Coat Colours and Patterns

G-Locus Horse (Grey)

G-Locus Horse (Grey) In horses, the gene for syntaxin 17 (STX17) is known as the Grey Locus (G-locus). A dominant mutation to this gene results in the gradual development of a grey coat. The mutation causes progressive depigmentation (fading) of the hair and is considered to be the “strongest” of...

A-Locus Horse (Agouti)

A-Locus (Agouti) In horses, black coat colour is a trait linked to the gene for the Agouti Signalling Protein (ASIP), also known as the Agouti Locus (A-Locus). Normally, ASIP is in part responsible for the distribution of dark and light pigment across the body. For instance, black colouration in wild...

Frame Overo Factor Horse (OLWS)

Frame Overo and Overo Lethal White Syndrome (OLWS) The Overo White Factor is an allele responsible for a splashed white pattern in horses, but breeding two carriers together can be risky as it leads to the death of homozygous offspring. This allele is caused by a semi-dominant mutation in the...

Coat Colour Introduction Horses

Introduction to equine coat colours In horses, coat colour is a complex trait influenced by a variety of genes interacting with each other. Mutations in these genes (or loci*) can interact in intricate ways, leading to a diverse range of coat colours and patterns. The original coat colour of the...

Appaloosa Patterns Horse (PATN1, CSNB, Leopard Spotting)

The Appaloosa spotting pattern, also known as Leopard Complex spotting (LP) includes a highly variable group of white spotting- or depigmentation patterns in horses. Appaloosa horses have three additional identifiable characteristics: mottled skin around the muzzle, anus and genitalia, striped hooves and white sclera round the eyes. LP is the...

E-Locus Horse (Chestnut)

E-Locus Horse (Chestnut) One of the most fundamental genes involved in the formation of a horse's coat colour is the Extension Locus (E-Locus). The E-Locus corresponds to the gene for melanocortin 1 receptor (MC1R), which is involved in the regulation of pigment production. Active MC1R causes a cell to “switch”...

Cream dilution

The cream dilution gene has an effect on both red and black pigment and dilutes the basic coat colour to lighter coat shades. In several breeds this is considered a desirable trait. The Cream dilution gene is responsible for the palomino, buckskin, smoky black, cremello, perlino and smoky cream coat...

Champagne Horse

Champagne Champagne dilution in horses is caused by a dominant mutation to the gene for solute carrier family 36 member 1 (SLC36A1). The Champagne dilution allele lightens the coat colour of the horse by diluting both dark and light pigment. Red hairs become gold, and black hairs become brown. The...

Dun Dilution Horse

Dun Dilution Dun dilution is a coat colour pattern in horses caused by a specific gene known as the Dun gene or D gene. It affects both dark and light pigment in the hair, resulting in unique colour variations. The Dun gene acts on the base coat colours such as...

Silver Horse

Silver Horse Silver coat colour, known as Silver Dapple, is a ‘dilution’ or lightening of the black pigment in the horse's hair, resulting in a silvery-grey or even white coat colour. It is a dominant trait, caused by a mutation to the gene for premelanosome (PMEL), and it is found...

Dominant White 1

White patterning in horses is known as Dominant White or White. Dominant White patterns are variable, ranging from minimal Sabino-like spotting to all-white horses. The eye colour of Dominant White horses is brown. There are about 20 different mutations identified that are associated with white patterns, all mutations are found...

Splashed White 1

Splashed white is a variable white spotting pattern characterized by a large blaze, extended white markings on legs, variable white spotting on belly, pink skin and often blue eyes. In other cases, the unpigmented areas are quite small and cannot be distinguished from horses with other more subtle depigmentation phenotypes....

Roan Horse

Roan Horse Roan coat colour, in horses also known as roaning, is a white patterning with a mixture of white and coloured hairs over the body. The head, lower legs, mane and tail remain coloured. In horses that inherit the classic Roan gene, the white and coloured hairs are evenly...

Brindle Horse

Brindle Brindle coat colour and texture in horses is distinguished by vertical stripes on the coat with a stripe-like change in texture along the neck, back, hindquarters and upper legs. A brindled coat may show a change in pigmentation. This phenotype, called Brindle 1 (BR1), can occur on any colour...

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