Rabbit Color Genetics

From the purest white of a Vienna-marked Blue-Eyed White to the inky black sheen of a Velveteen Lop, rabbit coats come in a kaleidoscope of colors. But how does such vibrant variety arise from these uniformly fluffy, hopping creatures? What hidden genes underlie the patterns that adorn our leporine friends? In this deep dive into rabbit color genetics, we'll explore how a handful of pigment and pattern genes interact to produce over one hundred dazzling coat varieties. From albinism to agouti, tan patterns to tortoiseshell, we'll uncover the wonder and complexity of one of the rabbit's most beautiful and intriguing attributes – its coat color. So hop aboard for an adventure into the genetics behind the rainbow beauty of bunnies!

Basic Color Genes

Rabbit coat color genetics determine the pigmentation and pattern of a rabbit's fur. There are several genes that control the production and distribution of pigments like melanin and pheomelanin, resulting in a wide variety of potential coat colors and patterns. Here are some of the main genes that control rabbit coat color:

Agouti Gene – This gene controls the distribution of black pigment. The dominant A allele results in a fur pattern of alternating bands of color called agouti. The recessive a allele results in solid black pigment.

C Locus – The C locus gene controls the production of pheomelanin, a red/yellow pigment. The full color allele (C) allows pheomelanin to be expressed. The albino allele (c) prevents pheomelanin from being made.

B Locus – The B locus gene controls the production of black pigment (eumelanin). The dominant B allele allows black pigment to be made. The recessive b allele limits black pigment production resulting in brown.

D Locus – The D locus dilutes black pigment into a bluish shade. The dominant D allele results in normal black pigment. The recessive d allele dilutes black to gray or blue.

E Locus – The E locus gene controls the production of yellow pigment (pheomelanin). The dominant E allele allows normal reddish pigment. The recessive e allele limits pheomelanin resulting in fawn coloring.

En Locus – The En gene can further restrict pheomelanin production to pale fawn/cream when homozygous recessive (enn enn).

By inheriting different combinations of these gene variants, over 100 coat color varieties are possible in rabbits!

Typical Rabbit Pigments

There are two main pigments that give rabbit fur its color:

Eumelanin – This is a dark brown/black pigment produced in the fur, eyes, and skin. The amount and distribution of eumelanin is controlled by genes like B, D, and Agouti. It results in black, chocolate, lilac, blue, and fawn rabbit coat colors.

Pheomelanin– This is a red/yellow pigment produced alongside eumelanin. It results in red, orange, and yellow fur colors. The amount of pheomelanin is controlled by genes like C, E, and En. Albino rabbits lack pheomelanin due to a mutation in the C gene.

In addition to these two main pigments, other genes can modify the hues. For example, the cocoa gene makes chocolate brown darker, the lilac gene dilutes black into a warmer brown, and the pearl gene dilutes black into a cooler very light gray. By mixing genes that control eumelanin and pheomelanin levels, over 100 different coat color varieties are possible!

Long and Short Hair Colors

Rabbit breeds come in two main hair types – long fur in angora breeds and short fur in most other breeds. The color genetics work similarly for both hair types, but long angora hair has some unique attributes:

Angora – In angora rabbit breeds like French, English, Giant, and Satin angoras, the long fur is made up of multiple hair shafts of different colors. This results in blended colors with beautiful shading and ticking patterns. Pointed white markings are common. Popular angora colors include ruby-eyed white, blue-eyed white, chinchilla, squirrel, and opal.

Short Fur – In short haired rabbit breeds, the coat color genetics result in solid, distinct color blocks. Agouti banding within hairs is visible. Self pattern solid colors are common like black, chocolate, or red. Broken pattern Dutch marking are also very popular with short fur breeds. Short fur color varieties include otter, seal, marten, tan, and tortoise shell.

While the genetics are similar between hair types, the phenotypes of the colors differ visibly between long angora fur which blends multiple hair shaft colors, compared to short single-colored fur.

Wild Rabbit Colors

In the wild, rabbit coloration is selected for camouflage against predators. Here are some of the most common wild rabbit color varieties:

Agouti – The agouti banding pattern results in fur that closely matches the colors of the rabbit's natural habitat. It is camouflage against the alternating shadows and sunlight on the ground. Common in wild cottontails, jackrabbits, and hares.

Brown – A solid brown coat helps rabbits blend into the earth tones of the environment. Browns range from sandy brown to dark chestnut. Very common in wild species.

Gray – Gray fur allows rabbits to blend into rocky environments and shadowy areas. Can range from light silver to charcoal gray. Seen in species like pygmy rabbits.

White – During winter, all-white fur camouflages rabbits against the snow. The ermine white color is common in varying hares that change coat colors seasonally. Some cottontails also turn white in winter.

Black Tips – In brush rabbits and some cottontails, black-tipped guard hairs overlay the undercoat. This creates an inconspicuous gray tone.

Nature selects muted, camouflaged colors in wild rabbits through evolution. This contrasts with the vivid novelty colors breeders have selected in domestic rabbits.

Color Gene Groups

Rabbit coat colors can be divided into several major gene groups based on the main pigments and patterns produced:

Agouti Group

The agouti gene (A) produces a coat pattern of alternating dark and light bands of fur. This mimics the natural striped shadow pattern of the rabbits' environment as camouflage. Agouti is dominant to self (solid) color.

Self Group

The recessive non-agouti (aa) genotype results in solid, self colored fur without banding. This allows for vivid, saturated colors like black, chocolate, or red. Popular self colors include black, blue, chocolate, lilac, and red.

Shaded Group

The A gene also comes in a shaded (at) version that causes darker fur on the belly, ears, feet, tail, and nose. Shaded rabbits have lighter fur on their sides for a unique two-toned appearance.

Tan Group

The recessive tan gene (atat) removes all black pigment from the fur, leaving only red/yellow pheomelanin. This results in a rich tan color over the whole body.

Himalayan Group

The Himalayan gene (ch) removes color from the body while preserving color on the nose, ears, feet, and tail. This temperature-sensitive gene results in the points color pattern.

Albino Group

The albino recessive c gene prevents the production of pheomelanin, resulting in white fur and red/pink eyes. Examples are ruby-eyed whites and pink-eyed whites.

Color Pattern Groups

In addition to the main color genetics, there are also genes that control the spatial distribution of color on the rabbit's body. These color pattern genes result in broken, spotted, and marked patterns.

1. Self

The self pattern is full-colored fur across the entire body. There are no markings or white spotting. Self pattens include solid black, chocolate, blue, and red rabbits. It is the default pattern with no pattern genes present.

2. Agouti

The agouti banding pattern causes individual hairs to have alternative black and yellow bands. This results in a salt-and-pepper ticking appearance as the hairs' bands show through. The agouti pattern provides natural camouflage for wild rabbits by mimicking dappled sunlight and shadows.

3. Tan

The tan pattern is a uniform rich tan color across the entire body due to the atat genotype preventing black pigment. Tan pattern rabbits will be a saturated reddish-orange color all over without any markings.

4. Himalayan

The Himalayan pattern has color concentrated on the "points" – nose, ears, feet, and tail. The body is white or very light. It is caused by the temperature-sensitive chinchilla gene.

5. Tortoiseshell

The tortoiseshell pattern has patches of red and black distributed randomly across the body due to the interaction of two color alleles at the E locus. Called "tort" for short.

6. Dutch

The Dutch pattern has white spotting characterized by a white blaze on the head, white front paws, white hind feet, and eye circles. Caused by the recessive spotting gene (En).

7. English Spot

English spotting has colored spots of various sizes over a white body. The spots do not conform to a patterned distribution like Dutch. It is caused by the dominant English spotting gene (EnJ).

8. Silver Marten

The silver marten pattern has tan/fawn color on the head, ears, feet, legs, and tail over a white body. It is caused by the interaction of wideband agouti, tan, and silvering genes.

9. Steel

The steel pattern has even, smooth silver-grey ticking over the body with darker slate undercolor. It is caused by the interaction of the steel gene (St) with agouti and brown/black pigment.

10. Silver Fox

Silver fox is very similar to steel but has a sparkly snow-white appearance rather than smooth grey ticking. It also interacts with the steel gene.

By combining color genes with pattern genes, rabbit coats display amazing diversity. Breeders continue to develop new color varieties by carefully crossing breeds and selecting offspring.

The Albino Color Gene

The albino gene (c) prevents the production of pheomelanin pigments. Albino rabbits have white fur, pink skin, and reddish eyes due to lack of pigment. There are two main types of albinism:

Rex or Ruby-Eyed White – REW rabbits have pure white fur with no coloring. They have pink eyes as kits that darken to a ruby red or dark pink as adults. This is from blood vessels showing through the unpigmented eyes. REW is the result of the ccrr genotype.

Pink-Eyed White – PEW rabbits also have pure white fur. However, they maintain pink eyes throughout their life because they carry an additional ruby-eyed white suppressor gene (Ws). PEW genotype is ccwscwsc. Some breeds like Californian use the PEW gene to create showroom-white coats.

Both REW and PEW rabbits are sensitive to sunlight due to lack of protective pigment in their eyes and skin. Care must be taken to provide shade and avoid overheating and sunburn. Wool in angora breeds helps protect albino rabbits' sensitive skin.

REWs (Ruby-Eyed Whites)

The Ruby-Eyed White coat color is one of the most popular varieties in rabbits. Here are some key facts about REW rabbits:

• Caused by homozygous recessive cc genotype on the C locus gene. Prevents pheomelanin pigments from developing.

• Fur is pure clean white with no coloring due to lack of pigment.

• Eyes are dark pinkish-red color from blood vessels showing through unpigmented eyes. Called "ruby eyes."

• Pinkish-white skin is sunburn-prone due to albinism. Sensitive skin care required.

• Found in many breeds from Netherland Dwarf to Flemish Giant. Very common in NZW meat rabbits.

• Bred by combining two c allele carriers to produce cc offspring. Test breeding required.

• REW x REW matings will always produce REW offspring. REW x Colored could produce REWs if colored parent carries c.

• Do not confuse with Himalayans which have colored points. REWs are fully white bodied and eyed.

REW is a beautiful, sharply defined white coat. But special care is needed to protect albino REWs from sunburn and overheating. Overall a popular color variety for both displays and commercial meat breeds.

BEWs (Blue-Eyed Whites)

The Blue-Eyed White rabbit has a pure white coat like the REW, but with vivid blue eye coloration. Here's an overview of BEW genetics and traits:

• Caused by the interaction of the albino c gene with the Vienna gene (wv) which modifies eye color.

• Fur is pure clean white with no pigment, like REW rabbits.

• Eyes are a distinct solid blue color compared to the red/pink eyes of REWs.

• Result from the genotype ccwscvwv. Require two separate recessive genes.

• Bred by combining a REW (cc) with a Vienna carrier (cwscvwv) to produce BEW offspring.

• Much rarer than REW due to the extra gene requirement. Most common in Checkered Giants.

• Blue eye color is slightly hypopigmented. Not fully albino, but vision may be slightly impaired.

• Sensitive skin and eye care is still important. Lack pigmentation like other albino varieties.

The striking blue-eyed appearance makes BEW rabbits very distinctive. Their unusual beauty and challenging genetics make them prized by breeders and exhibitors. But their sensitive albino traits require thoughtful husbandry.

Conclusion

In summary, rabbit coat color is a complex but fascinating attribute of one of our favorite domestic animals. With over 100 color varieties stemming from a handful of primary pigment and pattern genes, rabbits display amazing diversity. Breeders continue to develop new color combinations by carefully selecting breeding stock. What colors and patterns will we see next from these beloved, soft, hopping companions? The possibilities are endless when we explore the wonder of rabbit color genetics.

References:

https://rabbitbreeders.us/questions-and-answers/rabbit-color-genetics/
https://www.rabbitsforsale.com/questions-and-answers/rabbit-color-genetics/