E-Locus (e3) - Alaskan Husky, Siberian Husky

General description

Melanocytes (pigment-producing cells) are able to synthesize two types of pigments: yellowish-reddish pheomelanin and dark brown or black eumelanin. Melanocortin receptor 1 (MC1R) is one of the most important regulators of the pigment type switching. MC1R activation causes the melanocytes to produce eumelanin, while MC1R inhibition leads to the production of pheomelanin.

Two different genetic variants in the MCR1 gene can be associated with an almost white coat color in the Siberian Husky and Alaskan Husky breeds: e1 and e3. While the e1 variant is present in all breeds, the e3 variant has so far only been found in huskies. The ”white” coat color in huskies can be described more accurately than an extremely pheomelanistic (yellowish) color. The fact that black-and-white huskies are not black and brown suggests that pheomelanin-pigmentation in huskies is extremely pale, which is consistent with the almost white coat color of MC1R-deficient huskies.