Color Genetics

Introduction

One of the first thing many new breeders want to know, is how to produce rabbits of one particular
color or another. A basic understanding of color genetics can go a long way in helping the
breeder determine how to produce what they want. This series of articles is an attempt to teach
those basics and can be used as a reference.

As most people learn in high school biology, genes are a set of instructions and are inherited from
both parents, thus resulting in pairs. If the genes from one parent are exactly the same as the
genes from the other parent, it should be no surprise that the offspring’s gene pairs will also be
the same. In most cases, however, parents are not exactly the same and the offspring inherit a
pair of differing genes from the parents. These pairs can interact in different ways. Sometimes
offspring will look more like mom, or more like dad, and sometimes the result will be something
different than both. This all depends on what the offspring inherit. Will it be a particular gene that
is dominant (Always shows itself) or recessive (only shows up when nothing else is around), or will
it be a combination of the two? Examples of each of these interactions will be demonstrated later
on in this series.

The domestic rabbit comes in quite a large number of colors and patterns. The diversity is due to
the fact that there are many gene sets that determine the overall color. There are 5 major color
gene sets and then there are many other minor genes, some better understood than others. In
addition, many of the gene sets have more than two types of genes. It may be helpful to think of
the color gene sets as models with shoes. Each model has her own shoes. She may have more
than two types of shoes available to her feet, but she can only wear two shoes at a time. Likewise,
although there may be several genes for a particular color gene set, each individual will only have
two of them. For the rabbit, this means it possesses 10 major color genes and a host of minor
genes, always paired. Put all the models together and you have a fashion show of shoes. Put all
of the gene sets together and you have an array of colored rabbits.

Color Pattern

The first gene set is known as the Agouti (A) series. These genes determine the coat pattern of
the rabbit. There are three different types. In the order of dominance, they are the Agouti gene
(A), the Tan gene (at), and the Self gene (a).

The Agouti or A gene produces a rabbit with the classic wild type pattern: White belly, nostril
markings, eye circles, and underside of tail, etc. The colored hair shafts have bands or rings of
color. Since this is the most dominant one in the set, a rabbit need only possess one A to show an
Agouti pattern. If you want more Agoutis, you need to have at least one rabbit that shows, and
therefore has, this gene. Obviously the more rabbits you have with the gene the more chances
you have of getting even more. So as you breed or acquire stock, concentrate on those that have
the Agouti pattern.

The Tan or at gene produces a rabbit that has one color to the hair shaft, no bands or rings, but
possesses the same type of undermarkings as an Agouti. This gene is recessive to the Agouti
gene. This means that an Agouti rabbit could carry the tan gene, but you wouldn’t be able to see
it. To find out if this is the case you could check the pedigree. If there is any tan patterned
relatives on the pedigree, there’s a chance it might have been passed on. Ask someone who
knows their genetics and they may be able to give you a percentage figure on that chance.
However the only way to know for sure is to test breed and see if the tan shows up. Therefore if
you want to breed tan patterned rabbits, its best to start off with at least one tan and don’t bring
the Agouti rabbits into your program. As stated above, the more rabbits you use in the color you
want, the more you will produce. So look to bring more tan patterned rabbits into your program.
The tan gene is dominant over the self gene, however. This means that if you’ve got a self rabbit
with great type you could breed it to a tan patterned rabbit and still produce tans. This is what
many breeders do to improve other traits in their herd, without losing sight of the tan pattern.

The Self genes produce a rabbit with one basic color throughout the body. Since this gene is
recessive, if paired with either an Agouti or Tan gene it cannot be seen. The only way it can be
seen is if it is paired with another Self gene. (The exception to this rule are the Ruby-eyed whites
and the Blue-eyed whites. They are a whole ‘nother ballgame and will be covered later.) If you
want selfs you really need to breed selfs. An Agouti or Tan with a self parent will carry a self gene,
consequently you could use these animals, but only on a limited basis, since they will produce
more Agoutis and Tans than you want.

Color Pigment

The second set of genes is known as the B series and determines the dark pigment of the hair.
There are only two possibilities: Black (B) is the dominant gene and chocolate (b) is the recessive
gene. Therefore BB = black, bb= chocolate and Bb= black (You were perhaps thinking dark
chocolate? Sorry.) A rabbit could be carrying chocolate without you knowing it, since the Black
gene would hide the chocolate. Again, this is where information on parents and offspring can be
valuable in determining if the chocolate gene may be there in a hidden state, but if you want
chocolates or lilacs (dilute chocolate) it’s best to start off with them. If, however, one shows up in
your breeding program, you could start from there. Since chocolate only shows up when black is
not around, you could be sure that your chocolate rabbit is ALL chocolate. (mmmm!) You’ll also
know that the parents that produced it, carry one chocolate gene each.

Dilution (Color Strength)

Although out of order, the fourth gene series, known as D, is worth mentioning now because it is
very similar to the B series. There are only two possibilities: Full strength color (D) or dilute color
(d). In the first case, both DD and Dd exhibit full color. This is because there are many pigment
granules in the hair shaft and they are closely packed together. An animal with the dd
combination, has less pigment granules in the hair shaft, therefore the color is said to be diluted.
A black dilutes to a blue. A chestnut agouti dilutes to an opal. A chocolate dilutes to a lilac, etc.
This gene set will also influence eye color. If you want any of these dilute colors, again, its best to
start off with them. If however, a non-dilute has a dilute parent, it does carry one dilute gene.

A point to made here about the odds of producing one color over another. Since recessive genes
can only show when they are paired with a recessive partner, in the overall scheme of things, the
odds of producing rabbits that show the recessive genes are lower than those for producing
rabbits with the dominant genes. However, once you start breeding rabbits with recessive genes,
they will only throw the recessive genes to their offspring, since that is all they have. If you have
rabbits with mostly recessive traits, your individual odds to produce more recessives, would then
be higher than what is seen in the total rabbit population.

Color Saturation

The C series of genes is the most difficult to comprehend because there are at least 5 different
types. The C series determines the fullness of color on the rabbit. With the most dominant allele,
C, the color is as complete as it can be. At the opposite end of the spectrum, c, the color is
completely missing and you have an albino. There are varying color intensities in between. The
cchd, is the dark chinchilla. With this gene the rabbit can produce some, but not all of the
pigments. In an agouti or tan, this results in the loss of the orange or tan pigment, which leaves
white in between the dark bands. In the self rabbit, the difference may be hard to notice, but close
examination will often reveal a brownish-black color rather than an intense black. Sometimes the
fur color may be dark enough, but the eyes will be blue. The light chinchilla, cchl , works in much
the same way. However, it causes the dark pigment to lighten somewhat, giving us our sable
agouti or light chinchilla, and our sable. For some strange reason, however, eye color remains
dark. There is some debate on whether or not there may be a third chinchilla allele, the medium
chinchilla. Much of this is spawned by the diversity of colorings found in the chinchillas and
shadeds. It is also fueled by the different eye colors one gets with the chinchilla genes. Further
study is needed to definitively answer this debate. The himi gene, ch, is a very interesting one. It
is influenced by temperature. If the temperature of a certain body part is below a critical
temperature, color is turned on. If the temperature is above the critical point, the color is turned
off. Thus, in the cooler parts of the body, like the extremities and points, color is seen, and in the
warmer parts, like the main body, color is turned off . This is also the reason why you see better
color on your pointeds in the cooler months as opposed to the warmer months.

To sum it up, in order of dominance we have C, cchd and cchl (recessive to C, co-dominant to
each other, and slightly dominant over those that follow), ch, and c. If a rabbit possesses at least
one C gene it will have the full extent of color like you see in your black and Chestnut Agouti. Any
other gene paired with it, would be hidden. That’s our dominant-recessive combination again. The
chinchilla genes are responsible for your chinchillas and shaded rabbits. If your rabbit has one
dark chin gene and one light chin gene, characteristics of both are visible, thus this is co-
dominance. A chinchilla gene will hide the himi or REW gene it is paired with, acting dominant over
these two genes. Moving on, the himi rabbit possesses two possibilities,
ch ch or chc, although, your himi points are usually not very intense when the albino gene is
present. If you want dark points, stay away from breeding a ruby-eyed white to your himis for this
reason. Finally, an albino is the result of just one gene combination, cc, but it effects all other
gene series by completely eliminating any color. Any other gene combination might be present,
but none of the genes can work because the albino turns off all color production. The color genes
will reassert themselves, however, when they are passed on to offspring that don’t have the
double c, or albino combo.

Extension of Color

Finally we come to the last major color gene series, E. This one can also get confusing because
there are several varieties. In order of dominance they are E = normal extension, ES = extension
of dark color, e = extension of light color, ej = oh let’s just mix the whole thing up! Some dark
patches, some light patches, etc. Most breeds have only two, E and e. Simply put, E gives you
normal colors: blacks, chestnuts, sables, etc. The e gene results in the extension of light color,
changing these to torts, fawns, sable points, etc. A rabbit needs to possess two e genes to show
off this light extension. As for the other two genes in the series, ES provides us with the various
steels, and ej results in the harlequin pattern.

Tips for Breeding for Colors

Whenever a new breeder asks me what colors they should breed to and what they should avoid, I
answer them with a question: What do you want, and what do you have? Whereas it is true certain
color combinations should be avoided to reduce the chance of producing unrecognized and
therefore non-showable colors, if a person is limited by what they have, a particular no-no
breeding can sometimes get them what they want. The chances are just not as high. Many
experienced breeders will risk this type of breeding and once they get what they want, they work
with that. The other colors will be culled from the program as they appear. With that said, here are
some general tips in breeding for color.

Note: to simplify writing, only one gene for each series is written, but be aware that every rabbit
actually has two genes for each series. Ex. Pure Chestnut (A,B,C,D,E) genetically is (AA,BB,CC,
DD,EE) Sometimes the second gene is exactly the same as the first, sometimes it will be different,
depending upon what it inherited.

Agoutis: To breed for Agoutis you must have at least one animal in the herd carrying and
showing the A gene. It is best to breed rabbits that show B,C,D, and E genes in order to produce
Chestnuts. A rabbit carrying the chocolate gene (b instead of B) can produce Chocolate Agoutis.
(Unrecognized in some breeds). Rabbits with dilute genes (d instead of D) can give you Opals
(essentially dilute chestnuts) and Lynx (dilute chocolates also known as lilac version of chestnut.
Unrecognized in some breeds.) These recessive colors don’t often show up in the first breeding,
but rather require a second generation, at best, to produce them. Therefore, to introduce it, you
need to breed your chestnut to a rabbit with the desired color. Then you either breed two
offspring together or breed back to the parent that has the desired color. To avoid them, eliminate
animals with these colors from your breeding program.

As you breed, select offspring that show the Agouti pattern. If they all do, great! If some tans and
selfs show up, remember, they did not inherit the Agouti gene. Only use them if there is some
other outstanding attribute to them. Understand they MUST be bred to an Agouti to produce more
Agoutis. Although their parent(s) were Agoutis they did not inherit the Agouti gene (they inherited
the recessive gene instead) and therefore cannot pass it on.

If its Chincilla you want, you’ll need a rabbit with cchd instead of C. Stay away from cchl because
your chinchilla’s color will be brown-tinted. For this reason, use EXTREME caution if you feel you
MUST breed a shaded (like a sable or smoke pearl) to an Agouti. You are bound to get some
bunnies with bad and often non-showable color. Bring in another color only when trying to
improve other traits. Then be prepared to cull the non-showables. Squirrels are dilute Chinchillas.
Breed your chinchilla to a rabbit carrying dilute to produce it, but be prepared to wait a couple
generations. First the recessive gene has to be added in, then you have to breed two dilute
carriers together to get it to show up. Sometimes you get lucky and your chinchilla is a dilute
carrier to begin with. (A definite possibility if one of its parents was a dilute of some kind.) Once
you have it, you are locked in….keep breeding those animals that show it. Chocolate chinchillas
are not recognized in some breeds, nor are lilac chinchillas, so be careful bringing in or keeping
anything that is carrying chocolate, unless of course these are recognized varieties in your breed.
Bring them into the program the same way you would bring in the blue.

The e gene produces Agouti animals that appear to be one solid color on top. This is because the
gene eliminates the dark color and extends the light color. With the e gene, chestnuts become
Orange, Opals become Fawns, Chinchillas become Ermines. (The term ermine is not universal
within the breeds. It can be recognized as a nearly white rabbit with a smattering of dark ticking.)
Check your breed standard to see if these colors are recognized or not. Since e is recessive,
follow the guidelines for bringing in recessive colors stated above, if you want to produce rabbits
with the recessive e gene. If you want to eliminate this recessive gene, eliminate all animals that
not only show it, but also those that carry it hidden and produce it.

Ruby-eyed whites can often be used in an Agouti breeding program, particularly if the REW
carries Agouti. A blue-eyed white (BEW) and himis on the otherhand, should be avoided. BEW’s
bred to colors often produce white patches. Himis won’t hurt the Agouti, but increases the
chances of producing a Himi with bad color.

Just remember: Although other colors can be bred into an Agouti line, Murphy’s Law is usually at
work, and you may wind up with what you don’t want more often than what you do want. So stick
within the color group to reduce those unwanteds.

Tans: As stated above (see Color Pattern), you are best to start off with at least one animal
displaying the tan pattern. You could start off with an Agouti that carries it, but that dominant
Agouti gene will be a nuisance, showing up more than you want it. If it is all you have, once you
get the tan you are looking for, eliminate the Agouti and work with the tan. Not only will this help
you get more tans, but working with the visible color will help you improve the tan pattern. The
completeness of the tan pattern can vary, often eye circles will be incomplete and ticking will be
faulty. If you select the animals that show the best tan pattern, you will be more likely to get
offspring with best tan pattern. Most selfs (except BEW’s, torts and himis) are safe to use in a tan
breeding program, just be prepared to get a fair share of selfs in addition to tans.

Black Otters possess B,C,D,and E genes along with the tan gene. There is a chocolate version of
this (all genes the same except the b), blue version (the d gene is doubly present rather than the
D) and lilac version (Has bb, and dd). These rabbits possess a small band of tan or cream color
between the dark top and white bottom colors. Black Silver Martens, Blue Silver Martens,
Chocolate Silver Martens, and Lilac Silver Martens are essentially the dark chinchilla version of
otters, however, modifying genes are necessary to provide the right eye color and they do not
have the middle band of color. Sable Silver Martens, Smoke Pearl Martens are the light chincilla
versions. Not all of these varieties are showable in every breed. Check your breed standard.
Breeding for specific colors within the tan-pattern line works the same as it does for the Agouti.
Only here, rabbits with the light chinchilla gene are acceptable. Himi Martens, Tort Martens, Sable
Point Martens etc. are all genetically possible to produce but most are not showable. Keep Himis,
Torts, and shaded points, in addition to BEWs which cause white patches, away from your Tan
breeding program.

Selfs include shadeds and himis as well as solid color animals. Generally speaking any of the
colors within this group can be safely bred to any other color within the group and produce
showable colors, but there are exceptions. The solid colors include black (a,B,C,D,E genes), blue
(a,B,C,d,E), chocolate (a,b,C,D,E), lilac (a,b,C,d,E), REW*(-,-,c,-,-) and BEW*(-,-,-,-,-,v). Shadeds
include seals (a,B,cchl,cchl,D,E), sables (a,B,cchl,D, E), smoke pearls (a,B,cchl,d, E), torts (a,B,C,
D,e), blue torts (a,B,C,d,e), chocolate tort (a,b,C,D,e), lilac torts (a,b,C,d,e), sable points (a,B,cchl,
D,e) and smoke pearl points (a,B,cchl,d,e). There are chocolate and lilac versions of the points,
as well, which are often called "pearls". Some of the shadeds listed here are not recognized as
showable colors in certain breeds. Check your standard.

Himis include the black point (a, B, ch,D,E), blue point (a, B, ch,d,E), chocolate point (a, b, ch,D,
E), and lilac point (a, b, ch,d,E). Again, not all himis are showable so check your breed standard.

Ok, so what are those exceptions, you ask? BEW’s, Himis, and Torts(and its point relatives). (Are
you beginning to see a pattern here?) BEW’s will often produce white patches in your colors. Only
breed BEW to another color if you are trying to introduce a trait other than color. Then be
prepared to work a generation or more to get back to the right color. Himi’s and Torts don’t mix. A
Himi Tort would have the extension of light color, thus ruining your point color. What is true of
Torts, is true of any color that has the light extension gene, e, like the shaded points. Don’t use
them with your Himis. Lastly, as mentioned above (see Color Saturation) when REW is bred to
Himi it often lightens point color and this is undesirable.

*REW and BEW possess all the color genes but because of the nature of the albino gene, c, and
the vienna gene, v, no matter what other genes they may have they will still appear REW or BEW.
Therefore two REWs could be quite different genetically speaking. Ex. AABBccDDEE will be REW,
but so would AabbccDdee) This is why many breeders refer to REW’s or BEW’s as hiding traits.
Until they are bred, you don’t know what their other color genes are.

Well, there you are. More than you probably wanted to know about color genetics and breeding.
Hopefully this article hasn't been too confusing. I'd appreciate your feedback on it, so that
improvements could be made.

Contact me at swimbunnies@att.net

A request was made to have a chart, listing the colors in columns, with related colors, side by
side. The accompanying genes are listed in the reference chart provided below. Where ever a
dash is seen, think recessive. Any gene recessive to the one preceding the dash, could occupy
the dashed spot....these would be the genes that could be passed on to offspring without you
knowing it. This is not a complete chart of possible colors. Only recognized JW colors (and their
relations, recognized or not) are listed. Unrecognized JW colors are marked with a single asterisk.
A double asterisk is used to indicate an unsure gene makeup. This is due to the possibility of a
third chinchilla gene (medium) being responsible for the color or minor modification genes, not
part of the basic 5 sets. Please also note that some names used for certain colors are not
universally accepted.

Color genetics reference chart
(click here)

Blue-eyed whites are omitted from this chart because the gene set responsible for the color is not
part of the 5 major gene sets. A sixth gene set, called the Vienna gene set, is responsible for
blue-eyed whites. VV=normal color, Vv=normal color with some white patches, vv=Blue-eyed white.
Any combination above (except red-eyed whites and himis), coupled with the 6th gene set as vv,
would produce a blue-eyed white. (The exceptions would produce a "mock" red-eyed white.)
Additional gene sets (coupled with the combinations in the chart) are responsible for your brokens
and dutch-marked rabbits.

Color Genetics:
More then you want to know!

By Bunny Turley