What is the name of the gene that restricts black color to the points in horses?

The Agouti gene is responsible for the distribution of black color in horses, specifically by restricting it to the points—such as the mane, tail, and lower legs. This gene plays a crucial role in the color pattern of horses, particularly affecting those that carry the black base coat. When the Agouti gene is present, it inhibits the deposition of black pigment in certain areas of the horse's coat, resulting in a color pattern known as bay when combined with the red pigment. This selective expression of color helps produce a variety of coat colors and patterns, demonstrating the Agouti gene's significant influence on equine coloration genetics. Understanding the role of the Agouti gene is fundamental for equestrian enthusiasts and breeders interested in equine coat color genetics.