Heredity and Genetics

The Chocolate gene

The 2nd pair of genes determines whether a rabbit will become a "black" rabbit or a "chocolate" rabbit. A black rabbit [B] would be a black, blue, siamese sable, siamese smoke pearl, sable point, chestnut, chin, squirrel, opal, black and blue otters, black and blue silver martens, sable martens, smoke pearl martens, oranges, black and blue himalayans, fawns, torts are all black rabbits [B]. The black gene is dominant over the chocolate gene [b].

For a rabbit to be one of the above colors, he had to inherit at least one of the [B] black genes, from 1 of it's parents. It could be [B][B], or it could be [B][b]. The best combination for any of the "black" rabbits is [B][B]. The other possibility is if a rabbit inherits the chocolate gene [b] from both parents. Each of the parents MUST at least carry the chocolate gene, for the rabbit to come out "chocolate"...a chocolate rabbit could be the "self" chocolate [a][a]-[b][b] a "self" lilac would also have this combination of genes, as the gene that turns a chocolate into a lilac is the "D" gene, the chocolate and lilac himalayans would also have this combination as the himalayan is a "self" colored rabbit, the gene that turns the "self" chocolate into a chocolate himalayan is located in the "C" genes.

The lynx is also a chocolate rabbit--a chocolate "Agouti" colored rabbit. It is also a "dilute" rabbit (more about that in the D gene), if a lynx inherites even one of the "black" genes, it will become a cinnamon. It's interesting that the dilute (or blue) variety of the cinnamon (or lynx)is recognized and the full color "cinnamon" is not recognized.
A lynx will have the combination [A][?]-[b][b], the question mark means that any gene equal to or recessive to the first gene can be in that position. So the lynx could have [A][A], [A][a(t)], or [A][a] combination. The chocolate and lilac otters and silver martens will have the following combination of genes:

[a(t)][?]-[b][b]
The [?] in this particular rabbit, can only be [a(t)] or [a], if the rabbit had inherited even one of the more dominant [A] gene, he'd have been a lynx or cinnamon and NOT an otter or silver marten.
To sum it up:

For a rabbit to become chocolate...it must inherit the chocolate gene from each parent...both parents themselves must either be chocolate or else they both must carry the chocolate gene. If you breed 2 black rabbits and get even 1 chocolate rabbit the combination of both black rabbit must be [B][b]...as both rabbits must contribute a chocolate gene to the bunny [b][b].

[Back to the A gene]|[Next to the "C" gene]