Ticked Pattern (DKK4 gene, Abyssinian)

The "ticked" phenotype is characterized by the absence of a defined pattern of stripes and spots on most of the cat`s body, resulting from genetic alterations in the DKK4 gene.

Definition

The "ticked" phenotype, also known as Abyssinian, is distinguished by the absence of the traditional markings such as stripes, spots or swirls seen in other coat patterns. They may have some stripes on areas such as the head, legs or tail but not on the torso. This pattern is determined by the Ti locus, associated with the DKK4 gene, which is involved in Wnt signaling and regulation of hair follicle development. Variants in this gene affect the formation and distribution of melanin, resulting in a coat without the characteristic markings of tabby cats. This trait is common in breeds such as the Abyssinian, Burmese, Maine Coon and Oriental Shorthair.

Genetic basis

The ticked phenotype is associated with certain genetic variants in the DKK4 gene. In this case, we analyzed the c.188G>A variant, also known as the Ti^A allele, which causes a homogeneous distribution of melanin and the elimination of the traditional tabby or brindle patterns. This mutation is inherited in an autosomal dominant manner, so that a single copy of the allele is sufficient to express this type of coat. Another genetic variant has also been described in this same gene which, in compound heterozygosis (one copy of each variant), can give rise to the same ticked phenotype.

Other relevant information

An interesting fact about cats with the ticked phenotype is that their uniform fur improves their camouflage in natural environments, making them less visible to predators and more effective as hunters, which favors their survival.

Bibliography

Lyons LA, Buckley RM, Harvey RJ, et al. Mining the 99 Lives Cat Genome Sequencing Consortium database implicates genes and variants for the Ticked locus in domestic cats (Felis catus). Anim Genet. 2021;52(3):321-332.