Labrador Retrievers can be black, yellow, or chocolate in color, but did you know that their coat color is determined by just two genes? The genetics behind their coat color are quite fascinating.
The gene that codes for the production of the pigment eumelanin is responsible for the black and chocolate colors. This gene is inherited in an autosomal dominant pattern, meaning a dog only needs one copy of the gene to express the color.
The gene that codes for the production of the pigment phaeomelanin is responsible for the yellow color. This gene is also inherited in an autosomal dominant pattern, but it's a separate gene from the one that codes for eumelanin.
The interaction between these two genes determines the final coat color of a Labrador Retriever.
A fresh viewpoint: Chocolate Color Labrador
Labrador Retriever Coat Colour Genetics Basics
Labrador Retriever coat color genetics is a fascinating topic, and understanding the basics can help you appreciate the complexity of this breed's color variations.
There are two main genes involved in determining the coat color of a Labrador Retriever: the B gene and the E gene. The B gene determines whether a dog will be black or brown, while the E gene determines whether a dog will be yellow.
The B gene has two versions: the dominant B gene and the recessive bb gene. If a dog has the BB or Bb genotype, it will be black or brown, while a dog with the bb genotype will be yellow. However, the presence of the E gene can override the B gene, resulting in a yellow coat.
Here are the possible genotypes and phenotypes for the B gene:
The E gene also has two versions: the dominant big E gene and the recessive little e gene. If a dog has the EE or Ee genotype, it will not be yellow, while a dog with the ee genotype will be yellow. However, if a dog has the Ee genotype, it will be yellow only if the B gene is recessive.
In summary, understanding the basics of Labrador Retriever coat color genetics can help you appreciate the complexity of this breed's color variations.
Background
Labrador Retrievers are a popular dog breed in many countries.
There are three recognised colours, black, chocolate, and yellow, that result from the interplay among genes that direct production and expression of two pigments, eumelanin and pheomelanin, in the fur and skin of the dog.
The genetics of mammalian colouration has been studied in detail, and similar mechanisms have been identified across many species.
The genetics of coat colour in dogs has been studied extensively, with initial genetic studies published in the 1950s concluding that there were two main genes involved.
These two genes distinguish blacks from browns and blacks from reds and yellows.
A 1977 study using crosses within a population of purebred Labradors showed the involvement of two specific genes in production of the three main coat colours of Labradors.
The interaction of these genes is used by biology textbooks to demonstrate the genetic principle of epistasis, where multiple genes react synergistically to affect a single trait.
Labrador Retriever coat colour genetics is a complex topic, but understanding the basics can be fascinating and useful for breeders.
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Origin
So, where do yellow Labradors come from? The genetic information that creates a yellow coat comes from the E locus, which has two versions of the gene: big E and little e.
The big E gene is dominant and doesn't interfere with the B genes, while the little e gene is recessive and can mask the B genes, resulting in a yellow dog.
Here are the possible combinations of E and e genes:
- two dominant genes (EE)
- two masking genes (ee)
- or one of each (Ee).
Only the middle combination, Ee, will result in a yellow dog, as the big E gene will switch off the little e gene and the dog's color will be determined by its B genes.
Colouration Genes
Labrador Retrievers come in a variety of colours, but have you ever wondered what determines their unique coat colours? The answer lies in the interplay between two genes: the B locus, which determines the production of eumelanin, and the E locus, which affects the distribution of eumelanin.
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The B locus determines the production of eumelanin, with dominant alleles resulting in black or brown coat colours. The E locus, on the other hand, determines whether the eumelanin is deposited in the fur or solely in the skin. In Labradors, a highly-active mutated version of the K gene (K) is invariant, producing uniform eumelanin distribution.
Labradors with the genotype BbEe can produce all possible colour combinations, including black, chocolate, and yellow. Chocolate Labradors, with a genotype of bbEE or bbEe, will always have a yellow coat with black skin. Yellow Labradors with black skin, on the other hand, can have a genotype of BBee or Bbee.
Here are the different coat colours and their corresponding genotypes:
It's worth noting that the ability of the E locus to override the coat colour directed by the B locus is a classical example of epistasis, where multiple genetic loci affect the same observed trait.
Colour Inheritance
Labrador Retriever coat color genetics can be complex, but understanding the basics can help you predict the colors of your puppies.
The three basic colors passed on from one generation to the next are controlled by the B, E, and dilute genes.
You can determine the genotypes of breeding dogs for these genes with genetic tests, but this doesn't guarantee the pups will be born in all possible colors or in perfect proportions.
The B gene is dominant, which means it overrides the recessive b gene, resulting in a black coat.
A dog with BB genes will be black, while a dog with Bb genes will also be black because the dominant B gene turns off the recessive b gene.
Only a dog with a matching pair of bb genes will express the instruction for less eumelanin in their coat, resulting in a brown coat.
Here's a breakdown of the possible B gene combinations:
Generation after generation of black dogs can continue to have only black puppies if dogs with the Bb gene are only ever mated to dogs with BB genes.
Predicting and Testing
Genetic testing can reliably determine the number of copies of the MFSD12 gene mutation that a dog carries, which affects phaeomelanin dilution.
Carrier dogs (I/i) do not display an extreme phaeomelanin dilution, but when bred with another carrier dog, there's a 25% chance of having pups with light cream or white coat color.
Predicting Labrador puppy colors can be difficult without knowing the parents' genotypes, but puppy colors are easier to predict when both parents owe their appearance to the recessive genes b or e.
Genetic tests can determine the genotypes of breeding dogs for the B, E, and dilute genes, giving breeders valuable insight into the possible colors of their pups.
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Testing Tips
Genetic testing of the MFSD12 gene will reliably determine the number of copies of the intensity gene Mutation that a dog carries.
Reliable genetic testing is important for determining breeding practices. Dogs that are not carriers of an i mutation have no increased chance of having pups with a light cream or white coat color.
Phaeomelanin dilution associated with mutations of the MSFD12 gene is known to be inherited in an Autosomal Recessive manner in dogs.
Carrier dogs (I/i) do not display an extreme phaeomelanin dilution, but when bred with another dog that also is a carrier (I/i), there is a 25% chance of having pups with light cream or white coat color (if also e/e at the E Locus).
There may be other causes of this condition in dogs and a normal result does not exclude a different mutation in this gene or any other gene that may result in a similar genetic disease or trait.
Genetic Testing for Color Inheritance
Genetic testing can be a valuable tool for breeders who want to predict the colors of their Labrador puppies with more certainty. Knowing the genotype of your dogs can give you a better understanding of the possible colors that can appear in your litter.
Genetic tests can determine the genotypes of breeding dogs for the B, E, and dilute genes. However, knowing the genotype doesn't guarantee that all possible colors will appear in the litter, or in statistically perfect proportions.
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Breeders can use genetic testing to determine if they have a silver Lab litter. Genetic testing can also help breeders avoid or achieve specific colors, such as a silver Lab litter.
For example, genetic testing of the MFSD12 gene can determine the number of copies of the intensity gene Mutation that a dog carries. This can help breeders understand the likelihood of their puppies having a light cream or white coat color.
Here's a summary of the colors recognized by the AKC and the Kennel Club:
- Black
- Brown (more usually called chocolate or liver)
- Yellow
Genetic testing can give breeders valuable insights into the color inheritance of their dogs. By understanding the genetic code that controls Labrador color inheritance, breeders can make informed decisions about their breeding practices.
Additional reading: Curly Coated Retriever Breeders
Labrador Retriever Coat Colour Genetics
Labrador Retrievers have three basic coat colors: yellow, black, and chocolate. These colors are determined genetically, just like almost all of the traits that offspring get from their parents.
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The gene that determines if a Labrador Retriever is black or chocolate is Tyrosinase-related protein 1, or TYRP1 for short. There are four known alleles at this gene in the Labrador Retriever: one is the allele for black (designated as B) and three different alleles that result in chocolate (collectively designated as b).
Here's a breakdown of the possible genotypes for black and chocolate Labradors:
For a Labrador to be yellow, it must have two recessive alleles of the melanocortin 1 receptor (MC1R) gene (ee). This means both parents contributed a yellow allele (e).
Lab Color Guide
Labrador Retrievers come in three basic colors: black, yellow, and chocolate. These colors are determined by genetics, specifically by the interaction of two genes: the B gene, which determines black or brown color, and the E gene, which determines yellow color.
The B gene has two types: big B and little b. Big B is a dominant gene that causes a black Labrador coat, while little b is a recessive gene that causes a brown or chocolate coat.
Recommended read: Cute Chocolate Labrador
A Labrador must have two recessive alleles of the E gene (ee) to be yellow. If a Labrador has only one yellow-causing allele (Ee or e), they will be either black or chocolate.
Here's a simplified table to help you understand the possible coat colors and their genotypes:
Chocolate Labradors have grown steadily in popularity in recent years, but the dominance of the black color enabled our chocolate friends to remain hidden and rare with the breed, for many decades.
Knowing the parents' genotypes can help predict the colors of their puppies. However, genes can remain concealed within a family tree for decades, making surprises possible.
Labrador Retrievers have a pair of Dilute genes at the Dilute locus – DD, Dd or dd – which can affect the color of their coat.
Mosaics and Mis-Marks
Labrador Retrievers can exhibit unique coat patterns known as mosaics, where they display random black and yellow patches. This is a result of a genetic variation that can occur during early development.
One documented case involves a male Labrador Retriever born with a mosaic coat, the result of a black female heterozygous for yellow bred to a yellow male. This genetic combination led to puppies that inherited the expected yellow coat with black pigment.
Other "mis-marks" like brindle, tan points, white spots, and rings around the tails are not uncommon in Labradors.
More Unusual Colors
Labradors can come in some really unique colors, and it's all thanks to genetics. The dd genotype is responsible for diluting the other Labrador colors.
This genotype gives a softer, charcoal coat color in a black dog. It's fascinating to see how genetics can affect the appearance of our furry friends.
The dd genotype also affects other colors, such as giving a charcoal coat color in a black dog. But what does this mean for Lab lovers?
Some Labradors might carry the dilute gene, which can result in unusual colors like silver or charcoal. If you're interested in learning more about these colors, I recommend checking out our article on silver Labradors.
Here are some unusual Labrador colors that can occur due to the dd genotype:
- Charcoal (a softer, diluted version of the black color)
- Silver (a result of the dd genotype in combination with other genes)
These colors are not as common as the traditional black, brown, and yellow colors, but they're still beautiful and unique in their own way.
Nine Dog Breeds
Labradors come in a variety of colors. There are nine different possible genotypes in Labradors, each combination of B and E genes making them unique.
A black Labrador has four ways to express their color, while a yellow Labrador has three ways to do so. This results in a wide range of color combinations when a black Labrador is mated with a yellow Labrador.
Labradors can have a black coat, a yellow coat, or a combination of both, resulting in a variety of colors. The possible genotypes in Labradors make them a versatile breed.
Mating and Breeding
Mating a Yellow Labrador with a Chocolate Labrador can result in six different litter color combinations, ranging from all puppies being chocolate to all puppies being black.
A fresh viewpoint: Pictures of Yellow Labrador Retrievers
There are three ways to be yellow, and only two ways to be chocolate. A chocolate Labrador can be either Eebb or EEbb, while a yellow dog can be one of three different genotypes: eeBB, eebb, or eeBb.
The genotype of the parents determines the color possibilities of the puppies. Let's break it down:
Two black Labradors can indeed have yellow or chocolate puppies, depending on their genotype.
Labrador Retriever Coat Colour Genetics Resources
Labrador Retrievers can be black, yellow, or chocolate, but did you know that their coat color is determined by the production of two types of melanin: eumelanin and pheomelanin?
Eumelanin is responsible for the black and dark brown colors, while pheomelanin produces the yellow and golden hues. The interaction between these two types of melanin determines a Labrador's coat color.
The gene that controls the production of eumelanin is called the E locus, and it comes in three forms: E, e, and Ee. The E locus determines whether a Labrador will be black or not.
Labradors that have the E allele will be black, while those with the e allele will be yellow or chocolate. However, it's not that simple - the interaction between the E and B loci determines the final coat color.
The B locus controls the production of pheomelanin and comes in two forms: B and b. The combination of the E and B loci determines the final coat color of a Labrador Retriever.
Labradors with the EE or Ee genotype and the BB genotype will be black, while those with the ee genotype and the bb genotype will be yellow.
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- 10.1111/j.1365-2052.2007.01664.x (doi.org)
- "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)
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- 10.1002/ece3.2290 (doi.org)
- 10.1093/oxfordjournals.jhered.a108792 (doi.org)
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- “Identification of a premature stop codon in the melanocyte‐stimulating hormone receptor gene (MC1R) in Labrador and Golden retrievers with yellow coat color” (wiley.com)
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