Last week I began a series on Coat Color Genetics in Horses. In the previous article I discussed the Agouti Gene and the Extension Gene. These two genes control the base color. Today I am going to look at the Creme dilution and the Champagne dilution on the base colors.
The Creme dilution has 2 alleles CCR and C. This gene creates palomino, buckskin, smokey black, cremello, perlino, and other smoky creme colors. The allele C is recessive and does not dilute the base color. Only horses receiving the CCR will show diluted color. Recessive carriers can produce dilute foals.
Chestnut horses receiving the CCR copy of this dilute gene will be palomino, if the horse carries two copies of CCR (or alleles) for the creme gene they will be cremello.
Bay horses receiving receiving the CCR copy of the creme gene will be buckskin or dun(depending on the agouti gene). Bay horses receiving 2 copies of the creme gene will be perlino.
Black or Brown horses receiving the CCR copy of the creme gene will be smokey black or another smokey color.
The Champagne gene (Ch) is a dominant gene that affects the hair color and dilutes red (chestnut/sorrel) to gold and bay to tan with brown points. This dilute on red is often mistaken for palomino.
Horses showing this phenotype (what the horse looks like) will have pink to lavender skin tone, that can become speckled with age that will be noticed around the eyes, muzzle, and tail. Horses with this genotype will also have blue/green eyes darkening to amber as they age. This dilution is inherited independently of other color genes, although it is thought to be related to Solute Carrier 36A1 family.
For horses showing one copy of the Ch gene, they are expected to have the following phenotype red to gold with flaxen mane and tail, bay to tan with brown points, and black to a darker tan with brown points.
Horses who receive to copies of the Ch dilute gene are expected to show the double dilute in color often resembling perlino and cremello in color.
In the next article I will look at the grey, pearl, and silver gene in horses and the color variations that come with the those genes.
