Roan/Ticked (R Locus)

General Information: The R Locus, associated with the USH2A gene, influences the roan and ticked coat patterns in dogs. Roan is characterized by a mixture of colored and white hairs, creating a blended appearance, whereas ticking refers to small spots of color on an otherwise white background. Dogs with roan or ticked patterns can exhibit a variety of appearances, depending on their base coat color and the extent of the roaning or ticking. These patterns are commonly seen in breeds such as the Australian Cattle Dog and the English Setter. The presence and extent of these coat patterns can vary significantly, even within the same litter, and are determined by the genetic makeup of the R Locus. Roan patterns typically become more noticeable as the dog matures, whereas ticking can be present from birth. Understanding these coat patterns can be important for breed standards and aesthetic preferences in breeding programs.

Gene / Testing Information: Genetic testing for the USH2A gene can determine a dog’s R Locus status, indicating whether they will exhibit roan or ticked coat patterns. The R Locus operates in a dominant fashion, meaning a dog only needs one copy of the allele to display these coat patterns. Dogs that are heterozygous (carrying one copy of the allele) or homozygous (carrying two copies) at the R Locus can exhibit roaning or ticking. Identifying the R Locus status through genetic testing is essential for breeders who aim to produce dogs with specific coat patterns. By testing potential breeding pairs, breeders can predict the likelihood of offspring displaying these desirable patterns and make informed breeding decisions to meet breed standards and aesthetic goals. Genetic testing helps maintain consistency in breeding programs and supports the overall health and appearance of future generations.