eyes from birth. These animals are believed to manifest a form of dominant white , W3, a result of a nonsense mutation in DNA tracing to a single stallion foaled in 1996. It is possible that white mutations have occurred in Arabians in the past and it is likely that mutations other than W3 exist but have not been verified by genetic testing. One spotting pattern, sabino , does exist in purebred Arabians. Sabino coloring
19710-454: The show at WestWorld for the next 20 years. The show is highlighted in some of the colder climates as a way to get into warmer weather during the freezing temperatures of February in the northern U.S. In 2014, WestWorld unveiled a new light sculpture entitled "Impulsion", which was commissioned at a cost of $ 470,000. The statue is 40 feet long and 30 feet high, weighs over 1000 pounds, and was the work of Scottsdale artist Jeff Zischke. Aside from
19856-498: The single-stranded DNA curls around in a long circle stabilized by telomere-binding proteins. At the very end of the T-loop, the single-stranded telomere DNA is held onto a region of double-stranded DNA by the telomere strand disrupting the double-helical DNA and base pairing to one of the two strands. This triple-stranded structure is called a displacement loop or D-loop . In DNA, fraying occurs when non-complementary regions exist at
20002-514: The son of Abraham . In this story, the Angel Jibril (also known as Gabriel ) descended from Heaven and awakened Ishmael with a "wind-spout" that whirled toward him. The Angel then commanded the thundercloud to stop scattering dust and rain, and so it gathered itself into a prancing, handsome creature - a horse - that seemed to swallow up the ground. Hence, the Bedouins bestowed the title "Drinker of
20148-518: The strands separate and exist in solution as two entirely independent molecules. These single-stranded DNA molecules have no single common shape, but some conformations are more stable than others. In humans, the total female diploid nuclear genome per cell extends for 6.37 Gigabase pairs (Gbp), is 208.23 cm long and weighs 6.51 picograms (pg). Male values are 6.27 Gbp, 205.00 cm, 6.41 pg. Each DNA polymer can contain hundreds of millions of nucleotides, such as in chromosome 1 . Chromosome 1
20294-469: The sugar-phosphate to form the complete nucleotide, as shown for adenosine monophosphate . Adenine pairs with thymine and guanine pairs with cytosine, forming A-T and G-C base pairs . The nucleobases are classified into two types: the purines , A and G , which are fused five- and six-membered heterocyclic compounds , and the pyrimidines , the six-membered rings C and T . A fifth pyrimidine nucleobase, uracil ( U ), usually takes
20440-427: The superiority of the breed in endurance riding competition demonstrates that well-bred Arabians are strong, sound horses with superior stamina. At international FEI -sponsored endurance events, Arabians and half-Arabians are the dominant performers in distance competition. Some Arabians, though not all, have 5 lumbar vertebrae instead of the usual 6, and 17 pairs of ribs rather than 18. A quality Arabian has both
20586-430: The two separate polynucleotide strands are bound together, according to base pairing rules (A with T and C with G), with hydrogen bonds to make double-stranded DNA. The complementary nitrogenous bases are divided into two groups, the single-ringed pyrimidines and the double-ringed purines . In DNA, the pyrimidines are thymine and cytosine; the purines are adenine and guanine. Both strands of double-stranded DNA store
20732-438: The world by both war and trade, used to improve other breeds by adding speed, refinement, endurance, and strong bone. Today, Arabian bloodlines are found in almost every modern breed of riding horse. The Arabian developed in a desert climate and was prized by the nomadic Bedouin people, often being brought inside the family tent for shelter and protection from theft. Selective breeding for traits, including an ability to form
20878-507: Was also able to gather many remaining horses at her Sheykh Obeyd stud. Meanwhile, the passion brought by the Blunts to saving the pure horse of the desert helped Egyptian horse breeders to convince their government of the need to preserve the best of their own remaining pure Arabian bloodstock that descended from the horses collected over the previous century by Muhammad Ali Pasha, Abbas Pasha and Ali Pasha Sherif. The government of Egypt formed
21024-678: Was no pasture or water, the Bedouin fed their horses dates and camel's milk. The desert horse needed the ability to thrive on very little food, and to have anatomical traits to compensate for life in a dry climate with wide temperature extremes from day to night. Weak individuals were weeded out of the breeding pool, and the animals that remained were also honed by centuries of human warfare. The Bedouin way of life depended on camels and horses: Arabians were bred to be war horses with speed, endurance, soundness, and intelligence. Because many raids required stealth, mares were preferred over stallions as they were quieter, and therefore would not give away
21170-517: Was proposed by Wilkins et al. in 1953 for the in vivo B-DNA X-ray diffraction-scattering patterns of highly hydrated DNA fibers in terms of squares of Bessel functions . In the same journal, James Watson and Francis Crick presented their molecular modeling analysis of the DNA X-ray diffraction patterns to suggest that the structure was a double helix. Although the B-DNA form is most common under
21316-441: Was very important to the Bedouin, and they also believed in telegony , believing if a mare was ever bred to a stallion of "impure" blood, the mare herself and all future offspring would be "contaminated" by the stallion and hence no longer Asil . This complex web of bloodline and strain was an integral part of Bedouin culture; they not only knew the pedigrees and history of their best war mares in detail, but also carefully tracked
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