Description

nZ Horse

Silver Dilution is a dominant trait. This means, in order to inherit the trait, a horse requires only one parent to carry and pass on the gene. Somewhat similar to the Agouti gene, the Silver Dilution gene will only alter black pigmented horses (Ee or EE) and has no effect on red pigmented horses (ee). The Agouti gene alters the coat by controlling distribution of the black pigment whereas the Silver Dilution gene does so by diluting areas of black pigment.

The effects of the Silver Dilution gene can vary greatly. Dilution by the Silver gene on a horse with a uniform black base typically involves lightening of the mane and tail and a dilution of the body to a chocolate color, often dappled as well. A Bay horse carrying the Silver gene will usually have a lightened mane and tail, as well as lightened lower legs. It is important to know that although a red horse will not be diluted by the Silver gene, it can however be a carrier of the gene and thus potentially pass the gene on to its offspring.

Silver dilution has been identified in a number of horse breeds including the Quarter horse, the Rocky Mountain horse, the Icelandic horse, Morgans, Shetland ponies and the Miniature horse.


Reference:
Brunberg E, Andersson L, Cothran G, Sandberg K, Mikko S and Lindgren G. 2006. A missense mutation in PMEL17 is associated with the Silver coat color in the horse. BMC Genetics 7:46

Silver Dilution Testing

Animal Genetics offers DNA testing and detection of the gene mutations responsible for Silver Dilution.

Why Test For Silver Dilution?

There are a number of reasons testing for the silver dilution gene can be beneficial. 1) Since the Silver Dilution gene only dilutes black pigment and does not physically alter red pigmented horses, testing red based horses will identify carriers of the Silver gene. 2) For Silver horses and carriers of the gene, testing to determine zygosity (whether the horse has one or two copies of the gene) can help with color breeding programs. 3) In some situations, the Silver gene can cause a coat color that might look very similar to another. For example, Silver Dilution on a Buckskin might resemble a Palomino or, another example, some Silver Bays and Silver Dapples have been incorrectly referred to as Chocolate Palominos. Testing can help determine the actual color of the horse.

Cost

$25.00 US per sample.

Collect sample by pulling (not cutting) 20-30 mane or tail hairs with roots attached. It is important that you pull the hairs and confirm that the actual root of the hair is being collected. The root contains the genetic material of your horse that is needed for DNA testing. Therefore, cut hairs do not provide an adequate sample of your horse. Place the collected hairs of each horse in a separate zip-lock bag labeling the bags accordingly with the horses name or identification number. Download and complete a submission form for each sample and send along with payment to Animal Genetics for testing.

Submission Form -

Results

Results are given using the following symbolic notation: