Pearl gene
Encyclopedia
The Pearl gene, also known as the "Barlink factor," is a dilution gene
that somewhat resembles the cream gene
and the champagne gene
, but is neither. It is a somewhat rare dilution gene found in the American Quarter Horse
, American Paint Horse
, and Peruvian Paso
. The same mutation appears in Iberian horse
breeds such as the Lusitano
, Andalusian
. The existence of the pearl gene in Quarter Horses and Paints is probably because these breeds have some Iberian ancestors.
It is a recessive gene. If there is only one copy of the gene, it has no effect on black
, bay or chestnut
horses. If there are two copies, it lightens red coats to a pale, uniform apricot color that includes body, mane and tail and creates pale skin. Because of this effect, when research was underway to locate the specific gene involved, it was at one time referred to as the "apricot" gene.
The Pearl gene is also known to interact with the cream gene
to enhance its effects and, in horses with only one copy of the cream allele, to create "pseudo-double dilutes" sometimes called pseudo-cremellos or pseudo-smoky cream. A pseudo-double dilute will often have pale skin and blue or green eyes. Unlike the double cream dilute and the Pearl-cream pseudo dilute the double Pearl dilute typically has dark tan eyes. It is difficult if not impossible to tell a double cream dilute from a Pearl-cream pseudo dilute without genetic testing.
In the American Paint Horse
breed, the dilution was called the "Barlink factor" because it was linked to a mare
named My Tontime, and her grandson, the stallion
Barlink Macho Man, a chestnut splashed white
. Initially, the gene in Paints and Quarter Horses was thought to be a different allele
than that in the Iberian breeds, but research demonstrated that it was the same gene.
Dilution gene
Dilution gene is a popular term for any one of a number of genes that act to create a lighter coat color in living creatures. There are many examples of such genes:-General:...
that somewhat resembles the cream gene
Cream gene
The cream gene is responsible for a number of horse coat colors. Horses that have the cream gene in addition to a base coat color that is chestnut will become palomino if they are heterozygous, having one copy of the cream gene, or cremello, if they are homozygous. Similarly, horses with a bay...
and the champagne gene
Champagne gene
The champagne gene is a simple dominant allele responsible for a number of rare horse coat colors. The most distinctive traits of horses with the champagne gene are the hazel eyes and pinkish, freckled skin, which are bright blue and bright pink at birth, respectively...
, but is neither. It is a somewhat rare dilution gene found in the American Quarter Horse
American Quarter Horse
The American Quarter Horse is an American breed of horse that excels at sprinting short distances. Its name came from its ability to outdistance other breeds of horses in races of a quarter mile or less; some individuals have been clocked at speeds up to 55 mph...
, American Paint Horse
American Paint Horse
The American Paint Horse is a breed of horse that combines both the conformational characteristics of a western stock horse with a pinto spotting pattern of white and dark coat colors. Developed from a base of spotted horses with Quarter Horse and Thoroughbred bloodlines, the American Paint Horse...
, and Peruvian Paso
Peruvian Paso
The Peruvian Paso or Peruvian Horse is a breed of light pleasure saddle horse known for its smooth ride. It is distinguished by a natural, four-beat, lateral gait called the paso llano.-History:...
. The same mutation appears in Iberian horse
Iberian horse
The Iberian horse is a title given to a number of horse breeds native to the Iberian peninsula. At present, 17 horse breeds are recognized by FAO as characteristic of the Iberian Peninsula....
breeds such as the Lusitano
Lusitano
The Lusitano is a Portuguese horse breed, closely related to the Spanish Andalusian horse. Both are sometimes called Iberian horses, as the breeds both developed on the Iberian peninsula, and until the 1960s they were considered one breed, under the Andalusian name...
, Andalusian
Andalusian horse
The Andalusian, also known as the Pure Spanish Horse or PRE , is a horse breed developed in the Iberian Peninsula. Its ancestors have been present on the Iberian Peninsula for thousands of years. The Andalusian has been recognized as an individual breed since the 15th century, and its conformation...
. The existence of the pearl gene in Quarter Horses and Paints is probably because these breeds have some Iberian ancestors.
It is a recessive gene. If there is only one copy of the gene, it has no effect on black
Black (horse)
Black is a hair coat color of horses in which the entire hair coat is black. Black is a relatively uncommon coat color, and novices frequently mistake dark chestnuts or bays for black. However, some breeds of horses, such as the Friesian horse, Murgese and Ariegeois are almost exclusively black...
, bay or chestnut
Chestnut (coat)
Chestnut is a hair coat color of horses consisting of a reddish-to-brown coat with a mane and tail the same or lighter in color than the coat. Genetically and visually, chestnut is characterized by the absolute absence of true black hairs...
horses. If there are two copies, it lightens red coats to a pale, uniform apricot color that includes body, mane and tail and creates pale skin. Because of this effect, when research was underway to locate the specific gene involved, it was at one time referred to as the "apricot" gene.
The Pearl gene is also known to interact with the cream gene
Cream gene
The cream gene is responsible for a number of horse coat colors. Horses that have the cream gene in addition to a base coat color that is chestnut will become palomino if they are heterozygous, having one copy of the cream gene, or cremello, if they are homozygous. Similarly, horses with a bay...
to enhance its effects and, in horses with only one copy of the cream allele, to create "pseudo-double dilutes" sometimes called pseudo-cremellos or pseudo-smoky cream. A pseudo-double dilute will often have pale skin and blue or green eyes. Unlike the double cream dilute and the Pearl-cream pseudo dilute the double Pearl dilute typically has dark tan eyes. It is difficult if not impossible to tell a double cream dilute from a Pearl-cream pseudo dilute without genetic testing.
In the American Paint Horse
American Paint Horse
The American Paint Horse is a breed of horse that combines both the conformational characteristics of a western stock horse with a pinto spotting pattern of white and dark coat colors. Developed from a base of spotted horses with Quarter Horse and Thoroughbred bloodlines, the American Paint Horse...
breed, the dilution was called the "Barlink factor" because it was linked to a mare
Mare (horse)
A mare is an adult female horse or other equine.In most cases, a mare is a female horse over the age of three, and a filly is a female horse age three and younger. However, in Thoroughbred horse racing, a mare is defined as a female horse more than four years old; in harness racing a mare is a...
named My Tontime, and her grandson, the stallion
Stallion
A Stallion is a male horse.Stallion may also refer to:* Stallion , an American pop rock group* Stallion , a figure in the Gobot toyline* Stallion , a character in the console role-playing game series...
Barlink Macho Man, a chestnut splashed white
Splashed white
Splashed white or splash is a horse coat color pattern that produces pink-skinned, white markings. Many splashed whites have very modest markings, while others have the distinctive "dipped in white paint" pattern. Blue eyes are a hallmark of the pattern, and splash may account for otherwise "solid"...
. Initially, the gene in Paints and Quarter Horses was thought to be a different allele
Allele
An allele is one of two or more forms of a gene or a genetic locus . "Allel" is an abbreviation of allelomorph. Sometimes, different alleles can result in different observable phenotypic traits, such as different pigmentation...
than that in the Iberian breeds, but research demonstrated that it was the same gene.