A-Locus (Agouti)

Genes: A, at, a
The Agouti ("A") locus has three possible genes. They are listed in order of dominance: A, at and a. The genes in the A locus are responsible for the pattern of the coat.

A: AGOUTI

  • Most dominant gene, dominant over at and a.
  • Common varieties of A: chestnut, opal, chinchilla, red, fawn, orange
  • Possible gene combinations of the A locus with A as the dominant gene: AA, Aat, Aa​
Picture
Castor (chestnut) Rex bands (A_)
The A gene is the typical wild rabbit color pattern. Rabbits with this gene have white or cream markings (lacing) on the belly and chin, inside of the legs, around the nostrils, around the eyes, inside of the ears, and on the underside of the tail, and an orange, cream or white triangle of color at the back of the neck. The individual hair shafts will have color bands and/or ticking along their length. If you blow on the back of the rabbit you will see circular bands of color. Some breeds use special terms for these colors (I.E., in Rex chestnut is castor, in Satins it is copper, and in Flemish Giants it is sandy), but for the sake of consistency, we will use the more generic terms for these lessons.

at: TAN

  • Recessive to A, dominant over a.
  • Common varieties of at: otter, silver marten.
  • Possible gene combinations of the A locus with at as the dominant gene: atat, ata
Picture
Black silver marten Rex (at_)
Picture
Chocolate otter Rex junior (at_)
​The at gene is known as the tan pattern. For this gene to display on the rabbit, the second gene must either be an at or an a. If the second gene is an A (Agouti) the rabbit will carry the at but will show the A (agouti) since the A (agouti) is dominant. The at gene has the same overall pattern as an Agouti. They will have white or cream markings (lacing) on the belly and chin, inside of the legs, around the nostrils, around the eyes, inside of the ears, and on the underside of the tail, and an orange, cream, or white triangle of color at the back of the neck. However, the individual hairs will not have color bands but will instead be all one color.

a: SELF

  • Most recessive gene, recessive to both A and at.
  • Common varieties of a: black, blue, chocolate, lilac, tort
  • Possible gene combinations of the A locus with a as the dominant gene: aa
Picture
Blue Rex junior buck (aa)
Picture
Black Rex buck (aa)
​​The a gene is known as the self gene. Since this is the most recessive gene, the rabbit must have two a’s in the allele to show this pattern (aa). With this gene the rabbit will be one color throughout their body, and the individual hairs will be one color. Common self colors are black, blue, chocolate and lilac. Genes in other loci can cause the appearance of shading or a slightly lighter belly color, but aa rabbits will not display agouti or tan pattern markings.

On to the "B" Gene...