In other species: Tasmanian devil , common brushtail possum , gray wolf , coyote , dog , red fox , domestic cat , leopard , horse , pig , Arabian camel , llama , Western roe deer , impala , taurine cattle , goat , sheep , rabbit , tassel-eared squirrel , North American deer mouse , Mongolian gerbil , meadow voles , domestic guinea pig , fallow deer , alpaca , leopard cat , oldfield mouse , Kodkod , Colocolo , Asiatic golden cat , Northern mole vole , Eurasian water mole

Categories: Pigmentation phene

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 611742 (trait) , 600201 (gene)

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal recessive

Disease-related: no

Key variant known: yes

Year key variant first reported: 2015

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: Sun et al. (2017): "Donkeys have various coat colors with two major patterns: no light points (NLP) and light points (LP). . . . Animals with the LP pattern have black or grey to spotting and black or grey with cream to grey-white hair around the muzzle and eyes."

Mapping: Liu et al. (2023) "genome-wide association analysis was performed for the differences in coat color traits between the Sanfen (n = 97) [light points around the eyes, around the muzzle and under the belly] and Wutou (n = 108) [solid black] strains [of Chinese Dezhou donkeys] using a novel donkey 40K liquid chip ... . ... [The authors] identified one significant region on chromosome 15, with the most significant SNP located within the agouti signaling protein (ASIP) gene."

Molecular basis: Abitbol et al. (2015): a likely causal variant for the no light points (NLP) phenotype is c.349T>C; p.Cys117Arg

Prevalence: Sun et al. (2017): "All 20 solid-black Dezhou donkeys had the CC genotype, which indicates that the ASIP c.349T>C variant distinguishes between solid-black (genotype CC) and non-black (genotype TT and TC) donkeys, at least in the Dezhou donkeys and most likely also in other breeds. Our results will facilitate the selection of the solid-black coat color in donkeys." From a survey of 283 donkeys, Yu et al. (2020) reported "Donkeys homozygous for the ASIP [c.349]T‐allele all have light points, which are missing in all homozygous C‐allele genotype at c.349T>C (CC) animals . . . However, 27.8% of the NLP [no light points] donkeys are heterozygous, which has not been found previously. . . . The variable phenotypes of ASIP heterozygotes and of ASIP TT homozygotes indicate the involvement of one or more other genes that so far have not been identified."

Breeds: Âne de Provence, France (Ass) (VBO_0001837), Âne normand, France (Ass) (VBO_0001841), Dezhou, China (Ass) (VBO_0001799), Miniature, United States of America (Ass) (VBO_0001922).
Breeds in which the phene has been documented. (If a likely causal variant has been documented for the phene, see the variant table breeds in which the variant has been reported).

Associated gene: