Categories: Pigmentation phene

Mendelian trait/disorder: yes

Disease-related: no

Key variant known: no

Species-specific description: Brancalion et al. (2021): "“ticked” and “roan” . . . both describe the presence of flecks of color that vary in distribution and intensity within otherwise “clear” white markings. The appearance of the pigment in the white patterning caused by ticking and roaning intensifies in the weeks after birth. . . . Colloquially, ticked is regarded as the appearance of pigmented spots in white areas of the body. Pigmented spots from ticking range in size from only a few hairs to coin-sized and are most dense on the muzzle and legs . . . . In contrast, pigmentation in the white patterning associated with roan is a mixture of pigmented and white hairs throughout the areas of the coat that would otherwise be white (Little 1953), with the phenotype dispersed relatively evenly across the body."

Inheritance: Based on an analysis of coat-colour inheritance in more than 2,000 dogs in his Bar Harbor colony and on data collected on around 20,000 dogs from thousands of breeders, Little (1953) proposed a ticked locus with two alleles, the dominant T (ticked) allele and the recessive t allele for non-ticked. Little (1957) discussed evidence for this locus.

Markers: Brancalion et al. (2021) identified "three haplotypes in spaniels according to their putative functional variant profiles at [CanFam3.1] CFA38:11,111,286C>T (missense); [CanFam3.1] CFA38:11,131,841-11,143,239DUP.insTTAA (using strongly linked marker [CanFam3.1] CFA38:11,143,243C>T); and [CanFam3.1] CFA38:11,156,425T>C (splice site). In spaniels, the haplotypes work as an allelic series including alleles (t - recessive clear, T - dominant ticked/parti-color and TR - incomplete dominant roan) to control the appearance of pigmented spots or flecks in otherwise white areas of the canine coat."

Breeds: English Cocker Spaniel (Dog) (VBO_0200486), English Springer Spaniel (Dog) (VBO_0200497).
Breeds in which the phene has been documented. (If a likely causal variant has been documented for the phene, see the variant table breeds in which the variant has been reported).

Associated gene: