In other species: horse , cattle , meadow voles , pig , sheep , domestic cat , rabbit , dog , gray wolf , coyote , goat , Eurasian water mole , Northern mole vole , North American deer mouse , alpaca , leopard , Asiatic golden cat , leopard cat , ass , impala , Colocolo , Kodkod , Arabian camel , Mongolian gerbil , domestic guinea pig , Western roe deer , llama

Possibly relevant human trait(s) and/or gene(s)s (MIM numbers): 611742 (trait) , 600201 (gene)

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal

Considered a defect: no

Key variant known: yes

Year key variant first reported: 1997

Cross-species summary: This locus, ASIP, encodes the agouti signalling protein, a peptide antagonist of the melanocyte-stimulating hormone receptor (MC1R), which is the product of the extension locus. 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".

Species-specific description: Vage et al. (1997) cloned and characterized the fox agouti gene, and showed that a deletion in the first coding exon is responsible for the recessive agouti allele documented in the darkly pigmented Standard Silver fox. This dark pigmentation is presumably due to the lack of agouti product, i.e. the lack of an antagonist to the melanocyte-stimulating hormone receptor (which is the product of the extension locus).

Associated gene: