Cu Locus 2 (Curly Coat 2, C2) Cu locus

Genetics and characteristics

Curly coat in dogs is an important characteristic along with coat color, hair length, and growth pattern. Curliness is a trait characteristic of many dog breeds such as Poodle, American Water Spaniel, Australian Labradoodle, Chesapeake Bay Retriever, Goldendoodle, Portuguese Water Dog, etc. All that dogs have a common mutation within the KRT71 gene that is also known as Cu (Curly) Locus. KRT71 encodes keratin 71, a major structural component of hair and its variants are resulting in a dysfunctional protein that prevents keratin from binding together in a regular pattern which alters the structure of the hair and results in a curly phenotype.

Curliness in dogs is likely to have an autosomal dominant with incomplete penetrance mode of inheritance. That means not only dogs with two mutated genes are expected to have a curly coat. but also dogs carrying only one mutated KRT71 gene. However, since the trait has incomplete penetrance, dogs carrying only one mutated gene will show a milder form resulting in more wavy hair. Genetic testing can identify carriers and help breeders in future mating pairs selection.

Results Reported As

References:

Bauer, A., Hadji Rasouliha, S., Brunner, M. T., Jagannathan, V., Bucher, I., Bannoehr, J., Varjonen, K., Bond, R., Bergvall, K., Welle, M. M., Roosje, P., Leeb, T. (2021). Corrigendum: A second KRT71 allele in curly coated dogs. Animal genetics, 52(4), 575. https://doi.org/10.1111/age.13098

Salmela, E., Niskanen, J., Arumilli, M., Donner, J., Lohi, H., Hytönen, M. K. (2019). A novel KRT71 variant in curly-coated dogs. Animal genetics, 50(1), 101–104. https://doi.org/10.1111/age.12746

Cadieu, E., Neff, M. W., Quignon, P., Walsh, K., Chase, K., Parker, H. G., Vonholdt, B. M., Rhue, A., Boyko, A., Byers, A., Wong, A., Mosher, D. S., Elkahloun, A. G., Spady, T. C., André, C., Lark, K. G., Cargill, M., Bustamante, C. D., Wayne, R. K., Ostrander, E. A. (2009). Coat variation in the domestic dog is governed by variants in three genes. Science (New York, N.Y.), 326(5949), 150–153. https://doi.org/10.1126/science.1177808