Genetics Made Easy, by Julie Aversa

This article is not meant to be a complete guide to rabbit genetics. It will address those common to Jersey Woolies. As a breeder, it is very helpful to have a working knowledge of rabbit genetics. I get questions all the time; “can I breed this to this” or “what will I get if I bred this to that.”. Type should be considered first when breeding, but producing unshowable colors is undesirable. I like to have as clean of lines as possible.

For this article I am going to try and keep it simple. So, I will stick to the basics. The first thing is rabbits get 2 copies of each gene (Editor’s note: The word GENE refers to the genetic component that results in a trait. ALLELE refers to a version of a gene. Sometimes the terms are used interchangeably). The color genes we will discuss in this article are: A, B, C, D, and E. In each of these groups the rabbit gets 2 genes. Rabbits receive one allele from each parent. Each allele in a set of genes is either dominant or recessive. Dominant genes. All genes have a level of dominance. Dominant genes or alleles express (show) in the coat color. It is either visibly there or it is not present. It cannot be

carried. Recessive genes. You must have 2 copies of that gene for it to express in the coat. So, each parent must pass on that recessive gene. If only 1 copy is present, it does NOT visibly express in the coat. Order of dominance- in all color gene sets, there is an order of dominance of the alleles within that set. Note: We show by phenotype (how a rabbit looks), not by genotype, which is the rabbits genetic code. Therefore knowing the genotype is not required for showing your rabbit, but greatly helps with breeding.

A Allele

A Allele-order of dominance A (agouti), at (tan), a (self) A-agouti is dominant and cannot hide. The other (at, a) can hide behind A. So, an agouti can carry tan or self. Ex. Chestnut, opal, chinchilla, squirrel. at -tan is similar to agouti in markings, but without the

rings throughout the coat; meaning, ear lacing, eye circles, and triangle behind ears are present. Tan (at) is dominant to self (a), but recessive to A. So one at allele can express itself in the coat if the other allele is a, therefore the tan can carry self, but not agouti. Ex. otter, Blue Otter, Sable Martin, Smoke pearl martin, Black silver martin, Blue silver martin. a (self)- self is simple, a solid colored rabbit from head to tail. Self is the most recessive allele in this set. It can be carried by A (agouti), or at(tan), but is a true recessive and to be expressed one allele from each parent is necessary, aa.

AA=agouti, Aat=agouti carrying tan, Aa=agouti carrying self, atat=tan, ata=tan carrying self, aa=self

B Allele

B Allele- order of dominance B (black), b (chocolate) B (black) is dominant and cannot be carried. The rabbit is either black, or black based, or it is not. Ex. Black, Black Tort, Blue Tort, Blue, Chestnut, Opal, Seal, Siamese Sable, Smoke Pearl, or Sable Point. b (chocolate)- reduces the black pigment in the coat making it look brown. b (chocolate) is recessive so each parent would have to carry it to get a chocolate offspring. ex.Chocolate, lilac, Chocolate Martin, Lilac Martin

C Allele

C Allele-in order of dominance; C (full color), cchd (chinchilla), cchl (shaded), ch (Pointed White), c (rew). C (full color)- is very simple, it allows a rabbit to have an even distribution of full color over the entire rabbit. C is dominant and cannot be carried. Black, Blue, Black Tort, Blue Tort, Chestnut, Opal, Orange, Black Otter, Blue Otter, or Chocolate. cchd (chinchilla)- results in most of the yellow pigment removed from the coat. Therefore, it results in a white color where the yellow would have been. cchd is recessive to C but dominant over cchl, ch or c. So, it can be carried by C but not any other of the genes.

Ex. Chinchilla, Squirrel, Black Silver Martin, Blue Silver Martin, Chocolate Silver Martin, and Lilac Silver Martin. cchl (shaded)-this gene erases all yellow pigment from the fur AND some of the dark pigment. The expression of this allele can be affected by the hidden alleles after it. So, if the rabbit is homozygous (carrying 2 of the same alleles, cchlcchl) it will be darker in appearance (like seal or blue seal) than a heterozygous rabbit (two different alleles, cchlcch or cchlc) Rabbits that only have one shaded allele (cchl ) and a second recessive allele ( ch, c) will tend to be lighter. So cchl is recessive to C and cchd, but dominant over ch and c.

Ex. Seal, Siamese Sable, Smoke Pearl, Sable Point, Sable Martin, Smoke Pearl Martin. ch (Pointed White aka AOV) The ch allele eliminates all the pigment on the rabbit that is below a certain temperature. This usually results in a totally white rabbit with pink eyes, but with color on the tail, legs, ears and nose AKA points. Since it is temperature sensitive, in the heat of summer, the point color fades. (It can also be overly expressed throughout the body in an animal that is chilled.) ch is only dominant over c (rew). So Pointed White will only be expressed if it is chch or chc. Ex. Black Pointed White, Blue Pointed White c (rew)-eliminates all pigment, which expresses as a white rabbit with pink eyes. It is recessive so must be cc. But keep in mind it still has a full genotype hidden within the other allele sets (A,B,D,E, etc). Someone once told me that it is like a white blanket thrown over the rabbit. It can still carry: Agouti, tan, or self. It can also carry or be non-extension (tort), or broken pattern of any of the excepted colors. CC=full color, Ccchd=full color carrying chin, Ccchl=full col-

or carrying shaded, Cch=full color carrying pointed white, Cc=full color carrying rew, cchdcchd=chinchilla, cchdc =chin carrying rew, cchlcchl=seal, cchlch =shaded carrying pointed white, cchlc=shaded carrying rew, chch=Pointed White, chc=Pointed White carrying rew (not desired as it affects point color and size of smut)

D ALLELE

D Allele-in order of dominance D (dense), d(dilute) D (dense), full or dense expression of color. D is dominant and cannot be carried. Ex. Black, Chocolate, Chestnut, orange Chinchilla d (dilute)-dilutes the coat color to a more washed out appearance. d is recessive, you must have two copies of d to express in the coat. Ex. Blue, Lilac, Opal, Squirrel, Blue otter, Smoke Peal, Smoke Pearl Martin DD =dense, Dd =Dense carrying dilute, dd =dilute

E ALLELE

E Allele order of dominance E (extension), e (non-extension) There are several other alleles in this set, but they are not usually present in Jersey Woolies. E-extension leaves the hair normal. Dominant over e (nonextension). So, all rabbits other than tort, Sable Point or Orange are E. e-non-extension restricts the extension of the black pigment. Because of the modifiers and smut at work ee rabbits come in a wide range of hues within the same color. Self ee rabbits resemble a shaded rabbit, therefore, as we show phenotype, they are shown in the shaded group, although technically not a shaded. e is recessive, so will not be expressed unless there are 2 copies (ee) Ex. Black Tort, Blue Tort, Orange. Sable Point. Note: you want to keep this gene away from ch (pointed whites), and A (agouti)*. It will mess the color up on both and wash out rings on agouti. *unless working with oranges EE=full extension, Ee=Full extension carrying non-extension, ee=non-extension

In conclusion, I want to take a brief moment to mention broken. En=broken pattern en=solid enen=solid Enen=broken EnEn=Charlie This gene can be influenced by various modifiers, resulting in a variety of patterns. Any accepted color, coupled with the broken gene can be shown, except pointed white.