Ahh… the beauty of color genetics. Just as beautiful as the rabbits that hold this rainbow of colors we call black, blue, chocolate, lilac, opal, lynx, otter, etc. This is a fairly basic article, but my hope is to clarify some basic rules and genetic mumbo jumbo to those who may have little understanding of genetics. If you are bored or already know this stuff, hang in there. Look for more about color genetics in future newsletters, where I may delve in to a little more advanced material.
As a respected mentor of mine, Betty Chu (English Angora breeder) once said to me, “breeding without knowing color genetics is like breeding in the dark”. How I could not agree more, although there was a time that I struggled, exclaiming, “I WILL NEVER GET THIS!” This is my reason for this article.
Well, I got it. And, if you have not already, guess what… YOU CAN TOO.
Standby while I attempt to make some sense out of what is, to many, a very confusing subject. Please keep in mind that my personal expertise lies in Angora color genetics, although many or most genetic principles hold true across the board. For example, in French Angora, the proper term for what is called Sable Point in most other breeds is “Black Pearl”. However, the principle still holds true that we NEVER mix shaded colors (Sable Point and Black Pearl are both shadeds—same color, different name, depending on breed) with agouti.
OK! Here goes…
First off, rabbit coloring is made up of a series of five letters, each representing some aspect of the rabbit’s coloring.
The rabbit has two copies of each letter, one received from each parent.
Lowercase vs. capital letters have completely different meaning. These letters, simplified, are AABBCCDDEE. This particular color, AABBCCDDEE, would be Chestnut Agouti in Angora. But there are many other letter combinations, resulting in the variety of colors of rabbits that we see today.
1. Big A stands for Agouti vs. little a for non-agouti. Agouti is a dominant gene, the gene responsible for colors where more than one color in on the hair strand, most likely in bands. The best agoutis have the correct color order specified for the agouti color which the rabbit exhibits, and very obvious ring definition (unless we are talking the color, chinchilla, which does require at least one BIG A to be properly expressed, but does not have color rings on the hair shaft), as well as light rings around the eyes and a light-colored tummy (color of rings and tummy specified, depending on Agouti color and breed). Non-agoutis should not have eye circles. In a good agouti, complete eye circles are desired. I will say this throughout the article because the point cannot be made enough: NEVER breed agouti to shaded, AKA c(chl). Doing so can end up in such interesting surprises as a smoke pearl agouti (unshowable, and even if the judge doesn't always catch it--you don't want those mottled genetics in your litters, or to accidentally set customers up for failure). If you are thinking, "OH, NO! I ALREADY MADE THIS MISTAKE!" Don't worry. There is hope, and genetics can be cleaned up with effort. Stay tuned for next month's article about testbreeding using ruby-eyed white.
2. Big B stands for Black. Little b stands for brown. In Angora, and other rabbit breeds, we call brown "chocolate".
3. Big C stands for Color. Little c stands for absence of color, such as in the Ruby-eyed white rabbit, whose genotype is cc. The C series is easily the most confusing of the color genes. In this series, there is also c(chl) (most correctly referred to as the sable gene, a shaded gene that should never be mixed with agouti colors), c(h), or himi (pointed white), and c(chd), AKA chinchilla, which requires the capital A (agouti) to be correctly expressed. There is such thing as a self chinchilla, a rabbit with genetics that look something like: aabbc(chd)-E-. This would be a chocolate self chinchilla, an unshowable color, often (but not always) recognized by wrong eye color. There are also many other causes of wrong eye color.
4. Big D stands for Dense color. Little d stands for dilute color. Dense colors include black and chocolate, chestnut agouti, and chocolate agouti. Dilute colors include blue and lilac. Blue is the dilute of black, and lilac is the dilute of chocolate. Dilute agouti colors include chocolate agouti, and lilac agouti (named “lynx” in Angora), as well as opal.
5. Big E stands for extension. Little e stands for non-extension. By extension, I refer to extension on the hair shaft of the animal. Extended colors are self colors such as black, blue, lilac, and chocolate, and agouti extended colors include chestnut, opal, and others. Tort appears to be shaded not because of the c(chl), AKA sable, gene, which is a shaded gene. Instead, it appears shaded because it is ee. The ee (non-extension on the hair shaft) provides the shaded appearance, the body lighter than points, WITHOUT the c(chl) gene. In this way, tort is a bit of an exception to the rule. It is a shaded color that does NOT require c(chl). Other ee colors include fawn, pearl, cream, etc. The E series is another one, along with C, that contains other variations. These include E(s) for steel, and e(j) for Japanese.
What is a “self” colored rabbit?
Self-colored rabbits include black, blue, chocolate, lilac, and REW. These are rabbits of a solid color that are not hiding anything else in their background. As a general rule, they can be bred to anything. Self is represented by the gene aa. This means the rabbit received a small "a" from each parent. Self Black genetics look like: aaB-C-D-E- (dashes for unknown recessive genetics the rabbit could be carrying) Self Blue genetics look like: aaB-C-ddE- (notice the small d, which dilutes the black to make the color blue. Also, notice that there are two copies of dilute. The small d CANNOT hide behind a large d, so if the rabbit is blue, we know that it possesses two copies of the dilute gene, or d). Self Chocolate Genetics look like: aabbC-D-E- Self Lilac Genetics look like: aabbC-ddE- (again, notice the small d, as lilac is a dilute of chocolate).
An exception to the rule, because it is called and looks like a shaded rabbit, is the tort. In many ways, the tort is genetically very similar to a self rabbit. For example, black tort looks like this: aaB-C-D-ee(do you notice the only difference between the self black and the black tort? The lack of extension [i.e., big E]!)
Here are some other genetics rules that may help:
Dominant genes (such as agouti, or big, capital A), CANNOT hide behind the less dominant genes (such as little a). This also applies to B (black) being UNABLE to hide behind chocolate (b), C (full color) being UNABLE to hide behind c (ruby-eyed white, or albino), D (dense color, such as black or chocolate) being UNABLE to hide behind dilute color (d), such as blue or lilac. E (full extension) being UNABLE to hide behind e (non-extension). With this said, the recessive genes (just think of them as the lowercase letters) CAN and DO hide behind the CAPITAL letters. Think of it this way: a large rabbit (such as a Flemish Giant) CANNOT hide behind a Netherland Dwarf. No, just can’t happen. Color genetics work the same way. The lowercase letters can very well hide behind the uppercase letters, but not the other way around. NEVER breed Agouti to Shaded. This results in unshowable colors and mottled genetics in your lines! What we want is predictability. Examples of shaded colors include sable point, seal, sable, Siamese sable, and any of the pearl colors (in Angora), etc. Agouti colors include chocolate agouti, chestnut agouti, lilac agouti (called lynx in Angora), etc. Other colors in the "A" (agouti) family include fawns, creams, chinchillas, etc. DON’T breed these colors to shaded. Any color that, in its genetic makeup, contains an uppercase "A", should not be bred to a shaded/c(chl), or you're in for trouble. A REW (ruby-eyed white) rabbit is like a colored rabbit in the disguise of white paint, or wearing a white blanket. What you see is a white rabbit. What the rabbit is hiding is a different story. The “genetic code” for REW is cc, which masks all colors. With that said, a REW CANNOT carry SHADED (as in c[chl]). It CAN carry "ee", which could result in tort. Genetically, a tort is more like a self rabbit than the c(chl) shadeds, even though it is considered a shaded color. Additionally, REW CAN hide agouti, so watch out in your breedings! It can also carry A, a, B, b, D, d, or (as stated previously) E, e, or any combination of these letters. Another rule referring to REW: two REW, because they both carry the cc gene which hides all color, can ONLY produce REW. A true self rabbit (NOT a black that is possibly hiding sable, or a REW that is possible carrying agouti, but a TRULY genetically self rabbit) is like a black dress: it goes with just about anything! NEVER breed agouti to pointed white. Hold out for self, preferably black (unless you are aiming for a certain other color), as the points are temperature sensitive. Additionally, the best himis (or pointed whites) are those that hold two copies of the himi gene, c(h). This generally makes for darker, bolder points and better coverage.As a general rule, you CAN breed self to shaded, self to agouti, shaded to shaded, pointed white to self, agouti to agouti, and pointed white to (some) shadeds. Now… this is a simplified article on color genetics. I’m assuming that some of our readers know genetics like the back of their hand, while others are struggling, as I once did. If you are one who is struggling, don’t beat yourself up. We’ve all been there, and in some breeds, or if you are only breeding certain colors, color genetics simply does not matter as much. With that said, why limit yourself? Yes, type should usually be what is bred for. That’s my focus. With that said, I certainly am excited about my new litter of fawn French Angoras, and my pointed white Holland Lop project. It pays to know, if only not to get yourself into trouble (or mottled genetics) down the line. Remember, knowledge is POWER!
For those who would enjoy testing their knowledge, I offer you a quiz to fill out on your own computer and e-mail your answers to me. You may sail through hit like a breeze. Or you may struggle. Remember, no judgment. The important thing is to learn. And, in my opinion, learning is fun. If you’d like to complete the quiz and e-mail it to me to be graded, I applaud your efforts, and will return your e-mail as soon as is possible. Thanks in advance for taking the time!
1. Map out the following, using color genetics: A. Black Tort (“Tort”) B. Chocolate Tort C. Lilac Tort D. Blue Tort
2. Map out the following, using color genetics: A. Chocolate Agouti B. Lilac Agouti (“Lynx” in Angora) C. Opal (AKA, Blue Agouti) D. Chestnut (Black Agouti)
3. What is the MAIN difference, genetically, from most shaded colors and tort? Explain.
4. Which gene is responsible for chinchilla coloring? What might chocolate chinchilla look like when written in genetic code?
5. Using what you have learned about agouti colors, why might it be a bad idea to cross an agouti with a pointed white?
6. Special consideration should be taken in breeding using REW because, although they appear self, they can hide which of the following genes that could potentially cause problems if crossed with the wrong colors? A. c(chl) B. A C. aa D. None of the above.
7. A self black is bred to a self lilac. This breeding results in the following colors: blue, blue tort, and opal. Is this possible? Why or why not?
8. A self black is bred to a self lilac, and produces the following colors: blue, blue tort, black, and black tort. Is this possible? Why or why not?
9. Can a chocolate rabbit hide black? Why or why not?
Thank you for taking the time to read this article and take the quiz! I will happily grade your quiz if sent to: firstname.lastname@example.org