Sabino horse

Sabino is a group of white spotting patterns in horses that affect the skin and hair. A wide variety of irregular color patterns are accepted as sabino. In the strictest sense, "sabino" refers to the white patterns produced by the Sabino 1 (SB1) gene, for which there is a DNA test. However, other horse enthusiasts also refer to patterns that are visually similar to SB1 as "sabino", even if testing indicates the gene is not present. Use of the term to describe non-SB1 "sabino" patterns in breeds that apparently do not carry the gene is hotly debated by both researchers and horse breeders.

Sabino patterning is visually recognized by roaning at the edges of white markings, belly spots, irregular face markings, especially white extending past the eyes or onto the chin, white above the knees or hocks, and "splash" or "lacy" marks anywhere on the body, but particularly on the belly. Some sabinos have patches of roan patterning on part of the body, especially the barrel and flanks. Some sabinos may have a dark leg or two, but many have four white legs. Both blue and brown eyes are seen. At one end of the sabino spectrum, the SB1 gene, when homozygous, can produce a horse that is almost completely white with pink or only partially pigmented skin. Some forms of sabino genetics are also thought to be the most common reason for solid-colored horses with "chrome," a term which can refer to horses with bold white markings on the face and high white leg markings. The most generous definition of sabino can include horses with as little white as a chin or lower lip spot.

Even though horses with the Sabino 1 gene can be completely white, no forms of sabino are linked to lethal white syndrome.

Sabino 1 was identified in 2005 by researchers at the University of Kentucky. The Sabino 1 gene, and the associated spotting pattern, is found in Miniature horses, American Quarter Horses, American Paint Horses, Tennessee Walkers, Missouri Fox Trotters, Mustangs, Shetland Ponies, and Aztecas. SB1 is notably absent from the Arabian horse, Thoroughbred, Standardbred horse, Shire horse and Clydesdale. There are many proposed genes responsible for the sabino-like white spotting in these and other breeds. Researchers gave the allele they discovered the name "Sabino 1" with the expectation of finding genes yet to be named "Sabino 2", "Sabino 3", and so on.

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