As I said on my homepage, all my bunnies come pedigreed and genotyped. This means that on their pedigree, for each rabbit up to 3 generations is genotyped. A genotype is a series of letters (A,B,C,D, and E in the rabbit for color), half of which can be determined just by looking at the rabbit, the other half can be determined by breeding it, it’s parents, and sometimes by other siblings in its litter. This can be useful to purchasers because it allows them to know what the rabbit they purchased does carry and might carry so that you can wisely pick breeding pairs to decrease the probability of unshowable offspring.
Explaining the Letters of Rabbit Genetics.
The letters A, B, C, D, and E each represent different loci for color in a rabbit’s genome. Each rabbit has some variation on these five letters. The color of the animal is a result of what variation it has inherited from its parents. Each rabbit has two copies of each letter- these are called alleles.
A allele: Determines Pattern of rabbit.
There are only three patterns in rabbits. (Does not include broken, that is a different allele). They are Agouti, Tan Pattern and Self.
The alleles (in order of dominance)
A: Agouti. (Ringed Fur) ex.) castor, chin
Can show up in genotype as AA, Aat, or Aa
at: Tan Pattern ex.) Otter, martin
Can show up in genotype as atat or ata
a: Self Pattern ex.) Black, blue, chocolate, lilac
Can show up in genotype only as aa
B allele: Determines if the Rabbit is able to produce black color pigment.
There are only two variations that can occur in the rabbit reguarding this allele. Either it can make Black pigment, or it produces chocolate pigment.
The alleles (in order of dominance)
B: Can produce Black ex.) castor, otter, black
Can show up in genotype as BB or Bb
b: Can produce chocolate only ex.)amber, chocolate otter, chocolate
Can show up in genotype as bb only
This allele determines how much color is on the animal.
The alleles (in order of dominance)
C: Full color ex.) castor, otter, black
Can show up in genotype as Ccchd, Ccch, Cch, or Cc
cchd: Color, except middle band ex.) chin, silver martin, ermine
Can show up in genotype as cchdcchd, cchdcchl, cchdch, or cchdc
cchl: Shaded color on extremities ex.) sable, seal*
*The C series is codominant, which means that sometimes the “recessives” matter in the phenotype. This is most apparent in the sable and seal. Sables are cchl ch or cchlc. In order to have a seal, it must be a homozygote: cchl cchl.
ch: Californian allele- allows color only where there is a lower body temperature (the extremities)
Can show up in genotype as chch or chc
c: no color, albino ex.) white
Can show up in genotype as cc only
D allele: Determines if the color can be dilute
This allele determines how the color pigment is distributed in the hair follicle.
The alleles (in order of dominance)
D: Normal distribution of pigment- black section are black
ex.) castor, black, otter
Can show up in genotype as DD or Dd
d: Diltuion of black pigment- black sections are blue
ex.) opal, blue, blue otter
Can show up in genotype as dd only
E allele: Determines Extension of middle band color.
The dominant allele allows normal banding of agouti fur and the recessive allele allows only the middle band color to be expressed.
The alleles (in order of dominance)
E: normal extension ex.) castor, black, otter
Can show up in genotype as EE, Eej, or Ee
ej: random extension ex) harlequin, magpie, tricolor
Can show up in genotype as ejej, or eje
e: non-extension ex.) red, tort, fawn
Can show up in genotype as ee only
Brokens- The English Spotting Allele
I do not put this allele in my genotype on the pedigree because once you understand the concept of broken genetics it is unnecessary. There can not be “hidden” recessive genes when dealing with brokens.
“en en” is the genotype for solid
“En en” is the genotype for broken
“En En” is the genotype for a Charlie marked broken (very little color, usually only a nose spot and ear color, spine markings)