Curly Coat Locus (CURL)
Cu Locus, Curly Hair, Curly Coat Trait, Straight Coat Trait, Wavy Coat Trait, C1
Hair curl is an incomplete dominant characteristic caused by a mutation in the KRT71 gene. Incomplete dominance refers to the fact that a dog can carry one copy of the gene which will result in a moderately curly (known as “wavy”) coat or two copies of the mutation which will result in a tightly curled coat. Dogs lacking the mutation will typically have straight hair. This particular mutation can be found prevalently in some breeds that typically display a curly coat. The hair curl mutation can also be accompanied by other mutations such as coat length and furnishings that can also contribute to the overall look of a dog’s coat.
It is important to note there are two mutations that can lead to a curly coat. The first mutation known as Curl 1 or C1 is detected by this test. There is an additional mutation known as Curl 2 or C2 that has been identified in the Curly Coated Retriever, Chesapeake Bay Retriever, Bichon Frise, French Bulldog, Irish Terrier, Lagotto Romagnolo, Spanish Water Dog and American Water Spaniel that this test will not detect. Researchers that discovered C2 did find one Poodle with the C2 allele, although Poodles are expected to be virtually fixed for the Curl 1 or C1 mutation that this test detects. Researchers also noted that a small number of dogs with curly coats did not have either C1 or C2, suggesting that other yet unknown curly coat mutations may exist.
Reading Your Results
A. (CLEAR/NORMAL):
These dogs have two copies of the normal gene and will have straight hair.
B. (CARRIER/AFFECTED):
These dogs have one copy of the normal gene and one copy of the mutation associated with a curly coat type. Due to incomplete dominant expression, these dogs can have a “wavy” or moderately curly coat that is in the spectrum somewhere between a curly and a straight coat. They will also if bred, pass the mutation to 50% of its offspring, on average.
C. (AT RISK/AFFECTED):
These dogs have two copies of the mutation which typically results in a tight curly coat.
Additional Details
Inheritances
Autosomal Dominant (Incomplete Dominance)
Affected gene
KRT71
Chromosome
Ch. 27
Mutation
C.451 C>T
Publication:
Cadieu E, Neff MW, Quignon P, Walsh K, Chase K, Parker HG, VonHoldt BM, Rhue A, Boyko A, Byers A, Wong A, Mosher DS, Elkahloun AG, Spady TC, Andre C, Lark KG, Cargill M, Bustamante CD, Wayne RK, Ostrander EA. Coat variation in the domestic dog is governed by variants in three genes. Science. 2009 Oct; 326(5949):150-3. [PubMed: 19713490]
