Labrador Retriever coat colour genetics fur colour but those with black skin can potentially produce a Dudley. Dudleys breed true for both fur and skin. The ability of the E locus to override the coat colour directed by the B locus is a classical example of epistasis, where multiple genetic loci affect the same observed trait. The E locus also determines whether the phenotype due to the third genetic locus affecting coat colour will be evident. This locus is recognised as affecting coat colour through the expression of pheomelanin, the pigment responsible for red and yellow pigmentation. The effects on pheomelanin pigmentation are only seen
Labrador Retriever coat colour genetics characterized in mice and other mammals. Initial genetic studies of coat colour in dogs published in the 1950s concluded that there were two main genes involved, one distinguishing blacks from browns, and the other distinguishing blacks from reds and yellows. A 1977 study using crosses within a population of purebred Labradors showed the involvement of two specific genes in production of the three main coat colours of Labradors and described the underlying genetics of these colour varieties. The three recognised colours of Labrador Retrievers result from differences in two genetic loci that affect pigment expression. The first of these affects