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

Categories: Pigmentation phene

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

Links to MONDO diseases: No links.

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal recessive

Considered a defect: no

Key variant known: yes

Year key variant first reported: 2012

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".

Inheritance: Robinson (1969, 1970) provided evidence of autosomal recessive inheritance of the melanistic phenotype, based on the breeding records of 439 animals.

Molecular basis: By sequencing the candidate gene ASIP in "wild-type" non-melanistic leopards and melanistic leopards ("black panthers"), Schneider et al. (2012) showed that the "black panther" phenotype is due to a "non-synonymous mutation located in exon 4 (C333A) predicted to introduce a stop codon at amino acid position 111. All 11 analyzed melanistic leopards . . . were homozygous for this mutation, while the wild-type individuals (i.e. bearing a yellowish background coloration with black rosettes; . . .) were either homozygous for the ancestral ‘A’ allele or heterozygous."

Sooriyabandara et al. (2023) "used reference-based assembled nuclear genomes of Sri Lankan wild type and melanistic leopards and de novo assembled mitogenomes ... . ... [The authors] identified a single nucleotide polymorphism in exon-4 Sri Lankan melanistic leopard, which may completely ablate Agouti Signalling Protein (ASIP) function. The wild type leopards in Sri Lanka did not carry this mutation, suggesting the cause for the occurrence of melanistic leopords in the population."

Associated gene: