Agouti

Quick Summary

The agouti signaling protein interacts with the melanocortin 1 receptor to switch between black and red pigments, creating a banding pattern in individual hairs. Mutations in the agouti signaling protein gene (ASIP) prevent this switch from occurring, resulting in hairs of uniform color.

Close up view of Siberian cat fur
Close up view showing the agouti banded hairs of a Siberian cat

Phenotype: Non-agouti cats do not have alternating pigments in their hair and appear solid aka self-colored.

Mode of Inheritance: Autosomal recessive

Alleles: A = agouti, a = non-agouti

Breeds appropriate for testing: Most breeds

Explanation of Results:

  • Cats with A/A genotype will have agouti banded hair. They will transmit this agouti variant to all of their offspring, and all of their offspring will have banded hair.
  • Cats with A/a genotype will have agouti banded hair. They will transmit this agouti variant to 50% of their offspring, and the offspring of an A/a genotype cat can be agouti or non-agouti depending on the genotype of the mate.
  • Cats with a/a genotype will have self-colored (solid) hair. If bred to another non-agouti cat (a/a genotype), all offspring will also have non-banded, solid-colored hair.

Note: Overall appearance of the cat's coat also depends on expression of and complex interactions with other genes.

Price

$40 one test per animal

Panels Available
Additional Details

The agouti signaling protein (ASIP) gene, or Agouti, interacts with the melanocortin 1 receptor (MC1R) to regulate the switch from eumelanin (present as black, brown, cinnamon, or their respective dilutions) to phaeomelanin (present as red or yellow or their respective dilutions) pigment deposition in the hair shaft at certain points in the growth cycle of the hair. This results in individual banded hairs with the visual effect of an intermediate color between the two pigments. The length of the respective bands modulates the visual effect as well.

In domestic cats, a 2 bp deletion (c.123delCA) in the agouti signaling protein disrupts protein function. This mutation has an autosomal recessive mode of inheritance, thus when two copies are present, pigment switching is prevented from occurring. This results in a hair of uniform color (often called solid or “self-colored”). A separate gene causes patterns of dark stripes or blotches (tabby patterns) to be interspersed with lighter hairs. Hairs in the darker stripes do not undergo the shift between black and red-yellow pigment production during their growth, and thus remain uniformly dark. The areas outside of the dark tabby stripes are composed of agouti-banded hairs. In a non-agouti cat (a/a), the tabby pattern is still present, but it is just not visible since all the hairs in the pattern and outside the pattern are a uniform color.

There are instances where the tabby pattern can be seen despite a homozygous recessive (a/a) genotype at the agouti locus. A sex-linked red/orange cat will exhibit the tabby pattern regardless of whether it is agouti (A/A or A/a) or non-agouti (a/a). Under certain lighting conditions, faint tabby patterns are occasionally observed on the body in a/a cats, especially in kittens with the dilution variant. Lastly, melanistic (a/a) Bengal cats will often exhibit a faint tabby pattern as well.

Turnaround Time
2-6 business days
Type of Sample

Species

Cat

Type of Test

Results Reported As
Test Result Agouti
A/A Homozygous for agouti. All offspring will have agouti banded hair.
A/a Heterozygous for agouti. Offspring can be agouti or non-agouti depending on the genetics of the mating.
a/a Homozygous for non-agouti (solid colored). If bred to a non-agouti, only non-agouti offspring will be produced.
References

Eizirik, E., Yuhki, N., Johnson, W.E., Menotti-Raymond, M., Hannah, S.S., & O'Brien, S.J. (2003). Molecular genetics and evolution of melanism in the cat family. Current Biology, 13(5), 448-453. doi: 10.1016/s0960-9822(03)00128-3

Schmidt-Küntzel, A., Nelson, G., David, V.A., Schäffer, A.A., Eizirik, E., Roelke, M.E., Kehler, J.S., Hannah, S.S., O'Brien, S.J., & Menotti-Raymond, M. (2009). A domestic cat X chromosome linkage map and the sex-linked orange locus: mapping of orange, multiple origins and epistasis over nonagouti. Genetics, 181(4), 1415-1425. doi: 10.1534/genetics.108.095240

Kaelin, C.B., Xu, X., Hong, L.Z., David, V.A., McGowan, K.A., Schmidt-Küntzel, A., Roelke, M.E., Pino, J., Pontius, J., Cooper, G.M., Manuel, H., Swanson, W.F., Marker, L., Harper, C.K., van Dyk, A., Yue, B., Mullikin, J.C., Warren, W.C., Eizirik, E., Kos, L., O'Brien, S.J., Barsh, G.S., & Menotti-Raymond, M. (2012). Specifying and sustaining pigmentation patterns in domestic and wild cats. Science, 337(6101), 1536-1541. doi: 10.1126/science.1220893