Genetics of the Palomino horse; confirmation of the Salisbury-Britton hypothesis.

This research article is about the genetic properties of the Palomino horse, confirming the Salisbury-Britton hypothesis that a Palomino’s unique coat color is due to a dominant dilution gene and not albinism.

Study Overview

• Refuting long-standing beliefs, this study confirms Salisbury and Britton’s assumption that the Palomino horse’s signature coat color is due to a dominant dilution gene rather than a recessive albinism gene.
• The authors explain that the horse in question, a stallion, exhibits pink skin and blue eyes, characteristics explained by homozygosity for the recessive non-black allele of the B gene.
• Their observations demonstrated that when the stallion was mated with chestnut mares, all the offspring were Palomino, while half of the offspring from Palomino mares were “albino.”

Palomino’s Unique Coat Color

• The coat color of a Palomino horse is described as golden yellow, with the mane and tail being notably lighter, almost white. It was identified as a heterozygous character, which means it is determined by two different genes.
• This coat color does not breed true. This means that when two Palomino horses mate, their offspring could have varying coat colors.
• On average, about half the colts (young male horses) will be Palomino, while the other half would be split between chestnuts and albinos.

Offspring Coat Color Distribution

• The distribution of coat colors in the population of colts produced by mating two Palomino horses is estimated as 1 albino : 2 Palomino : 1 chestnut.
• According to the study, albino types, meaning horses exhibiting characteristics often mistaken for albinism – such as pink skin and blue eyes – are a result of a dominant dilution gene, not albinism.
• The authors further explain that albinos will breed true. Meaning that albinos, contrary to Palomino horses, will produce albino offspring.