Coat colours and patterns are highly variable in cats and determined by several genes. The charcoal coat pattern inheritance in Bengal cats appears as an incomplete melanism, thus the agouti signalling protein gene (ASIP) was investigated as a candidate gene for this phenotype. DNA was isolated from buccal swabs obtained from 72 Bengal cats, where 49 were presumed to be charcoal. The coding region of ASIP was amplified by polymerase chain reaction and subsequently directly sequenced. The resulting sequences were compared to that of ten Asian leopard cats and three control domestic cats. Polymorphisms were investigated within the gene. Two non-synonymous SNPs were observed in exon 2 (c.41G>C and c.142T>C) when comparing the control domestic cat sequence with the leopard cat sequence, resulting in amino acid changes in the leopard cat (Cys14Ser and Ser48Pro, respectively). One synonymous single-nucleotide polymorphism (SNP) was found in exon 3, substituting a cytosine for adenine in the leopard cat (c.162C>A). Forty-three charcoal cats presented as compound heterozygotes at ASIP, consisting of an Asian leopard cat allele and a domestic cat non-agouti allele (a). The compound heterozygote state suggests that the interaction between the Asian leopard cat allele and the domestic cat allele allowed for the recessive non-agouti allele to influence the markings of the hybrid Bengal cat, producing a darker, yet not completely melanistic coat pattern. This study presents the first validation of a Leopard cat allele segregating in the Bengal breed, affecting the overall phenotype of the pelage.

1.  Further investigation should be conducted to assess similar interactions in other genes, and how they would affect the accuracy of genetic tests within this breed.

2.  Further investigation should be performed to better illuminate the potential allelic interactions, and consequential phenotypic expression, within this hybrid breed.