OMIA 001199-9461 : Coat colour, extension in Lorisidae

In other species: cattle , dog , horse , red fox , pig , sheep , jaguar , jaguarundi , American black bear , woolly mammoth , domestic cat , rabbit , domestic guinea pig , goat , Arctic fox , rock pocket mouse , oldfield mouse , gray squirrel , lesser earless lizard , little striped whiptail , water buffalo , domestic yak , alpaca , , coyote , reindeer , Geoffroy's cat , Colocolo , ass , Arabian camel , Mongolian gerbil , raccoon dog , fallow deer , zebu , antarctic fur seal

Possibly relevant human trait(s) and/or gene(s)s (MIM numbers): 266300 (trait) , 155555 (gene)

Mendelian trait/disorder: unknown

Considered a defect: no

Cross-species summary: The extension locus encodes the melanocyte-stimulating hormone receptor (MSHR; now known as MC1R). This receptor controls the level of tyrosinase within melanocytes. Tyrosinase is the limiting enzyme involved in synthesis of melanins: high levels of tyrosinase result in the production of eumelanin (dark colour, e.g. brown or black), while low levels result in the production of phaeomelanin (light colour, e.g. red or yellow). When melanocyte-stimulating hormone (MSH) binds to its receptor, the level of tyrosinase is increased, leading to production of eumelanin. The wild-type allele at the extension locus corresponds to a functional MSHR, and hence to dark pigmentation in the presence of MSH. As explained by Schneider et al. (PLoS Genet 10(2): e1004892; 2015), "The most common causes of melanism (black coat) mutations are gain-of-function alterations in MC1R, or loss-of function alterations in ASIP, which encodes Agouti signaling protein, a paracrine signaling molecule that inhibits MC1R signaling". Mutations in MC1R have been associated with white colouring in several species.

Species-specific description: Munds et al. (2021) "found several MC1R amino acid substitutions that appear to influence the hair color, and possibly skin color, of Lorisidae primates. In particular, the substitutions on the Perodicticus branch are strongly correlated to other vertebrate studies that found similar MC1R substitutions to be associated with lighter hair and/or skin color. Although putative, such a finding is supported by our phenotypic analyses which demonstrate that Perodicticus possess a monochromatic, lighter phenotype in comparison with Lorisinae."

Reference


2021 Munds, R.A., Titus, C.L., Moreira, L.A.A., Eggert, L.S., Blomquist, G.E. :
Examining the molecular basis of coat color in a nocturnal primate family (Lorisidae). Ecol Evol 11:4442-4459, 2021. Pubmed reference: 33976821. DOI: 10.1002/ece3.7338.

Edit History


  • Created by Imke Tammen2 on 14 Aug 2021
  • Changed by Imke Tammen2 on 14 Aug 2021