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The Genetic

Before I show you the colors directly, I'm going to explain a little bit about genetics and the different alleles and loci.

The Alleles


A wild gerbil will always be Agouti. It is the basic color. The genetic code of a basic Agouti gerbil will be this :

  • A- C- D- E- P- Uw-

The letters represent what are called Alleles. Those in capital letters are what is called a Dominant Allele. This one will always have priority over a recessive allele in the writing order but also in the appearance of the gerbil. In general, we will not write the two dominant alleles in order to lighten the writing. When ignoring an allele, we will use a dash (-) or an asterix (*).

  • example :

    • AA CC DD EE PP UwUw is hard to write/read

    • A C D E P Uw is more refined

    • A- C D E- P Uw shows that we ignore the second allele of A and E.


A recessive allele will be written in lower case and cannot be expressed if it is alone. It must absolutely be double to be able to appear on the gerbil and we must therefore write it. If the gerbil has a dominant allele and a recessive allele, it will be said to be a carrier.

  • example :

    • aa C D E P Uw will be a Black gerbil.

    • Aa C D E P Uw will be an Agouti gerbil carrying non-agouti

The Loci

There are 7 loci in the gerbil. Each of them will influence the appearance of the coat and the final look of the gerbil.

  • A, the Agouti locus. Manages the intensity of the yellow color in the coat, as well as the black tip.

    • A, is going to be the normal color, with a white belly.

    • a, or not agouti, will order that the color is uniform over the whole body.

  • C, the Color locus, or Albino locus. This locus is normally used for the albino mutation (no color). As the cc does not (yet) exist in the gerbil, there is no real albino. It will control the accumulation of color in the hair of the gerbil.

    • C, the color will, by default, be uniform all over the body.

    • c[h], or Himalayan, is on the same chromosome as the albino. The gene controls the intensity of the color by fading it. In the presence of genes ee or pp, only one switch is needed to create an effect. Basically, it's the gene of Light. This gene is sensitive to temperature changes, and will darken if it is cooler (the extremities being colder than the body, they will be darker).

    • c[chm], or Chinchilla Medium, will fade the color while keeping the tips of the original color. Basically, it's the gene of Colorpoint ! This gene is sensitive to temperature changes, and will darken if it is cooler (the extremities being colder than the body, they will be darker).

  • D, the Dilute locus, manages the depth of the color.

    • D, will let the color express itself normally.

    • d, will distance the pigments in the hair, which will reduce the intensity of the color. Fewer black pigments in one place will give a gray tint instead, for example.

  • E, the Extension of Black locus. The gene will control the level of black in the hair. It is excessively sensitive to stains and fading.

    • E will define the extent of the black on the tip

    • e, or Extension of Yellow, will increase the amount of yellow in the hair at the expense of the black tip

    • e[f], or Fading, will do like e but drastically lightening the gerbil with age.