The yellow Labrador coat is a beautiful sight to behold. Their coat is a result of genetics, specifically the interaction between two genes: the B locus and the D locus.
Labradors have two types of melanin: eumelanin and pheomelanin. The interaction between these two types of melanin determines the color of their coat.
The B locus determines the production of black and dark brown pigment, while the D locus determines the production of yellow pigment.
Labrador Coat Genetics
Labrador coat genetics can be a bit complex, but it's actually pretty fascinating.
Three genes determine a Labrador's coat color: MC1R, Agouti, and CBD103. If a dog has wild-type alleles at all three genes, it will have a yellow coat.
The E locus also plays a role in determining coat color, and it affects the expression of pheomelanin, the pigment responsible for red and yellow pigmentation.
Pheomelanin is visible only in yellow Labradors because dark eumelanin masks it in other colors.
Broaden your view: Labrador Chocolate Color
The genetic locus for this trait was long thought to be the same as the one regulating pheomelanin in other mammals, but it's actually distinct.
The Chinchilla trait, which affects pheomelanin in other species, is not the same as the one responsible for the yellow Labrador's coat color.
The E gene is unique to yellow Labradors and Golden Retrievers, and it's thought to have arisen before these breeds became distinct.
The E gene affects the distribution of eumelanin in the fur, and a recessive mutation in this gene truncates the protein, producing a non-functional receptor.
This mutation is responsible for the yellow coat color in Labradors, and it's also found in white coyotes around Newfoundland.
Labrador coat genetics are a result of the interplay among genes that direct production and expression of eumelanin and pheomelanin in the fur and skin.
The recognized colors of Labradors, black, chocolate, and yellow, result from two genes, while a third gene affects the range of coloration observed within the yellow Labrador.
The genetics of mammalian coloration has been studied in detail, and similar mechanisms have been identified across many species, including dogs and other mammals.
Recommended read: Rabbits Fur Turning Yellow
Labrador Coat Colors
Labrador retrievers come in a variety of colors, but the most dominant color in history is black. Black was the only color in the original St. John's dogs, the ancestors of modern Labradors.
The breed standard for Labradors was first registered with the Kennel Club of England in 1903, and later with the AKC in 1917. This means that before then, breeders didn't value colors like chocolate and yellow.
A series of genes determine what color an individual Labrador retriever will be, including the "B" genes for black and brown coats, and the "E" genes for yellow coats. The sire and dam that produce the litter of puppies pass down these genes to the offspring.
The dominant "E" gene can't cancel out the black or brown coats, but if both parents have a recessive "e" gene to pass on and a puppy receives them from both parents, those combined recessive genes will overpower either the black or brown trait and present a yellow coat.
Expand your knowledge: Labrador Golden Brown
Labradors with the widest range in coat color while remaining within the AKC breed standard are yellow Labs. They must have dark, heavily-pigmented noses, eyes, and lips, but their fur can range from a lighter vanilla to fox red.
The genetics of Labrador coat colors can be complex, but understanding the basics can help you appreciate the beauty and diversity of this breed.
Labrador Coat Characteristics
Labrador coat characteristics are determined by genetics, with different combinations of genes resulting in different coat colors. A series of genes, including MC1R, Agouti, and CBD103, work together to determine a dog's coat color.
The E locus, which affects the expression of pheomelanin, is responsible for the yellow coat color in Labradors. This locus is distinct from the Chinchilla trait, which affects pheomelanin in other mammals, and the cream gene, which dilutes pheomelanin in horses.
In yellow Labradors, the E locus allows pheomelanin to be expressed, resulting in a range of colors from light cream to copper-red. This is because the dark eumelanin pigment is not present in yellow Labradors, allowing the pheomelanin to shine through.
Curious to learn more? Check out: Doberman Pinscher Coat Colors
Mosaics and Mis-marks
Labradors can exhibit unique coat characteristics, such as mosaics and mis-marks, which can be fascinating to observe.
A mosaic Labrador is a rare occurrence, where a dog displays random but distinct patches of black and yellow throughout its coat. This can happen when a dog inherits a combination of genetic traits from its parents.
These patches can appear anywhere on the dog's body, and their distribution can vary greatly from one dog to another.
The genetic causes of mosaics and mis-marks are not fully understood and can be influenced by both genetic and environmental factors.
One possible explanation for mosaics is a somatic mutation early in development or a fusion between two zygotes that leaves some cells with genetics capable of producing dark fur, and others without.
Other mis-marks, such as brindle, tan points, white spots, and rings around the tails, are not uncommon in Labradors, but their underlying causes can be complex and varied.
Here are some examples of mis-marks that can occur in Labradors:
- Brindle
- Tan points
- White spots
- Rings around the tails
Labs with Pink Noses
Labs with pink noses are more prone to complications from a health perspective.
These dogs often have light brown or pink noses, lips, and eyes, which can make their skin more prone to sunburn or melanoma.
The recessive "e" gene makes the coat yellow, but it also affects the nose, eye rims, and lips, giving them less pigment like those of a chocolate Lab.
Chocolate Lab parents can pass on this trait to their yellow Lab offspring, making them more susceptible to skin issues.
Labs with black noses, lips, and eyes are more protected from the sun and have better vision for outdoor work.
This is why yellow Labs with the eyes, lips, and nose of a black Lab are more desirable for working, trial, or hunting dogs.
A light nose can also affect a dog's ability to work properly in the field, making it harder for them to see and perform tasks.
Curious to learn more? Check out: What Food Is Good for Dogs Skin and Coat
Labrador Breeds and Variations
Labrador breeds and variations are quite fascinating. The traditional Labrador Retriever colors are black, with other colors like chocolate and yellow emerging from other bloodlines.
Black is the most dominant color in the history of Labrador retrievers. Before the 20th century, breeders didn't value these other colors, and would often cull the runts or any weird-colored dogs.
The breeders wanted to avoid the reputation that their females weren't true full-blood, even if they were. People would think that if a dog had a funky color, it wasn't a purebred.
Eventually, dog owners began to value chocolate and yellow Labs, and official kennel clubs around the world started accepting these coat colors as part of the breed standard. The Labrador retriever was first registered as a breed with the Kennel Club of England in 1903.
See what others are reading: Exploring Dachshund Varieties: Sizes, Coats, and Colors
Frequently Asked Questions
Are yellow Labradors calmer?
Calmer Labradors are more about breeding than color, with yellow Labs often bred for therapy and service work, making them a great choice for those seeking a calm companion
Sources
- 10.1093/oxfordjournals.jhered.a110430 (doi.org)
- 10.1093/jhered/esi079 (doi.org)
- 17519392 (nih.gov)
- "A noncoding melanophilin gene (MLPH) SNP at the splice donor of exon 1 represents a candidate causal mutation for coat color dilution in dogs" (unibe.ch)
- 10.1534/genetics.107.074237 (doi.org)
- 27547348 (nih.gov)
- 10.1002/ece3.2290 (doi.org)
- 10.1093/oxfordjournals.jhered.a108792 (doi.org)
- Labrador Retriever coat colour genetics (wikiwand.com)
- AKC registered them (akc.org)
- Labrador retriever breeder (shadowglenlabradors.com)
- Labrador Retriever Club (thelabradorclub.com)
- Genetics of Labrador Coat Color (mapleleafvet.com)
- Coat Color Inheritance in the Labrador Retriever (ucdavis.edu)
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