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.The hnRNP associated with lethal yellow gene (RALY gene) defines whether tan points or saddle tan is expressed in Basset Hounds and Pembroke Welsh Corgi dogs. Black and tan colour is characterized by light colour on the muzzle, above the eyes (tan points) and on the undersides of the dog on otherwise dark coat. Saddle tan resembles black and tan colour but the lighter areas are expanded leaving usually only the back to have dark patch. Saddled tan dogs are usually born black-and-tan and the black recedes as the dog grows. The coat colour is further complicated by the interaction with the E-locus, K-locus, A-locus and a yet unidentified gene. In order for the saddle tan pattern or tan points to be expressed, the dog needs to have at least one copy of the E or Em allele at the E-locus, two copies of the ky allele at the K-locus and one or two copies of the at allele at the A-locus. The Coat Colour Saddle tan vs black-and-tan test (H353) tests for the genetic status of the RALY gene. The RALY gene has two variants (alleles). The allele WT is dominant and causes the saddle tan coat colour. Only when the dog has two copies of the recessive allele dup the coat colour is black-and-tan. The saddle tan coat colour is present in a limited number of dog breeds including some of the terriers, scent hounds and herding dogs. In breeds that have only tan point dogs and no saddled tan dogs, the tan pointed dogs can have any genotype for the RALY gene. This suggests that more complex interactions are behind tan points in breeds that are not able to express saddle tan.
Test specific information
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 15 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
This DNA test is available for the following breeds: Basset, Pembroke Welsh Corgi.
Sample type
For this DNA test we accept the following materials: Blood EDTA, Blood Heparin, Tissue, Semen, Hair. Please contact PharmaDNA if you wish to submit other material as listed.
Result
Coat colours and coat types 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.
