The Colour Code: Deciphering the Genetic Patterns of Rabbit Coat Colour

A stands for Agouti, which is the colour patterning and banding on each hair shaft, not the colour.

In the A locus, there are 3 different alleles:
A(agouti)
a^t(Tan)
a(self – solid colour)

The A allele is completely dominant, and will override the pairing. AA is super dominant, while the “a” in the Aa will be overridden.

The A allele also makes the rabbit have a white or ivory belly with a base colour of slate-blue or dove-grey under the white fur.

Wild rabbits have banding on their hairs, usually starting with white at the bottom, then slate-blue (about 1/2 of the length of the hair), rufus (red or orange), then it is tipped with black.

The rufus (orange, red) colour shines through the black tipping which creates the mahogany or chestnut colour.

a^t is recessive to A but dominant to a.

Tan rabbits must carry a^t least one at, with either an a or another a^t, but not an A as it would be overridden with the Agouti allele, and no longer be classed as Tan.

Tans have fire-red or orange bellies and Otters have grey, ivory or white bellies. The orange bellies on Tan rabbits is created by the recessive ww alleles.

The Tan a^t provides specified places of colouring. The back and sides will have a solid colour. Where the top colour meets the belly, there will be a narrow band of the intermediate-band colour on the hairs. It also makes the intermediate-band colour appear on the ears, neck triangle, and throughout the dewlap and chest. Tans and Otters should have intermediate-band coloured ticking between the belly and top colours.

Martens carry one a^t with an a and have one of the many chinchilla c genes which removes the yellow and replaces it with white.

Self coloured rabbits have the a allele. The a allele removes all banding on all hairs, making the rabbit a single solid colour, all over.

a is recessive to a^t and A, therefore the rabbit must carry the aa to be considered self.

B stands for black and it controls the intensity of the black pigment.

It is considered the wild-type gene, where all wild European rabbits are all black based.

Agoutis, can have black tips on their hair shafts, and a slate-grey undercolour.

B is dominant, b is recessive.

B is full-strength eumelanin, it produces a black base.

b is weak, or immature eumelanin and it produces a dark brown colour, which can be called chocolate or brown.

bb rabbits have a lighter, dove-grey undercolour.

The only way to tell if your black rabbit is either a dominant BB or a half-recessive Bb is to breed them with a chocolate rabbit. If they produce any chocolate coloured kits, it means the black rabbit was Bb not BB.

D stands for dense. d stands for dilute.

The Dutch gene is Du (dominant) or du (recessive).

DuDu causes no Dutch patterns, Dudu partial white or coloured patterns, dudu causes the belted Dutch pattern.

With some modifiers, Hotot’s with the genes Dudu EnEn can be bred (with a lot of minus modifiers) from the Du gene.

It is different to the Broken and English Spot patterns.

Some breeders use inbreeding (parent to young, or sibling to sibling) to create the Dutch pattern, because you can get more Dutch patterned rabbits in a litter.

Apparently, it can get quite complex to work with the Dutch pattern if you don’t inbreed, because the set of Dutch pattern genes are very complex to work with.

The Dutch pattern requires homozygous DuDu or dudu genes to display the colours correctly.

Mostly, only 25-50% of a litter will display Dutch markings, others will have blazes, white toes, a dot, lopsided Dutch markings, or no white markings at all.

E^d is dominant, where the whole shaft is a single colour. It will make a chestnut coat look black, an opal coat look blue, and so forth.

The blacks in E^d are very deep and dark in colour and most likely won’t have scattered white hairs throughout the coat, like a true black does.

E^d is very rare. Most bunnies will be a true self colour (aa) (black, blue, chocolate, lilac) instead.

You can tell if your bunny is an E^d if it produces agoutis when bred with a true self (aa).

E^s (steel) is supposedly the most dominant of all of the options. Although it has been shown to be not the case. Therefore it is known as incomplete. It does overpower other colours, and sends black pigment most of the way up the hair shaft, and leaves a little light colour on the top of the guard hairs.

E^s invades and takes over the normal pattern of colour. Steels have E^s E. Double steels have E^sE^s, but it is considered too dark for a true steel colour.

A steel is produced when it is mixed with the agouti gene.

A steel coloured rabbit should have a single E^s with an E (E^s E). They put the E^s first because it is stronger than the other E alleles.

A proper steel coloured rabbit will have the undercolour extending all the way up the hair shaft, and remove the white belly on an agouti.

Self aa and Tan a^t patterned coats have single coloured hairs. There is no way a steel gene can show in aa or a^t patterned animals, because there is no room at the top of the shaft for a light tip.

E is the original dominant allele, and codes for correct presentation of black pigment.

Most rabbits carry EE.

The E allele controls the quality and quantity of the black pigment on the hair shaft, and how far the pigment extends up the shaft.

E is linked chemically to the A genes, and many E genes won’t show their “true colours” unless they are on an agouti coat.

Normal rabbits have EE, E e^j, or e^j e.

e^j is the harlequin and magpie patterning, which is made of areas of over-produced black, and other areas of under-produced black pigmentation.

It is dominant to e, but recessive to E.

If you add a broken gene En to the harlequin, you get a broken tri-coloured rabbit, such as a Rhinelander. Without the En allele, a Rhinelander will be like a harlequin.

The e^j gene only works properly if the rabbit has the agouti gene.

If a rabbit has the harlequin e^j e, c^chd and the enen, it will be a magpie, where the orange is removed and replaced with white.

e means non-extension, and is recessive, which means it doesn’t carry black pigment. It makes oranges, reds, cream, frosty, sable and fawns.

When e is mixed with other modifiers, you get greying around the ears, nose, feet and tail, which is called smut.

ee wipes out the black pigment, creating red, orange or fawn rabbits. They can only have these colour variations when other modifiers are in the genome.

The Spotting gene is known as the dominant white spotting locus. It is determined as incompletely dominant (when two genes are partially expressed which results in an intermediate phenotype). Homozygous rabbits with enen are self coloured. While heterozygous Enen rabbits are spotted. EnEn rabbits are nearly all white.

En is also known as KIT, the KIT gene is added to the end of the genome, after the Extension gene. It affects the pattern, not the colour. Therefore it can overlay on top of any colour. It dictates the extent of the white patterning over the base colour.

The broken EnEn is dominant and cannot skip a generation. A single copy of the En is needed to visibly express in the rabbit.

A “Charlie” is a homozygous broken, which is when two EnEn “brokens” are bred together. Charlies are produced when the EnEn gene is created, they have very little colour. A true Charlie will never produce a non-broken rabbit.

The REW and BEW can hide the broken pattern, but the rabbit will still genetically carry the broken gene and produce broken rabbits.

All solid colour with forelegs that are white. Blue eyes.

VV is almost all rabbits, Vv no known breeds, vv Blue-Eyed Whites.

Blue-Eyed Whites (BEW) have the Vienna gene v.

v is used to specify the Vienna gene, while V is used to specify non-Vienna rabbits.

The v gene will hide the base colour of the rabbit in it’s homozygous form. For example, a black rabbit with vv will appear white with blue eyes.

All solid colour with the front of the rabbit being white. Blue eyes.

Heterozygous Vienna Vv might not be expressed visually, but can pop up many generations later.

It is important to note in their pedigree if Vienna is in the genome, or if BEW is generations back.

The white patterns on the face are called a blaze.

Some Vienna carriers won’t have blue eyes.

You cannot tell by looking at the rabbit whether it is a Vienna carrier or not.

Rabbits that carry the Vv gene may have white markings on their faces and toes, but this is not always the case.

Sometimes the patterning might look similar to the Dutch pattern.

It is possible to have a rabbit that does not have white on it, but it still carries the Vienna gene, as it may hide for many generations.

Sometimes Vienna carriers may have blue eyes, but their body is a solid pigmented colour.