Roan (horse)

A horse has stichelhaariges or color changer by the roan gene ( Rn) a strong interference of white hairs in the colored coat. The interference is returned as the dominant white color and several forms of spotting a mutation of the KIT locus.

Stitchhaired horses are also known as iron mold, permanent mold, or if the underlying color is black, as a Moor's head mold. Horse lovers who take the genetics important to refer to these compositions with mold often than wrong, as the color of the horse stichelhaarigen genetically created completely different from the color of the mold. However, these color names are still in use.

Stitchhaired horses are rare.

Used the word in a broader sense, any other horse is called stichelhaarig that has interspersed some single white hairs in colored fur.

Appearance

A stichelhaariges horse has interspersed in the resulting by its other color genes color white hairs in the coat. Of these, which is primarily the undercoat affected, so that areas of the body with little undercoat as the head and legs and tail and mane are darker than the body.

Many stitchhaired horses are lighter when they get their winter coat in the fall, as the winter coat has a particularly dense undercoat. They are darker again as soon as they get their summer coat that has less undercoat.

But most of Roan show both in winter and in summer their Stichelhaarigkeit.

The amount of scattered white hairs can vary considerably from horse to horse, but remains apart from the seasonal changes throughout life the same. A horse has stichelhaariges therefore. Than yearling already so many white Stichelhaare such as adult animal

Individual Stichelhaare can also occur with normal colored horses, for example in the form of a fox with Stichelhaaren without the horse is a true roan. A Roan but can never be completely without Stichelhaare.

Also a stichelhaariger fox, but much brighter

Stichelhaariger Brown

Stichelhaariger brown with clear color coding on the head

Stitchhaired Cents or Mohrenkopf mold

Genetics

This stitchhaired lightening the hair of a horse's color is inherited by the roan gene. This is a mutation of the Kit locus, ie by an attenuated form of the leucism.

The same gene is at Tobiano, the mutated dominant white color of the horse and the Sabinoscheckung. If ( the gene therefore has twice) a horse for one of these four genes is homozygous, it can have none of the other two genes. If it is not homozygous, it can have at most two of these investments. Nearby on the same chromosome is the extension locus of the horse so that the chestnut color is often inherited together with the stichelhaarigen color.

The Stichelhaarigkeit arises because emigrate during embryonic development is not sufficient stem cells of melanoblasts ( ancestors of the dye-forming cells) from the neural crest, so that many hair follicles do not receive melanocytes after completion of fetal development that could produce dyes. The hairs lacking these cells therefore remain white.

Several studies only heterozygous Roans could be detected, so situations in which only one copy of the gene is present. It is therefore assumed that homozygous foals that were shared by both parents, the roan gene are not viable and die in utero. The frequency of the gene is located in the race in which it occurs at all, less than 5%. Therefore, only rarely two stitchhaired parents will be paired with each other, and the absence of known homozygous horses can therefore also be random.

Only a single breed of horse, the Quarter Horse, there are several stallions of the Hancock bloodline exclusively stitchhaired horses witnessed and therefore had to be homozygous. But that could also be characterized to explain that this is a different, yet unknown roan gene.

Possible confusion

Used to " stichelhaariges horse" in a broader sense, any other horse is called stichelhaarig, has interspersed the single white hairs in colored fur the term. Animals that meet this expanded definition of " Horse Stichelhaariges " are often externally easily confused with it. Here they are listed with their exact name.

• Mold: Mold foals are born dark and then gradually get more and more white hairs. For them, the head is usually lighter than the body.
• Rabicano: Mainly on the belly interspersed white hairs, while the head, neck, legs, shoulders and withers, and the hind legs up to rump ( butt ) remain darker.
• Varnish Roan: The face only a V-shaped drawing remains dark, the dark color on the legs extends only up to the knee and ankle.
• Frosty Roan There is obviously a Roan gene that causes white Stichelhaare on the back of the horse, in mane, tail, as if it had snowed on the horse. Head and legs are dark like the stichelhaarigen horse.
• Sabino Overo The Sabino gene sometimes calls a stitchhaired color produced, which can be quite different, pronounced, but is always associated with a blaze or lantern.