E-Locus (Recessive Yellow, Melanistic Mask Allele)


Description:
MC1R, also known as the extension gene, controls production of pigment in melanocytes. The dominant form of the gene, the "E" allele, allows the dog to produce eumelanin, which is a black pigment. A mutation in the MC1R gene causes the pigment-producing cells to only produce phaeomelanin, which is a yellow pigment. This form of the gene is represented as the "e" allele. The "e" allele is recessive, meaning that a dog must have two copies of the MC1R mutation to express the solid yellow coat color.

A third allele exists in the extension gene, Em which is also dominant. This causes the dog to have a black mask on their face, also known as a melanistic mask. This allele acts similarly to the E allele, in that it causes a black-based coat. Because it is dominant, a dog only needs one copy of the Em allele to express this trait. In solid black dogs with a copy of the Em allele, the mask is hidden, however, it can still pass on the melanistic mask to future offspring.

The "ee" genotype can vary in expression between different breeds. In some breeds, the difference between a black or brown dog and a yellow dog is obvious, such as in Labrador Retrievers. However, in other breeds, such as Cocker Spaniels, this difference may be more subtle. Other breeds express the "ee" phenotype as a red color.

It is important to note that the Extension gene is only one of 4 important genes in determining the coat color of a canine. The dogs color can vary greatly with different alleles at other gene. Dogs that are "ee" will always be yellow, however, there is a great deal of variation of dogs that are "EE" or "Ee", depending on the B-Locus, A-Locus, and K-Locus.


BE

Be

bE

be

BE

BB/EE (pure for black)

BB/Ee (black carrying yellow)

Bb/EE (black carrying brown)

Bb/Ee (black carrying brown and yellow)

Be

BB/Ee (black carrying yellow)

BBee (pure for yellow, black nose)

Bb/Ee (black carrying brown and yellow)

Bb/ee (yellow carrying brown)

bE

BbEE (black carrying brown)

BbEe (black carrying brown and yellow)

bbEE (pure for brown)

bbEe (brown carrying yellow)

be

BbEe (black carrying brown and yellow)

Bbee (yellow carrying brown)

bbEe (brown carrying yellow)

bbee (brown-nosed yellow)



E Locus Testing:
The MC1R gene, or E Locus, has three possible forms Black (E), melanistic mask Em, and Yellow (ee). The E-Allele test determines how many copies of the recessive "e" alleles a dog carries. The EM-Allele test determines how many copies of the Melanistic Mask allele a dog carries.


Sample Type:
Animal Genetics accepts Buccal Swab, Blood, and Dewclaw samples for testing. Sample collection kits are available and can be ordered at Test Now.


Testing is Relevant For The Following Breeds:
All Breeds.


Results:
Animal Genetics offers DNA testing for both E and Em alleles. The genetic test verifies the presence of these mutation as and presents results as one of the following:

E/e-Allele Results:
EE Black The dog carries two copies of the dominant E allele. The dog will have a black-based coat, and will always pass on the "E" allele to any potential offspring.
Ee Black carries Yellow Both the dominant and recessive copies of the E allele are present. The dog will have a black-based coat, but carries the allele responsible for the yellow phenotype. The dog can pass on either allele to potential offspring.
ee Yellow Two copies of the recessive allele are present. The dog has a yellow coat, and will always pass on the recessive allele to all potential offspring.


E/M-Allele Results:
EmEm Black Mask The dog carries two copies of the melanistic mask allele. The dog has a melanistic mask, and will always pass on a copy of the Em allele to potential offspring. All offspring will also have a melanistic mask.
Emn Black Mask One copy of the melanistic mask allele is present, and the dog will have a black mask. The dog has a 50% chance of passing on this allele to potential offspring.
nn No Black Mask Dog tested negative for the melanistic mask allele. The dog will not have a black mask, and cannot pass a copy on to any offspring.


To Submit a Sample For Testing:
Please download a submission form, or order canine sample collection kits at Test Now.


Mail samples to:
Animal Genetics UK,
PO BOX 107, Truro,
Cornwall, England.
TR1 2YR.



Animal Genetics UK
COLOUR & GENETIC TRAITS:
A-Locus (Fawn/Sable Allele)
A-Locus (Recessive Black Allele)
B-Locus (Black/Brown)
D-Locus (Dilution)
E-Locus (Recessive Yellow Allele)
E-Locus (Melanistic Mask Allele)
K-Locus
Hair Curl
Hair Furnishings
Hair Length
Bobtail Gene / Short Tail

CANINE GENETIC DISEASES:
CLAD - Canine Leukocyte Adhesion Deficiency
CD - Cone Degeneration
CNM - Centronuclear Myopathy
Canine Cystinuria
DM - Degenerative Myelopathy
Gray Collie Syndrome - Cyclic Neutropenia
EIC - Exercise-Induced Collapse
FVII - Factor VII Deficiency
CF - Canine Fucosidosis
HC - Hereditary Cataracts
NEwS - Neonatal Encephalopathy with Seizures
MDR1 - Multi-drug Resistance
MLS - Musladin-Lueke Syndrome
PFKD - Phosphofructokinase Deficiency
PRA - Cord1-PRA
PRA - Dominant PRA
PRA - rcd1-PRA
PRA - rcd3-PRA
PLL - Primary Lens Luxation
TNS - Trapped Neutrophil Syndrome
vWD Type1

DNA TYPING SERVICES:
DNA Profile
Parentage Testing

CANINE INFECTIOUS DISEASES:
Canine herpesvirus 1 (CHV-1)
Canine Adenovirus

OTHER SERVICES:
Bird Rings
"Buddy" Digital Egg Monitor
Avian Testing
Equine Testing
Feline Testing
Sheep Testing
Equine Coat Color Calculator
Pricing: 45.00 per test (inclusive of tax, certification included free of charge)
Turnaround time: 5-7 business days.
Results: Phoned, faxed or e-mailed. Testing certificate dispatched after conclusion of test.