There are many genes involved in producing a rabbit's fur color and coat pattern. These genes act in a predictable manner, so when armed with enough information, breeding results can often be predicted.
In the example of breeding black x blue, if the pair is homozygous in all gene series, all the offspring will be black. However, most rabbits are generally not completely homozygous and can carry many recessive genes.
The first gene series is "A" (agouti). Both black and blue are homozygous recessive "aa", so cannot produce any tan pattern "At" or agouti "A" offspring.
The second gene series is "B" (brown). The recessive is chocolate "b". Both black and blue can carry the recessive gene, so can produce chocolate as well as lilac offspring if both rabbits also carry blue.
The third gene series is a little more complex. Both black and blue are dominant "C" for full color. The other recessive genes in the series eliminate red in the coat and can also reduce black to some degree. The "cchd" dark chinchilla gene produces the chinchilla coat pattern when in combination with the agouti gene "A". "cchl" shaded produces colors such as sable or sable point when in combination with the non-extension "ee" gene. The next gene in the "C" series is "ch" himalayan which limits color to the points and removes all pigment from the eyes. The last "C" series gene is albino "c". The black and the blue rabbit can carry any of the above recessive genes, so could potentially produce colors such as sable, seal, pointed white, ruby-eyed white, and sable point.
The fourth gene series is easy - "D" full color, "d" dilute (blue). The blue rabbit is homozygous "dd". A black rabbit can carry recessive "d". If it does, the black x blue combination could produce blue as well as black rabbits.
The 5th gene series is another complex one. "Es" is the dominant steel gene. Blue and Black are normal "E". "ej" is the brindling gene that produces the harlequin coat and "e" restricts black in the coat producing the tort color. Both black and blue can carry the brindling gene as well as the non-extension gene, so bred together could produce a harlequin coat or tortoises.
There are also coat pattern genes including Dutch marked, English Spotting, Silvering, Blue-eyed white, and Wide Band.
So, to answer your original question, black x blue could potentially produce black, blue, chocolate, lilac, seal, sable, albino, pointed white, tortoise, smoke pearl, or sable point.
If we are familiar with the rabbits ancestors as well as any offspring the rabbit has produced, we can further refine the possibilities because we can fill in some of the "blanks" as to what recessive genes the rabbits may carry.
Check out my coat color website for lots of photos and info!
http://www.geocities.com/pamnock/coat_colors1.html
Pam
.
