Post by Haley on Jan 12, 2010 15:20:31 GMT -6
Pearl: The pearl gene (formerly known as the Barlink or apricot gene) is a recently discovered recessive and cream activated dilution. Because it is recessive, one copy of the pearl gene will not affect coat color (if the cream gene is not present). Two copies if the pearl gene act as a double dilute on the coat, mimicing cremello, perlino, and smoky cream shades. The pearl gene combined with one cream gene produces horses that look very like the champagne dilutions. For more information about this gene and pictures of pearl horses, please visit the New Dilutions website. Heterozygous is (nPrl) and homozygous is (PrlPrl).
Pearl cream: bay + 1 cream + 1 pearl
Palomino pearl: chestnut + 1 cream + 1 pearl
Smokey Black Pearl: black + 1 cream + 1 pearl
Grey: Contrary to popular belief, grey is not so much a color as it is a pattern (or more accurately still, a color modifier). Grey is a dominant gene that causes the horse's natural coat color, whether it be bay, black, dun, or palomino roan, to slowly "depigment" as the horse ages, much like human hair, regardless of the color, "greys out" with age. Most greys go through a lovely dappled phase, ending up nearly white or sometimes fleabitten. Because grey is a dominant gene, all grey horses will have at least one grey parent. Foals usually show evidence of greying on their faces first, particularly around the eyes. Also, the tip of the tail on most greys lightens up early on. Heterozygous is (Gg) and homozygous is (GgGg).
Grey (born black) with dapples
Some bay and chestnut based greys go through a phase called rose grey, like the horse above. Some rose greys dapple out and some, especially Arabians, tend to lighten up quickly without really dappling while still retaining a rosy hue.
Roan: The roan gene acts by interspersing white hairs throughout a horse's coat, but the head, legs, mane, and tail remain "dark." Roan can act on any of the base colors as well as on any dilute or patterned color. For example, you could have a red roan (chestnut + roan), a strawberry roan (bay + roan), a blue roan (black + roan), or even a palomino roan (chestnut + cream + roan). Roan is often confused with grey, but it should be noted that roan horses look the same throughout their lives while grey horses fade out to nearly white (as seen above). Heterozygous is (Rr) and homozygous is (RrRr).
Chestnut Roan: Chestnut + Roan
The chestnut coat is sprinkled with white hairs except on the head, legs, mane, and tail. Sometimes called a red or strawberry roan.
Bay Roan: Bay + Roan
The bay coat is sprinkled with white hairs except on the head, legs, mane, and tail. Sometimes called a red or strawberry roan.
Black Roan: Black + Roan
The black coat is sprinkled with white hairs except on the head, legs, mane, and tail. Sometimes called a blue roan.
A palomino roan (chestnut + cream + roan). Even with 2 different dilution genes at work, this horse's head and knees retain traces of the dark palomino color.
Pinto Patterns: Pinto is a term that refers to several different patterns of white. The patterns fall into two catagories, tobianos and overos. The overo catagory includes frame overo, sabino, and splash white. A horse with a combination of tobiano and one or more overo patterns is known as a tovero.
The tobiano pattern is dominant, and it is characterized by white crossing the horse's back between the withers and the dock, as well as by areas of color on the head, chest, and flanks. Most tobianos have normal face markings like stars and blazes, and they almost always have four white feet. Heterozygous is (nT) and homozygous is (TT).
This is Skip A Raindrop owned by Rocklyn Paints. She exhibits a minimal tobiano pattern as well---again, note the white patches on her withers and above her tail. Those prove she is a tobiano and not an overo, as the spot on her side might lead one to believe.
A typically marked tobiano---note the all white topline and the characteristic patches of color on the head, chest, and flanks. Tobianos frequesntly have spots with rounded edges.
This is The Eagle's Gift, a lovely tobiano Paint mare who exhibits cat tracks, the small spots on her shoulder. Cat tracks are often somewhat roany looking and are typical of homozygous tobianos.
Frame overos are characterized by having a dark topline between the withers and dock, with blocks of white on their sides and necks. Frame overos usually have large blazes or apron markings.The feet are usually dark, but may be white if combined with the tobiano, sabino, or splash genes. Heterozygous is (nO).
This is Cupid's Snoopie Leo owned by Happy Trails. He is a typically marked frame overo with a wide blaze, spotting on his sides, and no socks.
Another lovely example of frame overo, this one with a bit more white, likely due to the presence of sabino.
A filly owned by Painted Badlands Ranch who exhibits an extreme overo pattern. Note that her topline is still dark from the withers to the tail. She very likely also has the sabino pattern.
Sabino is a pattern that comes in many forms. In its minimal form, it only manifests itself as small socks and a star or blaze, if that. More extreme sabinos will have white patches, often with roaned edges, creeeping up their sides from the underside of the belly. The most extreme sabinos will look entirely white or almost so, often retaining a few patches of color along their toplines, particularly on the ears or in the mane. Heterozygous is (nSb) and homozygous is (SbSb).
This is Marquetry, a minimally marked sabino. Note the odd spot on his left front knee and white chin, typical sabino indicators.
This is Airdrie Apache, a more boldly marked sabino.
This handsome guy is Puchingui, sire of many modern sabino TBs.
This is The White Fox, an extreme sabino son of Patchen Beauty. His first four dams tail-female are white extreme sabinos. Quite a remarkable family.
Splash white horses look as if they've literally been splashed with white paint from the underside or dipped in white paint. Splash white is an incomplete dominant. Homozygous spashes will have more white than heterozygous splashes. Splash markings tend to have smooth, crisp edges, and most splashes have blue eyes (especially the homozygous ones). Heterozygous is (nSpl) and homozygous is (SplSpl).
A minimally marked splash white. He is likely a heterozygous splash.
Another fairly minimally marked splash.
A very typically splash white foal.
A more extremely marked splash white. Definitely a homozygous splash.
All pinto patterns can range from minimal expressions (a nearly solid colored horse) to extreme expression (an all-white or nearly all-white horse). White horses resulting from tovero and sabino patterns are completely viable. White horses that are homozygous for frame overo (OO), however, are known as lethal white overos (LWO).
A lethal white overo. This foal died shortly after birth.
This is Oroneeka, a Spanish Mustang exhibiting the tovero pattern, a combination of tobiano and overo.
This is an extreme variation of the tovero pattern known as Medecine Hat. The horse only retains color on it's flanks, around the eyes, and over the ears.
This is Designated Hitter, another tovero who exhibits the Medecine Hat pattern.
Appaloosa: The wild spotting pattern typified by the Appaloosa breed is caused by a group of genes called the leopard complex (Lp). The pattern can be manifested in several ways: varnish, blanket, leopard, snowcap, and few spot. Horses who are heterozygous (Lplp) for the leopard complex will exhibit the varnish, blanket, or leopard patterns. Horses who are homozygous (LpLp) for the leopard complex will exhibit the snowcap or few spot patterns. According to recent studies, the appaloosa pattern in it's heterozygous state seems to manifest itself similarly to the pinto genes. Moderately expressed appies will have a small blanket, more boldly marked horses will have larger blankets, and the most boldly patterned horses are entirely covered by the blanket, meaning they are leopard appaloosas. For more information on the ongoing project of mapping the appaloosa genome, please check out The Appaloosa Project. Appaloosa pattered horses also have distinct markings besides their spots---they have striped hooves, mottled skin, and white sclera. Heterozygous is (nLp) and homozygous is (LpLp).
A small blanket.
A larger blanket.
A larger blanket, sometimes called semi-leopard.
Leopard appaloosa.
Varnish roan appaloosa.
Ima Starr Dancer, a snowcap with a larger blanket. Notice the complete lack of spots, signifying his homozygosity.
JR's Shado, a few spot appaloosa, also homozygous for the leopard complex.
Rabicano: Rabicano is a pattern that is often confused with true dark-headed roan. The rabicano gene, however, is entirely seperate from the roan gene, though it does create a pattern of white hairs that can be similar to roan. It is usually manifested as a sprinkling of white hairs radiating out from a horse's flank, sometimes spreading across the barrel and onto the shoulder. Rabicanos also have a white-topped tail, known as a coon tail or skunk tail. There is some thought that rabicano may be tied to or somehow related to sabino as the rabicano pattern is often found in conjunction with sabino. Rabicano can act an any coat color.
This is Colorful Tour, a chestnut rabicano TB.
This TB, aptly named Skunktail, is clearly a rabicano and a sabino---look at the distinctive points on his socks---a typical sabino indicator.
Sooty: Sooty is a common color modifier that can act on both red and black based coats. Sooty, also known as smutty or countershading, causes dark hairs to be spread throughout a horses coat, usually concentrated from the top of the back down. Sooty horses often have spectacular dappling because of the contrast of colors in their coats. Sometimes the sooty hairs are concentrated into lines resembling leg barring and dorsal stripes on non-dun horses. Some horses are so sooty that their true color is unrecognizable. For example, some sooty buckskins have been mistaken for dark bay or black horses. For example, some sooty buckskins have been mistaken for dark bay or black horses, such as the pony pictured below.
This is Tide Creek Augustus, a very dark sooty buckskin Section B Welsh Pony.
This is Cooper, a purebred bay Arabian, sporting a countershading dorsal stripe.
Pangare: Pangare is a modifier that acts by lightening certain portions of a horse's coat, usually the muzzle, the belly, the inner forearms and thighs, and sometimes even the chest or around the eyes. When it acts on a chestnut coat, the horse usually will have a flaxen mane and tail. It can act on any color, and varies in intensity. It is often found in pony and draft breeds, such as Haflingers, Fjords, Exmoors.
This is Mitch, a handsome Haflinger gelding, who exemplifies dramatic pangare shading.
These Exmoor ponies show the effect of pangare on a bay coat.
Brindle: Brindle is an unusual pattern of dark, vertical lines on a lighter-colored coat. Though it is seen in a variety of breeds, it is quite rare. The genetics of brindle are unknown, but according to Dr. Philip Sponenberg, the man who literally wrote the book on equine color genetics, "brindle seems to require sooty black countershading for its expression, and reorganizes sootiness into vertical stripes instead of a more uniform sprinkling of hairs." I have included a few pictures of brindle horses below, but for more information on the history of brindle horse and more photos, please check out Sharon Batteate's excellent site: members.aol.com/brindlehos
This is Reckless Dan, an unusual grey brindle Quarter Horse.
The brindle coat pattern is occassionally caused by a rare genetic occurence called chimerism. Dunbar's Gold, pictured at left, is an example of this odd phenomonon. In a nutshell, a chimeric horse develops when two non-identical twins fuse into one embryo in utero. Dunbar's Gold, therefore, has two sets of DNA, resulting in his brindled coat. For more information about his fascinating story, check out this article published in the February 2006 American Quarter Horse Journal: www.aqha.com/magazines/aqhj/content/06february/oneinamillion.pdf
Reverse or White Brindle: Most brindle horses have dark stripes on a lighter body color, but a rare few have white stripes on a dark body color. As with regular brindles, the genetics of white brindles are not understood. It is possible that the white hairs from sabino or rabicano markings are arranged into lines like sooty hairs are in regular brindle coats. It is also possible that white brindles are chimeric, but I do not believe that either of the two horses pictured below have been tested with that in mind.
Below on the left is Catch A Bird, a bay Thoroughbred with white brindling. CAB, who was sadly euthanized in April of 2007, was a fascinating enigma. He sired 4 foals that were phenotypically true, dark-headed roans. The roan gene, however, is not present in the TB gene pool, so it is likely that CAB carried some sort of random mutation. To date, none of his roan foals have produced offspring (as far as I know).
The late, great Catch A Bird.
Natal, a Brazilian Warmblood.
Manchado: Manchado is a rare coat pattern that has only cropped up in Argentina in a handful of horses from various breeds (Criollo, Hackney, Arab, and TB so far). Because it is only found in Argentina and it has not proven to be hereditable, it is believed to be the result of environmental factors rather than genetic ones. The pattern is NOT related to appaloosa, sabino, or chubari/Tetrarch spots.
This is Royal Manchado, a Thoroughbred stallion.
This is Trabag, a champion Arabian mare.
Trabag's other side. None of her foals inherited her strange coat.
Seeing Spots: A variety of non-Appaloosa spots do occur in many breeds:
Birdcatcher spots, named for the Thoroughbred stallion who exhibited them, are small, round, white spots scattered throughout a horse's coat. In many cases, the spots appear and grow in number for a period of years, and then gradually fade away. Sometimes, the spots will persist throughout a horse's lifetime.
Chubari spots are similar, but are usually larger, often egg-shaped and egg-sized. They seem to occur almost exclusively on grey coats, and of course, fade as the grey coat fades. Most grey TBs and grey horses with TB breeding can trace their spots back to The Tetrarch, a brilliant racehorse in England in the early 20th century. The spots are sometimes refered to as Tetrarch spots for that reason.
Bend Or spots are also named for the TB stallion who bore them. They are random dark spots on a lighter coat, often seen on chestnuts and palominos. They vary in size, sometimes only dime-sized, and sometimes as big as an outspread hand.
Birdcatcher spots on an Arabian.
The Tetrarch sporting his large chubari spots. He was nicknamed the Spotted Wonder.
The Thoroughbred stallion Big Country exhibiting Bend Or spots.
Bloody Shoulder Markings: Bloody shoulder markings are random patches of color on grey horses that simply do not grey out. Despite the name, they can be found anywhere on a horse's body.
This is Charmander, a bay-based grey Thoroughbred filly. She is pictured here at about 3 years of age.
This is Laska de Thaix, a grey with a bloody shoulder mark on his head.
This is Brilliant Bird, a Thoroughbred with markings on his shoulder, barrel, and flank.
Gulastra Plume: A gulastra plume, named thus by Arabian breeders, is an interesting manifestation of sabino that creates a light colored tail on an otherwise solid-colored horse. It is not to be confused with rabicano.
Donatello, a handsome Thoroughbred.
Badger Face: A badger face marking is usually the result of a skewed sabino pattern. It resembles a reverse blaze.
A badger-faced sabino Paint owned by Yarnelle Farms.
A lovely badger-faced tovero (probably tobiano + sabino) Gypsy Vanner.
Other horse face markings:
Leg markings:
Leg markings:
