A-locus rabbit colors. Breed rabbits smartly by understanding rabbit coat color genetics pertaining to the 2 A-locus color genes carried by domestic rabbits.
'A' stands for 'Agouti,' meaning, the agouti pattern on a rabbit's hair shaft.
Genes of the the A-locus color series are ‘A,’ 'at,’ or ‘a.’ These determine the pattern of the hair shaft, without influencing the actual rabbit color. Agouti rabbits come in many colors, but the one thing that makes them agouti is the banding on the hair shafts. In addition to the bands, the agouti gene (A) also results in a white or ivory belly with a base color of slate-blue or dove-gray ring under the white fur.
The typical 'wild rabbit' look is due to the 'A'
Agouti pattern of rings on the hair shaft. Here is how the rings look
in the case of a chestnut agouti rabbit (A_B_C_D_E_):
The overall effect of the rufus red glistening through the black tipping is one of mahogany or chestnut brown.
The 'A' gene is completely dominant. No matter what the second gene is at the A-locus, an 'A' will override all the effects of the other gene.
The rabbit needs only one A gene to
produce an agouti patterned hair shaft. Agouti rabbits are:
Over time, two additional A-locus rabbit color mutations have occurred, resulting in a total of 3 options at the A-Locus for rabbit colors. Each of these mutations affects pattern, not color.
A-Locus Rabbit Color 'at' = tan pattern
The distinctive tan pattern produces a solid color over the back and the sides. Where the top color meets the belly color is a narrow band the color of the intermediate ring, if the animal still had one (it doesn't). A tan pattern also gives intermediate ring coloration in the ears, the neck triangle, and intermingled coloration on the chest and dewlap. Plus, tans and otters should have intermediate-colored ticking near the junction of top and belly colors.
Tan rabbits (the breed) have fiery red bellies, compliments of the recessive 'ww' wide band recessive gene combination. Ticking is not found in Tan rabbits.
Tan pattern 'at' is recessive to Agouti, but dominant to selfs (‘a’).
A ‘tan pattern’ rabbit carries at least one ‘at.’ The second gene of the A-locus could be either 'at' or ‘a,’ but not 'A' (agouti). Why not 'A'? Because 'A' is completely dominant. If the rabbit carried an ‘A’ with its ‘at,’ the rabbit would be an agouti, as above.
Rabbits with tan-pattern coats are:
A-Locus Rabbit Color 'a' = "self" pattern
The 'self' mutation removed all banding whatsoever, leaving a rabbit with one color all over, top to bottom.
Self is recessive to both tan 'at' and agouti 'A.' Therefore, a self rabbit must carry ‘aa’ at the A locus.
Selfs are black, blue, chocolate, or lilac, depending on the actions of the B, C, D, and E genes.
The rabbit pictured is a chocolate (self) Mini Rex Rabbit. He is chocolate-colored all over, including the belly, neck triangle and inside the ears.