OMIA 002264-9615 : Coat colour, ticked in Canis lupus familiaris

Mendelian trait/disorder: yes

Considered a defect: 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, English Springer Spaniel.

Associated gene:

Symbol Description Species Chr Location OMIA gene details page Other Links
USH2A Usher syndrome 2A (autosomal recessive, mild) Canis lupus familiaris 38 NC_051842.1 (11776697..11089431) USH2A Homologene, Ensembl, NCBI gene

References


Note: the references are listed in reverse chronological order (from the most recent year to the earliest year), and alphabetically by first author within a year.
2021 Brancalion, L., Haase, B., Mazrier, H., Willet, C.E., Lindblad-Toh, K., Lingaas, F., Wade, C.M. :
Roan, ticked and clear coat patterns in the canine are associated with three haplotypes near usherin on CFA38. Anim Genet :, 2021. Pubmed reference: 33539602. DOI: 10.1111/age.13040.
1957 Little, C.C. :
The Inheritance of Coat Color in Dogs Comstock Publishing Associates, Cornell University Press, Ithaca, NY :, 1957.
1953 Little, C.C. :
An analysis of coat-color inheritance in the dog (abstract only) Science 118:572 only, 1953.

Edit History


  • Created by Frank Nicholas on 05 May 2020
  • Changed by Frank Nicholas on 05 May 2020
  • Changed by Frank Nicholas on 06 Dec 2020
  • Changed by Frank Nicholas on 06 Feb 2021
  • Changed by Imke Tammen2 on 25 Feb 2021