Tobiano is a spotted color pattern commonly seen in
Pinto horses, produced by a dominant gene. The tobiano geneproduces white-haired, pink-skinned patches on a base coat color. The coloration is present from birth and does not change throughout the horse's lifetime, unless the horse also carries the gray gene. ("see below")
Other spotting patterns seen in Pinto horses include
overoand the sabino markings. In the United Kingdom, Tobianos are frequently referred to as "Coloured" or as Piebald(black and white) or Skewbald(white and any base color other than black). However, Bay and white horses are also referred to as Tri-Coloured.
Tobiano traits generally include the following:
* White legs from the hocks and knees down
* White crossing the back between the withers and the dock of the tail
* White is arranged in a vertical pattern
* Facial markings are similar to those of a traditionally solid-colored horse. i.e. star, snip, strip, or blaze. Extreme white facial markings suggest the presence of additional color pattern genes beyond Tobiano
* White patches which are usually rounded or oval in shape, rather than jagged (see
* Dark color extending down the neck, giving the appearance of a shield
Tobiano is a dominant gene. [ [http://www.vgl.ucdavis.edu/services/coatcolor.php "Introduction to Coat Color Genetics"] "from" Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, Davis. Web Site accessed January 12, 2008] Therefore, one parent must be a tobiano for the pattern to occur, and the coat pattern will occur with a single copy of the Tobiano gene present (i.e. the horse is
heterozygousfor Tobiano). Furthermore, when a horse is homozygousfor Tobiano coloring, all of that horse's offspring will be spotted, with only a few exceptions: If either parent passes the dominant gray gene to the foal, then it's spots will be visible while it is young, but will gradually become lighter until finally, as the gray gene acts upon all coat colors, the entire horse's coat fades. In the case of horses born Tobiano but turn gray, the skin will retain pigmented and unpigmented skin beneath its hair that may produce "ghost" markings. A homozygous Tobiano that also carries a dilution gene, such as a Pinto with a base color of palominoor buckskin may not reliably produce spotted offspring if bred to another horse with a dilution gene, as a double-dilution may "wash out" the base color.
The Tobiano gene itself is not linked to
lethal white syndrome. However, some Tobiano horses may be carriers of the gene if they have overoancestors, and thus have produced affected offspring when bred to another horse that is also a carrier. [Paul D. Vrotsos RVT and Elizabeth M. Santschi DVM. University of Minnesota Genetics Group. [http://www.apha.com/breed/lethalwhites03.html "Stalking the Lethal White Syndrome"] . "Paint Horse Journal". July 1998.] In some cases, a horse which carries both Tobiano and Overo genetics may display white markings that combine both patterns, and are referred to as Toveros.
Genetic testing is available to help determine the presence of the Tobiano gene. Originally, there was no direct test for Tobiano, the early Tobiano tests utilized six genetic markers, including a marker on the KIT gene on Horse
chromosome3, which were closely linked to Tobiano but could not be used to officially prove homozygosity. [ [http://www.vgl.ucdavis.edu/services/tobiano.php "Tobiano"] "from" Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, Davis. Web Site accessed January 13, 2008] However, in 2008 it was determined after some years of research from the University of Kentucky, that Tobiano coat pattern is the result of a chromosomal 'inversion' of the KIT gene. [ [http://www.animalgenetics.us/Tobiano.htm "DNA Testing for Tobiano"] "from" Animal Genetics Incorporated] This inversion was finally mapped for genetic testing and is now offered by some laboratories as a more direct Tobiano assay. Testing is most often intended to determine Homozygosity, but is also useful in cases whereby a horse has greyed out, or if a horse has an unexplained loss of pigmentation.
* [http://www.vgl.ucdavis.edu/services/coatcolorhorse.php "Horse coat color tests"] "from" Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, Davis. Web Site accessed January 12, 2008
* [http://www.vgl.ucdavis.edu/services/coatcolor.php "Introduction to Coat Color Genetics"] "from" Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, Davis. Web Site accessed January 12, 2008
Equine coat color genetics
Equine coat color
American Paint Horse
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Look at other dictionaries:
tobiano — adj. s. m. 1. [Brasil] Diz se de ou raça de cavalos. 2. Relativo a Tobias Barreto … Dicionário da Língua Portuguesa
tobiano — tobiano, na adj. Arg. y Ur. Dicho de un caballo overo: Cuyo pelaje presenta grandes manchas blancas. U. t. c. s.) … Diccionario de la lengua española
Tobiano — Links: Braunschecke, Rechts: Rappschecke Als Tobiano oder Dominante Plattenscheckung wird das häufigste Scheckungsmuster bei Hauspferden bezeichnet. Inhaltsverzeichnis 1 Wortherkunft … Deutsch Wikipedia
tobiano — ► adjetivo Argentina EQUITACIÓN, ZOOLOGÍA Se aplica al caballo cuyo pelaje presenta manchas blancas en la parte superior del cuerpo. * * * tobiano, a (Arg., Chi.) adj. Se aplica a los *caballos de cierta raza que tienen la piel con grandes… … Enciclopedia Universal
tobiano — (Sp. model spelled same [tobjáno], origin not found) A pinto horse with smooth, regular markings and a white color that starts at the back and rump of the animal and extends downward. See also overo. The DRAE glosses tobiano as an adjective… … Vocabulario Vaquero
tobiano — pop. Pelaje caballar con manchas grandes de varios colores … Diccionario Lunfardo
tobiano — na adj. Se dice del caballo o yegua cuyo pelaje es de dos colores formando grandes manchas … Diccionario Castellano
tobiano — /toʊbiˈanoʊ/ (say tohbee ahnoy) noun a horse with large areas of white in its coat, especially a white area crossing the spine, white legs and a white tail, and with patches of underlying pink skin. Compare overo, sabino … Australian English dictionary
Idioma tobiano — El idioma tobiano, también llamado Tobi o Hatohobei es la lengua micronesia hablada en el sur de las islas de Palaos, específicamente de las islas de Tobi (o Hatohobei), Pulo Anna, Merir, Fana, Helen Reef y Sonsoral (o Sonsorol). Existen unos 100 … Wikipedia Español
Idioma tobiano — El idioma tobiano, también llamado Tobi o Hatohobei es la lengua hablada en el sur de las islas de Palau, especificamente de las islas de Tobi (o Hatobohei), Pulo Anna, Merir,Fana, Helen Reef y Sonsoral (o Sonsorol). Existen unos 100 hablantes de … Enciclopedia Universal