E Locus in Dogs: How the Cream, Red, and Yellow Coat Color Gene Works
One gene explains why some dogs are solid yellow, cream, apricot, or red — regardless of what else is in their DNA
If you have ever wondered why a Labrador can be yellow even when both parents look black, or why a red Poodle can produce apricot puppies — the answer is the E locus. It is one of the most influential color genes in dogs, and understanding it is essential for predicting litter outcomes.
What Is the E Locus?
The E locus (Extension locus) controls whether a dog can express black or brown pigment in the coat at all. The gene involved is MC1R (melanocortin 1 receptor), which regulates the switch between eumelanin (black/brown pigment) and phaeomelanin (red/yellow pigment).
There are several alleles at the E locus, but the most important for breeders are:
E (dominant) — Allows normal pigment expression. A dog with at least one E allele can show black, brown, sable, brindle, or other patterns depending on other genes.
e (recessive) — Blocks the production of eumelanin in the coat. Dogs with two copies (ee) can only produce phaeomelanin — the red/yellow spectrum.
The ee Dog: Yellow, Red, Cream, and Apricot
A dog that is ee at the E locus will be some shade of red, yellow, apricot, or cream regardless of what other color genes it carries. It cannot express black or brown in the coat because MC1R is not functioning to switch pigment production.
This is why:
- Yellow Labradors are ee — they carry genes for black (B locus) but cannot express them in the coat
- Red and apricot Poodles are ee — the underlying genes might be for black but ee masks them
- Cream Golden Retrievers carry ee which suppresses darker pigment
- Red and cream Dachshunds are ee
The nose, eye rims, paw pads, and eye color are controlled by other loci (primarily B and D) and are not masked by ee. This is why a yellow Lab has a black nose — the nose pigment follows different rules than coat pigment.
Intensity: Why Some ee Dogs Are Deep Red and Others Are Pale Cream
All ee dogs are "red" in the genetic sense, but the actual shade ranges from deep mahogany to nearly white. This variation is controlled by intensity genes — a set of modifiers (sometimes called the I locus or intensity polygenes) that are not fully mapped in dogs but clearly influence phaeomelanin saturation.
- High intensity → deep red, mahogany, apricot
- Low intensity → cream, pale gold, nearly white
When breeding two ee dogs, the intensity of the offspring will depend on which intensity modifiers they carry. Two pale cream dogs are likely to produce pale cream offspring. A deep red bred to a cream may produce a range of shades.
E Locus and the Em Allele (Melanistic Mask)
There is a third important allele at the E locus: Em, which produces a melanistic mask — the dark muzzle seen on German Shepherds, Boxers, Pugs, and many other breeds.
The order of dominance at E locus is: Em > E > e
A dog with one Em allele will show a dark mask (if other genes permit). A dog with two e alleles (ee) will not show a mask even if it carries Em, because ee blocks all black pigment in the coat.
Breeding Outcomes: Predicting E Locus Colors
| Parent 1 | Parent 2 | Possible Offspring |
|---|---|---|
| EE (black/brown) | ee (red/yellow) | All Ee — non-red, possible mask carriers |
| Ee | Ee | 25% EE, 50% Ee, 25% ee — one in four puppies will be red/yellow |
| Ee | ee | 50% Ee, 50% ee — half the litter may be red/yellow |
| ee | ee | All ee — entire litter will be red/yellow shades |
What This Means for Stud Dog Selection
If you want to produce red, apricot, or cream puppies, both parents must carry at least one e allele. If your dam is ee, any stud that is EE will produce zero red/yellow puppies.
If your dam is Ee and you want some red/yellow puppies, choose a stud that is Ee or ee. A stud that is EE will not produce any ee puppies with an Ee dam.
Ask stud dog owners for their dog's E locus genetic result. A DNA color panel from Embark, Paw Print Genetics, or UC Davis Veterinary Genetics Lab will include E locus results.
Summary
The E locus determines whether a dog can express black or brown pigment at all. Two copies of the recessive e allele (ee) produces red, yellow, apricot, or cream dogs regardless of other color genes. Intensity modifiers determine how deep or pale the color appears. To predict litter colors accurately, both parents should be DNA tested for E locus status. This one gene explains more surprising color outcomes in breeding programs than almost any other.