Long Hair 2

The length of the hair covering both the body and the limbs and tail of the dog has been related to a single gene, called FGF5.

Definition

The trait refers to the variant causing long hair on the body, legs and tail. The variant is found in the FGF5 gene, which is involved in the regulation of hair growth in the hair follicle.

Genetic basis

The variant is recessive, therefore, the long silky coat will only be expressed in dogs with two copies of the c.284G>T variant. In the case of a single copy of the c.284G>T variant or none at all, the dog is likely to show a short coat length. However, several variants have been identified in the FGF5 gene which, when combined with this variant in compound heterozygosis (one copy of each variant), could also generate a phenotype characterized by a longer coat.

Other relevant information

Long hair in dogs can be described as fluffy (in Corgi) or shaggy coat. It is believed that the long hair comes from ancestral wolves, which had a long coat that acted as a thermal insulator in cold climates. Long-haired dogs require more thorough maintenance of their coat. Brushing, bathing and trimming are important to avoid the development of tangles that can cause discomfort and even skin lesions. In fact, long hair can be straight or curly and fine or coarse, so some breeds will require more maintenance than others. Breeds that most frequently exhibit this variant include the Afghan Hound, Border Collie, Cocker Spaniel, Collie, Dachshund, German Shepherd, Golden Retriever, Pomeranian and Samoyed. However, additional studies, such as that of Cadieu et al. (2009), have identified the presence of this variant in other dog breeds.

Bibliography

Cadieu E, Neff MW, Quignon P, et al. Coat variation in the domestic dog is governed by variants in three genes. Science. 2009 Oct 2;326(5949):150-3.

Housley DJ, Venta PJ. The long and the short of it: evidence that FGF5 is a major determinant of canine `hair`-itability. Anim Genet. 2006 Aug;37(4):309-15.