Test Detail

Coat pattern variant that removes the tabby stripes from the body and produces a uniform flecked coat (ticking), typical of breeds such as the Abyssinian. The Ti (ticked) allele corresponds to the Ticked locus, independent of the tabby locus (LVRN gene, formerly Taqpep) with mackerel and blotched alleles, and acts epistatically over it: a Ti/- cat masks the underlying tabby pattern on the body. Its molecular basis is two missense variants of the DKK4 gene described by Lyons et al. (2021). It is not associated with disease.

Phenotype characteristic of breeds such as the Abyssinian, Singapura and Siamese in its primitive form, but present as a variant in all breeds. The frequency of the Ti allele is lower than that of Ta and tb in the common domestic cat. Limited data on allele frequency by breed in Spain.

- Uniform flecked coat without stripes on the body
- Residual stripes only on the face, legs and tail (facial barring and leg barring)
- No systemic manifestations

The ticked pattern is characteristic of ancestral breeds such as the Abyssinian, the Singapura or the primitive Siamese, and was consolidated as a selection trait throughout the 20th century. The Mendelian characterisation of Ti as dominant over the body tabby pattern was established through classical crosses; Eizirik et al. (2010) demonstrated that ticked is independent of the mackerel and blotched tabby alleles (a distinct locus, on another chromosome). In 2021, Lyons and the 99 Lives consortium identified in DKK4 the variants Ti^A (p.C63Y) and Ti^CK (p.A18V) associated with ticked. Ticked retains variable facial and limb barring.

- Use two separate loci when planning the cross: the Ti locus (Ti/ti alleles) and the Taqpep locus (Ta/tb alleles)
- To obtain pure body ticked: mate Ti/Ti × Ti/Ti (100% of the litter Ti/Ti, stable ticked); or Ti/Ti × Ti/ti (100% body ticked, half Ti/Ti and half Ti/ti)
- Ti/ti × Ti/ti produces 75% body ticked (Ti/Ti and Ti/ti) and 25% non-ticked (ti/ti)
- The Taqpep genotype (Ta/Ta, Ta/tb, tb/tb) is expressed on the body only in ti/ti cats; in Ti/- cats it is masked and only the facial/limb barring is visible
- Inform the buyer that it is an aesthetic trait with no pathological value

Ticked is epistatic over the underlying Taqpep pattern on the body: a Ti/- cat may be Ta/Ta, Ta/tb or tb/tb underneath, and the Taqpep genotype is phenotypically relevant only in ti/ti animals. Differentiate ticked from agouti: agouti is necessary for any tabby to be expressed, but Ti removes the body stripes independently of the Taqpep allele. Assessment of facial and limb barring is subjective and depends on each breed's standard.

1. Lyons LA et al. (2021) Mining the 99 Lives Cat Genome Sequencing Consortium database implicates genes and variants for the Ticked locus in domestic cats (Felis catus). Anim Genet 52(3):321-332. PMID: 33780570
2. Lyons LA (2015) DNA mutations of the cat: the good, the bad and the ugly. J Feline Med Surg 17(3):203-219. PMID: 25701860
3. Kaelin CB et al. (2012) Specifying and sustaining pigmentation patterns in domestic and wild cats. Science 337(6101):1536-1541. PMID: 22997338
4. Eizirik E et al. (2010) Defining and mapping mammalian coat pattern genes: multiple genomic regions implicated in domestic cat stripes and spots. Genetics 184(1):267-275. PMID: 19858284
5. OMIA:001484-9685. Coat colour, ticked (Abyssinian) in Felis catus. https://omia.org/OMIA001484/9685/