Background
During the last decades, a large number of scientific publications have described the genetic principles of coat colour and coat variation. Coat colours and coat variations are influenced by many hereditary factors. The DNA-tests are based on physiological effects in the body, in which the production and distribution of pigments result in many coat colour variants. In several cases, the coat colour of an animal may only be decided using DNA-tests. Roan is a white patterning coat colour trait of intermixed white and coloured hairs in the body while the head, lower legs, mane and tail remain colored. Roan horses are born with the pattern, though it may not be obvious until the foal coat is shed. The white and coloured hairs are evenly mixed in horses that inherit the classic Roan gene, which can differentiate this from several mimic patterns called roaning. Roaning patterns tend to be uneven in the distribution of white hairs and the
Inheritance
of roaning has not been defined. The mutation causing the Roan coat colour has not yet been identified. The Coat Roan test (P659) tests for DNA markers that are associated with Roan coat colour in several breeds, the DNA markers can be used to determine if a horse has the Roan mutation and how many copies. This test detects three variants (alleles), Rn, Rn* and N. The allele Rn is dominant. One or two copies of the Rn allele result in a Roan coat colour. The allele Rn* is very uncommon and not always associated with the Roan coat colour, this allele has only been observed in Tennessee Walking horses and Rocky Mountain horses. The allele N is recessive and does not have an effect on the basic colour.
Test specific information
This test is performed by UCDavis.
Since 2015, two brands have been developed. CombiGen?
is mainly directed at veterinarian applications, whereas CombiBreed?
is mainly directed at breeders and/or owners.Detailed information about Coat Colours and Coat Variation is presented at www.pharmaDNA.com.
Age
Most coat colours and coat types are usually visible directly after birth.
Throughput
Normally the result can be expected within 25 working days. This turn-around-time starts when both the sample and the fully filled-out and signed submission form have been received.
Location of disease or trait
Genetic factors influencing coat colours and coat types are usually visible on the outside of an individual. Several factors may be hidden by the external variation.
Breed dependence
For this test samples from all breeds are accepted.
Sample type
For this DNA test we accept the following materials: Hair, Blood EDTA, Blood Heparin, Semen, Tissue. Please contact PharmaDNA if you wish to submit other material as listed.
Result
Coat colours are based on many genetic factors. For each factor, a separate test result will be returned.
Inheritance
Various genetic factors influencing coat colour and coat types are inherited in a dominant or recessive mode. Coat colours are influenced by a large number of genetic factors.
Severity of Disease
Factors influencing coat colour and coat types are usually not related to diseases.
